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#71
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In article ,
Cub Driver writes: There's no descendant of the P-59A. But every airliner that flies, with its engines hung in pods beneath the wings, owes something to the Me-262. Not true. Just like every airliner that flies with the engines embedded inside the wings or fuselage does not owe something to the Yak 15 or P-80. There was a Boeing engineer with Operation Paperclip. He cabled back to hold the development on the XB-47, which was then in design. He came back with engineering studies that showed the advantages of swept wings and pod-mounted engines. These were duly incorporated in the B-47, which was the granddaddy of all Boeing airliners, and by extension all Airbusses as well. To be sure, the pods on the 262 were a work-around. It was only when wings were swept that the Germans discovered that the pods served brilliantly as air dams. Dan, the pods on the B-47, as best as I've been able to find, didn't spring from any German concepts. Boeing was certainly influenced by the Swept Wing data that it saw, and which was also corroborated by the data they were receiving from the N.A.C.A. and R.T. Jones, (BTW, the Boeing engineer that was tagging along with the Paperclip teams sent his information to everybody, not just Boeing.) When Boeing decided to enter the Medium Jet Bomber competition, they decided to leap the pack (North American, with the XB-45, the interim winner, Convair with the XB-46, and Martin with teh XB-48, all straight wings with integral wing-mounted engine pods, and although not al that different in basic concept than the Arado 234, really Piston-Engine shapes with jets scabbed on) adn go with a thin, swept wing. The integral pods as used in te Me 262 and Ar 234 weren't acceptable from a structural (danged heavy), safety, (A thrown turbine bucket, which happened pretty often back then, would cut through an adjacent structure like a red-hot bullet. If the adjacent structure is Wing Spars and Fuel Tanks, it's very bad) aerodynamic, (The integral pods added a really hefty chunk of Interference Drag, and, although they hadn't doped it out yet, raised all sorts of problems with cross-sectional Area Distribution and Transonic Drag.) and maintenance problems. (Can't reach to top of the engine, and on a big airplane, it's way high off the ground) As I recall, initially they wanted to use one or 2 large engines buried in the fuselage, but the large engines weren't happening quickly, and they needed the internal volume for fuel and bombs. They then went with a sort of Flying Fishlike configuration, with 4 or more smaller engines in the upper fuselage over the wing center section, fed by a large nose inlet. That wasn't working either, and the thin wing was showing signs of being very marginal in torsional resistance, and therefore flutter-prone. Somebody in Boeing's Aerodynamics section suggested using the engines as anti-flutter weights, and Boeing used their new high speed wind tunnel to come up with an engine pod design that was well separated vertically from the wings, reducing interference drag, and well forward, keeping the engines clear of any vital structure. The improved flutter resistance allowed the flexible wings to work, and hhe pylons gave teh added bonus of being nifty wing fences to help resist the pitch-up tendency that swept wings have. When it was discovered that they'd need a bit more power, they initially scapped an engine to each wingtip. They then discovered that they'd want a bit more wing area, so they extended the tips out past the outboard engines, and that became the B-47. While there was soem German influence in the B-47, the pod configuration was Boeing's idea. It's really well described in "The Road to the 707", (William H. Cook, TYC publishing, 1991) Cook was one of Boeing's Aerodynamicists, and spearheaded their High Speed Tunnel effort. I think the Dimond Library has a copy. -- Pete Stickney A strong conviction that something must be done is the parent of many bad measures. -- Daniel Webster |
#72
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"Gerdeus" wrote in message
om... "John Mullen" wrote in message ... "Gerdeus" wrote in message om... There's no descendant of the P-59A. But every airliner that flies, with its engines hung in pods beneath the wings, owes something to the Me-262. Not true. Just like every airliner that flies with the engines embedded inside the wings or fuselage does not owe something to the Yak 15 or P-80. Name one. Boeing 727. Nope. It had three engines in pods at the tail. One was served by an air intake at the front of the fin. See http://www.cactuswings.com/psa/hangar/727.shtml Rather like the DC 10, the L1011 or the Trident. John |
#73
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John Keeney wrote:
