3 ms·

Edit: after re-reading the passage, I think that what happened is that the elevator had stalled, not the wing? So it wasn't a "normal" stall. Original comment b

Edit: after re-reading the passage, I think that what happened is that the elevator had stalled, not the wing? So it wasn't a "normal" stall. Original comment below. > It stalled, because of the load. What he did, because he was smart, is something that no other pilot would do: He pushed over into the dive more, This part made me chuckle. The fact that you need to go nose down to recover from a stall is one of the first things new pilots learn[1], it's not "something no other pilot would do", but I get it, they're trying to make the story interesting for the general public. [1] https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/airplane_handbook/media/06_afh_ch4.pdf https://www.faa.gov/regulations_policies/handbooks_manuals/a...

joshvm 5y ago
Also pushing the nose down is the first thing you're taught as a glider pilot for engery management: launch failures, stalls, spin recovery, etc. Flight Chops did a video on this - it's drilled into commercial pilots (as well as glider pilots), but not GA nearly as much Think it's this one: https://m.youtube.com/watch?reload=9&v=m_tKShlf_gU https://m.youtube.com/watch?reload=9&v=m_tKShlf_gU
- throckmortra 5y ago
  Wouldn't take advice from that guy https://www.avweb.com/news/pilot-arrested-after-airport-incident/ https://www.avweb.com/news/pilot-arrested-after-airport-inci...
- mastazi 5y ago
  > is the first thing you're taught as a glider pilot I love gliders, I grew up near a glider school, near Rome, Italy. I live in Australia now and it seems that glider culture is not as strong as in Europe. > it's drilled into commercial pilots Probably even more after Air France flight 447 > but not GA nearly as much Really? It was one of the first things I learned as I was studying towards the PPL (I haven't finished it yet because flying is expensive :-( but I'm done studying the theory). I'm in Australia BTW, not in USA - maybe things are different
doctor_eval 5y ago
Well, you’re trained to push the nose down in a stall because stalls normally happen at a very high AoA, when there is not enough airflow over the wings, typically when you’re pointing up, not when you’re in a dive, and certainly not when you’re in a Mach 1.01 dive. And this was an elevator stall. You’re not taught to pitch down when there is no elevator authority - in fact you wouldn’t be able to, by definition. But the problem here was too much airflow over the horizontal stabiliser - from what I can see, it hadn’t really stalled. Pitching down relieved the load and let them move the stabiliser. I suppose the combined deflection of the stabiliser and then the elevators was enough to get it under control again. I for one am always pretty impressed with stories like these because they show just how well the pilots understand their aircraft.
- mastazi 5y ago
  > But the problem here was too much airflow over the horizontal stabiliser Yes, after thinking about it, maybe they shouldn't have used the word "stall" because in this case it's a bit ambiguous
Syonyk 5y ago
I would assume they were talking about the stabilizer trim motor not being able to run the stabilizer trim because of the loads. > When he pulled back, the elevator was ineffective; it didn’t do anything, so he said, “Well, I’ll use the stabilizer,” and the stabilizer wouldn’t run. It stalled, because of the load. Key in there: "Wouldn't run." Almost all transport class aircraft have the same sort of trim setup on the tail - they have the movable elevator at the trailing edge, and then the entire horizontal stabilizer can tilt up/down for trim. This is a lot lower drag than having the elevator deflected, and gives you an extra control surface for emergency use as well - usually, the control authority of the entire moving stabilizer is more than the control authority of the elevator, so you can use that in an emergency for pitch. That the elevator wouldn't work effectively in the transsonic region was known - that's why they planned to use the whole moving stabilizer to pull out of the dive. Just, the air loads on it were too high with what limited authority the elevator still had, so they had to unload it again to run the trim, at which point they were able to recover. The term "stalled" is overloaded an awful lot in aviation, but I'm pretty sure in this case, it didn't refer to an aerodynamic stall of the tailplane. There's virtually no way it could be aerodynamically stalled at ~Mach 1 without ripping pieces off.
- mastazi 5y ago
  Yes you are right it was the stabilizer not the elevator. I knew that airliners have a stabilizer, but I wasn't familiar with how it functions since I've only ever studied in relation to small planes, thanks for adding some details. And yes I think it was a "stall" in quotes, not a stall ;-)

