sferrin wrote:idesof wrote:toan wrote:Personally, I think if you change "800 miles" to "800 km", then we will get a more reasonable result:
1. For their performance, which started at 2:40 p.m., Shower and Bergeson took off from Langley, 800 "miles --> km" away, at about 1:25.
A: 800 km / 1.25 hr = 640 km/hr = With the average speed of 0.6 Mach for this 800 km long trip that fits the National laws (Of course, the average speed is not equal to the maximal speed during this trip).
2. But we did the math and figured we could be there if we supercruised in about 25 or 30 minutes.
A: 800 km / 25~30 mins = 1600~1920 km/hr = With the average supercruise speed of 1.51~1.81 Mach for this 800 km long trip.
Toan, I said EXACTLY the same thing. However, Sferrin said he calculated the distance as being 800 miles. I have a feeling that someone is messing up their metric and English units. Again, if NASA and Lockheed and dozens of rocket scientists (literally rocket scientists) can screw up with their measurements, so can two pilots who get carried away bragging about their plane.
Except that it 800 MILES from Langley to Oshkosh.
Right. I don't disagree with that, as I noted. However, do you think perhaps the pilot in question mixed up his English and metric units?
However, I just crunched the numbers. From Langley to Oshkosh, it took them one hour and 15 minutes, for an average speed of 640 mph. As stated, for an 800-mile trip, that is indeed equivalent to about Mach 0.9. They should have known that to say "25 to 30 minutes" it would mean they would have to go 2.5 to 3 times as fast. It really is puzzling.
By the way, they cite sonic boom as a concern while flying over CONUS. Question: can one get any kind of an accurate fix on an airplane on the basis of its sonic boom? Now, while the hypothetical listening station would already be far behind the airplane by the time the sonic boom hits it, could it relay the info to a station further up ahead? Tell an IR sensor, for instance, exactly where to look? I don't want anyone in the U.S. military to answer this question, nor to threaten me, please. I am asking CIVILIANS with some knowledge of aerodynamics and without any sort of security clearance. Thank you.