Page 8.928WWII Supersonic Trainer
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Associated pictures, drawings and chart;...On
Simulators, ...Representation of
Reality; ...Mathematical Model of
Flight; ...Simulation without Combat
Time; ...The Supersonic
Trainer; ...War that Won't End; ...Airborne Radar;
...ATOMIC BOMB MISSION OVER NAGASAKI;
. ...Facts about the Bomb; ...Truth
about the B-29 3350 Engine; ...
It is a little known story that won't be told unless I tell it. I would rather it be read now than too late. You'll just have to take my word that pictures exist. I plan to send them and related material to the New England Air Museum at Windsor Locks, Connecticut. There the process of housing a fully restored B-29 and memorabilia, including mine, dedicated to the 58th Bomb Wing of the 20th Air Force is under way.
Associated pictures, drawings and chart.
Eddie Allen background of 58th Bomb Wing Training Center Staff on site. (Sidebar Article covering the death of Eddie Allen, action of plane and reason for being at Training Center. (Gene Whitt below co-pilot's window.)
1950's glossy of Supersonic Trainer being used at Mather AFB, Sacramento CA.
Life magazine picture of APQ-13 radar station in B-29 at end of war.
Cut-away drawings of Supersonic Trainer components
Color WWII aeronautical chart of Nagasaki-Fukuoka region with pencil marks of simulations used on trainer.
Map of Tinian showing pertinent locations related to article.
Present day picture of Gene Whitt by replica of Nagasaki's Fat Man plutonium bomb.
The beauty of the Supersonic Trainer was that the flight sequence, surface depiction on the PPI (Plan Position Indicator) scope was very close to what would actually exist in flight. The speed of the aircraft was accurately depicted with the changes in the picture displayed on the scope. The effect of the wind on the speed and direction were as valid as when in actual flight.
Representation of Reality
Every aircraft flight over any considerable distance requires many specific considerations as well as awareness of the variables likely to occur. While the various members of a B-29 crew had duties that were independent of the others, all the duties were blended into what was required for a successful mission.
The Supersonic Trainer was designed to work with three of the crewmembers
and the autopilot of the aircraft. The radar operator had a scope picture that
would show a circular display in shades of yellow to black for 150 miles in
all directions. The greatest contrast existed between water and land. Ships
and land bordered by water show best. Cities and buildings show differently
than fields and mountains. Rivers and lakes are displayed clearly, as are
peninsulas and islands.
The experienced radar operator can learn to interpret the screen to detect distant storms, aircraft and terrain. The spread of the radar beam reduced the echo return from a distance and changes the interpretation into an art form. The region immediately below the aircraft was not displayed due to the concentration of the signal and certain atmospheric conditions could cause the appearance of ‘grass’ or random flashes of light on the screen. The ability to adjust the display screen was an art form as well.
There can be as many as three PPI scopes on a B-29. The navigator has a
display that is useful in confirming the accuracy of other forms of navigation
such as making a specific landfall arrival or in finding your island home
field. Additionally, there may be a scope with a timed camera to take pictures
every so many rotations of the antenna during a bombing run. The pictures
taken would give a pictorial record of the electronic sequence of events. This
camera and scope was not on my trainer.
The radar operator had primary control of the radar equipment and all scope displays. The antenna can be rotated for 360 degrees or set on a sector scan that covers the area immediately ahead of the aircraft. The sector scan is usually centered on the lubber line depicting the line of flight. Additionally a slant range arc can be displayed that is set on the target. As the aircraft approaches the target the aircraft autopilot is coupled so as to maintain a constant altitude, ground speed and tracking angle required to keep the lubber line and the bombing arc crossed on the target. In the meantime the bombardier has activated his bombsight to make a visual tracking angle on the target. Once the bombsight is visually tracking on the target, it too is electrically connected to the autopilot and will track along with the radar. Visual sighting of the target was the preferred bomb release method and the atomic bomb missions were required to have visual on the target before bomb release.
Mathematical Model of Flight
The Supersonic Trainer modified the aircraft procedure by eliminating the autopilot, navigator and pilots. As the mechanic and operator of the trainer I had a console into which I could set some of the parameters for the training run. I did not have the figures for the type of bomb nor time of fall. These would be varied from mission to mission. I could pre-set the altitude of the crystal above the bottom surface of the water tank. This distance figured in scale of 1:200,000 to the assigned mission bombing altitude was a fraction of an inch. The scale of 1:200,000 was based upon the relative speed of the crystal wafer vibrations under water compared with the 186,000 miles per second of radio waves in the atmosphere. The scale of the maps above and below the water were scaled at the same ratio and were vertically aligned using a plumb-bob as accurately as possible. The speeds of winds and movement of the crystal over the map were proportional to the map scale.
The Supersonic Trainer control console allowed that winds be preset for direction and speed in miles per hour. A circular slide rule used in aviation known as the E6-B made it possible to figure the wind correction angle from the selected winds to be plotted into the heading of the aircraft and it’s selected airspeed. Using the E6-B the resulting figures would be an aircraft course and ground speed.
The Supersonic Trainer was able to reproduce the movement of a pen over and a crystal under the water of the tank that would also give a radarscope picture sequence of events. The scope and pen would show the track of the aircraft proceeding to the target, the pen would drop off the paper at bomb release and would stop where the ‘bombs’ would hit. The movement was controlled by an over water trolley and carriage system using cables and pulleys. The alignment test used to assure proper operation was to have the device draw a circle.
Simulation without Combat Time
In an hour’s time it would be possible to make three practice bombing runs. At any point in the process it could be stopped and the situation could be discussed. The advantage of repetitive flight helped the radar operators to overcome errors in navigation, ground speed and accuracy. Until the low-level fire bombing began the jet-stream winds over Japan made high altitude accuracy very poor. The bombsight was unable to accurately adjust for the speed range and wind correction angles caused by the jet stream. The Supersonic Trainer could not produce the turbulence or weather as was frequently occurring over Japan. The bomb run was tracked on the paper below the above water map. After the run the radar operator and bombardier could check the red pen mark as tracked on the mission. As a time saver we started the run at the initial point. It was from this point some distance from the target an effort was made to fly a straight line to the target.
The Supersonic Trainer
The story of the supersonic trainer as it related to the war with Japan has not to my knowledge been told. It was an innovative invention originated by the Navy that made it possible for radar operators, navigators, and bombardiers to see and 'fly' radar simulations over Japan and Europe without the hazard of combat flying. On Tinian, as a member of the 58th Bomb Wing Training School I was responsible for the operation and maintenance of a supersonic radar-bombing simulator.
I flew from Florida to India via North Africa in 1944 and a year later
sailed by troopship to Tinian Island in the Central Pacific. Several months
after my arrival on Tinian, I was selected from the 468th Billy Mitchell
Group, for assignment to the 58th Bomb Wing Training Center. During my year
plus at the Army Air Force Radar Training School at Boca Raton, Florida I had
avoided boredom by taking classes about every piece of equipment in the
inventory. I was initially assigned to the Wing's school because I knew the
operation and calibration procedures for the second generation of airborne
LORAN known as the APN-9.
For a couple of months I conducted classes for both new and old navigators of the 58th Bomb Wing. New planes arrived and were assigned to veteran crews while new crews were given older aircraft with older equipment. This meant that every navigator involved in an airplane swap would require the appropriate LORAN instruction. I encountered considerable resistance from my officer students due to the frequent failures of electronic equipment at high altitudes. Navigators proficient in celestial navigation were reluctant to place reliance on electronic boxes. At the same time the supersonic trainers arrived on Tinian, I was wearing out my welcome as a LORAN instructor. I had rubbed too many officers the wrong way by my enthusiasm for LORAN. Being a twenty years old corporal didn't help much either. Being the teacher, I was in charge of the classroom without regard of a student's rank and I took advantage of it.
When the large boxes arrived at the 58th's Training Center with the
disassembled supersonic trainers I was reassigned. My new job was to take a
series of rather large Tech Order manuals and assemble one of the three
trainers together. It was a daunting challenge since the diagrams in the books
did not always correspond with the parts in the boxes. I was in Erector Set
heaven for two weeks. My trainer was the first of the three put into operation
with the APQ-13 microwave airborne radar set.
The supersonic trainer was a device that enabled a radar operator and bombardier to simulate an actual radar-bombing mission over most areas of Japan. The equipment consisted of a large water tank with a control console at one end. It came with several different glass map-pairs for major target areas of Japan.
I was responsible for the installation, operation, alignment, and maintenance of the trainer. There were two other similar installations in the Quonset building but my memory has it that mine was the first to become operational and the most frequently operationally ready to be used. The following is the story as I recall it.
The supersonic trainer got its name because a submerged crystal wafer was electrically vibrated briefly at a supersonic frequency that enabled the crystal to act as both a transmitter and receiver while submerged in water. The crystal is the essential part of the central station since it acts as the airplane in its movements. The crystal rotates in unison with the rotation of the plan position indicator (PPI) or scope used by the radar operator. The height of the crystal above the map was measured to be proportional to the planned bombing altitude. It was usually just a fraction of an inch above the sand terrain of the submerged map.
