minitour

Help settle a bet. What's the max aircraft speed one can safely use an ejection seat?

"The other guy" says Mach .99.

I'm saying it's got to be significantly higher than that (or else what's the point in a lot of cases?).

Thanks.

-mini

XHooker

You're both wrong... and both right to a lesser degree. I believe there have been successful supersonic ejections, but in general, with a modern "zero-zero" (airspeed-altitude) seat, the slower the better to prevent "flail" type injuries.

minitour

I guess I should have clarified. He's saying at Mach 1, the body "disintegrates" if you punch out. I'm saying "no way".

(I guess the dude that jumped out of that balloon in the 40s (50s? 60s?) didn't count....)

Could you do it at 2? 2.5? 3? with reasonable chances of survival?

-mini

USMCFLYR

Ah! I love these questions - - bets!

The answer is - IT DEPENDS.
Each seat will have its' own ejection envelope.
Speed at the top end being one defining feature of that envelope.

So in my opinion - neither of you win because it is too broad of a question; BUT - if I had to say one was more correct than the other - I'd say "the other guy" gets the nod only because of survivability.

There was a Replacement Pilot who ejected out of a Hornet back in late 2005 down around Key West. He was too fast at the merge for his own good, went vertical (down) and blacked out. Came to once the G was off, but as is often the case disoriented. Didn't know where he was but saw nothing but ocean and decided to eject. I believe he was MORE THAN 500 kts indicated at the time. He survived but was basically a Raggedy Ann doll with limbs hanging on by a thread when they fished him out of the water

NACES seems to be the most plentiful seat out there in my former community and I believe that 600 kts was considered the top end of the envelope, with betwen 250-350 being the ideal ejection airspeed - but it has been awhile since I looked.

USMCFLYR

minitour

Thanks for the info!

-mini

Adlerdriver

Aces II max speed was always listed as 600 KIAS (at least in the F-15). There was an F-15E crew that got out at 780 KIAS below 10,000 feet after getting disoriented at night. WSO was killed, front seater recovered after a long rehab and went back to flying.

So, wouldn't settling this "bet" using KIAS instead of Mach be a better method. (although I guess the ejection above actually disproves the .99 limit - 'cuz 780 below 10K is mo' definitely above .99).

It would seem like ejecting supersonic at higher altitude would have less potential for injury than the same Mach number at lower altitude. Indicated airspeed will be lower the higher you are (i.e. less of those air molecules to batter your body in the more rarified air).
Am I out to lunch?

minitour

Not at all. To this (never been in the military) guy, it certainly is a solid argument.

And I'd say your post puts me in the "win" a beer column, so I like it even more (as opposed to "lose" a beer, which would really just peeve me off).

-mini

bcrosier

I don't know any of the specs on it, but the B-58 Hustler used an escape pod system, which I would suspect was capable of supersonic ejection. Granted it's more that just an ejection seat, but the ultimate goal of the device is the same.

Ftrooppilot

From Wikipedia:

Six pilots have ejected at speeds exceeding 700 knots (1,300 km/h; 810 mph). The highest altitude at which a Martin-Baker seat was deployed was 57,000 ft (from a Canberra bomber in 1958). Following an accident on 30 July 1966 in the attempted launch of a D-21 drone, two Lockheed M-21[5] crew members ejected at Mach 3.25 at an altitude of 80,000 ft (24,000 m) The pilot was recovered successfully, however the observer drowned after a water landing. Despite these records, most ejections occur at fairly low speeds and altitudes, when the pilot can see that there is no hope of regaining aircraft control before impact with the ground.

N9373M

As did the F-111 Aardvark. Seem to recall a Vietnam 111 ejection and the bad guys shot the "capsule" on its way down.