Dennis wrote: > Just a thought but.... > 1. Isn't the possible end of Concorde due purely to falls in pax numbers, > not mechanical problems? Yes, but with the spectacular crash, the media is very quick to report the slightest flaw, which no doubt causes the rich-and-famous to hesitate before flying. > 2. Aren't some of the features on Concorde (the museum piece) still not > incorporated/copied on some 'modern' aircraft? Most, like the variable engine air inlet geometry, are peculiar to supersonic flight and likely found on military aircraft but not necessary on subsonic aircraft. > 3. Don't other aircraft loose the odd bit in flight every now and again - > and special procedures put in place to try to prevent recurrences? But not at Mach 2.0 and 60,000 ft, where the margins are much thinner. > 4. Was the extensive cabin refurb post crash a waste of money/ill > conceived if it hasn't put a lot of rejuvenated bums on seats? Yes. > 5. Isn't it a piece of equipment, carefully maintained (according to > cycles etc) to keep it in current condition? Forever? Not economically. There reaches a point where it is no longer economically viable to maintain any piece of machinery. It's theoretically possible, just not economically feasible. For my Cherokee, about 20,000 hours I think (it has 3500). For transport-category aircraft, there's also the no. of cycles. Concorde does have some advantages here: low cycles, and low corrosion due to skin heating at supersonic speeds. > 6. Is Concorde really the only a/c which requires special handling > procedures? Consider this: no flaps. No slats. Variable engine air inlet geometry. Need to change the CofG envelope in flight by pumping fuel fore-and-aft. Seventeen separate fuel cells. Delta wing. The Concorde by virtue of no flaps has very poor low-speed handling at very high angle of attack. Consider this data from the accident report: to maintain level flight with all engines running, it must maintain 185 knots. With one engine out and the gear down, Concorde needs to maintain at least 205 knots. With two engines out (never mind both on one side), it requires greater than 300 knots, a speed it had no hope of achieving after losing the second engine in the Paris crash. The report says that this speed Vzrc is peculiar to Concorde. So yes, it handles much different from your average Boeing or Airbus. > 7. How would a Jumbo fair if I put a piece of metal (equivalent to a > railway sleeper in this case) on the runway just prior to its takeoff? It would not be equivalent to a railway sleeper. The structural integrity of a 747 is about the same as a Concorde (same order of magnitude at least), so to pierce the skin (actually the tire as the metal pierced the tire, not the skin) of a 747 would require about the same size piece and force as for Concorde. It's relative to skin/rubber thickness and strength, not aircraft size. However, the 747 has leading-edge slats, and flaps, all of which improve low-speed handling. That said, two out on a 747 at MGTOW, is a very, very serious situation. Especially on the same side. However, consider this: a blown tire on the Concorde caused the fuel tank rupture. It was not the metal piece that likely punctured the fuel tank, but rather chunks of tire. Have 747s survived tire blowouts before? I suspect very many. Yet two Concordes have suffered tire blowouts with serious damage. One was nearly catastrophic (the fuel leak did not ignite). The other WAS catastrophic (the fuel leak did ignite). > 8. Wasn't Concorde an Anglo/French project that nobody else has been able > to accomplish? Other SST projects were on the books (Lockheed, Boeing and Douglas I believe all had plans). What killed them was not technical know-how (or lack of same) but economics. Don't get me wrong. The Concorde is a beauty. An engineering marvel, and until the crash one of the "safest" aircraft in the world (statistically). After the crash though, one of the most dangerous (statistically). Economically though, it makes little sense. It is a "prestige" program for BA and AF. The crash did not enhance "prestige". At some point, emotion gets sidelined in favour of bean counters. Mike Gammon