The power source and microsecond timing for the crystal comes from an electronic unit called the echo simulator. Just as with radar, the crystal would pause after every electrical trigger for a couple of microseconds during which time it would act as a receiver to any ‘echo’. The vibrations or waves created by the crystal moved in water at 1/200,000 the speed of radar frequencies (l86,000-miles-per-second) do through atmosphere. Any surface in the water below the crystal would give reflections, as would radar pulses off the earth. The signal from the crystal was fed into receiver of an APQ-13 radar set and would give scope pictures in very close simulation as would an actual flight over Japan. Just as with the radarscope (oscilloscope) a sector-scan could be directed over an arc just in the forward direction with a heading lubber line and bomb release arc displayed over the scope picture. Variable range circles are superimposed over the display depending on the range selected. This is exactly the way RADAR works except for the scale differences.
The glass-plotting map was aligned level with and two feet above the underwater map. This plotting map has a line drawing of the underwater map with printed identification of cities, water, and islands. Beneath it was a large roll of taunt paper stretched the length of the map. Below the paper a tracking pen would plot the track 'flown', the bomb release point where the pin would drop from the paper, and bomb impact point. Navigational and bombing accuracy could be determined by reference to the paper and plotting map.
The flight simulator part of the system was about the length and width of 8 by 12 carpet and standing three feet high. A large plate glass with sand and beads carefully made to represent Japanese islands and cities was submerged about ten inches under water. The map area was covered by a shallow tank of water about 5 by 8 feet and ten inches deep. The bottom of the water tank would contain any one of several interchangeable large plate glass maps of the Japanese islands. There were several pairs identified by major cities. They were Nagasaki-Fukuoka, Kobe-Osaka, Yokohama-Tokyo, Hiroshima-Okayama, and Kyoto-Nagoya. The underwater maps reproduced the terrain and the flight simulator produced the motion of an aircraft over it.
A large console on one end of the tank made it possible to preset and remotely control the trolley system and its crystal and co-located pen as it moved over the map just as an aircraft would. Aircraft headings and speeds could be set via a system that consisted of a spinning metal disk upon which a metal ball rotated along its radius. The speed of the ball and a corresponding aircraft speed could by varied by moving the ball in and out from the center of the disk. The speed and direction dials on the control console were set according to parameters of the exercise. The voltage settings of the dials would gave a composite aircraft track combining aircraft direction, speed and the wind effect called drift. The voltages were sent via servomechanisms to a traveling crane that carried the central station made up of the underwater transmitter-receiver crystal and the tracking-pen. This crane's two trolleys that were moved by pulleys as are the overhead cranes used in large steel mill buildings. The large trolley moved the length along the X-axis and the smaller trolley moved sideways along the Y-axis. One of the alignment tests used consisted of flying a circle with zero wind and once again with a wind applied.
The map design was covered with glued sand layers to represent land surface and small coated beads for cities while glass would represent water. The surface was specifically designed and tested to give the reflective radar display on the trainer's scope as would appear on the scopes of a B-29 in combat over Japan. The essence is that the scale of the underwater map, height of the crystal above the map and speed of the crystal vibrations all were calculated to be exactly proportional to the real world and to each other. Only with this proportional fit would the scope display be an accurate simulation of an actual flight over the glass maps of Japan with the appropriate radar display. As with some of the B-29s, there could be an auxiliary display with a camera to take pictures of the scope when triggered. Even less that perfect radar performance could be duplicated.
The trainer control unit was a console-type panel that allowed the technician (me) to act as pilot and wind by using dials, instruments and switches. The altimeter is from a Link Trainer and can be set to a desired proportionate altitude. The heading-airspeed controls are to the far right of the panel. The index pointer on the azimuth dial indicates true heading. The true airspeed was obtained by direct reading off a voltmeter made variable by a knob. The usual speed used was 210 miles per hour. The headings can be set and turns performed at a variable rate of turn as required by the calculated aircraft ground speed.
Bomb control instruments include a bomb release switch and a time-of-fall timer. These cause the tracking pen to drop off the paper when bomb release occurs and the timer causes the device to shut off at the bomb impact point. The Norden sight can also remotely activate the bomb release. The training bomb run was begun outside the IP (Initial Point) which was usually selected for ease of radar identification.
The Lincoln-head penny played and important but little know part in the bombing attacks on Japan. The turn to the bombing run was based upon the approach speed of the B-29 and could be a rather complex computation requiring a very precise standard-rate turn to be made. By coincidence the 210 bomb run speed of the B-29 and the circumference arc of a Lincoln-head penny worked perfectly for these B-29 rate turns on the aeronautical charts used. A bombardier gave me this shortcut to do the job both simply and accurately while I was setting up the trainer. Prior to every simulated mission I had to plan for such a turn in order to establish the desired track to target. The training bomb run was begun outside the IP (Initial Point) which was usually selected for ease of radar identification.
The wind control instruments were on the left side of the console and
included both wind direction and wind velocity. The 100 mile-per-hour maximum
speed allowed on the trainer was not adequate to represent the jet stream wind
speeds that were first encountered aloft over Japan. This problem existed with
the bombsight as well and accounts for a good proportion of the poor bombing
results before the firebombing program commenced at lower altitudes. Below the
control console are two clutch handles that released the trolley friction on
the cables. This allowed the central station to be positioned manually quickly
for another bombing exercise.
The supersonic trainer was able to produce a moving radar picture of a target area very similar to an actual flight over selected areas of Japan. In a few minutes it was possible to run repeated bombing problems with wind and course variables likely to occur at a given target. The actual flight in the B-29 at appropriate speeds, headings and altitudes could be represented. The wind direction and velocities could be inserted so as to require compensation both for navigation and bombing as would exist in combat conditions. The radar detectable checkpoints for the mission were pre-planned as required. The actual ground track of the aircraft was recorded on the paper sheet along with bomb release point. The trainer stopped moving at the impact point.
Wing headquarters would tell the officer in charge of the school to have
the trainers set up to allow simulations over a particular map area of Japan
and have it ready for training sessions by a certain day and time. At least
one-day lead-time was required to change maps. Several people were required to
remove and install the glass for any map change. Once the proper maps were
installed, I would set up the trainer and run practice alignment exercises to
make sure that everything was functioning correctly. Considerable effort was
required to keep the trainer leveled, cables tight and the maps aligned for
each change. The glass was unframed and relatively fragile because of its
The Story behind the Nagasaki Chart
There were three squadrons per group of usually twelve aircraft per squadron and four groups in the wing. Additionally there were specialized aircraft in each group for reconnaissance, Dumbo (Air sea rescue), photography, homing (navigational aid) and radio/radar jamming. Total aircraft per group would vary around 40 aircraft since there were specialized aircraft and crews.
I was assigned to the 58th Bomb Wing Training Center in the last
months of WWII. That meant that I no longer had to work day and night on the
aircraft of all three squadrons of the 468th Bomb Group also known as
The Billy Mitchell Group. I was the only member of the RADAR sections of our
group that was trained in operation and maintenance of both the APN-4 and APN-9
LORAN sets. Because of this I was required to to LORAN calibration and third
level maintenance on aircraft from every squadron. In India LORAN was not worth
the weight of the equipment. Its best range at night was about 600 miles. The
signal stations required for LORAN were neither sufficient in number nor well
enough placed for the requirements of the region.
The move to Tinian made a great difference in the viability of LORAN although the stations were quite far apart the range of the signals was over 2000 miles. For unknown reasons there was never any Japanese effort to jam the LORAN signals. In addition to the improvement of the signals there was a 50% reduction in the size and weight of the LORAN receivers with the introduction of the APN 9. My 1975 C-172 has a set that is the size of a cigar box. The arrival of newer and better B-29s with new crews of lower seniority raised the need for training. Senior crews took the newer aircraft with the APN-9 LORAN and gave the newly arrived crews older aircraft with the APN-4 LORAN. The switching of aircraft and crews required specific retraining of the navigators in the exchange. Although the signals were still the same the operation of the LORAN receivers were sufficiently different that schooling was required. For this reason I was assigned to the 58th Wing Training Center to establish, install and teach the LORAN set operation required by the switching of crews.
Under the military rules of classroom operation, the teacher is in charge, regardless of rank. I had been thoroughly trained in the operation of both the APN-4 and the APN-9. I was a strong believer in its usefulness in flights all the way to Japan with only a 2% probability of system error on landfall at the islands of Japan. That was an error of 28 miles. In conjunction with the APQ-13 radar set this error could be reduced to zero when within 100 miles of the islands. The APQ-13 gave a quasi-pictorial view of land services adjacent to water. I was a believer but the LORAN experience of crews flying in India/China had been entirely negative. They were not believers and had every reason to be distrustful of the reliability of everything electronic in aircraft. This attitude did not take long to infect the new arrivals.
I was a corporal who had been put in several classrooms full of officers
every day. The officers were there against their will to learn about something
they had experienced as not worth their time or lives. I lasted in this
situation for about two months. Things got better with time but not much better.
LORAN was proving to be useful and somewhat more reliable in its Pacific
operations. But, my assignment to teach LORAN was about to end.
On morning, at the end of the Quanset building were six large dumpster sized wooden boxes. they contained parts of three radar simulator devices known as Supersonic Trainers. I was one of three chosen to assemble, calibrate, operate and supervise the trainer. I finished my first, perhaps because I was youngest; perhaps because I was enjoying the work but mostly because I put in the extra hours at night needed to get it done.
At some point in the last few weeks of the war I was told to put the Nagasaki
glass map pair on my trainer. .It took about two days to change the maps and get
the trainer calibrated to give a fairly accurate depiction of what a radar
APQ-13 would see over the Nagasaki area of Japan. At that time my trainer had
been modified to the very latest APQ-23 bombardment system.
