Shoulder straps and head collision with instrument panel

[Jenisch]

Hello,

I already read many stories from WWII pilots saying they hit the head in the instrument panel in a forced landing.

Any reason for the shoulder straps not prevent this? I think it could have been because they loose them in order to have more mobility to see the ground.

[pbfoot]

I heard that it was usually the gunsight that they kissed ,

[tyrodtom]

Even in modern cars seat belts stretch, and your body contorts under the extreme forces of crashes.

I race circle track, and have had several crashes. No matter how tight you have those belts ( 5 point belts, 3 inch wide) you'll have some movement.

[Jenisch]

Introduction To The P-39 (1942) - YouTube

At 10:04 we can see the pilot is apparently well secured against collisions with anything, and the instructor is just saying it's for avoid collisions.

[Jenisch]

Even in modern cars seat belts stretch, and your body contorts under the extreme forces of crashes.

I race circle track, and have had several crashes. No matter how tight you have those belts ( 5 point belts, 3 inch wide) you'll have some movement.

I understand. Thank you for the explanation.

[Edgar Brooks]

In violent movements, the Sutton harness could (and did) break; pilots were often thrown out of the cockpit, without first releasing the clip, in fact (though he never admitted it) it's believed that Bader was thrown out of his cockpit, since he was seen with two black eyes immediately afterwards, which was usually a sure sign of a violent departure.

[FLYBOYJ]

On older aircraft sometimes you have to set the seat harness tension, modern aircraft uses inertial reel restraints that take up the slack in the event of a crash. It could be a matter of the pilot just forgetting to tighten his harness.

[mikewint]

One thing that adults forget is that the human head has about the same weight as a bowling ball, 18lbs (8kilos) or more. Straps restrain the body but not the head. Forces during a crash depend on speed and time. The shorter the time the greater the force required to stop. Those forces can reach hundreds of g's during the crash (air bags/crumple zones make the crash last longer reducing the forces). On a sudden stop the head continues forward until stopped by the neck. In a very violent crash the top of the cranium can separate from its base literally ripping the brain in two (basilar skull fracture). After Dale E's crash the helmet restraint system was made manditory. So your 18lb head suddenly weighs 1800lbs or more. Not easy to restrain

[tyrodtom]

The seat belts in most aircraft are there to restrain you in violent flight manuvers, and minor crashes. If the aircraft structure was sturdy enough to protect you in a major crash, it would never crash, because it'd also be too heavy to fly.

Some of the modern fighters have made some amazing advances in crash survival though. Some WW2 fighters had good reputations, under some circumstances.

[Siegfried]

Hello,

I already read many stories from WWII pilots saying they hit the head in the instrument panel in a forced landing.

Any reason for the shoulder straps not prevent this? I think it could have been because they loose them in order to have more mobility to see the ground.

Just check out some of the German car magazines near your area or your own Belgian ones for that matter. They obsessively post freeze frame studies of cars doing impact tests into objects at only 65 kim/h. The head always hits the dashboard, admitedly this is with lap sash belts only. Belt pre-tensioners and/or airbags are a neccesity. The body just is so flexible under these loads.

I daresay things weren't studied enough. I'd say the Luftwaffes systematic studies of egress and ejection were among the first such cases of conncern.