Ed, THE Air Force Museum is truly a sight to behold. I haven't been for a couple of years (maybe next week), but in the then latest building you went in and looked off in the distance to the right to see the Globe Master and B-18. Off in the distance to the left, the F-117, a 'Nam vet' B-52 up on a display stand and a Dagger. Above you hung many a quaint and curious relics of the "X-" age and Observation types. But from that vantage point in that brightly lit, open room you couldn't see the XB-70, the Blackbird, X-15, B-57, B-58, MH-47 or the not insignificant displays of 90 and Century series fighters. The other rooms in the complex still housed huge displays and yet another building of like size has been opened since to take some of the overflow. Definitely a great display of aircraft and history. Obviously US-centric as a US Air Force Museum should be. Perhaps back in the early 90's I saw one of the most touching displays of the human cost of war I've ever seen. It was an item on loan from the government of New Guinea IIRC. A simple door panel from a C-47 (???) with a diary written on it. The plane had gone down in the SWPA during WWII with 10 or so survivors. Each day, for a time, recorded the hope of being spotted by rescue aircraft. Every few days, a death of a survivor was noted. And on it went for some time until eventually, the "diary" grew silent. Don't know if it's still there or not, but made a very strong impression on me. SMH |
#74
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Stephen Harding wrote:
John Keeney wrote: Ed, THE Air Force Museum is truly a sight to behold. I haven't been for a couple of years (maybe next week), but in the then latest building you went in and looked off in the distance to the right to see the Globe Master and B-18. Off in the distance to the left, the F-117, a 'Nam vet' B-52 up on a display stand and a Dagger. Above you hung many a quaint and curious relics of the "X-" age and Observation types. But from that vantage point in that brightly lit, open room you couldn't see the XB-70, the Blackbird, X-15, B-57, B-58, MH-47 or the not insignificant displays of 90 and Century series fighters. The other rooms in the complex still housed huge displays and yet another building of like size has been opened since to take some of the overflow. Definitely a great display of aircraft and history. Obviously US-centric as a US Air Force Museum should be. Perhaps back in the early 90's I saw one of the most touching displays of the human cost of war I've ever seen. It was an item on loan from the government of New Guinea IIRC. A simple door panel from a C-47 (???) with a diary written on it. The plane had gone down in the SWPA during WWII with 10 or so survivors. Each day, for a time, recorded the hope of being spotted by rescue aircraft. Every few days, a death of a survivor was noted. And on it went for some time until eventually, the "diary" grew silent. Don't know if it's still there or not, but made a very strong impression on me. SMH God, that must have been wrenching...It really get's to me to come across something like that in a museum when I'm with family or friends (and not 'steeled' for it). It seems that the older I get the less handle that I have on my emotions and that sight certainly would have done me in... Thank you for passing it along. -- -Gord. |
#75
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"John Mullen" wrote:
"Gerdeus" wrote in message . com... "John Mullen" wrote in message ... "Gerdeus" wrote in message om... There's no descendant of the P-59A. But every airliner that flies, with its engines hung in pods beneath the wings, owes something to the Me-262. Not true. Just like every airliner that flies with the engines embedded inside the wings or fuselage does not owe something to the Yak 15 or P-80. Name one. Boeing 727. Nope. It had three engines in pods at the tail. One was served by an air intake at the front of the fin. See http://www.cactuswings.com/psa/hangar/727.shtml Rather like the DC 10, the L1011 or the Trident. John Comet/Nimrod. -- -Gord. |
#76
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"Gord Beaman" wrote in message
... "John Mullen" wrote: "Gerdeus" wrote in message . com... "John Mullen" wrote in message ... "Gerdeus" wrote in message om... There's no descendant of the P-59A. But every airliner that flies, with its engines hung in pods beneath the wings, owes something to the Me-262. Not true. Just like every airliner that flies with the engines embedded inside the wings or fuselage does not owe something to the Yak 15 or P-80. Name one. Boeing 727. Nope. It had three engines in pods at the tail. One was served by an air intake at the front of the fin. See http://www.cactuswings.com/psa/hangar/727.shtml Rather like the DC 10, the L1011 or the Trident. John Comet/Nimrod. Yep, I think you'd have to go back that far. Podded engines are safer and easier to replace/service John. |
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