The APQ-23 had bombsight type range and azimuth knobs for control of the aircraft auto-pilot and remote synchronization with the aircraft bomb sight.. The radar sets themselves were identical only the bombing system was different so the change to the trainer itself was slight.
The APQ-23 was the first prototype of two now very common small aircraft electronic devices. The first is the DME or distance measuring equipment. This measured the distance to the target and the ground speed of the aircraft. Unlike GPS Global Positioning System of today the DME measured slant range since it was for dropping bombs. The APQ-23 also could do offset bombing. This means that a target invisible to radar could be put into its, primitive by today standards, computer with a known distance and azimuth from a visible radar target. The guidance system of the autopilot and bombsight would have the corrections put in by the APQ-23 to hit the target. There I was at the very cutting edge of radar and electronic technology and not allowed to know what I knew.
Usually just a radar operator would arrive but occasionally a bombardier would come to confirm the ability of the self-synchronous system to cause the radar bombing-arc to conform to the bombing angle used by the bombsight. The trainee would give me a proposed target, altitude, IP (initial point), bomb characteristics, wind conditions, and aircraft speed. I would set the console dials on the trainer to meet the desired parameters. To prepare the trainer I had to become proficient both with the E6B navigational computer, the bombsight and the operation of the radar. I still have my brass E6-B and the government issue (G.I.) Hamilton watch needed to time events as they happened. Keeping a log of the exercise was a part of my job. I have no idea of what happened to these logs after the war. I made no copies of the training logs I had made.
The bomb run with the radar set required that altitude, true airspeed, wind correction, bomb characteristics, slant range to target, and ground speed be computed. Correctly done both by autopilot of the plane and the radar operator, the scope would show the terrain below with a brighter track line crossed over by a bomb-arc that would track automatically as the plane approached the target. The track line corrected for any wind blowing the aircraft off course. Bomb release was automatic at the computed release point by either the bombsight or the time-of-fall timer of the trainer. Since there was no remote control of the supersonic trainer flight simulator it was necessary for the mechanic/operator (me) to follow instructions to dial in the heading changes required to correct for wind drift.
As the radar mechanic operator of the supersonic trainer I was required to
keep a log of the mission parameters to verify that the mission was performed
as required. I had to set airspeed, wind, altitude, and time-of-fall into the
trainer's console. I had to preflight the trainer and have it warm,
calibrated, aligned and ready to perform. Once in motion I had to make heading
changes and turns to new headings as directed. The top plotting map would have
the mission plotted with grease pencil as planned by the mechanic. The
recording pen under the paper would mark the actual track 'flown'. The
comparison of the two markings was one way used to determine flight and
The entire mission starts at a specific point and altitude. Once underway the radar operator is expected to use the E-6B to determine the wind direction and velocity, make the required heading adjustments to maintain the desired track and note time at specific intervals during the flight. Once the trainer was activated the trainees would sit at the radar set and view the scope as though they were actually over Japan. They could make wind and course computations as though in actual flight and request changes which I would put into the dials on the console. Thus, I performed the function of the pilot for the APQ-13 and later the autopilot for the APQ-23. Since we were starting near the IP it would be possible to execute three or four practice runs in an hour. Most of us would stand by the trainer and watch the pen track the bomb run.
Several runs to the same target would be sequenced with the first being tutored and the later runs as either practice or test runs. The trainer allowed the radar operator to develop proficiency in radarscope interpretation, navigation and bombing when visual use of the Norden sight was not possible. When the bombardier was present the teamwork coordination required via the intercom could be readily realized. The radar operator would synchronize the movement of the scope bomb arc with the tracking angle of the Norden sight. Use of the correct terminology between the two was critical. The navigator, using an auxiliary scope could assist the radar operator in making wind corrections and navigational corrections. The initiation of turns at the proper moment was critical and a common source of error. The supersonic trainer was able to produce a moving radar picture of a target area very similar to an actual flight. In an hour it was possible to run repeated bombing problems with wind and course variables likely to occur at a given target.
Later supersonic trainer post-war programs required the presence of a multi-qualified navigator-bombardier radar instructor but in my situation none existed so I was instructed to set up the trainer with a specific glass pair of maps. The targeted plan did not exist until someone walked in the door and told me the specifics of a mission. It is my belief that the accompanying aeronautical chart contains the specifics of a particular exercise. As the 'pilot' I was given a place to start, an altitude to set into the trainer, the wind direction and velocity and the true airspeed to be used. With these parameters set into the trainer the exercise would commence. Usually two very precise standard rate turns had to be made prior to entering the final bombing run. A standard rate turn is made at three-degrees per second Practical experience of a visitor taught me that the standard rate turn could be easily and correctly drawn by using the circumference of a Lincoln head penny.
In the last two months of the war I was chosen to change my supersonic trainer over from the APQ-13 to the APQ-23. The change had to do with the radar bombing capability and not the supersonic trainer. By today's microchip standard the APQ-23 was most primitive. All input voltages were from wire-wound resistors. The readouts were on odometer type numbered wheels. The actual bomb tracking was done with knurled dials just like those on the bombsight. On an adjacent desk was a completely operational radar set sans transmitter and a bombsight which was servo linked and moved and tracked with the radar track and bomb release angle but without any visual reference. On actual mission the radar was coordinated with the visual bombsight so that if visual conditions should suddenly prevail the bombsight would be tracking on target. This occurred in the atomic bombing of Nagasaki using the older less accurate APQ-13. Result was that the desired impact point was missed by three miles.
There were several levels of supersonic trainer instruction. On Tinian the crewmembers I worked with were well-practiced in navigation and crew coordination. What was needed was becoming familiar with the change from the APQ-13 to the APQ-23. Traditionally, new crews brought over new planes. Senior crews took the new planes and gave new crews old aircraft. The operation of the radar was the same. The major differences were in the method by which the azimuth track was changed on the bomb run and how the bomb arc on the scope is controlled. The APQ-23's servomechanisms were designed to lead the Norden sight into the target as well without the APQ-13 's required oral communication to the pilot and bombardier. Radar operators, bombardiers and navigators had to become familiar with the change of equipment and the differing capabilities. The supersonic trainer was the most efficient use of available resources.
The significance of this changeover deserves elaboration. The APQ 13 established a basic standard for surface depiction that was surpassed only through electronic miniaturization, computerization and digital display. The APQ 23 was the very first radar instrument capable of direct electronic synchronization with the Norden Bomb sight. The APQ-23 had knurled knobs that functioned just as effectively as does the identical ones of a bombsight. Using these, a trained operator could remotely control the flight path of an aircraft and adjust the bomb release arc on the radarscope to track with the target. A Bombardier's Norden bombsight could be electrically coordinated in case the target became visual. The APQ-23 made it easy to get a direct odometer type reading of the ground speed and slant range to target. This was the first distance measuring equipment (DME) that was later adapted to the very high frequency omni-range navigation system (VOR) throughout the post war world.
If cloud-cover were to obscure the target, the APQ 23 could control the autopilot of the aircraft using the radar display, as could the Norden in visual conditions. This would correct track for drift; it could adjust the bomb release point on the target for aircraft speed. In addition to the autopilot the APQ-23 was synchronized to track with the bombsight. It could allow the bombardier to assume visual control, conditions permitting, with a minimum of adjustment. How primitive this device was compared to the electronics of today can only be appreciated by understanding that all the trigonometric functions to get the odometer read-outs were done by linear electric taps taken from wire-wound resistors. Limited stateside production of the APQ-23's mechanism was the inhibiting factor of its expanded use before the war ended.
Another innovation of the APQ-23 was its ability to preset and fly an
offset bombing procedure. A target that was difficult to discern on radar
could be made viable by locating a nearby body of water or island. Practice
mission was preset by putting the azimuth and distance from the target to the
place that was radar discernable into the dials of the APQ-23. This done, it
was possible to track on the scope to what was seen on the radar while the
aircraft would actually fly to and bomb the target invisible to radar. This
was also adapted to the VOR navigation system of today's civil aviation and
called RNAV. VORs can be moved electronically to one side of and airway and
the route flown well clear of other traffic.
I have no way of knowing just how effective the trainer was but my impression was that usually I was working with lead pathfinder crews. The bombardiers were quite impressed with the ability of the APQ-23 to synchronize with the bombsight so much better than the APQ-13. There was little for them to do during a training exercise since the bombsight was being remotely controlled by the APQ-23. They probably served as 'pathfinders' who would mark the target with incendiary bombs especially designed to leave easily recognized aiming points for subsequent aircraft.
In mid-August 1983 I received a surprising letter from the Admiral Nimetz State Historical Park, located at Fredricksburg, Texas. The superintendent, Douglass Hubbard, at the museum was asking about a map of the Nagasaki area of Japan. The year before I had given Denny Pidhayny, the 58th Wing Historian some of my WWII memorabilia to send to the Nimitz museum. I had donated a map of a part of Japan along with the plans of the troop ship General C. G. Morton, and some other pictures and papers to the Museum.
I had possession of the aeronautical chart because at one time shortly
before the end of the war I had been ordered to use it to set up the
supersonic trainer using that chart area of Japan. The chart was on display as
the background of a glass-enclosed collection of memorabilia in the B-29 room
of the Nimitz Museum until early 2002. The letter from Hubbard indicated that
the chart showed multiple bomb-runs on Nagasaki. The perception is in error.
