Comparison - ejection seats with and without rocket pack.


State of the art MB F-35 seat features / capabilities:

Salute!

What's funny is they eject thru the canopy, more or less, in the F-35. The Harrier folks demanded a very quick system, and it was easier to put primacord all around the bottom several inches of the canopy and blow it at the same time as the seat blows. That was what the maintainer told me when I had one of the close up tours. The primacord or whatever it is is clearly visible and there are warning notes all around the canopy.

In any case, the first ejection was from a Bee (USMC) and worked like a charm.

Gotta tellya that I was very comfortable in the Viper with that ACES seat, and the infamous T-Bird ejection at Mt Home is proof positive. As a matter of fact, my deputy flight commander punched out in a family model when the motor quit pulling off a low altitude drop. Looked like the Snowbird except he didn't turn/stall and he asked the front seat student to initiate the sequence so he would know the student was gonna follow shortly. Didn't even lose the pencils on his shoulder pocket.

Gums sends...

The `squipper on the Hawk at Valley who strapped me in said they close the canopy very, very carefully - to avoid setting off the primacord...!

I instructed on this jet 35 years ago so let me set a few things straight (those things I can remember!). I also want to say there are those of us who have been there/done that and for those who are "armchair quarterbacks" ..... IT IS EASY TO CRITICIZE WHEN YOU ARE SITTING BEHIND A DESK DOING ZERO KNOTS. You have no idea how rapidly situations develop and how quickly you need to make split-second decisions of life and death. Everything below is pure speculation.

• seat is a 0/60 seat (ground level but requires minimum 60 kts forward velocity to assist with 1-swing chute inflation). Optimal glide speed is 130 kts.
• each ejection seat sequence is independent. First one to the handles is the 1st one out.
• canopy shed is part of the process prior to going up the rails. The seat has a ram in case the canopy removal does not trigger so you can go through the canopy if it does not release.
• there is no gyro-stabilization; straight rocket vector so a/c angle and trajectory is the most important factor in a successful ejection.

Ejection sequence:

• pull the handles/slam your head back into the headrest as the belt tensioner will pull you back into the seat (you do not want your head down when the rocket fires due to neck injury).
• canopy release fires; hopefully canopy separates (otherwise you are going though the canopy with the ram leading the way)
• rocket seat initiates up the rails
• seat drogue fires to provide drag to the seat to help with man/seat separation.
• seat/man separator fires . This releases the 5-point harness and a "kicker" pushes the body/seat pack (which contains the survival equipment) out of the seat.
• as you exit the seat a lanyard is attached to the harness which initiates chute deployment

I have looked at the video many times. It appears to me there was an engine issue (single engine jet) at low velocity at low altitude (my worst nightmare when I flew this type). Could be bird ingestion, compressor stall or engine failure.

Initial reaction (straight ahead zoom) was perfect but for some reason the pilot elected to commence a left turn. This is sub-optimal as in a single engine jet you want to maximize kinetic energy for potential energy (any turn reduces the amount of kinetic-to-potential energy you have). This jet was in a very low kinetic energy state to begin with so a wings level zoom was optimal.

Looking at the google map data provided by other it appears the left turn actually took the jet towards population whereas straight ahead was nothing but a river. This indicates to me he was not steering from population so what was his plan? I suspect he thought about a 180 degree gliding return back to the airport.

It appears to me as he hit the top of zoom he stalled the a/c initiating a right wing drop. At this point he needed to get the a/c level to best achieve successful ejection so rolled as best he could towards wings level. Unfortunately the vector at this point was well beyond the seat envelope. He is very fortunate to have survived while the passenger (who initiated fractionally later) was not so fortunate.

Time for Ejection Seat Upgrade?
 

There's much more capable ejection seats available and a number of videos showing low level saves.

It's common for non pilots to ride in the Tutors. A command pilot ejection initiation should eject both.

The Kamloops weather observations seem to have been embargoed. With diminished airspeed and thrust deficiency at the top of the zoom added to local topography, windshear could be behind the apparent loss of control. I have seen how quickly you can end up inverted on a steep downline.

Here's a plot of a brief clip of a couple of seconds of the audio from the Corey Pelton video of the mishap as posted on YouTube. You can see the pop in the middle of the waveform plot at .83 seconds into this short excerpt and then reduced volume possibly from automatic gain control as you say.

https://cimg7.ibsrv.net/gimg/pprune....5f2d82fcce.jpg


The audio of this short excerpt is attached as a .zip file which will open on most computers but not most tablets or phones.

The takeoff was reported to be at about 11:45 am local, 1845Z on May 17.

