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The NTSB concluded that 990 was a homicide. A relief pilot assumed control after take-off and then deliberately crashed the aircraft. From what I hear, it wasn'
by bhickey 15y ago
The NTSB concluded that 990 was a homicide. A relief pilot assumed control after take-off and then deliberately crashed the aircraft. From what I hear, it wasn't a fun week at the RI Medical Examiner's office.
- nikcub 15y agothe other similar incidents are Birgenair Flight 301, where the pitot tubes were blocked because of insect nests, resulting in pilot confusion: http://en.wikipedia.org/wiki/Birgenair_Flight_301 http://en.wikipedia.org/wiki/Birgenair_Flight_301 and Aeroperu Flight 603, where the pitot tubes had been covered by maintenance workers and not removed prior to takeoff, also resulting in pilot confusion and lack of confidence in instrument readings: http://en.wikipedia.org/wiki/Aeroper%C3%BA_Flight_603 http://en.wikipedia.org/wiki/Aeroper%C3%BA_Flight_603 With these similar incidents you would think that air crews would have learnt from these disasters. If you read the reports on those two accidents, the similarities to the AF disaster are remarkable.
- Simon_M 15y agoConsidering how many incidents there seems to be due to the loss of these airspeed sensors it seems crazy not to have an additional, different method of calculating airspeed. Is there a reason GPS is not suitable here?
- andrewmccall 15y agoGPS can only tell you how fast you're moving over the ground. It can't tell you how fast you're moving through an airmass that might be moving with or against you, this is far more important to keeping a plane in the air than how fast you're moving between point a and point b.
- al_james 15y agoI wonder if GPS could be used to estimate the air speed by means of a permanently refining mathematical model? E.g. If I know I have heading X, ground speed Y, weight Z, thrust A, you should be able to work out your predicted ground speed. Any variation in real ground speed and estimated ground speed is got to me made up of wind direction and velocity right??? Just a thought. (Disclaimer: I know nothing about aerodynamics so this may be nonsense)
- mtts 15y agoGiven the speed at which the readings in my android phone update while driving a car, I'd say yes.
- alpyne 15y agoIt can't give you the relative speed of the air around the aircraft.
- aperiodic 15y agoGPS gives you speed relative to the ground, not speed relative to the air, which is what's important for aerodynamics.
- eftpotrm 15y agoYes, but when groundspeed with a slight lag is all that's available is it really that much worse than nothing, which seems to be the failure mode at present? I stress I'm not a pilot and I'm sure you'd want to have a Big Flashing Warning Light telling you that ground speed <> air speed, but there'd seem to be some benefit over nothing at all.
- jrockway 15y agoThe ground speed is not useful information. You can be moving backwards relative to the ground and still be overspeed. The only thing that matters to the airframe is the airspeed, and the only way to know the airspeed is to sample the air around the plane.
- lutorm 15y agoYou can be moving backwards relative to the ground and still be overspeed. That's not true. The wind even at altitude won't be more than ~100knots. It's true you can't land using GPS speed, but if your GPS tells you 90 knots ground speed at 37000ft, you know something's not right regardless of wind.
- jrockway 15y agoThe margin between stall and overspeed is something like 20 knots at that altitude. You're not going to be able to calculate your airspeed from the groundspeed within that margin. (FWIW, I'm pretty sure this GPS speed information is available in the cockpit already. If not, you can get it off your iPhone if you really care.) Finally, the flaps-down speed range of a Cessna 152 is 35-85 kts. So if you're facing into 85kt winds with the flaps down, you're flying backwards and are overspeed. (This can happen with the flaps up too, of course, but winds of 149 kts are a little hard to believe :)
- rwmj 15y agoGPS gives you ground speed. Airspeed is a different thing -- imagine if you're flying into a strong headwind.
- Shivetya 15y agolet alone we forget losing a B2 bomber during take off for similar reasons. http://en.wikipedia.org/wiki/Andersen_Air_Force_Base_B-2_accident http://en.wikipedia.org/wiki/Andersen_Air_Force_Base_B-2_acc...
- afterburner 15y agoYes, I keep hearing about pitot tube problems... I thought the Egypt Air flight I was thinking of had the same problem but I can't find information about it. It might be harder to find because I'm not sure the plane actually crashed.