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John B (Sc)

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Everything posted by John B (Sc)

  1. To be honest this sounds more and more like an accident which had been waiting to happen, thanks to procedures which sound to have far too many potential failure points. Essentially this seems to rely on perfect human performance every time. Far too tight a set of margins and reliance on visual identification at night. I'd suggestthose at higher level in the operations, both in ATC Management and in the military command should look carefully at what has been permitted - perhaps due to progressive 'creep' over time. A visual ident at night in a brightly lit busy environment like Washington is dubious; I'm surprised visual separation is allowed., Since it apparently was part of routinely permitted ATC operation, the controller was simply following normal practice in approving that request. The helicopter wass apparentl;y conducting routine familiarisation or re-familiarisation as part of their operational tasking. It sounds as if that includes (potentially) use of NVGs, no doubt something which needs considerable practice. Use of NVGs according to colleagues who have used them, does considerably impede scan and it makes keeping a wider situational awareness harder. Any night visual flying is hard, and I imagine very low level especially over and around a brightly lit city is much tougher. I wonder if the military authority was asking too much, with the extraordinary tight tolerances required here. Each time, every time. The preference will always be to ease higher whenver possible. Height spacings between traffic on such routes should take that into account. All in all, perhaps too much reliance on "it's always been OK". A simple either-or rule could have prevented this, but 'normalisation' of the risks means we don't seethe nbeed for that. Either clear an aircraft on that approach or clear a helicopter along that route. Not both simultaneously. A 200ft maximum height limit helicopter route when an aircraft may be down to 300-350ft on finals is too tight. (Hence of course the expectation of a horizontal separation as well. ) Oh blast it - so sad, so needless.
  2. That's my understanding for the Yak-38 too. Soviet/Russian escape systems and ejection seats were and are impressively effective - some cunning design. For the F-35, presumbalythe auttoamtics look at diveregence rates - pitch and roll especially to determine whether (automatic) ejection is needed. Spearate tothe computer controlled flight systems. The Harier could 'depart' very suddenly in some circumstances, and get outside safe ejection limits very quickly. That dreadful airshow accident - where the pilot 'reversed' against the wind just too fast and went beyond the control limits - comes to mind. Not enough time. Thank you for that comment/explanation Enzo. I have several friends who are ex-military pilots. One clearly opted for the 'professional pilot' route and ended up as a well known and very respected operator - he is still is, even well into retirement. Another went the other way and went to high rank. Equally impressive and also a very competent pilot, but quite different ! ( I have a suspicion that you might know either or both of them, aviation being such a small world!)
  3. I'm not sure the systems available are that sophisticated or subtle. What yiou are suggesting would be nice to have - but how to ensure that any such automatiated selectionwoudl be reliable is a major challenge, I suspect. In a combat training situation for example things can change very fast in a 3D environment, plus the topgraphy around the machines can vary rapidly and affect the situation. The high altitude, or higher altitude case you mention is quite rare. Generally, high altitude gives the crew more time and space to explore ways to get the machines back home. Ejection is the last resort, so unless control has been totally lost, the crews will be working hard until energy, height and time are running out . Incidentally even quite modern jets have been successfully landed engine off in emergency. I recall seeing some practice engine failure recoveries by jet fighters - the 'circuit' or high and low key height positions were very impressive ! Modern ejection systems are rather more benign than the early explosive cartridge only systems. They probably do 'adjust' the accelerations if conditions permit - heck some systems even appear to have vectoring rocket thrusting to change escape vectors, but I suspect the worst case accelerations are still fairly marginal. If the choice is probable injury but survival, or death, I know which I'd want to design for. Some of the escapes in recent years have been very impressive. I seem to recall reading that the F-35 will eject its pilot on its own iniative inthe landings equence if all goes wrong. I'll bet that is a surprise to the pilot !
  4. Thanks Tweeky, I stand corrected on the number of ejections - after three I suspect most of us would have had enough anyway ! Oh indeed it is ultimately the impact on the vertebrae themselves which is the concern as you say, because if the cartilage is compressed too far, not enough room remains for flexing before bone to bone contact and damage as you describe - which of course seriously risks the spinal cord. Its impressive our skeletons are so damage resistant really.
  5. US figure skaters do seem to have a bad record with aircraft. One of the early transatlantic jet crashes took out the entire US figure skating team way back inthe Sixties when they were coming over to Europe for a World Championships, and I have a vague recollection of another accident that kiiled several more, years later.
  6. I think part of the issue was that if you were in a combat environment - real or simulated, likely there is a lot of twisting and bending, plus arm and leg actions. Spine needs to straighten, shoulders back , elbows and legs in and braced with stomach in, head up, looking straight for best outcome.
