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I think I may like to see a cite for that. I have no doubt there was a wheels-up warning (among, undoubtedly, many others).
It's noteworthy that the envelope protection kept the aircraft from stalling several times. Something Sullenberger knew the flight software could and would do while operating in Airbus Normal Law. In other words, he knew his aircraft to the nth degree. The proof of that, to my mind, has always been that he immediately powered up the APU. Not a checklist item at that stage, just a professional going with gut and instinct. 100% he right decision: APU running = aircraft has multiple electricity sources = aircraft is certain to remain in Normal Law.
lol then go look for it. the AAR is still online - ever read one? I make it a hobby. Fascinating detail.
Didnt say he got a wheels up warning, i said that being wheels up the software limited what he was able to do. IIRC pay attn to sections 1.16 and 1.17. The airbus software analyzes a lot of stuff and determines what the allowable trims and attitudes are. Sully himself said he wanted flaps 2 rather than flaps 3 as this would allow a higher nose attitude. But he complained in more than one post crash interview that his actions on the side stick were being ignored and indeed, the post crash simulation of the aircraft based on the recorded parameters show that the software was preventing the nose up condition he wanted. at 100ft and less - as he put it to minimize the effect the engines would have hitting the water. every knot, is a couple tons less stress on the airframe.
It took the FAA 14 years after that accident to finally issue an Advisory regarding bird strike testing, and they still have not added the requirement for a test with birds of the size that took down Flight 1549. They dance around that test with analysis and hand waving, because the engine manufacturers know they can't build an engine that will survive the ingestion of large Canada Geese.
But they at least changed the test so that the ingestions are done at lower fan speeds such as are encountered during approach. These can be more damaging because the bird has more opportunity to enter the engine core, causing stall or turbine damage. At redline speed where they used to run the test, the bird is sliced/diced and slung to the OD of the fan thus more easily avoiding the core intake. But this is not what happens in the real world, even during takeoff and climb the engine is not running at redline speed.
Here is the new Advisory Circular. Still not a regulation, it is "optional".
Didnt say he got a wheels up warning, i said that being wheels up the software limited what he was able to do. IIRC pay attn to sections 1.16 and 1.17. The airbus software analyzes a lot of stuff and determines what the allowable trims and attitudes are. Sully himself said he wanted flaps 2 rather than flaps 3 as this would allow a higher nose attitude. But he complained in more than one post crash interview that his actions on the side stick were being ignored and indeed, the post crash simulation of the aircraft based on the recorded parameters show that the software was preventing the nose up condition he wanted. at 100ft and less - as he put it to minimize the effect the engines would have hitting the water. every knot, is a couple tons less stress on the airframe.
Interesting, that's the one I read too. There's a bit in section 2.7.2 about envelope protection kicking in - "The flight envelope protections allowed the captain to pull full aft on the sidestick without the risk of stalling the airplane." Not finding anything regarding gear-up configuration changing the behavior. Meh.
They dance around that test with analysis and hand waving, because the engine manufacturers know they can't build an engine that will survive the ingestion of large Canada Geese.
But they at least changed the test so that the ingestions are done at lower fan speeds such as are encountered during approach. These can be more damaging because the bird has more opportunity to enter the engine core, causing stall or turbine damage. At redline speed where they used to run the test, the bird is sliced/diced and slung to the OD of the fan thus more easily avoiding the core intake. But this is not what happens in the real world, even during takeoff and climb the engine is not running at redline speed.
Here is the new Advisory Circular. Still not a regulation, it is "optional".
That's interesting - never realized the low-speed/high-speed angle, but it makes sense once laid out like that. Intuitively, you'd expect high-speed to be the harder case. Learned something today.
Interesting, that's the one I read too. There's a bit in section 2.7.2 about envelope protection kicking in - "The flight envelope protections allowed the captain to pull full aft on the sidestick without the risk of stalling the airplane." Not finding anything regarding gear-up configuration changing the behavior. Meh.
because gear down, and <100ft it assumes its a normal landing and the flareout can be more pronounced when in the ground effects - far less risk of a stall. I dunno if there is an airbus 'ditch switch' that tells it all bets are off.
because gear down, and <100ft it assumes its a normal landing and the flareout can be more pronounced when in the ground effects - far less risk of a stall. I dunno if there is an airbus 'ditch switch' that tells it all bets are off.
Location: We_tside PNW (Columbia Gorge) / CO / SA TX / Thailand
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I'm sure Airbus has pitch protection to avoid tail drag, which is what Sully thought would benefit the initial touchdown, to slow velocity prior to engine contact and that abrupt drag / impact on airframe. Good idea that he had the foresight to consider the risk of breaking up on impact. The result would have been very different if the wings had separated due to drag of engines (attached to wings), and momentum, weight, and inertia of fuselage.
Good illustration / learning for airframe design requirements. It all held together. / Do not open rear exit in water landing, use overwing and forward exits.
Definitely a 'miracle' of things that went right, rather than wrong. Much thanks to a seasoned and experienced pilot. I credit several 'pilot saves' to the rigor and exposure of military trained and experienced pilots. The ex-military pilots I know had plenty of emergency 'saves' as a course of normal operations. Not something you expect (or desire) to get in commercial flights. Cargo, charter, or scheduled.
its in there but not in as much detail as on airline pilot websites. I know a coupla 'bus drivers that said their respective airlines used this as a training update...
Good illustration / learning for airframe design requirements. It all held together. / Do not open rear exit in water landing, use overwing and forward exits.
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and you forgot: dont hit birds!
for a number of years I lived across the river from stewart (SWF) near newburgh NY. since it is military the land surrounding it is cordoned off and is sort of a no mans land. They would lottery off permits each year for select few local hunters (using shotgun only) to blow the bejeezus out of the deer and goose population lest a C5 (at the time) catch one - the GE TF39/CF6s can literally vacuum a 200lb buck (or ground crew) right off the pavement at full go.
The ANG kids would do touch and go's all afternoon including practicing for unsecured LZ use- it would be a spectacular crash...
Given the wetlands, Im actually surprised JFK does not kill birds all day. LGA is mostly gulls.
Location: We_tside PNW (Columbia Gorge) / CO / SA TX / Thailand
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Quote:
Originally Posted by RetireinPA
and you forgot: dont hit birds!
... They would lottery off permits each year for select few local hunters (using shotgun only) ...
Yes, we have participated in local airport bird culling (goose).
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