stalling behaviour with large airliner
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stalling behaviour with large airliner
it it true that if a large airliner stalls, it will flip over on its back and head straignt down nose first?
is there any simulator program that simulates this? Ive heard that on a sim the stall can be approached but not actually experienced
is there any simulator program that simulates this? Ive heard that on a sim the stall can be approached but not actually experienced
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Deep stall demonstrations in large jet aircraft produce a good deal of an onset buffet to let you know you better get your head out of your butt and do someting about it.
If you ignore the stick shaker, and the onset buffet, it just gets more pronounced and the jet just starts to lose altitude while the nose is still above the horizion. When you unload the jet by releasing the back pressure on the control column, and allow the nose to come through the horizion it recovers very nicely. I've stalled the 727, 737, and 757. I have to tell you these aircraft recover alot better than the Bellenca Viking or the old Cessna 310.
Caution... deep stalls in jets cause white caps in the coffee.
If you ignore the stick shaker, and the onset buffet, it just gets more pronounced and the jet just starts to lose altitude while the nose is still above the horizion. When you unload the jet by releasing the back pressure on the control column, and allow the nose to come through the horizion it recovers very nicely. I've stalled the 727, 737, and 757. I have to tell you these aircraft recover alot better than the Bellenca Viking or the old Cessna 310.
Caution... deep stalls in jets cause white caps in the coffee.
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When you unload the jet by releasing the back pressure on the control column, and allow the nose to come through the horizion it recovers very nicely.
it it true that if a large airliner stalls, it will flip over on its back and head straignt down nose first?
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...it true that if a large airliner stalls, it will flip over on its back and head straignt down nose first?
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My 737 does the opposite if I remember the function of the speed trim system correctly - tries to create speed stability at low speed thus making it more difficult to enter the condition in the first place.
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Well, lynn, if you look at the bank angles achieved in the case of the Perpignan airbus accident, yes, it is true for a medium airliner - if mishandled.
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If not wings levelled, it will fall into a spiral-like dive, not like a real spin (like in aerobatics planes), like a corkscrew. If wings-levelled, as mentioned, it will increase sink rate with a nose down tendency, depending on trim setting.
hth,
Dani
hth,
Dani
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A simulator will simulate a stall.
Post stall behaviour is generally not modelled for transport category aircraft even in engineering sims and as such it is difficult to program with any degree of accuracy.
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Even PC sims like X-Plane can simulate post-stall behaviour reasonably sensibly. It's just another set of equations to solve, sometimes the inertial components aren't represented that well, but if its modelled well the behaviour is often quite surprisingly realistic...
Agree with the bootfull of rudder comment... likewise a handful of underslung turbofan thrust, rather than two symmetric handfulls?
Agree with the bootfull of rudder comment... likewise a handful of underslung turbofan thrust, rather than two symmetric handfulls?
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Originally Posted by HarryMann
Even PC sims like X-Plane can simulate post-stall behaviour reasonably sensibly.
Originally Posted by HarryMann
It's just another set of equations to solve
PBL
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Reports of stall accidents
Two I can think of - recent West Caribbean MD82 report, does have FDR data: available at avherald, search using 'West MD 82'.
Northwest Airlines 727 accident due to pitot freezing (heating off), NTSB report AAR-75-13 (google it), descended from 24,800ft to impact in 83 seconds, report states FDR data was retrieved and used, and suggests it may have been available for the public hearing, but is NOT actually shown in report.
Those both T-tails however.
Northwest Airlines 727 accident due to pitot freezing (heating off), NTSB report AAR-75-13 (google it), descended from 24,800ft to impact in 83 seconds, report states FDR data was retrieved and used, and suggests it may have been available for the public hearing, but is NOT actually shown in report.
Those both T-tails however.
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In the late 80s, early 90s, I carried out a number of post major inspection air tests in the RAF's VC10s.
In most configurations she stalled like any aeroplane, with aerodynamic as well as stick shake to announce the on coming stall, wings level and don't touch the rudders and at the stall the nose dropped away and standard recovery unload, apply power and recover. How anyone could not recognise what was about to happen is beyond me - it required strength and determination to get there!
However, the 10 had a 'stick pusher' fitted to prevent a true deep stall (the reason why this was fitted only to T tail aircraft on the British register is a long story). The pusher speed was calculated and you used a lot of muscle power to keep the IAS coming back to that figure. In addition an AoA indicator was temporarily installed on top of the coaming in front of the captain and if you got to the magic figure (+14 degrees seems to ring a bell) before the push you got out of it quickly by unloading etc. Try again and if still no push then the system was u/s and needed recalibration.
Contrary to some comments above, the flight simulator did a good job (and still does) of reflecting the whole stall and recovery process - not absolutely the same but good enough to train before the air test.
1106
In most configurations she stalled like any aeroplane, with aerodynamic as well as stick shake to announce the on coming stall, wings level and don't touch the rudders and at the stall the nose dropped away and standard recovery unload, apply power and recover. How anyone could not recognise what was about to happen is beyond me - it required strength and determination to get there!
However, the 10 had a 'stick pusher' fitted to prevent a true deep stall (the reason why this was fitted only to T tail aircraft on the British register is a long story). The pusher speed was calculated and you used a lot of muscle power to keep the IAS coming back to that figure. In addition an AoA indicator was temporarily installed on top of the coaming in front of the captain and if you got to the magic figure (+14 degrees seems to ring a bell) before the push you got out of it quickly by unloading etc. Try again and if still no push then the system was u/s and needed recalibration.
Contrary to some comments above, the flight simulator did a good job (and still does) of reflecting the whole stall and recovery process - not absolutely the same but good enough to train before the air test.
1106
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HarryMann: Even PC sims like X-Plane can simulate post-stall behaviour reasonably sensibly.
PBL:The aerodynamicists involved in designing large commercial jets emphatically do not agree.
Type1106:Contrary to some comments above, the flight simulator [of the VC-10] did a good job (and still does) of reflecting the whole stall and recovery process - not absolutely the same but good enough to train before the air test.
PBL:The aerodynamicists involved in designing large commercial jets emphatically do not agree.
Type1106:Contrary to some comments above, the flight simulator [of the VC-10] did a good job (and still does) of reflecting the whole stall and recovery process - not absolutely the same but good enough to train before the air test.
PBL
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...it true that if a large airliner stalls, it will flip over on its back and head straignt down nose first?
