B717 split-S
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B717 split-S
Does anyone have any backstory to the infamous B717 split-S video? Was it a test flight, was it intentional, etc?
Joined: Jul 2013
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From: Everett, WA
I can't imagine doing that on purpose.
Educated guess - they were doing stall testing, and it got away from them. Although I don't know why they'd being doing low speed stall testing in a turn.
There is something we call a wind-up turn that's done to test the engine inlets at high AOA - basically set the test engine at high power, and start pulling a turn tighter until the aircraft stalls and falls out of the turn (holding altitude constant). But that appears to me to be a low speed stall, not a constant speed stall (which is what is done in a wind-up turn).
Educated guess - they were doing stall testing, and it got away from them. Although I don't know why they'd being doing low speed stall testing in a turn.
There is something we call a wind-up turn that's done to test the engine inlets at high AOA - basically set the test engine at high power, and start pulling a turn tighter until the aircraft stalls and falls out of the turn (holding altitude constant). But that appears to me to be a low speed stall, not a constant speed stall (which is what is done in a wind-up turn).
Joined: Apr 2004
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From: Planet Earth
Difficult to tell if they exceeded barber pole from that fuzzy picture
If I remember correctly there were several flight test personnel in the cabin, I can’t imagine they enjoyed that too much
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From: Aus
They were stalling the aircraft purposely with side slip in an attempt to determine the reason for unusual stall characteristics that came up during test, rolling off on a wing, this was the first 717 built, production aircraft didn't have the problem, cause of the roll was never determined
Previous post on the subject here,
Inverted 717...not a Sim
Previous post on the subject here,
Inverted 717...not a Sim
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From: Seat 1A
Originally Posted by Stilton
Difficult to tell if they exceeded barber pole from that fuzzy picture
Joined: Dec 2013
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From: US
[QUOTE=stilton;11757062]Difficult to tell if they exceeded barber pole from that fuzzy picture
If I remember correctly there were several flight test personnel in the cabin, I can’t imagine they enjoyed that too much[
I am having a hard time understanding why he held positive G’s while 15 degrees nose low inverted. Can’t quite read airspeed ect and he may have had no pitch authority but an unload followed by a roll to the nearest horizon would seem to be in order.
If I remember correctly there were several flight test personnel in the cabin, I can’t imagine they enjoyed that too much[
I am having a hard time understanding why he held positive G’s while 15 degrees nose low inverted. Can’t quite read airspeed ect and he may have had no pitch authority but an unload followed by a roll to the nearest horizon would seem to be in order.
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From: USA
Unless you're doing it every day, the moment you get upside down, your brain tends to turn into mush and just do what is instinctive. I.e., apply the (what is normally the) "oh **** make the airplane go up" control, i.e., aft elevator, regardless of which way was was actually up. Note also, how he said "easy roll to the horizon" which was to the left, but went right instead.
All this on top of the fact that it was trimmed for +1 G at near stall speed, which will naturally give a few positive G's past the barber pole.
All this on top of the fact that it was trimmed for +1 G at near stall speed, which will naturally give a few positive G's past the barber pole.