The fact is there are no lines on the map that could only be related to
Nagasaki. The only other city of any size on the chart is Sasebo. Beside
Sasebo is the inked 90%, which indicates the city as being 9/10 destroyed at
the end of the war. Not a likely target. The practice runs are apparently
directed to Sasebo North Auxiliary airport. This would be an excellent target
for an offset bombing mission.
Notation of GS 279 at top of chart would be indicative of a ground speed of 279 knots. I could control and set both direction and groundspeed of the aircraft desired for the mission. Presetting the wind direction and velocity as well meant that the track of the aircraft simulation would represent a blending of these figures just as in the real world of flying. Seventy-knot winds were very common at 20,000 feet above Japan and could exceed 200 knots. The high altitude attacks on Japan made the high altitude jet stream a focal point of meteorology study for years to follow. It was possible to get ground speeds so fast or slow that the bombsight could not track them. Some closing speeds in head-on attacks once exceeded the ability of the B-29 remotely controlled machinegun turrets to track as well. The two gun top-front turret on Bockscar indicates a CFC (Central Fire Control) unable to cope well when closure speeds exceeded a certain level. Later models had a four-gun turret top-front. These difficulties created mission analysis figures of survival and bombing accuracy that justified opening the window to the midlevel fire bombing of Japan. Interesting to note that only the Enola Gay had turrets and guns removed to move the top speed from slightly over two hundred miles per hour to well over 300 miles per hour.
The variety of lines intersecting on the chart could have been used against other targets, for timing, or even for initial trainer set-up and alignment of the glass plates. Near the middle is a freehand illustration of a scope with a bomb-arc and both a heading and track line drawn. On the far right side, near the city of Isahaya, that is 60 nautical miles, Northeast of Nagasaki would seem to indicate that missions #50 and #141 were flown there by the 58th Bomb Wing. The smaller city of Omura may have been hit, as well. Nagasaki and Karatsu to the North are the only viable targets for any practice exercises remaining on the chart. Karatsu has one very short line in the vicinity. Too short for a bombing run. Line is most likely a timing intersection line for the other lines related to other targets. The ink notations are post-war.
I phoned Douglass Hubbard, superintendent of the Nimitz facility and
suggested that he contact the Air Force Museum near Dayton, OH where Bockscar
is on display. This was to determine the possibility that the crew of "Bockscar"
might have used my supersonic trainer. At one point in time I had installed
the Nagasaki-Fukuoka map although at the time I had no way of knowing anything
about the target selected for the simulated bombings. My trainer had been
equipped with the APQ 23 for the last two months of the war and had been used
by some crew practicing in the vicinity of Nagasaki. I was told that
there were at least six B-29s in the Marianas equipped with the APQ-23.
We contacted the United States Air Force Museum at Dayton, Ohio in an effort to determine if the B-29 Bockscar had an APQ-13 or the APQ-23 at the time of the bombing. The data from the Air Force Museum showed that the APQ-23 was not installed until 1946, after the war. Although nothing definitive was determined it is still possible that my supersonic trainer may have been used in preparation for dropping the atomic bomb because of its innovative direct servo-linkage to the bombsight. This practicing could be done without revealing the actual target involved.
If cloud cover were to obscure the target, the APQ 23 could control the flight of the aircraft to the target using the autopilot. This would correct track for drift; it could adjust the bomb release point on the target for aircraft ground speed. In addition to the autopilot the APQ-23 was synchronized to track with the bombsight. It could allow the bombardier to assume visual control, visual conditions permitting, with a minimum of adjustment. The atomic bombs were only to be dropped visually. Bockscar made several radar runs before dropping and missing aiming point by three miles. The last run was made primarily via radar with a very brief time of visual sighting of the target. As it was, the aircraft was so low on fuel because of its repeated runs, it initially landed on Okinawa instead of Tinian for fuel.
In the early l950s the APQ 23 was the standard radar used on the B-47 jet bomber. The supersonic trainer was being used for the training of the triple threat radar, navigator, and bombardier officer in the B-47. In order to finance my education at San Jose State College in the years from 1950 to 1952 I had joined the Air Force Reserve. Once a month I would spend a weekend at Mather AFB on reserve duty where my primary duty was to teach basic electronics to enlisted men of my squadron. On several occasions I was able to have access to the training facility of the base where I recognized that the process of training the triple-threat radar operator, bombardier and navigator for the B-47 using my old friend the supersonic trainer.
No pictures were allowed of our training facility on Tinian or of the supersonic trainer itself. A couple of years before Mather AFB closed I made a visit and was given some material that was declassified, including a picture of the supersonic trainer in action and an Operations Manual.. I don't know of any such pictures taken in the Pacific during WWII. How primitive this radar simulator and flight device was can only be appreciated by understanding where we are today. I wonder and doubt if an electronic radar simulator preceded this one? I doubt that any one of the many trainers exists in this year 2003. However, I do believe a quarter sized model with moving parts could be made to show how it worked and what it was capable of doing.
In the summer of 1987 I spent a day in Seattle. I visited a shop specializing in old magazines. I was looking for articles about B-29's. After I got home I looked more extensively through the August 20, 1945 issue of Life. I found a full-page pictorial of the radar display such as could be shown by the supersonic trainer or in a B-29. It was featured as one of the major technical achievements to come out of the war. Thus, years after the war, I came to know what I may have done during the war.
When the war ended I proceeded to dismantle and box the trainer for shipment back to the states. I spent my spare time in the adjacent building flying one of eight Link trainers. My instrument skills were well developed by sixty days of at least five hours a day instrument training. I recall the Link operators having pilots due to fly Stateside to McCelland Army Base in Sacramento, CA watch me fly the radio range instrument landing procedure then standard. Twenty years later I was able to afford flying lessons at age 42. I was able to utilize all the skills in navigation and instrument flying that I had acquired on Tinian. I had to unlearn some my Link skills, however. The instructors insisted that I look outside the airplane.
In April of 2002 I passed my ten-thousandth hour of logged pilot in command
flight time of which about 8,300 were as a flight instructor. In 2005 I have
passed 11,000 total hours and 10,000 instructional hours.
I have a two-million (3-million in 2005) word web site directed toward primary flight instruction and learning. See http://www.whittsflying.com . The site is used worldwide by both new and old general aviation pilots.
I have often wondered if this supersonic device was the predecessor of all the subsequent uses of supersonic vibrations. I know it is used for cleaning delicate scientific and medical instruments. It is now used by dentists for cleaning teeth. Likewise, epoxy glues appeared too late. Ultra-sound is used for medical analysis, imaging. and pulverizing kidney stones. The list will continue to grow.
That the primitive radio range instrument landing system was primary during the war is unfortunate since the far superior ILS localizer/glide slope system existed as early as 1930. Its use was short-stopped by governmental inertia until after WWII. Statistics seem to indicate that aircraft casualties prior to and during WWII caused by weather conditions exceeded actual combat casualties. I have reason to believe that 'operational' casualties in my B-29 Wing exceeded those that occurred in combat. As of April 1945 out of 170 B-29 lost 84 were considered combat losses. In my 468th Group only one of the four groups in India the operational losses were 21 and combat losses were 10. That shows that two out of three lost aircraft were due to causes other than Japanese contact.
Memories of the EDDIE ALLEN
One morning during the summer of 1945 a half-track (the front end like a truck and the backend like a Caterpillar) came up the hill towing the hulk of a B-29 fuselage. The tail had been removed for salvage. The center section of the wing protruded just past the inboard engine nacelles. It took better part of the day to position what remained of the aircraft between the two large training school Quonset buildings. It was the remains of the "Eddie Allen" from the 40th Bomb Group, named after the famous test pilot killed in an early B-29 test flight that crashed into a Seattle factory complex. At the school it was to be used as a ditching trainer.
During the last months of WWII I was serving as a LORAN instructor/mechanic teaching transitional operation between the APN-4 and APN-9. In the last three months of the conflict I served as one of three Supersonic Trainer technicians at the wing training school of the 58th Bomb wing on Tinian Island of the Marianas. At the time I had absolutely no recognition of the historical or aviation significance of this aircraft. Now, years later, I know I saw part of a great story.
The school was located in two barn-sized quonset buildings on a hill near the western edge of the island. These buildings were much larger than the barracks size in common use. They were bolted to cement slab floors. One of the buildings contained eight link trainers. The other had three Supersonic Trainers and a corner room with ten Loran sets. The LORAN corner was an after-thought because all of the new B-29s were being taken from the new crews and given to the old-timers who had 'rank'. The new planes had the
APN-9 that was operationally more efficient and improved over the APN-4. The aircraft switch meant that many navigators had to be retrained for the appropriate LORAN set.
There was open space of about 75 feet between the buildings in which was
located the diesel powered generator. It was usually my duty every morning to
get the diesel started to give the required power to the buildings and
electronic equipment. This produced 110 volt 60 cycle for the lights and 28
volt 400 cycle for the electronics. Ample room remained for the Eddie Allen.
It was my understanding that the aircraft had taken a shell hit on a raid over Japan. The shell had hit but not exploded on the main wing spar. The wing had held well enough to safely return the crew to Tinian but could no longer support the bomb/fuel overloads of war. Anyone who has ever seen the wingtips of a loaded B-29 bend upward six feet on liftoff understands this.
