Abraham Wald and the Missing Bullet Holes

[pellinore]

This is an interesting logic problem:

'You don’t want your planes to get shot down by enemy fighters, so you armor them. But armor makes the plane heavier, and heavier planes are less maneuverable and use more fuel. Armoring the planes too much is a problem; armoring the planes too little is a problem. Somewhere in between there’s an optimum. The reason you have a team of mathematicians socked away in an apartment in New York City is to figure out where that optimum is.

The military came to the SRG with some data they thought might be useful. When American planes came back from engagements over Europe, they were covered in bullet holes. But the damage wasn’t uniformly distributed across the aircraft. There were more bullet holes in the fuselage, not so many in the engines.

The officers saw an opportunity for efficiency; you can get the same protection with less armor if you concentrate the armor on the places with the greatest need, where the planes are getting hit the most. But exactly how much more armor belonged on those parts of the plane? That was the answer they came to Wald for. It wasn’t the answer they got.

The armor, said Wald, doesn’t go where the bullet holes are. It goes where the bullet holes aren’t: on the engines.'

Abraham Wald and the Missing Bullet Holes | by Penguin Press | Medium

Edited November 27, 2022 by pellinore

[Sir Wearer of Hats]

It’s counter-intuitive but makes perfect sense. The ones with the holes still came back, so those holes were not terminal.

[MGB]

18 minutes ago, Sir Wearer of Hats said:

It’s counter-intuitive but makes perfect sense. The ones with the holes still came back, so those holes were not terminal.

Exactly. Cover all the areas needed to keep the aircraft in flight. Engines, flight control mechanisms, etc..