METAR CYKA 171800Z 12008KT 30SM FEW010 SCT030 OVC048 14/10 A2970 RMK SF2SC2SC4 SLP062 DENSITY ALT 1500FT=

SPECI CYKA 171854Z 12004KT 40SM FEW010 SCT022 OVC054 14/10 A2970 RMK SF2SC3SC3 SLP064 DENSITY ALT 1500FT=

METAR CYKA 171900Z 13004KT 40SM FEW010 SCT023 BKN058 14/10 A2970 RMK SF1SC2SC3 SLP063 DENSITY ALT 1600FT=

Respect. Thanks for those valuable insights.

Since you and a former leader have commented perhaps I could add something further based on real life experience on a similar jet albeit over 40 years ago.
Having trained and instructed ( and ejected from) a very similar jet, the Jet Provost 3 and 4 I agree wholeheartedly with your comments.
We do not know if the power loss was total or partial, if partial then the decision to turn back MAY well have been justified, if total, not so sure
That said, what no one has mentioned is the fact that the top of the zoom, if the handling pilot was in the right seat he would probably have his view of the runway, which he would need to asses the situation and his decisions, obstructed by the left seat occupant.
There is a good chance he would be leaning forward to get that vital view of the runway. So, low speed, turning, lots of bank, perhaps a touch of back stick to help the Tighten turn and off it went into a spin, which I would suggest, from experience of a lot of spinning in the JP as a QFI was totally unrecoverable from such low height. Attempting a recovery in that situation is futile and immediate ejection the ONLY option before you get out of the seat’s envelope in the worst situation, ejecting at low level from a descending aircraft, where you need an additional height of at least 10% of your ROD.

I really do deeply sympathise with that crew, I know from experience that the time from pulling the handle to the seat moving, seems an eternity. God knows what it was like at low level in a steep dive.

One of my IOT colleagues was killed at Leeming after a low level power loss, the instructor survived ( Martin Baker Mk 4 seat, 0- 80 Knots) the student did not, he was still in the jet when it hit the ground, so this accident brings back sad memories.

Kind of true Gums, but not driven by the Harrier community alone. Rocket canopies don't work in all scenarios and can be fatal in others - especially for ship operations. An MDC / LDC disrupted canopy is quick for sure but also works above and below the surface, does not provide a collision risk with the ejectee in unfavourable attitudes/airspeeds, does not fall back towards the aircraft when zero/zero with a tailwind, does not plow back towards the deck / parked aircraft / deck personnel when ejecting from a soft cat or bow EFATO etc.

For land ops some of these don't apply or mitigated in a different way. The last MB-equipped aircraft I flew had a rocket canopy and an LDC around the transparency, to add to the variety of yellow & black handles around the cockpit.

I am not going to speculate about the cause of the accident or worse (I think) pontificate about the aircrew's actions. What it brings home to me is a reminder of just how quick a perfectly normal, routine situation can change to one where you have to make an instant life or death decision to eject or not.

I remember attending a flight safety briefing given at Brough about 12 years ago by Pete 'Whizzer' Wilson who had had more than his fair share of this type of incident. The most powerful example he used in the briefing was a reconstruction/replay of the Tornado accident involving a BAe Warton crew at Squires Gate airport in Blackpool. The time between the aircraft starting to roll as they overshot and Paul Hopkins shouting "F***ing hell, get out" was remarkably short but if there has been even the slightest delay the accident would have had fatal consequences for the crew. In the event they both survived and the aircraft ended up on the sand, just past Blackpool pleasure beach.

Walbut

The audio in my previous post was from the Corey Pelton video.

I'd like to add a bit to Dune's excellent technical post on the ejection system. I'm no expert on military stuff though, only being a PPL / skydiver / trained aero engineer.

Modern military ejection systems -- for over 40 years -- tend to get the parachute out faster, by using some sort of mortar system to fire a slug to pull out drogue and/or extraction chutes and with the momentum at slow speeds also drag the canopy and lines out to full stretch. Or have the mortar or other pyrotechnic mechanism to throw the whole canopy away from the seat in a container. Designs differ between say ACES II and Martin Baker. Yeah I'm a little hazy on the details but that's roughly how it works. One can see it on various ejection seat videos online.

The "initiates chute deployment" that Dune talks about for the Tutor, that in contrast is old school seat technology: The pilot is wearing the parchute on their back, and initiation just means having the ripcord pulled. After which a spring loaded pilot chute jumps out, hopefully doesn't catch in the burble behind the person for more than a split second, catches air, and drags the main chute out from the apex. Basically like a skydiver from the 1960s. That's going to take longer than any modern system that gets the canopy and lines stretched out by pretty much pyrotechnic means at slower speed.