Beneath the pilot's window was the logo "Eddie Allen" along with almost a dozen bomb symbols and seven camels as a visual record of the aircraft's missions. The accompanying photo the aircraft in this position and condition. The picture was taken after the end of the war. The plane served as a backdrop for a group picture of the training school staff. I am standing directly below the co-pilots window.
The addition of the fuselage to the training school was to provide a ditching trainer at the school. There was to be no additional training staff, however. Each aircraft commander was to conduct his own training program and drill. I have no idea as to how often the Allen was used for this purpose since my time was fully occupied inside the buildings.
I have no recollection of having ever entered the aircraft. Yet, every morning for the last few months of the war and for a couple thereafter I would walk the length of the fuselage to fire up the diesel generator that provided all the required electricity for the Training Center. Several times a day I would pass by the nose of the aircraft. I may not have been the last but I was near the last to see the end of its service life. I was not there to see the final removal or disposition of the Allen. I don't know that I want to know. Since we dumped much of the abandoned military equipment off the cliffs of Tinian, my guess is that the same happened to the 'Eddie Allen".
War that Won't End
During the three-day hiatus between the dropping of the two bombs there was a significant change in the behavior and morale of those B-29 airmen based on Tinian, Saipan and Guam. Several raids were planned and cancelled at various stages. Planes were called back when airborne, briefings were scheduled and crews aboard aircraft when missions were cancelled, missions were scheduled and cancelled before briefings. The flight and maintenance crews were becoming increasingly frustrated by the top-level appearance of inertia confusion and uncertainty. I never fail to be surprised that
so little is said about the middle day and what happened then. Russia declared war on Japan.
A day or two after the raid on Nagasaki took place every soldier and sailor on the island was required to attend an assembly relating to the malaise affecting the troops. The assembly I attended took place at a large open-air theater cut into a hillside. An officer took a few minutes to explain the end of the war situation as being quite "fluid" causing the mission cancellations. He went on to explain as best I can recall the following pertinent items. Immediately prior to the Hiroshima bombing we were sending 800 B-29s over Japan every four days. 200 B-29 were capable of the firebomb destruction of a medium sized city. Were the war to continue for two more months there would be 2000 B-29s in action with most carrying larger bomb loads from Okinawa. We were rapidly running out of worthwhile targets. Coincidentally, the two bombs we dropped were the only two we had in the Pacific Theater.
The final bit of information related to the impending invasion of Japan. On Tinian only a mile from our assembly they were in the process of building living quarters for seven hundred nurses. These were to staff the future hospital meant to care for casualties anticipated during the invasion. Many more such facilities were under preparation elsewhere.
Early in WWII, the British government showed the United States how to use the cavity magnetron in the development of microwave radar. Together, they developed an airborne radar system with a transmitter tube three thousand times more powerful and effective than that used previously. Our operational successes in the Pacific or Atlantic were relatively few until augmented by magnetron powered microwave radar. Yes, the same power as is today used in a microwave oven. The magnetron was the power behind all microwave radar.
Most of us are familiar with the echo like qualities of radar. A microwave radio frequency pulse is triggered from the magnetron heart of the transmitter and sent through a tuned wave-guide to the antenna about every 200 microseconds. During the wait period a very small portion of the signal might be returned as an echo. The intensity of the echo return depends on the reflective ability of a given target. Water gives little return and objects in the water are readily apparent on radar. Rivers show well as being less reflective than the surrounding land areas. The buildings of a city are far more reflective than land. A city partially bordered by water shows very well on microwave radar. The essentials of the APQ-13 airborne radar set are the transmitter, receiver, synchronizer, rotating parabolic antenna and the PPI (plan position indicator) circular scope. Today all such presentations are digitally filtered and enhanced for clarity and motion. Aircraft usually carry transponders to give coded identification replies back to radar interrogators.
Navigation was a primary initial benefit of the APQ-13. It would show
rivers, bays, islands, and such with considerable clarity. A comparison of
the radar display with an aeronautical chart would greatly facilitate
landfall recognition and location of assembly areas. The ability to navigate
and locate by radar saved thousands of lives in WWII. Hardly a ship or
airplane today moves without the presence and comfort of radar. The greatest
difference between electronics of WWII and today lies in the use of
transistors and microchips instead of vacuum tubes to reduce size and weight
while increasing efficiency.
The only external sign of radar in the B-29 and other radar capable aircraft usually consisted of the plastic dome that could be extended or retracted from the bottom of the aircraft between the dual bomb bays. Retracted it improved aircraft performance a bit. Extended the dome improved radar detection and ranging capability significantly. For secrecy, the existence of this dome was removed from most WWII photos of the B-29. The interior of the dome was filled by the rapidly turning parabolic reflector on which was centered a microwave transmitting and receiving antenna. The reflector inside the dome could be tilted up and down according to the desired range selected.
The APQ 13 transmitter and wave-guide to the antenna had to be maintained as a pressurized unit for proper operation. Its curvature and length functioned much as a tuned exhaust stack does in a racing car. It was all too common to have this pressurization leak and fail at high altitudes. The entire assembly fed the transmitted signal out into space and received the very small target echo to be fed by the pressurized rectangular frequency tuned wave-guide back to the PPI phosphor display of the radar operator. The power and waveform of the antenna could be checked by use of a neon bulb. By walking around a stopped antenna you could plot the signal pattern being projected by the antenna. The APQ 13's magnetron transmitter had sufficient power to make the bulb light with the microwave radio frequency for hundreds of feet from the antenna. The bulb gave an indication of both focus direction and power of the radar set.
As the antenna turns, transmits and receives microwave signals a
five-inch phosphorescent PPI screen would be turning, receiving and
displaying echoes. The aircraft was usually located at the center of the
screen and the electron beam moving around and out synchronously with the
antenna and the transmitted pulse. The small portion of the transmitted
pulse that returned as an echo to the antenna would be shown in relative
brightness on the PPI scope. Considerable experience and skill are required
to tune, focus and interpret what appeared on the early scopes. A second
scope was in the Navigators position for his use. The navigational benefits
of the radar display were limited by altitude and display power to a
line-of-sight one hundred fifty miles. The APQ-13 was the standard
navigational and bombing radar set used in much of WWII
At the squadron level very little repair was done. Usually the components were removed and replaced with spares. Defective units were sent to the service squadrons for repair. Numerous cables interconnected the components of the APQ 13. No matter how carefully these cable connections might be made the effects of humidity, corrosion, and vibration could cause radar failure. In the event of failure the connections were the first thing checked. In an era of vacuum tubes the failure of any one of the thirty or forty tubes in each component was more a probability than not on any given flight. A major difficulty seemed to lie in the inability to obtain a reliable and consistent regulated level of electrical power from the 400 cycle alternators. The hollow wave-guide leading from the transmitter to the antenna had to be kept pressurized. All of these requirements made high altitude operations more difficult.
I was a radar mechanic, with the military occupation specialty number as MOS 718 or airborne radar mechanic, who came to India by way of North Africa along with actor Pat O'Brien's USO Troupe. Fifty of us flew half way around the world in small groups. First across the Atlantic, then across Africa and finally across the near east and India. We were divided among all the B-29 groups and squadrons based near Calcutta. The China, Burma, India (CBI) theater of the war was the initial proving ground for the B-29 aircraft and operations.
(I did not learn until 2003 that the reason I flew to India on the second highest priority for military travel.. I was one of fifty radar mechanics for replacement for those B-29 troops who were lost in the sinking of the troop ship HMS Rhona. Sunk by a German radio guided flying bomb off the coast of North Africa the month before).
The B-29 had to ferry a large portion of its fuel and bombs over the Himalayas to China. A mission to Japan required at least three 'Hump' trips. Camels on the aircraft would indicate flights over the Himalayas. Each trip required a 600-mile climb to gain the required altitude. The metals and cooling requirements of the B-29 engines were inadequate for the demanding climb. In early 1945 all of the 58th Bomb Wing B-29s were flown from India via China to Tinian island in the Marianas. Ground crew went on a forty-two day voyage by ship around Australia to the Pacific and Tinian. Aircraft and electronic equipment performance improved dramatically with the change of location. Time between engine changes often occurred within thirty hours in the CBI. A year later in the Pacific 800 hours became the average. With the change of location the B-2l9 operations became far more efficient but bombing accuracy was poor until incorporated with incendiary bombs.
The following release was written by William L. Laurence, Science writer for the New York Times, and Special Consultant to the Manhattan Engineer District and former Pulitzer Prize winner. The story can be released with or without the use of Mr. Laurence's name.
WITH THE ATOMIC BOMB MISSION TO JAPAN, AUGUST 9 (DELAYED)--We are on our way to bomb the mainland of Japan. Our flying contingent consists of three specially designed B-29 Superforts, and two of these carry no bombs. But our lead plane is on its way with another atomic bomb, the second in three days, concentrating its active substance, and explosive energy equivalent to 20,000, and under favorable conditions, 40,000 tons of TNT.
We have several chosen targets. One of these is the great industrial and shipping center of Nagasaki, on the western shore of Kyushu, one of the main islands of the Japanese homeland.
I watched the assembly of this man-made meteor during the past two days, and was among the small group of scientists and Army and Navy representatives privileged to be present at the ritual of its loading in the Superfort last night, against a background of threatening black skies torn open at intervals by great lightning flashes.
It is a thing of beauty to behold, this "gadget." In its design went millions of man-hours of what is without a doubt the most concentrated intellectual effort in history. Never before had so much brain-power been focused on a single problem.
This atomic bomb is different from the bomb used three days ago with such devastating results on Hiroshima.
