About 1963, one of my early assignments after transferring to the Douglas Long Beach plant was as a member of an accident investigation team. Douglas had produced the C-133 Cargomaster transport plane for the Air Force, powered by four turboprop engines. Fifty of these planes had been built, and most of them called Dover (Del) Air Force Base home.
Douglas C-133 Cargomaster
During the year or so before my assignment, a couple of these big planes had crashed at sea shortly after leaving Dover for Europe. The authorities were baffled as to the cause of the losses. When another C-133 at Dover suffered damage which made it unrepairable, our team of investigators was invited to examine that airplane with a fine-tooth comb, disassembling any parts we thought relevant, to look for anything which might be implicated in the accidents.
There were four of us, and we boarded a DC-6 or DC-7 bound for Philadelphia, with intent to take a Greyhound bus to Dover. As our plane neared the East Coast, however, the pilot announced that “ Due to the weather, we have been diverted to Dulles airport at Washington DC.” There was a blizzard in progress.
When we reached that vicinity, we circled about for a very long time, until our fuel reserves must have been very low. We could see that we were in a severe snowstorm, but occasionally we could make out things on the ground. Eventually, we descended and made a pretty rough landing. As we rolled to a stop, the pilot announced, “Surprise! We’re in Baltimore.”
They have snow emergency laws there, which say that all private vehicles are banned from the highways. The only things permitted to move are emergency vehicles, and Greyhound busses. We were able to get tickets on a bus to Dover Air Force Base.
We arrived at the bus station near the air base at about 2:00 AM, a bit behind our schedule of 6 or 7 PM. There was no transportation available to get us to the motel where we had reservations. But we had the name and phone number of the resident Douglas representative at Dover. Our team leader called him to ask if he would pick us up and drive us to the motel. He had almost closed he deal, when the sleepy voice on the other end said, “Who did you say you were?” Turned out we had a wrong number.
The right number was dialed, and we persuaded the Douglas rep to come get us. I’m not sure why he was allowed on the road, but he wasn’t challenged. We were a bit late getting to bed.
The next day (actually the same day) we got to work. The carcass we were to dismember was a C-133 which had the right wing burned off in a fueling accident. I had purchased one of those adjustable inspection mirrors, and proceeded to minutely inspect the hydraulic system. Every tube and hose, every fitting, every actuator, every valve. The other guys studied other systems, structure, etc.
The first evening there, I fell into conversation with a Colonel who was a C-133 pilot. He asked why we were there, and when I told him, he said, “You guys are wasting your time. These pilots have just been stalling the airplanes during the climb to altitude. They climb out at an airspeed just above the stall speed when they are heavily loaded. It’s possible for some turbulence or wind shear to reduce the speed just enough to stall the airplane. And the effectiveness of the elevators is such that they can’t pull out of a dive if it happens at a low altitude”
I knew the airplanes had a stall-warning system. I asked about that, and he said, ”Yes, they have stall warning systems, but when the alarm goes off, they just reach overhead and pull the circuit breaker.” In other words, they turn it off and ignore it. Big mistake.
I reported this conversation to our team leader, but it was received skeptically. We continued with our physical examination of the C-133. I found nothing which was a potential danger to the airplane. I interviewed mechanics, “crew chiefs”, who maintained the hydraulic systems, and learned of no concerns by those who had day to day hands-on experience with the airplanes.
We finished our post-mortem on the airplane, and submitted our findings. They were all analyzed and combined with input from our aerodynamicists. The final report was written a few weeks later. The conclusion? The pilots were ignoring the stall warnings, and stalling the airplanes at an altitude too low to permit a recovery.