  7. Effectively using visual separation at night, it seems. Very surprising in such a busy environment and so close to the nation's capital. (Though apparently quite common in US thinking) I believe the helicopter crew were from a VIP transport Squadon, so you'd expect them to be amongst the best. Just goes to show = we can all get it wrong. Stay awake, stay alert and never assume you can't make an error ! Especially with only perhaps 150 ft vertical separation, good horizontal separation is essential. That cna really only come from ATC; at night mis-ident by the crew in a busy possibly confusingly lit environment is far too easy. John B
  8. Mike, I believe some of the early seats produced in the range of 15 to 20 G accelerations. Brutal and damaging, hence the strong emphasis on posture, and why the face blind was used - to encourage the best posture for that impact. The point was that some fair chance of survival was better than none. I rather doubt that those rules would be relaxed - it can take some time to recover (probably longer than any intense campaign can last) and if sig damage has occurred the odds of permanent incapacitation go way up. We certainly did have variable rules and waivers for some unplasant purposes - those of us of a certain age will recall the 'War Emergency Dose' limit, which was 75 Roentgens as I recall. Not a value to encourage later family, but intended to keep essential people'operational' without terminal sickness or short term cancer risk during a nuclear exchange. Wunder bar ! The days of the 'Thin Red Line' and the Fulda Gap worries.
  9. I believe with the early Martin Baker setas it was typically two ejections only, then not permitted to fly fast jets. It may also have ben a mater fo persoanl medical checks and measurement, because everyone is different. It's all about the amount of squashing (not the technical term!) of the cartilages in the spine. Once they get too squashed, any later ejection will cause fracture - and likely paralysis or death. Pperhaps with enough informationand mesurement there may be dispensationallowed - I did know one chap who had ejected twice and had lost almost two inches in height, which stopped further fast jet work. . Apparently one ejection was especially bad for his spine because he hadn't had proper time to brace.
  10. Good grief. Sounds like far too many lawyers have far too much infleunce on these companies today. Desperately risk averse, except where legal feees are concerned ? Very sad. So much for UK engineering history.
  11. Quite ! I make it three Spitfires - or is it four?- in this year's announcements. At least there was a Hurricane tucked away in there too! But a new Wesses - whee. And hopefully much more accurate. Shall have to build at least one in SAR markings as well !
  12. I was amused bythe speculations on possible biplanes earlier in this thread. Why does no-one ever mention the rather bonny Stampe - the SV4. Even the Bucker Jungmann has had a good ICM 1/32 kit issued, but the poor old Strampe still languishes with the old Heller 1/50 scale effort. After all, the Rothmans team flew Stampes for years, most impressively.
  13. The US market for car models has always intrigued me. Why are they so popular there, and virtually nowhere else?
  14. As something slightly different, do you suppose a 1/35 scale Auster might be a possibility? Given the recent fine 1/35 kits and the age of the old Airfix Auster Antarctic, it might be different enough to annoy just about everyone guessing on here !
  15. Good thinking, though I suspect when you add in manufacturing costs, overheads and enough profit to justify the investment risk that probably adds another 50% - so maybe 900 needed for a better break even point, Worldwide ? Are there enough of us crazy enough? I have no idea.
  16. Wow ! Ignoring the technical challenges, which can probably be dealt with under USA's 'experimental ' rules with abit of assistamce and some 'reverse engineering' if necessary, that's got to be a very high cost, and high risk exercise.
  17. I wonder if any others of John's extensive range of kits and superb additional detail items will becaome avaialibe agian, Hopefully, his masters still exist - though perhaps some have worn to below his exacting standards. Meantime, this is all good news !
  18. Indeed - though John seems to greatly enjoy displayng his 'Stackton Tressle' (I think) aerodrome at various shows around the country. Each time I see it there is a new addition. I think that is one of his happy retirement pleasures. Always great fun to have a crack with John ! And I agree - great news if some of the superb Aeroclucb - and Skybirds - items become available again. Must complete the two or three Aeroclub kits I still have 'in stock'. John B
  19. I'd quite enjoy seeing either of those back. Any chance of the Islander/Defender returning soon too, do you think? I have a vague memory of someone saying the mould for the Islander had been damaged, but maybe I am mis-remembering. John B
  20. A truly extraordinarty bit of work, that Vimy. What scale is it?
  21. Thanks Colin. Shall have a dekko next time I'm down there. John B
  22. Strewth - now you mention it I remember building a Keilkraft Lysander myself - very very badly ! I couldn't get it to fly worth a darn, probably due to faulire to understand what the importance of Cof G was. I shall definitely want a night intruder version of the Lysander with, say, 138 Sqn or 161 Sqn - a kit which I hope instead of a gunner will come with an agent or two ready to climb up the ladder into the rear cockpit - or racing across the grass to the machine, in a dark field 'somewhere in France'. The skill - navigational and piloting - and bravery of those pilots has always impressed me as much as that of the agents. A type of cool, long courage that is hard to maintain.
  23. Which sounds so ironic, given Revell's origins. When I was a kid 'Revell' and 'Monogram', along with 'Renwal' were the measure by which the top end range of kits were measured. Ah, happy days, lang syne ! (Anyone got a Renwal 'Skysweeper' kit for rebuild repair or assembly? That, along with the old Monogram Avenger with the folding wings, was in my youthful view the pinnacle of kit provision !)
  24. There was indeed a point at which they were on sale at absurdly low prices ; I got a couple from, I think, Wonderland at around £15. I had bought one when they wer first issued. (And then hoped for a two seater!) I'm not sure why they failed to sell well, unless Frank Brown's superb vacform had cut away the real enthusiast's market. It had everything - superb well researched drawings, beautiful decal scheme, excellent white metal parts and a very nicely made vacform set up. You could build pretty well any single seater variant from his vacform. The finest vacform I've ever had the pleasure of working on. That might have undercut quite a bit of market. John B (Colin - I'd be most interested to know where that Dutch T7 is ! )
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