SE (Six Engine) IFR ops
My first post and it is thread drift I know, how many engines is enough? An engine probs - airport below minima accident from the 50s...
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Aircraft Commander 1st Lt. Oliver Hildebrandt, Pilot 1st Lt. Walter Ross, and Co-pilot Captain Wilbur Evans, and a crew of thirteen took off from Carswell AFB in B-36B, 44-92035 of the 26th Bomb Squadron of the 7th Bomb Wing at 5:05 A.M. on November 22,1950. The planned 30-hour training mission consisted of air-to-air gunnery, bombing, simulated radar bombing, and navigational training.
Immediately after take-off, the #4 alternator would not stay in parallel with the other three alternators, so it was taken off-line and de-excited three minutes into the flight.
About one minute after the #4 alternator was shut down, flames 8 to 12 feet long erupted from around the air plug of the number-one engine. The left scanner reported the flames to the pilot. Six minutes after take-off, the flight engineer shut down the number-one engine, feathered its propeller, and expended one of its Methyl bromide fire extinguishing bottles. The mission continued on the power of the remaining five engines.
44-92035 cruised to the gunnery range on Matagorda Island at an altitude of 5,000 feet. It arrived at 7:00 A.M. and the gunners began practicing.
Radar Observer S/Sgt. Ray Earl manned the tail turret. The charger for the right gun burned out, so he expended just half of his ammunition. Then the APG-3 radar for the tail turret started acting up, so S/Sgt. Earl secured the set.
Aircraft Commander 1st Lt. Oliver Hildebrandt noted that the vibration from firing the 20mm cannons increased significantly during the fourth gunnery pass. Immediately afterward, radar operator Captain James Yeingst notified Hildebrandt that the APQ-24 radar set blew up and was smoking. Vibration from the firing of the guns was causing shorting between the internal components of the radar. Then the liaison transmitter failed as well.
The cannons in the left forward upper turret and the left rear upper turret stopped firing. The gunners attempted to retract the gun turrets, but the failed turrets would not retract. Gunner S/Sgt. Fred Boyd entered the turret bay, but other problems began to take precedence over the stuck turrets. Boyd was called out of the bay before he could manually crank the turret down.
At 7:31 A.M. the number-three engine suffered an internal failure. The torque pressure fell to zero. The manifold pressure dropped to atmospheric pressure. The fuel flow dropped off, and the flight engineer could not stabilize the engine speed.
The pilot shut down the number-three engine and feathered its propeller. The B-36B had only one operating engine on the left wing, so the pilot aborted the remainder of the training mission and set course for Kelly Air Force Base.
Flight engineer Captain Samuel Baker retarded the spark, set the mixture controls to "normal", and set the engine RPMs to 2,500 to increase the power from the remaining engines. Unknown to Captain Baker, the vibration from the guns had disabled the electrical systems controlling the spark settings and fuel mixture. He immediately discovered that the turbo control knobs no longer affected the manifold pressure.
The B-36B could not maintain its airspeed on the power of the four remaining engines. It descended about 1,000 feet and its airspeed bled off to 135 miles per hour. The pilot called for more power. The flight engineer attempted to increase engine speed to 2,650 RPM and enrich the fuel mixture, but got no response from the engines except for severe backfiring. The fuel mixture indicators for all of the engines indicated lean.
The second flight engineer, M/Sgt. Edward Farcas, checked the electrical fuse panel. Although the fuses appeared to be intact, he replaced the master turbo fuse and all of the individual turbo fuses. He noticed that the turbo-amplifiers and mixture amplifiers were all cooler than normal. He climbed into the bomb bay to check the aircraft power panels and fuses, but could not find any problem there.
Kelly Air Force Base had a cloud overcast at just 300 feet and the visibility was restricted to two miles. The weather at Bergstrom Air Force Base not as bad, with scattered clouds at 1,000 feet, broken clouds at 2,000 feet and 10 miles visibility. Carswell Air Force Base was clear with 10 miles visibility, but it was 155 miles farther away than Bergstrom.
Air traffic control cleared all airspace below 4,000 feet aead of the crippled B-36B. Aircraft Commander Hildebrandt was flying on instruments in thick clouds.
The poor weather at Kelly Air Force Base convinced Hildebrandt to change course from Kelly to Carswell Air Force Base, passing by Bergstrom Air Force Base on the way in case the airplane could not make it to Carswell.
Bombardier Captain Robert Nelson made two attempts to salvo the 1,500 pounds of practice bombs in the rear bomb bay, but the bomb bay doors would not open by automatic or manual control, or emergency procedure.
There was no way to dump fuel to reduce the weight of the B-36B.
The flight engineers resorted to holding down the switches used to prime the fuel system in an attempt to increase fuel flow to the engines. M/Sgt. Edward Farcas held down the prime switches for the number-two and number-four engines while Captain Baker held down the prime switch for the number-five engine and operated the flight engineer's panel. The configuration of the switches did not allow them to prime the number-five engine and the number-six engine at the same time.
The high power demand coupled with the lean fuel mixture made the cylinder head temperatures of the engines climb to 295 degrees C. Flight engineer Baker jockeyed the throttles, decreasing the throttle setting of the engine with the highest cylinder head temperature until another engine grew even hotter. The high temperature caused the gasoline/air mixture in the cylinders to detonate before the pistons reached top dead center, diminishing power and damaging the engines.
Despite the critical situation with the engines, Aircraft Commander Hildebrandt decided to continue past Bergstrom Air Force Base to Carswell. Bergstrom was overcast and its runway was only 6,000 feet long. Carswell offered a much longer runway.
By the time the B-36B reached Cleburne, the backfiring on all engines increased in violence. The number-2, number-5, and number-6 engines were running at 70% power and the number-4 engine was producing only 20% power. The airspeed had dropped off to 130 miles per hour.
Aircraft Commander Hildebrandt attempted to restart the number-one engine, the one that had spouted flames on take-off, but fuel was not getting to its induction system. He tried to restart the number-three engine, but could not unfeather the propeller on that engine.
As the bomber passed to the west of Cleburne, the right scanner reported dense white smoke, oil, and metal particles coming from the number-five engine. After a short while the number-five engine lost power, and Aircraft Commander Hildebrandt feathered the propeller on that engine while still twenty-one miles from Carswell Air Force Base.
The B-36B could not stay airborne on the power of the three remaining failing engines. It was flying at just 125 miles per hour, seven miles per hour above the stall speed, losing both altitude and airspeed.
Howard McCullough and W. Boeten were flying Civil Aeronautics Authority DC-3 N342 near Cleburne. They were notified by Meacham Tower to be on the lookout for 44-92035. They spotted it about five miles south of Cleburne. They observed that the number-one and number-three propellers were feathered and the number-five engine was on fire. They turned to follow the descending bomber.
Aircraft Commander Hildebrandt ordered the crew to bail out of the stricken bomber.