We are aerospace engineering professors and brothers who write about flying from both technical and personal points of view. We we both trained in aeronautical and astronautical engineering at MIT. Steven Hall teaches Aeronautics and Astonautics at MIT and flies a Cessna Cutlass RG. Kenneth Hall teaches Mechanical Engineering at Duke Univeristy and flies a Cessna Skyhawk.
Hi guys,
With interest I read your conclusions about the Asiana crash. I am a 777 flight instructor and check airman with a major carrier and very keen to find out what happened to this unfortunate crew.
Firts of all the NTSB preliminary concluded from flight data that their Vref was 135 kts whichs to me seems an approach with flaps 30 where the United flight Vref was 140+ which to me seems an approach with flaps 25.
That Asiana came in too steep seems clear and that their ATS was not used also seems to be clear , because a 777 with ATS on can simply not reach a speed as slow as 110 kts….
For me the following question seems to rise: what vertical mode did they use? Was it VNAV? Or did they use VERT SPD or even FPV? At my company we always fly these kind of approaches either in VNAV or FPV. The fact that they came in too steep, lets say on an average glidepath of 4 degrees and more, in combination with the fact that their ATS may have been switched off, may have contributed to this event. Time will tell.
Best regards, Ferry van der Geest