I haven't tried to analyze the videos frame by frame, but it took a while for the parts of the ejection sequence to happen. Even given the old technology, it seemed to take an awfully long time for any parachute to appear. Wish someone knew the timing of the Tutor's Weber seats, eg, how long from leaving the aircraft to the seat-man separation and parachute deployment initiation.

On one of the videos, I only saw a little bit of canopy start to partially inflate, for one person, just before they went behind the treeline.

NOT an impressive ejection, unlike say Anatoly Kvochur at the 1989 Paris airshow, or the CF-18 at Lethbridge Canada in 2010, with modern seats. Clearly there are many factors in this accident, not just the old seat design but the bad timing of the engine problem, stalling it out on the climb, and the ejection while low and headed steeply downhill.

The retired RN who tried to revive Captain Casey was quite clear that the seat was beside her, and the chute visible but not open.

Thanks for the info..

From what I'm reading and to give context IMHO it doesn't seem this Weber seat, as being described, appears to be significantly worse in terms of main chute deployment performance than the similar generation M.B. products - reason being that Dunes says the Weber seat on the Tutor is declared as a 0/60 whereas the M.B. Mk 4, with drogue gun/mortar and subsequent main chute extraction by the drogue, was declared as I recall it as a 0/90 seat, (I've seen 0/80 mentioned so my memory might be failing me..it certainly wasn't a 0/60 or anything like).

I know technology has moved on but I think any potential users of these things have always been aware that at low level it is possible to get outside the seat envelope very quickly.

BTW (?Dunes) was the teaching with the Weber seat on the Tutor to try and "beat the seat" with regard to the D- ring at low level? I understand that was the teaching on some early American seats.

The. Martin Baker Mk 4 seat was declared as 0/80, ie safe to use at ground level WITH ZERO descent rate, but 80 knots MINIMUM IAS, and was EXTREMELY reliable, I am pleased to say, having used it in anger.

That said, MB guidance was that if descending then an additional height of at least 10% of ROD was required.

Applying MB guidance, Consider those Snowbird ejections:

It was descending almost vertically at at least 120 K ias, a conservative estimate but maybe even higher.

That is a descent rate of about 12,000 fpm.

That means a minimum ejection height should be about 1200 Feet.

Looking at that video it would appear that ejection was initiated below that height, ie outside the seats capability.

I dont think the seat performed poorly.

On a recent visit to the MB factory they proudly showed me the F35 seat with its auto eject function.

That seat is state of the art and from initiating the ejection to a full chute is extraordinarily fast, I believe less than 2 seconds. The Weber seat is not in that league.

According to Martin Baker's website where they list all their seats, the Mk 4 was 0/90.

http://martin-baker.com/products/mk4-ejection-seat/

My apologies, yes it WAS 90 knots, must be my age.

The. 80 figure was the gun velocity, fps.

My apologies for that.

A few points.
 

I’ve been reading this thread with interest and a few things spring to mind for me.

Firstly, I think worrying about the functioning of the seat is a bit of a red herring. Watching the video would suggest that very few seats could have saved their occupants from the parameters at which ejection was initiated.

Secondly, we are all assuming the jet suffered an engine failure of some sort. That may, of course, prove to not have been the case.

If this was indeed an engine failure I cannot help but think the pilot was a little aggressive with his pitch up. Indeed by rewatching the HUD video of the Moose Jaw Hawk ejection in 2005 the initial zoom and turn seemed equally aggressive and ultimately mistaken. He reached 2.8G which is only going to deplete energy when it is needed most. Maybe Moose Jaw actively teach this method.

I was the Stds O on 419 at CFB Cold Lake a few years back and I would not have expected someone to be quite so aggressive in such a situation. I have also operated out of Kamloops and I personally would have made a straight ahead, more gentle zoom with the side of a hill or the river as my desired aircraft impact point should the need arise. My aircraft would have needed close to 300 IAS to make a successful reciprocal EFATO approach. I cannot say what a Tutor would have needed. I doubt there was ever sufficient energy to get back to the airfield.

Finally I have to question (as I did when I worked there) the logic of a 2014 decision to cease practicing emergencies airborne. In the wake of a Cormorant accident where switches were inadvertently moved during a practice which resulted in a crash, all emergencies training was confined to simulators.

I cannot help but think that Canadian pilots will be more prone to the startle instinct as a result of this decision.

I have other thoughts on the issue but I will keep them to myself.

All fatal aircraft crashes are tragic and this is no exception. They become even more tragic when it appears subsequently that ‘the system’ may have set the individuals up for failure.

I desperately hope I am proven wrong on all counts.

BV

Thank you but no apologies necessary. The grey matter fades with time and I’ve forgotten more than most. If you speak with Wiggy, he’ll tell you I didn’t know much in the first place.

JN