In 1950's No Way Out, Sidney Poitier and Mildred Joanne Smith play nice Black hospital people who have to deal with a White racist criminal patient. Smith's promising career was cut short on 11 February, 1952, when she was aboard National Airlines Flight 101, a DC-6 departing Newark Airport, when, it suddenly began to veer left while losing altitude. Two minutes later, it clipped an apartment building and plunged into the ground, "narrowly missing an orphanage," says Wikipedia, and bursting into flames. Twenty-nine of 63 people aboard perished, along with another four from the apartment building. Smith survived, but with severe injuries, including a broken back.
The CAB determined that the cause of the accident was the accidental reversal of the propeller of the No. 3 engine. Coupled with the crew's mistaken decision to feather the No. 4 engine, Flight 101 was pretty much a brick. This was three weeks after the crash of an American Airlines Convair 240, with the loss of all onboard and two girls associated with the girl's school near which it crashed, and two months after the crash of a Miami Airlines Curtiss C-46 with the loss of all onboard, again with additional losses on the ground in spite of managing to crash into a warehouse district. Neither of the earlier two accidents go to the subject of this post, which overworked postwar airscrews, turbines, rotors and closely associated spinning things, but they are a pretty good reminder of just how dangerous postwar civil aviation actually was. Having the propellers of a major airliner be subject to three separate Airworthiness Directives in four years, warning of separation of neoprene layers in the propeller core, overspeeding, and engine overheating issues doesn't help. (That's the Stratocruiser, if you were wondering. The poor British taxpayer just can't catch a break.)
. (A joint venture of Rolls-Royce and Bristol, because why should you let the little guys get their beaks wet?)
although I could also point to the Vickers Vanguard. The tedious moral of the story is presumably about learning by doing. Mecahnical engineering had no doubt about its ability to deliver rotating-blade propellers in 1934, but it turns out that the devil was in the details, and that people would still be dying of their mistakes in 1952. That the problem was solved has to be explained by someone's patient underwriting of a long struggle to learn to build these systems by building them. The most obvious beneficiaries of mechanical engineering's long struggle to create reliable load-bearing systems that spin at tens of thousands of rpm are probably helicopter manufacturers, and they are also wear I would look for practice making perfect.