Hacker News new | ask | show | jobs
by crote 301 days ago
It makes you wonder if it would be possible for ejection seats to have a safer bailout mode. Sure, the "compress your spine" mode is definitely appropriate during a wartime situation where someone has shot your wings off, but is it really required when a mechanical failure leaves you unable to land yet in a more-or-less stable flight at a reasonably low speed? Perhaps a 6g ejection might be more appropriate in those cases?
5 comments
Aurornis 301 days ago
The ejection force is to ensure the pilot clears the airplane as they enter the airstream. Think about how much force you feel when you hold your hand out a car window at 60MPH, then remember that wind resistance increases with the square of speed. You have to be launched hard to get away from the tail.

Also the last thing you want in the critical emergency safety gear is more levels of complexity and additional things for the pilot to consider.

link
HPsquared 300 days ago
That airspeed is highly variable though, the plane can go supersonic or at approach/landing speed with flaps extended. Probably 10x+ less aerodynamic force going at low (indicated) airspeed.
link
lazide 301 days ago
Did you watch the latest Tom Cruise mission impossible movie? Unless you want to be the bad guy at the end, you need to be very clear of the aircraft if you’re ejecting. For a fighter aircraft, that necessarily requires very violent forces.

It’s a major concern with skydiving too - there are many aircraft it’s impossible to safely exit in flight without impacting some part of the airframe.

link
the__alchemist 301 days ago
I wonder about that. Maybe the added complexity is a con? I.e. the default would still be full force, but a controlled ejection mode could be gentler, but still capable of clearing the aircraft reliably in straight/level flight.
link
LorenPechtel 300 days ago
Straight and level isn't the issue, airspeed is.
link
prmoustache 301 days ago
Did you see how the plane went down in the video? It is like he just had shutted down completely and was in free fall. Better eject fast when you have no idea in which angle and how fast the plane is about to fall.
link
HPsquared 301 days ago
Maybe they want it to be a bit injurious so people only do it as a last resort.
link