The Vulcan XH558 & General Aviation Thread

[mtskull]

I'd be surprised if it didn't have zero-zero seats, even though on this occasion they weren't used. The Sea Vixen was withdrawn from squadron service in 1972 while the first test of a zero-zero seat in this country with a human occupant took place as far back as 1961

I have done a little homework, courtesy of the excellent Martin Baker website. The ejection seat fitted to the Sea Vixen was a Martin Baker Mk4, the operational minima of which are zero altitude/90 Knots IAS.

Interestingly, one of the differences between the Mk4 seat and the first "zero/zero" seat (the Mk7), was the addition of "canopy breakers" On the Mk7, to facilitate ejection through an un-jettisoned canopy.
Maybe I am over thinking this but, if the reason for the 90 Knot minimum is simply the need to get the canopy clear before ejecting, then jettisoning the canopy early, in anticipation of a low speed ejection, would be a very sensible thing to do; it must be painful trying to eject through a canopy in a seat that wasn't designed for it....

Nigel, this has sparked my interest in the subject. Thank you for your reading recommendation; I have just ordered a copy.

[quicksilver-wsr]

As you know, the 'canopy breakers' take the form of explosive charges in the canopy material that shatter it milliseconds before the seat leaves the aircraft, ensuring the ejection isn't impeded. Presumably the Sea Vixen didn't have this - hence the need to jettison the canopy manually.

I should know for sure, as I've stood on the ladders of that aircraft while the crew were strapping-in for an airshow engagement years ago, but I was more absorbed by the Vixen's incredible shape than I was by little details.

When I was a kid, I was utterly aircraft-obsessed. A neighbour bought me a Christmas present which combined three aircraft books in one cover. One book was The Man in the Hot Seat and Doddy Hay's vivid story has always stayed with me. You don't hear about it much these days. It's a super read.

There's one glaring error in it, though. Hay refers to, "the late Chuck Yeager". Back in 1970 when I read it, I naturally assumed that Yeager was a goner. Of course, he's still with us to this day. I imagine Hay blushed mightily when his gaffe was pointed out!

Nigel

[mtskull]

As you know, the 'canopy breakers' take the form of explosive charges in the canopy material that shatter it milliseconds before the seat leaves the aircraft, ensuring the ejection isn't impeded. Presumably the Sea Vixen didn't have this - hence the need to jettison the canopy manually.

Please don't get me wrong (I do not purport to be an authority on the subject) but the "canopy breakers" I was referring are simply two pieces of metal, each forming a spike pointing upwards, attached to the seat structure either side of the pilot's head.
That said, a further look at the M-B website reveals that these were also fitted to the (non zero-zero) Mk5; furthermore, not all Mk7 seats were fitted with them.
It's a fascinating topic; I'm off to find out more....

[quicksilver-wsr]

Yes, I'd forgotten about those (the 'canopy breakers'). It's easy to forget how far the technology has moved on from the crude old stuff that used to be.

Bang-seats are a world in themselves. Some years ago, a popular and highly-experienced test pilot was ejected to his death from a Harrier in flight due to a malfunction. One second he was minding his own business, the next he was outside with no 'chute to speak of. A similar case to the equally tragic Red Arrows episode more recently.

And then there are the downward-firing seats the F-104s had. While the B-52 had some seats that fired up and some that fired down, depending on where you sat!

Doddy Hay's book was written eons ago and goes up as far as the Vulcan/Harrier era. There's the controversy about only equipping two flightcrew members with bang-seats in the Vulcan, leaving the other three to muddle through, and Bill Bedford's spectacular escape at low-level and low speed/high sink-rate at Yeovilton in 1961. But it starts at the very beginning, and includes the moment when James Martin first used the word "rockets". It's a rollicking read that offers insights not only into ejection-seat development but also the British post-war competition parachuting scene and the tight-knit world of the test pilot.

Nigel

[mtskull]

My copy of "The Man in the Hot Seat" arrived today. Made the mistake of starting to read it straight away and haven't been able to put it down since.
Nigel, thank you again for the recommendation.

[quicksilver-wsr]

Glad you're enjoying it!

Nigel

[mtskull]

The book has already provided the answer to my earlier ponderings as to why you need to be travelling at 90 knots to successfully eject at ground level in the Mk4 seat. I was wrong, it has nothing to do with the canopy; it is so that the parachute opens in the slipstream, as the ejection charge doesn't fire the seat high enough for it to open normally.

PS: Just ordered the biography of Sir James Martin. Now that should be another good read....

[quicksilver-wsr]

So strongly is Jimmy Martin associated with ejection seat development that he is generally forgotten as the aviator he started out as. The short-lived MB 5 was possibly the ultimate piston-engined fighter of the Second World War, but going back further than that, it is a little-known fact that Amy Johnson had planned to make her famous England to Australia flight of 1930 in a Martin-designed aircraft, but it wasn't ready in time - hence the ascent into immortality of de Havilland Gypsy Moth G-AAAH.

Nigel

[quicksilver-wsr]

Yikes! Good job there was no fire, or I don't think he would have made it.

Nigel

[Renegadenemo]

How did he manage that in the first place? Slammed the wheel brakes on? Fell down the hill? It's an uncommon sort of an accident...