Originally Posted by Clandestino
Impossible. Somatogravic illusion means longitudinal acceleration or decelaration gets interpreted as pitch-up or pitch-down. AF447 was flying steadily when CM2 pulled first time and subsequent deceleration was not very quick anyway,
The PF on AF447 attempted to recover the Altitude loss of 400 ft (due loss of mach correction), but for some unexplained reason he continued to pull achieving 7,000ft per min RoC. According to the final report
http://www.bea.aero/docspa/2009/f-cp...nexe.03.en.pdf the graph of ground speed shows a reduction from about 500 kts to 400 kts in 30 seconds (between times 02:10and 02:10:30). i.e. about
3 kts per second. Apparently you don't believe that rate of deceleration could cause a somatogravic illusion.
Yet from the incident report of Air Transat Airbus A310-308 C-GPAT (to which you posted the link
happless crew), says
1.11.4 At about 1440:44, (I think they meant 19:40:44) at the end of the climb, the perceived attitude reached greater than 30° whereas the actual attitude was about -3°. (Due to Somatogravic illusion).
The table in Appendix A shows the aircraft speed and time base.The aircraft accelerated from 0 at 19:39:38 to 209 kts by time 19:40:44 (i.e. 66 secs or about
3.1 kts per second) and produced a somatogravic illusion of 30 degs error in perceived pitch.
The fastest acceleration I can see is between times 19:40:44 at 209 kts and 19:41:29 at 345 kts (VMO) i.e. 136 kts in 45 secs again about
3 kts per second.
Please explain why the crew of C-GPATcould have suffered from Somatogravic illusion with an acceleration of 3 kts per second, but according to you, the crew of AF 447 could not have.
Impossible?