by Wilfred K.
I was employed as a
draftsman in Baltimore in 1941. By 1950, I was recognized as a better-than-average
electrical engineer, having designed and tested the electric power system for
the Martin P4M four-engine bomber. I later designed the electrical circuitry
for the Martin-patented Automatic Propeller Feathering Control System for
Takeoff Power Failure for the Model 2-0-2 aircraft. In 1951, I was assigned as
project electromechanical engineer on the XB-5I bomber. My duties covered
electrical, hydraulics and armament. The XB-51 was an excellent medium bomber,
and it performed well beyond all specification requirements. It had many unique
features including a bicycle landing gear. The forward pair of wheels turned
for steering, and its pivoting wing with geared flaps when the pilot moved his flap
control for lift during takeoff or landing. The wing leading edge moved up,
pivoted over the hinged rear spar and the geared flaps moved down. The aircraft
had a rotating bomb door. Before flight, the bombs were loaded on top of the
door, which was then hoisted into a cavity in the aircraft belly. For bomb release,
the door was rotated 180 degrees exposing bombs to the air stream. Westinghouse
air brakes provided maximum braking during landing, along with a small
parachute the airplane braked to stop in less than 2,000 feet. Brake control
was provided by a brakes-on and -off switch on the panel. The pilot flipped the
switch to “on” after touchdown and had maximum braking until the plane stopped.
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| The XB-51, Martin's Phantom Strike Aircraft |
Soon after I reached my
office, I had to attend an after-flight meeting with a meeting of the pilot and
several engineers. The pilot complained about the high amount of lateral trim.
On airplanes with ailerons, lateral trim is achieved by a trim tab on the
aileron. Deflection of the trim tab 0 to 5 degrees causes a small opposite
deflection of the aileron. Since the XB51 had no ailerons, lateral control was
achieved by large flaps to top of the wing, and lateral t rim was provided by a
small trim flap on the trailing edge of the wing. Trim was achieved by trim
flap motion of zero to 15 degrees. I suggested that we could change the trim
indicator to read “0 to 5” instead of
“0 to 15.” George Trimble, chief of new
design, thought it was a great idea!
During 1950, the XB-51
completed all required flight tests. In 1951 all armament tests were to be
done. Early in the year, the airplane was moved into the gun firing revetment. There, Werner Buechal and I observed testing of gun aiming accuracy. Four 20mm cannons
were mounted in the nose of the XB-51. During aiming test, each gun was separately
loaded with five live rounds, followed by a dummy round. As each gun was fired,
its accuracy was checked and adjusted if necessary. At the completion of the alignment
of the four guns, we were ready for bomb drops. By specification, we were
required to make eight drops of the nine 500 pound bombs at high speed and low
altitude. I was asked to take pictures of the bombs as they left the airplane.
I asked Herm Meyer, our aerodynamics group engineer, to provide me a plot of
the relative location of the bombs and the airplane as the bombs dropped to the
ground. After several computer runs, Meyer told me the bombs position during
drop was constant 45 degrees aft of vertical
I met with the flight test
instrumentation group. We removed the front center bomb and loaded a 45-degree
aft-pointing gun camera in its place. The gun camera was connected to the bomb
release wiring, so the camera would start running as the bombs were released. A
small aerodynamically faired box was mounted on the bottom of the wing carrying
a second camera pointed below the airplane to view the bombs as they separated. Captain Willard Horn
piloted the plane for each of the eight required bomb drops at 625 mph at 50
feet above the ocean. The results were spectacular! We recorded pictures of
each group of eight bombs from release to impact in the ocean. The side camera
showed the bombs as they separated. They were completely stable with no
tumbling. This was in comparison to problems with B-47 bomb release at 350 mph,
with bombs tumbling in the bomb bay after release.
After a flight competition
over the Martin airfield between the XB-51 and the British Canberra, Martin was
awarded a contract to design and build B-57 bombers based on the British
Canberra and the XB 51 contract was terminated. Bob Williams, the XB-51 assistant
project engineer was reassigned to head the B-57 project and I was promoted to fill
his place. With the XB-51 program terminating, Ralph Draut was reassigned and I
became the project engineer.
In January 1952, I signed
the contract paperwork with Captain Horn who flew the airplane to Muroc Air
Force Flight Test Base in California. He had to stop midway to refuel the
airplane, so we sent two mechanics ahead to help with the turnaround. After Horn
took off our mechanics flew to Muroc to help the Muroc ground crew to become acquainted
with the XB51.
I was summoned to the
sales office. I learned that I was assigned to fly to Muroc to talk to Major
Lathrop who was to fly the XB-51 while it was at Muroc, and hopefully to speak
to General Wolff about the merits of the airplane. I spent some time with
Major Lathrop, but learned I would not be able to speak to General Wolff because
he was being transferred to Wright Patterson Air Force Base.
After my stay at the base,
I drove to the Los Angeles railroad station where I boarded the Santa Fe Super
Chief to Chicago. The train stopped in Pasadena and left in the night. The next
morning, we awoke to daylight in Winslow. I really enjoyed the trip east
viewing the desert, buttes and mountains for the first time as we passed
through Flagstaff Gallup, Albuquerque, Santa Fe and Raton Pass. We continued overnight
to Chicago, where I changed trains and went to Baltimore on the B&O Capital
Limited. When I returned to work, I learned that I was assigned to be XP6M-I
assistant project engineer.
In April 1952, we learned
that the XB-51 number one crashed during an air show at Muroc. A grandstand was
erected beside the runway and was full of Air Force personnel and members of
the media along with many cameras including a 35mm motion picture camera
handled by a cameraman from Hollywood. Major Lathrop was the pilot. The airplane
made two passes, the first at 600+ mph, the second slow with a roll in front of
the grand stand. On the slow speed pass, Major Lathrop approached at 250 mph, during
the roll the airplane lost altitude and at 270 degrees a wing tip touched the
ground. The airplane crashed and tumbled on the runway until it stopped, a pile
of aluminum scrap.
