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In article ,
"Emmanuel Gustin" writes: "robert arndt" wrote in message om... http://mach1.luftarchiv.de/weisse_9.htm "White 9" deserves the credit, not "Glamorous Glennis"! This seems complete nonsense to me. The Germans did fly high-speed tests with the Me 262, of course. The senior Me 262 test pilot, Zeigler, has described how they climbed to 10.000 to 12.000 m, and then put the aircraft into a steep full-throttle dive. At 7000 meter they would reach 950 km/h, close enough to Mach 1 at that altitude to produce a deep rumble as the airflow detached, followed by a strong tendency for the nose to drop and the aircraft to roll. The Me 262 then entered an out-of-control dive until it had descended into the denser air at low altitude. The dive achieved only Mach 0.86 at 5700 m. It ought to be pointed out that on a Standard Day, 950 km/hr at 7,000m is Mach 0.84. At that point the Me 262 is just entering into the mach number range where the Drag Coefficient is increasing extremely rapidly. It is also claimed that in July 1944 a modified Me 262 with a low-drag canopy reached slightly over 1000 km/h at 10.000 m in level flight, or Mach 0.92. But the type was firmly subsonic. In service Me 262 were 'red-lined' to stay out of compressibility problems, as they tended to become (quite unlike the XS-1 or F-86) completely uncontrollable at high Mach numbers. Just so. As, it should be pointed out, were the P-80, the P-84, and the Meteor. In the case of the P-80 and P-84, the difference in dive speed available due to the higher Limiting Mach of the Me 262 worked out to a whopping 15 mph (15 kph), and the P-84 was dead even. Both American types had more power adn less drag in level flight. But the Me 262 actually had quite good decent aerodynamic characteristics for transsonic flight compared to the Meteor, which initially suffered from control problems already at Mach 0.71 to 0.74, because the engine nacelles of the early Meteors were too fat and disturbed the airflow. Which was fixed by the longer nacelles of the Meteor IV. The Vampire, though, with its faily thick wing, was stuck at about Mach 0.75 or so. Of the propeller fighters the Spitfire got closest to Mach 1 because its thin wing had less drag at such high speeds even than the laminar flow wing of the Mustang. Tony Martindale reached 0.92, not without blowing up the gearing of the overspinning propeller, and bringing back the aircraft without propeller. There also is a claim that a weather reconnaissance PR.IX reached 0.96 in an uncontrolled dive from high altitude over Hong Kong. The Spit actually had the best high Mach number drag characteristics, and handling behavior of all of the WW 2 era fighters. (The Spitfire also ended up with better high-speed bahavior that its laminar-winged successor, the Spiteful.) During WWII there were claims to have achieved Mach 1 in various fighters in dives, but most of these would have been transsonic dives, with airflow over the aircraft only being locally supersonic -- and airspeed indication probably becoming very unreliable as a result. It is characteristic of the true performance of these aircraft that when designers decided to install Mach meters, these had scales ranging only up to 0.8. -- Pete Stickney A strong conviction that something must be done is the parent of many bad measures. -- Daniel Webster |
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