joshvm 5y ago

Also pushing the nose down is the first thing you're taught as a glider pilot for engery management: launch failures, stalls, spin recovery, etc. Flight Chops did a video on this - it's drilled into commercial pilots (as well as glider pilots), but not GA nearly as much Think it's this one: https://m.youtube.com/watch?reload=9&v=m_tKShlf_gU https://m.youtube.com/watch?reload=9&v=m_tKShlf_gU

throckmortra 5y ago
Wouldn't take advice from that guy https://www.avweb.com/news/pilot-arrested-after-airport-incident/ https://www.avweb.com/news/pilot-arrested-after-airport-inci...
mastazi 5y ago
> is the first thing you're taught as a glider pilot I love gliders, I grew up near a glider school, near Rome, Italy. I live in Australia now and it seems that glider culture is not as strong as in Europe. > it's drilled into commercial pilots Probably even more after Air France flight 447 > but not GA nearly as much Really? It was one of the first things I learned as I was studying towards the PPL (I haven't finished it yet because flying is expensive :-( but I'm done studying the theory). I'm in Australia BTW, not in USA - maybe things are different

doctor_eval 5y ago

Well, you’re trained to push the nose down in a stall because stalls normally happen at a very high AoA, when there is not enough airflow over the wings, typically when you’re pointing up, not when you’re in a dive, and certainly not when you’re in a Mach 1.01 dive. And this was an elevator stall. You’re not taught to pitch down when there is no elevator authority - in fact you wouldn’t be able to, by definition. But the problem here was too much airflow over the horizontal stabiliser - from what I can see, it hadn’t really stalled. Pitching down relieved the load and let them move the stabiliser. I suppose the combined deflection of the stabiliser and then the elevators was enough to get it under control again. I for one am always pretty impressed with stories like these because they show just how well the pilots understand their aircraft.

mastazi 5y ago
> But the problem here was too much airflow over the horizontal stabiliser Yes, after thinking about it, maybe they shouldn't have used the word "stall" because in this case it's a bit ambiguous

Syonyk 5y ago

I would assume they were talking about the stabilizer trim motor not being able to run the stabilizer trim because of the loads. > When he pulled back, the elevator was ineffective; it didn’t do anything, so he said, “Well, I’ll use the stabilizer,” and the stabilizer wouldn’t run. It stalled, because of the load. Key in there: "Wouldn't run." Almost all transport class aircraft have the same sort of trim setup on the tail - they have the movable elevator at the trailing edge, and then the entire horizontal stabilizer can tilt up/down for trim. This is a lot lower drag than having the elevator deflected, and gives you an extra control surface for emergency use as well - usually, the control authority of the entire moving stabilizer is more than the control authority of the elevator, so you can use that in an emergency for pitch. That the elevator wouldn't work effectively in the transsonic region was known - that's why they planned to use the whole moving stabilizer to pull out of the dive. Just, the air loads on it were too high with what limited authority the elevator still had, so they had to unload it again to run the trim, at which point they were able to recover. The term "stalled" is overloaded an awful lot in aviation, but I'm pretty sure in this case, it didn't refer to an aerodynamic stall of the tailplane. There's virtually no way it could be aerodynamically stalled at ~Mach 1 without ripping pieces off.

mastazi 5y ago
Yes you are right it was the stabilizer not the elevator. I knew that airliners have a stabilizer, but I wasn't familiar with how it functions since I've only ever studied in relation to small planes, thanks for adding some details. And yes I think it was a "stall" in quotes, not a stall ;-)