I saw the atomic substance before it was placed inside the bomb. By itself it is not at all dangerous to handle. It is only under certain conditions, produced in the bomb assembly, that it can be made to yield up its energy, and even then it gives up only a small fraction of its total contents, a fraction, however, large enough to produce the greatest explosion on earth.
The briefing at midnight revealed the extreme care and the tremendous amount of preparation that had been made to take care of every detail of the mission, in order to make certain that the atomic bomb fully served the purpose for which it was intended. Each target in turn was shown in detailed maps and in aerial photographs. Every detail of the course was rehearsed, navigation, altitude, weather, where to land in emergencies. It came out that the Navy had submarines and rescue craft, known as "Dumbos" and "Super Dumbos," stationed at various strategic points in the vicinity of the targets, ready to rescue the fliers in case they were forced to bail out.
The briefing period ended with a moving prayer by the Chaplain. We then proceeded to the mess hall for the traditional early morning breakfast before departure on a bombing mission.
A convoy of trucks took us to the supply building for the special equipment carried on combat missions. This included the "Mae West," a parachute, a life boat, an oxygen mask, a flak suit and a survival vest. We still had a few hours before take-off time but we all went to the flying field and stood around in little groups or sat in jeeps talking rather casually about our mission to the Empire, as the Japanese home islands are known hereabouts.
In command of our mission is Major Charles W. Sweeney, 25, of 124 Hamilton Avenue, North Quincy, Massachusetts. His flagship, carrying the atomic bomb, is named "The Great Artiste," but the name does not appear on the body of the great silver ship, with its unusually long, four-bladed, orange-tipped propellers. Instead it carried the number "77," and someone remarks that it is "Red" Grange's winning number on the Gridiron.
Major Sweeney's co-pilot is First Lieutenant Charles D. Albury, 24, of 252 Northwest Fourth Street, Miami, Florida. The bombardier upon whose shoulders rests the responsibility of depositing the atomic bomb square on its target, is Captain Kermit K. Beahan, of 1004 Telephone Road, Houston, Texas, who is celebrating his twenty-seventh birthday today.
Captain Beahan has been awarded the Distinguished Flying Cross, the Air Medal, and one Silver Oak Leaf Cluster, the Purple Heart, the Western Hemisphere Ribbon, the European Theater ribbon and two battle stars. He participated in the first heavy bombardment mission against Germany from England on August 17, 1942, and was on the plane that transported General Eisenhower from Gibraltar to Oran at the beginning of the North African invasion. He has had a number of hair-raising escapes in combat.
The Navigator on "The Great Artiste" is Captain James F. Van Pelt, Jr., 27, of Oak Hill, West Virginia. The flight engineer is Master Sergeant John D. Kuharek, 32, of 1054 22nd Avenue, Columbus, Nebraska. Staff Sergeant Albert T. De Hart of Plainview, Texas, who celebrated his thirtieth birthday yesterday, is the tail gunner; the radar operator is Staff Sergeant Edward K. Buckley, 32, of 529 East Washington Street, Lisbon, Ohio. The radio operator is Sergeant Abe M. Spitzer, 33, of 655 Pelham Parkway, North Bronx, New York; Sergeant Raymond Gallagher, 23, of 5727 South Mozart Street, Chicago, Illinois, is assistant flight engineer.
The lead ship is also carrying a group of scientific personnel, headed by Commander Frederick L. Ashworth, U.S.N., one of the leaders in the development of the bomb. The group includes Lieutenant Jacob Beser, 24, of Baltimore, Maryland, an expert on airborne radar.
The other two Superforts in our formation are instrument planes, carrying special apparatus to measure the power of the bomb at the time of explosion, high speed cameras and other photographic equipment.
Our Superfort is the second in line. Its Commander is Captain Frederick C. Bock, 27, of 300 West Washington Street, Greenville, Michigan. Its other officers are Second Lieutenant Hugh C. Ferguson, 21, of 247 Windermere Avenue, Highland Park, Michigan, pilot; Second Lieutenant Leonard A. Godfrey, 24, of 72 Lincoln Street, Greenfield, Massachusetts, navigator; and First Lieutenant Charles Levy, 26, of 1954 Spencer Street, Philadelphia, Pennsylvania, bombardier.
The enlisted personnel of this Superfort are the following: Technical Sergeant Roderick F. Arnold, 28, of 130 South Street, Rochester, Michigan, flight engineer; Sergeant Ralph D. Curry, 20, of 1101 South 2nd Avenue, Hoopeston, Illinois, radio operator; Sergeant William C. Barney, 22, of Columbia City, Indiana, radar operator; Corporal Robert J. Stock, 21, of 415 Downing Street, Fort Wayne, Indiana, assistant flight engineer; and Corporal Ralph D. Belanger, 19, of Thendara, New York, tail gunner.
The scientific personnel of our Superfort includes: Staff Sergeant Walter Goodman, 22, of 1956 74th Street, Brooklyn, New York, and Lawrence Johnson, graduate student at the University of California, whose home is at Hollywood, California.
The third Superfort is commanded by Major James Hopkins, 1311 North Queen Street, Palestine, Texas. His officers are Second Lieutenant John E. Cantlon, 516 North Takima Street, Tacoma, Washington, pilot; Second Lieutenant Stanley C. Steinke, 604 West Chestnut Street, West Chester, Pennsylvania, navigator; and Second Lieutenant Myron Faryna, 16 Elgin Street, Rochester, New York, bombardier.
The crew are Technical Sergeant George L. Brabenec, 9727 South Lawndale Avenue, Evergreen, Illinois; Sergeant Francis X. Dolan, 30-60 Warrent Street, Elmhurst, New York; Corporal Richard F. Cannon, 160 Carmel Road, Buffalo, New York; Corporal Martin G. Murray, 7356 Dexter Street, Detroit, Michigan, and Corporal Sidney J. Bellamy, 529 Johnston Avenue, Trenton, New Jersey.
On this Superfort are also two distinguished observers from Great Britain, whose scientists played an important role in the development of the Atomic Bomb. One of these is Group Captain G. Leonard Cheshire, famous RAF pilot, who is now a member of the British Military Mission to the United States. The other is Dr. William G. Penney, Professor of Applied Mathematics London University, one of the group of eminent British scientists which has been working at the "Y-Site" near Santa Fe, New Mexico, on the enormous problems involved in taming the Atom.
Group Captain Cheshire, whose rank is the equivalent of that of Colonel in the AAF, was designated as an observer of the Atomic Bomb in action by Winston Churchill when he was still Prime Minister. He is now the official representative of Prime Minister Attlee.
We took off at 3:50 this morning and headed northwest on a straight line for the Empire. The night was cloudy and threatening, with only a few stars here and there breaking through the overcast. The weather report had predicted storms ahead part of the way but clear sailing for the final and climactic stages of our odyssey.
We were about an hour away from our base when the storm broke. Our great ship took some heavy dips through the abysmal darkness around us, but it took these dips much more gracefully than a large commercial airliner, producing a sensation more in the nature of a glide than a "bump" like a great ocean liner riding the waves. Except that in this case the air waves were much higher and the rhythmic tempo of the glide much faster.
I noticed a strange eerie light coming through the window high above in the Navigator's cabin and as I peered through the dark all around us I saw a startling phenomenon. The whirling giant propellers had somehow become great luminous discs of blue flame. The same luminous blue flame appeared on the plexiglass windows in the nose of the ship, and on the tips of the giant wings it looked as though we were riding the whirlwind through space on a chariot of blue fire.
It was, I surmised, a surcharge of static electricity that had accumulated on the tips of the propellers and on the dielectric material in the plastic windows. One's thoughts dwelt anxiously on the precious cargo in the invisible ship ahead of us. Was there any likelihood of danger that this heavy electric tension in the atmosphere all about us may set it off?
I express my fears to Captain Bock, who seems nonchalant and imperturbed at the controls. He quickly reassures me:
"It is a familiar phenomenon seen often on ships. I have seen it many times on bombing missions. It is known as St. Elmo's Fire."
On we went through the night. We soon rode out the storm and our ship was once again sailing on a smooth course straight ahead, on a direct line to the Empire.
Our altimeter showed that we were traveling through space at a height of 17,000 feet. The thermometer registered an outside temperature of 33 degrees below zero centigrade (about 30 below Fahrenheit). Inside our pressurized cabin the temperature was that of a comfortable air-conditioned room, and a pressure corresponding to an altitude of 8,000 feet. Captain Bock cautioned me, however, to keep my oxygen mask handy in case of emergency. This, he explained, may mean either something going wrong with the pressure equipment inside the ship or a hole through the cabin by flak.
The first signs of dawn came shortly after 5:00 o'clock. Sergeant Curry, who had been listening steadily on his earphones for radio reports while maintaining a strict radio silence himself, greeted it by rising to his feet and gazing out the window. "It's good to see the day," he told me. "I get a feeling of claustrophobia hemmed in in this cabin at night."
He is a typical American youth, looking even younger than his 20 years. It takes no mind reader to read his thoughts.
"It's a long way from Hoopeston, Illinois," I find myself remarking.
"Yep," he replies, as he busies himself decoding a message from outer space.
"Think this atomic bomb will end the war?" he asks hopefully.
"There is a very good chance that this one may do the trick," I assure him, "but if not then the next one or two surely will. Its power is such that no nation can stand up against it very long."
