Red Arrrows Death Inquest

  morddwyd 21:29 30 Jan 2014
Locked

My knowledge is not current enough to speak about the over tightening of the drogue nut and bolt the coroner mentioned

click here it's a poor engineer who can overtighhten a pivot bolt, and in my own time in charge of seat seat maintenance I would have expected a torque wrench to have been used.

However, the possibility of the safety pin being wrongly inserted was well known from the time a handle in front of the crutch (the "seat pan handle")replaced the one ever the head (the "face screen handle"), in the 50s/60s.

It was a specific after flight check, and was certainly taught as a hazard (I was RAF Training Supervisor for seat technicians in the 70s).

It was not an uncommon occurrence for the handle to be dislodged by anti g connevtors, oxygen connectors, snubbing straps (to pull the legs in tight), radio leads etc. and for a pilot, exhausted after a very intensive work spell, to put the pin back in without actually engaging the handle. The normal procedure was to check the actual firing sear, to which the handle is connected, had not become dislodged (if it had it was a whole new ball game!), and re-engage the handle and pin properly.

I know that there is at least one on here who remembers the pilot's eye view of the set up.

I hasten to add, for the FE's benefit, that, like everybody else, I only know what has been reported, but from what has been written,, this simply looks like a bad case of an error of skill, not design.

though

  oresome 10:59 31 Jan 2014

As is usual with accidents, it seems a number of failings conspired to result in the fatality.

From what I read, there had been a number of opportunities to inspect the release handle and no one had spotted the error with the safety pin.

It strikes me as a design flaw if a safety pin can be inserted with the handle in an unsafe position.

For the parachute to then fail to open was the final straw.

The manufacturers did have concerns over some aspects of the design and issued some safety bulletins, but not to all their users including this one.

Unlike morddwyd I have no knowledge of the devices and only paraphrase what I have read in the past from the coroners inquest.

  spuds 12:13 31 Jan 2014

Perhaps adding to the above, I have no knowledge on this subject. But I can only assume from the prompt 'grounding' of the aircraft, then back to duty, the fault must have been soon picked up, or possibly known?.

  morddwyd 19:13 31 Jan 2014

"It strikes me as a design flaw if a safety pin can be inserted with the handle in an unsafe position."

I don't think I can agree there.

If you are inserting a pin, be it a safety pin, a clevis pin, an axis pin or even a bolt through the steering knuckle on your car, if the holes are not lined up it won't do the job it is supposed to.

That is not a design fault, it is a simple engineering fact.

  oresome 19:43 31 Jan 2014

I can only presume that the pin wasn't fully inserted if the holes didn't line up?

  morddwyd 11:25 01 Feb 2014

Not quite.

To take a simple example, if you were putting the arm on a pair if spectacles, if the screw hole was not quite lined up, yes, you wouldn't get the screw in, but if is was out of alignment just a little bit more the screw would do up but the arm would drop out very quickly.

On the seat fitted to the Hawk, a Mk 10, if the handle is not fully home in its housing it is fairly obvious, or should be.

That is the purpose of an after flight inspection.

On the facts reported the engineers should have picked it up.

  john bunyan 12:22 01 Feb 2014

Without wishing to prolong this , in deference to the tragic events, surely - even if the ejector seat went off because of the pin, the parachute should have deployed and hopefully reduced the consequences? Is the deployment of the parachute a separate issue or the same one? I have only , on one occasion (apart from military "normal" parachuting), come close to using an emergency parachute in a military aircraft - a RN Gannet, but there was no ejector seat and the pilot aborted the emergency exit!

  morddwyd 13:13 01 Feb 2014

"Is the deployment of the parachute a separate issue or the same one? "

It's all one operation. Once the seat fires a small drogue deploys to stabilise the seat in a fairly upright condition and the seat falls in this stabilised condition unit about 10,000 ft. (Breathable oxygen).

Then seat separation takes place and the main chute deploys (if already at low level this takes place straight away of course).

Unfortunately, in this case there seems to have been a double fault condition, and, as reported, the main shackle had been overtightened.

This is a scissor shackle, and after reaching the correct conditions it should open, allowing the seat to fall away, and main chute deployment.

On modern seats this should work even at ground level (zero, zero, meaning no height, no speed).

  johndrew 14:52 01 Feb 2014

For those of you who are truly interested in the function of the Hawk seat there is a .pdf giving the history and development of MB ejection seats with the Mk10 seat starting on page 39. It may answer a number of questions raised here, but you should note it is not a service manual by any means.

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