3 ms·
Temperature is the limiting factor for speed, I remember SR71 pilots on a panel saying the aircraft flew faster in winter than in the summer for that reason.
by cm2187 4y ago
Temperature is the limiting factor for speed, I remember SR71 pilots on a panel saying the aircraft flew faster in winter than in the summer for that reason.
- StrangeATractor 4y agoI'm fuzzy on details but I remember reading it had some pretty crazy thermal expansion. I think the pilot had to wait quite a while (hours?) before opening the cockpit to give the plane time to cool enough.
- AdamN 4y agoIt's also cool that the whole thing was machined 'loose' so that it would expand as it heated up. Apparently the plane would leak fuel and oil when it was on the ground ...
- ridgeguy 4y agoYep, JP-7 [1]. Special low vapor pressure to mitigate accidental ignition hazard. The Sled leaked like a grad student's '69 VW bus in the hangar. Leak-free above > 1.5 Mach. (edit to add link) [1] https://en.wikipedia.org/wiki/JP-7 https://en.wikipedia.org/wiki/JP-7
- sbaiddn 4y agoWhat does winter mean at 80 000 ft and Mach 3? The jet stream is insanely fast at that altitude mixing the air, and at Mach 3 the surface weather changes in fractions of a minute.
- psd1 4y agoWinter means that your nearest pole is tilted away from the sun. Your half of the planet is cooler, especially towards the poles.
- weard_beard 4y agoFor instance the James Webb telescope gets clearer pictures in summer because in winter the astronauts breath can fog up the lens.
- deleted 4y ago[deleted]