This was not my own view. I had heard it expressed all around a few hours earlier before we took off. To anyone who had seen this man-made fireball in action, as I had less than a month ago in the desert of New Mexico, this view did not sound over-optimistic.
By 5:50 it was real light outside. We had lost our lead ship but Lieutenant Godfrey, our Navigator, informs me that we had arranged for that contingency. We have an assembly point in the sky above the little island of Yakoshima, southeast of Kyushu, at 9:10. We are to circle there and wait for the rest of our formation.
Our genial Bombardier, Lieutenant Levy, comes over to invite me to take his front row seat in the transparent nose of the ship and I accept eagerly. From that vantage point in space, 17,000 feet above the Pacific, one gets a view of hundreds of miles on all sides, horizontally and vertically. At that height the vast ocean below and the sky above seem to merge into one great sphere. I was on the inside of that firmament, riding above the giant mountains of white cumulous clouds, letting myself be suspended in infinite space. One hears the whirl of the motors behind one, but soon becomes insignificant against the immensity all around and is before long swallowed by it. There comes a point where space also swallows time, and one lives through eternal moments filled with an oppressive loneliness, as though all life had suddenly vanished from the earth and you are only one left, a lone survivor traveling endlessly through interplanetary space.
My mind soon returns to the mission I am on. Somewhere beyond these vast mountains of white clouds ahead of me there lies Japan, the land of our enemy. In about four hours from now one of its cities, making weapons of war for use against us will be wiped off the map by the greatest weapon ever made by man. In one-tenth of a millionth of a second, a fraction of time immeasurable by any clock, a whirlwind from the skies will pulverize thousands of its buildings and tens of thousands of its inhabitants.
Our weather planes ahead of us are on their way to find out where the wind blows. Half an hour before target time we will know what the winds have decided.
Does one feel any pity or compassion for the poor devils about to die? Not when one thinks of Pearl Harbor and of the death march on Bataan.
Captain Bock informs me that we are about to start our climb to bombing altitude.
He manipulates a few knobs on his control panel to the right of him and I alternately watch the white clouds and ocean below me and the altimeter on the Bombardier's panel. We reached our altitude at 9:00 o'clock. We were then over Japanese waters, close to their mainland. Lieutenant Godfrey motioned to me to look through his radar scope. Before me was the outline of our assembly point. We shall soon meet our lead ship and proceed to the final stage of our journey.
We reached Yakoshima at 9:12 and there, about 4,000 feet ahead of us, was "The Great Artiste" with its precious load. I saw Lieutenant Godfrey and Sergeant Curry strap on their parachutes and I decided to do likewise.
We started circling. We saw little towns on the coastline, heedless of our presence. We kept on circling, waiting for the third ship in our formation.
It was 9:?? when we began heading for the coastline. Our weather scouts had sent us code messages, deciphered by Sergeant Curry, informing us that both the primary target as well as the secondary were clearly visible.
The winds of destiny seemed to favor certain Japanese cities that must remain nameless. We circled about them again and again and found no opening in the thick umbrella of clouds that covered them. Destiny chose Nagasaki as the ultimate target.
We had been circling for some time when we noticed black puffs of smoke coming through the white clouds directly at us. There were 15 bursts of flak in rapid succession, all too low. Captain Bock changed his course. There soon followed eight more bursts of flak, right up to our altitude, but by this time we were too far to the left.
We flew southward down the channel and at 11:33 crossed the coastline and
headed straight for Nagasaki about a hundred miles to the west. Here again
we circled until we found an opening in the clouds. It was 12:01 and the
goal of our mission had arrived.
We heard the pre-arranged signal on our radio, put on our ARC welder's glasses and watched tensely the maneuverings of the strike ship about half a mile in front of us.
"There she goes!" someone said. Out of the belly of the Artiste what looked like a black object came downward.
Captain Bock swung around to get out of range, but even though we were turning away in the opposite direction, and despite the fact that it was broad daylight in our cabin, all of us became aware of a giant flash that broke through the dark barrier of our ARC welder's lenses and flooded our cabin with an intense light.
We removed our glasses after the first flash but the light still lingered on, a bluish-green light that illuminated the entire sky all around. A tremendous blast wave struck our ship and made it tremble from nose to tail. This was followed by four more blasts in rapid succession, each resounding like the boom of cannon fire hitting our plane from all directions.
Observers in the tail of our ship saw a giant ball of fire rise as though from the bowels of the earth, belching forth enormous white smoke rings. Next they saw a giant pillar of purple fire, 10,000 feet high, shooting skyward with enormous speed.
By the time our ship had made another turn in the direction of the atomic explosion the pillar of purple fire had reached the level of our altitude. Only about 45 seconds had passed. Awe-struck, we watched it shoot upward like a meteor coming from the earth instead of from outer space, becoming ever more alive as it climbed skyward through the white clouds. It was no longer smoke, or dust, or even a cloud of fire. It was a living thing, a new species of being, born right before our incredulous eyes.
At one stage of its evolution, covering missions of years in terms of seconds, the entity assumed the form of a giant square totem pole, with its base about three miles long, tapering off to about a mile at the top. Its bottom was brown, its center was amber, its top white. But it was a living totem pole, carved with many grotesque masks grimacing at the earth.
Then, just when it appeared as though the thing has settled down into a state of permanence, there came shooting out of the top a giant mushroom that increased the height of the pillar to a total of 45,000 feet. The mushroom top was even more alive than the pillar, seething and boiling in a white fury of creamy foam, sizzling upwards and then descending earthward, a thousand old faithful geysers rolled into one.
It kept struggling in an elemental fury, like a creature in the act of breaking the bonds that held it down. In a few seconds it had freed itself from its gigantic stem and floated upward with tremendous speed, its momentum carrying into the stratosphere to a height of about 60,000 feet.
But no sooner did this happen when another mushroom, smaller in size than the first one, began emerging out of the pillar. It was as though the decapitated monster was growing a new head.
As the first mushroom floated off into the blue it changed its shape into a flower-like form, its giant petal curving downward, creamy white outside, rose-colored inside. It still retained that shape when we last gazed at it from a distance of about 200 miles.
Technical report by John P. Marshall of the Office of Scientific Research and Development's National Defense Research Committee.
"The Supersonic Radar Trainer Project," NDRC Report 14-294, 1945 Issued by Office of Technical Services as PB-23330
Facts About the Bomb
The Nagasaki atomic bomb missed its aiming point by three miles and killed over 45,000 when it exploded the morning of August 9th, 1945. Control plugs and radar antennae served to detonate the bomb at a pre-selected altitude. Nagasaki is a city of many hills much as is San Francisco so the destruction was not as wide spread as with the flat region of Hiroshima.
The 10,000-pound ‘Fat Man’ was a different design than was ‘Little Boy’. It was eight inches over ten feet long and had a diameter of 60 inches. Special measures were required both for loading and fitting the bomb to the B-29. A pit was dug and the bomb lowered into the pit and Bockscar was towed over the pit for loading. Special interior and exterior modifications were required to the bomb bay. The complex operation of the bomb only was first tested at the Trinity Site in New Mexico.
This was the second try of this method. A core of beryllium-polonium was centered inside the bomb and surrounded by a hollow sphere of plutonium. Around this sphere were thousands of pounds of ordinary explosive. The explosion of the explosive on all sides of the sphere would compress the plutonium-239 sphere into the core of beryllium-polonium thus creating the critical mass reaction needed for an atomic explosion. The yield of the explosion was equal to 23,000 tons of TNT. Only the hilly terrain and missing the aim point reduced the relative damage to Nagasaki.
The Truth about the B29's
Kevin Cameron,s Background
I spent the latter 1960s and the 1970s as a builder/tuner in motorbike road racing, but I've always had a from-a-distance interest in aviation. At one point I became friends with Graham White, author of "Allied Aircraft Piston Engines of WW II", and one day he phoned to tell me that the New England Air Museum was divesting itself of some of its "outdoor collection" of engines. The two of us waved $1200 at the museum, for which we got three R-4360s that had been outdoors for 20 years. Two of them are here in my shop.
Later I became interested in the problems of the 3350, and that interest took
off when Kim McCutcheon invited me to spend some time with him and his laptop
and scanner in Teterboro, NJ, going through 8 four-drawer file cabinets full of
Wright Aero historical stuff. Thanks to him I now have records of 3350 dyno
tests that go 'way back, plus stuff from the National Archives - the 3350 Case
History, plus lots more. I have learned so much about the problems of engine
development - things that happened to 3350s dovetail nicely with my own racing
experience with detonation, scoring, piston ring sticking, and all the rest of
it. It makes it all terribly real to me.
I now write regularly for their 6-times-a-year magazine "Torque Meter", which deals with historic aircraft engines and technologies. It does seem that governments are too often so interested in the Big Picture or in making things look a certain way that they forget how paramount details are. It was wise of you never to volunteer to fly in a B-29!
The B-29’s R3350 Engine
I read with interest your presentation of wartime orders in connection with the incendiary bombing of Japan. There are many details of the R-3350 engines used on the B-29s that were for years obscured by understandable "we won the war" desire to tell a can-do story - "Great Engines, Great Planes" was one title I remember. The facts are much more interesting.
The sodium-filled or internally cooled exhaust valve was an innovation of Sam Heron, the air cooling specialist who worked at the US Army Air Corps air development center near Dayton, Ohio, in the 1920s. It had been in general use for quite a while at the time the Wright R-3350 development began in 1936.
