Originally Posted by
JD-EE
sensor validation, If I am reading Wikipoodle correctly the speed of sound at commercial aircraft altitudes is around 660 MPH or 573 kn. That gives a speed of 7.8 nm/s for .82 Mach. If the plane flew on the entire time the radius would be 31 nm.
Indeed - you also have to allow for wind speed, and if you calculate distances between the history of 10 minute locations you get about 80nm per 10minutes - so the initial +40nm position was 5 minutes of forward flight, or 4min + dive slope. There was some confusion about the pedigree of this report in initial days after crash see
Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data for example. Much discussion here about possible location - including turn back and south of LKP, and expectation of 10nm radius - but rather than change it seems BEA stuck with the initial determination 'most likely within 40nm'.