The R-3350 was actually not a great advance in engine design or performance, but was a bold attempt to package two rows of 9 cylinders very compactly. Based upon the company's previous success in rapidly developing the R-1820 (used on the B-17) single-row 9-cylinder, the Duplex Cyclone should have been a piece of cake. In fact, it was plagued from the start with overheating, reduction gear failure, chronic oil leakage, accessory drive failure, cylinder scoring, and exhaust valve failure.
The response of the Wright company to this 'sea of troubles' was to do as little as possible. A couple of studies of the company have concluded that its management and board were mainly finance-oriented, and begrudged every cent spent on development. This was in fact the reason why Frederick Rentschler, the Wright president, quit in 1924, then later formed Pratt & Whitney, taking with him a distinguished engineering group.
As foreign orders poured in after 1936, US aviation companies expanded rapidly. Wright insisted upon owning all their expansion plants, and upon staffing them with their own engineers. As a result of several such doublings of size, Wright engineering was reduced to what I like to call 'a homeopathic dose'.
Just two examples. First, it took Wright seven years to make the 3350's propeller reduction gear (sun gear, 20 planet pinions, and a surrounding 'bell gear') reliable. The mistakes they made reveal that the people responsible for this development did not understand power gearing. This, given the company's great success with the 1820, seems surprising, but it must be remembered that Wright did not even do their own prototype work, but farmed it out.
The second big problem was cylinder overheating. At least five different designs of cylinder and head cooling air baffles were serially employed, at at least as many different designs of the cylinder/head assembly as well. They just could not get this right. When the aircraft were raggedly deployed to CBI in the spring of 1944, there were failed or crashed aircraft all across Africa and southern Asia. All aircraft were grounded while retrofit teams were sent out with yet another design of baffle, plus rocker box interconnects of a type that had long been used on other makes of engine, plus changes in cowl flaps. Meanwhile, in desperation at the years of delay and frankly, lame excuses, General Arnold ordered the NACA to sort out the engine's problems in its new refrigerated altitude wind tunnel at Cleveland. A program that ran from May to September redesigned the cooling air baffle system yet again (see this system on the -57 fuel injection engines that came late in the war) and tried to mitigate the worst of the engine's fuel mal-distribution problems with a redesigned pair of carburetor spray bars.
Literally hundreds of aircrew died as B-29s crashed on take-off, following loss of one or more engines. Fuel mal-distribution had been bad in 1937, when prototype engines had sneezed their induction pipes right off, but it was still there in 1944, creating on some engines a lean condition that caused cylinders to backfire. The backfiring started induction fires which then burned through either the aluminum induction pipes or the magnesium supercharger diffuser. Pilots have said 'Curtiss-Wright killed more B-29 aircrew than the Js ever did'.(Gene says: Losses were 5% in combat vs 26% operational comes out to five times as many deaths.)
When this occurred during take-off, power was lost on the affected engine and the heavily loaded A/C too often rolled into the failure, stalled that wing, and crashed. Occasionally an especially adroit or lucky pilot would be able to get the gear up, fight off the stall, salvo the bombs, and gain enough altitude to return and land. One of the first to achieve this was an ex-commercial pilot with 7000 flight hours. (Gene says: Early bomb -bay doors were electric and slow. Later came hydraulic which snapped open and shut.)
Or, during cruise, cylinder heat warpage would destroy the cooling effect of valve seating. leading to a stuck or broken-off exhaust valve. Top cylinders in the rear row were especially prone to this. With the valve missing or stuck open, during the intake strokes fresh mixture would blaze through the cylinder ("torching") and eventually burn through the exhaust pipe, causing an engine fire. If the two fire bottles didn't do the job, the crew had about 60 seconds to get out before the fire buckled the main spar.
Although later engines carried improvements such as better cooling baffles, fuel injection, or improved carb spray bars, there were still plenty of engines that failed. One crew chief who served on the Marianas said he never saw an engine go more than 100 hours. The story that engines were averaging 800 hours at the end of the war was a whitewash by the company's very capable sales engineer, Robert Johnson (Johnson was also an amateur poet - I had the pleasure of spending 2 1/2 days with his files - lots of great hand-written notes from wartime meetings). (Gene says: Lessons learned about cooling was that partially opened cowl flaps allowed higher climb speeds and better cooling of rear cylinders.)
One additional reason for the decision to abandon high level "precision attack" in favor of low level (5000-8000') area incendiary attack was that the aircraft in Hansell's command overheated seriously above 20,000 feet and so had to be operated "auto-rich". Even so, his aircraft availability was very low. Operation at low level enabled the engines to survive missions with minimum self-destruction, making aircraft availability rise remarkably.
Men simply had to steel themselves against the too-frequent sight of a B-29 burning at the end of the runway. That was why Paul Tibbets insisted that the 509th Group's strike aircraft have the latest fuel injection engines (much better margin against backfiring) and the new reversible Curtiss Electric props. (Gene says: Witnessed post destruction of one plane's
salvoing bomb load at end of runway. Unarmed bombs wrecked havoc in tent area of anti-aircraft tent area.)
The aircraft didn't improve much even after the war - the same kinds of failures continued, as documented in Robert A. Mann's book "The B-29 Superfortress".
The postwar R-3350 was an entirely different engine with the same name. It had a 4-piece crankcase instead of 3-piece, a longer crank, a completely redesigned connecting rod system, direct piston cooling via oil jets, a new supercharger elbow and diffuser, and cylinder heads machined from solid forgings instead of cast. Cooling fin pitch went from the wartime ,220" down to .132" and total cooling area nearly doubled. A simplified and highly effective cooling baffle system was provided, evidently to at least some extent resulting from the company's wartime examination of the BMW 801 engine's baffles.
Where are they now? Curtiss-Wright today is a modest manufacturer of aerospace subsystems. The wartime experience, coupled with a similar performance in the company's efforts to develop the J-65 jet engine, made the armed services less and less willing to take a chance. Even with their many improvements, their later piston engines were none-too-reliable parts-eaters in both civil and military service. The company's once-immense engine business was frittered away to nothing.
Incidentally, in many places you will read that the 3350 had a magnesium crankcase. In fact both the wartime 3-piece case and the later case were of forged steel. It was the supercharger diffuser that was magnesium - as it was on nearly all other large radials of the time.
I worry about history. The first versions, written shortly after the events they describe, are so often glosses that present everything in black and white. Ten years later, professional historians repeat these errors, but now with footnotes. Then finally, 50 or 60 years later, people begin to find that "it wasn't that way at all", and begin to dig out the real facts of the matter. This is "safe" because most of those who were making the decisions back when, are now gone, and the rest have mostly forgotten or never knew. But the digging is fun and what is to be discovered is much more interesting than the old official stories.
One man who was a ground crewman in CBI said, describing their problems with
cracking and leaking R-3350 exhaust manifolding, and with lack of spare parts,
that "That summer we lived by torch and rod". I wish I knew what was
in the update kits that were sent out when Arnold grounded the B-29s after so
many were disabled in trying to fly across N. Africa in the spring of 1944. Were
they Wright people? Were they serving Army people? Or did all that have to wait
until Vic Agather's group made it over there? Wright did send a man to CBI and I
have his reports here. Yet they have some of the flavor of what went on in WW I,
when the British and French so tightly controlled news from the western front
that they began to believe their own rosy version and to act upon it. The Wright
CBI report acts as if many or most engines were running 175-300 hours, whereas
other sources say that teams were constantly busy changing the top three to five
cylinders in the second row, at 25 hours.
What is clear is that very high CHTs were causing creep in the metal surrounding the exhaust valve seats of the cylinders in the second row. Soon the valve and seat no longer made more than point contact, causing the valve to run much too hot. This led to changes in the metallurgy in the valve stems, leading in turn to reduced strength and early failure. Or, alternatively, the valve stuck open, since all its heat was now being carried down the stem by the sodium filling, coking the lube oil there (if there was any - this was another problem) into solid form.
Writers speak of the B-29's problems being "well in hand" by spring, 1945, but in the Korean War, in which only later-model aircraft were used (no 42-6000-series at all!) crewmen speak of regularly seeing aircraft burning at the far end of the Kadena or Yokota runways, like it was a fact of life. This was the same as was described in CBI and on the Marianas. I have collected dates and accounts of many of these accidents, which usually arose from loss of one or more engines during or shortly after the take-off run. Postwar writers repeat the old claim that "poorly trained aircrew lacked the sophistication to operate such advanced equipment", or some such rubbish. The fact is that if you had a couple of "bad ones" on your aircraft - engines whose problems stacked up to result in CHTs that soared unless they were run rich all the time with a bunch of cowl flap opening - it didn't matter how clever or experienced your flight engineer was - your were headed for low fuel, could not keep formation (formation flying was dropped mainly for this reason) and would be especially vulnerable to fighters. Everyone in those aircraft knew that the longer an engine ran hot, the more likely it was to catch fire. Talk about courage.
Yet the great majority of aircraft were able to get into the air, and some flew 40 or 50 missions and were rotated back to the US as "war-weary". Most of those then went to the drop-knife and portable smelters at Pyote. The stats say 414 B-29s were lost, only 147 of which were to enemy action. The rest went to weather, failed fuel transfer systems, icing, and the various forms of mechanical failure. Quite often that was either power loss on take-off or in-flight fire.
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To be continued--
I have been unable to return to flying, my wife, children, and country all that I have been given, but I will continue trying long after I am gone.