Sully could have made it back to Laguardia

[Phil Bunch]

See this article for the ultimate in hindsight.

http://online.wsj.com/article/SB10001424052748703612804575222482042335978.html?mod=WSJ_hps_MIDDLEForthNews#printMode

Excerpt:
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Documents indicate nearly two dozen emergency simulations were flown by experienced aviators, including an Airbus test pilot, at the manufacturer's headquarters in Toulouse, France. Four out of four attempts to return to the closest La Guardia runway were successful, according to the safety board's summary. There were nine additional simulated attempts to land at La Guardia, either at different runways or under a scenario in which the plane was more severely disabled. Of those, three were successful.

But only those pilots who immediately decided to turn back toward La Guardia after the simulated engine problems made it. The board's document concludes that such a scenario fails to "reflect or account for real-world considerations such as the time delay" in recognizing the bird strike and to "decide on a course of action."

Still, the simulations have sparked some consternation and controversy among investigators, since they were completed almost a year ago, industry and government officials say. Early on, Airbus officials were so squeamish about potentially being seen as second-guessing the heroic actions of the pilots, according to people familiar with the details, that they broached the idea with the safety board of keeping the results private.

The data eventually made it into the board's public file and has since been mentioned in passing in at least one book about the accident. Nonetheless, both Airbus and safety board officials privately acknowledge they are still playing down the results, primarily to avoid the image of minimizing, in any way, the accomplishments of the crew of US Air Flight 1549.

Now retired, the silver-haired captain became a national icon for saving all of the 155 people aboard. Praised at the White House and during network television interviews, Mr. Sullenberger's reputation as a homespun hero continued to grow. He snared a six-figure book contract, served as the grand marshal of the Rose Parade and became a sought-after fixture on the national speaking circuit. Just last week, the crew of Flight 1549 was honored by the National Air And Space Museum in Washington.

Spokesmen for Airbus and the safety board declined to comment. While a senior federal investigator said the simulations "were an important part" of the probe, other government and industry experts said the issue is likely to get a relatively brief mention at Tuesday's public hearing.

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As best I can follow the transcripts, he concluded at the time that he couldn't make it to Laguardia or any other nearby airport.

Should Sully have figured out that it was safe and reasonable to fly back to Laguardia?

[Hardy Heinlin]

At pilot school (small aircraft) I've been taught to never ever return to the runway in case of an engine failure after take-off. Lots of accidents happened before because pilots have tried to return and then stalled because the turn took too much height and distance, i.e. better land straight ahead on a field or street at a stable speed and pitch than doing turns near the stall speed.

I don't know what airliners think about that rule in general, -- on the other hand: an aircraft is an aircraft.

...

Aside from that, in the simulator the dose of adrenaline is a bit lower than it is in real life.


Cheers,

|-|ardy

[Will]

I think the excerpt says it best: if no time passed at all between Sully's bird strike and the time that he initiated a turn back to the airport, the simulations showed that he could have made it back.  But a few seconds elapsed as the crew was evaluating the situation, attempting corrective action, and ultimately deciding where to land; and by then, the airport was no longer an option.  It's hard to turn this into retrospective advice for Sully, much less a rule for others to follow.  

Just because this airplane, in this instance, could have made it back to the airport doesn't mean that they should have tried.  Based on the animations that were posted here in the past, I find it very hard to find fault with his decision-making.  (Turning back is also very risky... There were other aircraft using the runways, for example.)

An opposite case was the Sioux City Iowa crash (United 232), when the DC-10 lost all the hydraulics and yet managed to land without a total loss, using nothing but differential power.  If I recall correctly, no pilots in the sim were able to land without a total loss.

And another accident with a divergent sim outcome: American 191, which lost an engine after takeoff out of O'Hare.  I heard that the loss of the engine distorted the wing and caused uncommanded slat retraction (since hydraulic fluid was lost).  The crew was trained to pitch to fly V2, which they did, but when they got to V2 they lost control because the altered geometry of the wing had actually increased V2 above the computed value.  In the sim, if pilots maintained their present airspeed, the plane remained controllable.  That actually led to a change in operations, because you could generalize the rule to other circumstances.

[Hardy Heinlin]

Just because this airplane, in this instance, could have made it back to the airport doesn't mean that they should have tried.

Exactly. What they did in the simulator was a test. At the time when they started the test they didnt know if they would make it to the runway. In this moment they didn't know more than Sully knew. So, the risk was the same.

However, a crash in the simulator isn't deadly. That's the difference.

The journalist should have asked the simulator test pilots if they would do the same test in a real aircraft with passengers on board.

OK, now one could say the test was not supposed to degrade Sully's decision; the purpose was just to develop a new generalized emergency procedure. But is that possible at all? How would that new procedure look like? "If you are at xx ft, at xx knots, at xxx intercept heading, at xxx yyy zzz ... then return to the runway". -- Something like that? What would be new then?


Cheers,

|-|ardy

[Jeroen Hoppenbrouwers]

... build it into the compu^H^H^H^Haircraft ... so it can decide what it can do and what not. And then a few years later, let the AP capture command when it knows that it can make it, but the pilot has no time to allow it to make it ... scary.

[Hardy Heinlin]

Or ask if a hair-dresser is on board :-)

[Jeroen Hoppenbrouwers]

Joking about computers ...

Would the fact that this particular type of aircraft has all kinds of stall protection software in the control loop make it less dangerous to do steep turns near stall speed? If the software takes the danger out, it may get some miles extra, reliably.

Not to say that this would take any danger out of returning into active runways, or simply not making it anyway, so heading for the Hudson still was an excellent decision.


Jeroen

[Avi]

Doesn't the term "could have" is wonderful?
You put pilots on a simulator, where the only thing that can prevent them from going back home in one piece is a car accident or something like that, they know exactly what is going to happen, they know exactly – in advance – what they are going to do, and then if everything works well, they say that the pilot on the real thing "could have".

I remember the same thing happened after the El-Al 747F disaster in Amsterdam in 92. Some pilots succeeded to land in a simulator, although I don't know how accurate the damage to the structure of the wing was simulated, and then they said that the pilots "could have" land if...

[Jeroen Hoppenbrouwers]

There is sense in "could have" but not as it is usually deployed. If you think future incident then the knowledge that in certain circumstances such a malfunction is survivable certainly will ease pilot's minds a bit... and they may have a clue what not to do (such as extending flaps).


Jeroen

[Will]

I think it's great that Airbus ran the simulations, but I absolutely understand their reluctance to release the results.  The public will get confused about generalizable "could have's" and non-generalizable "could have's."  Sully turning back was the latter; he could have made it, but it's unlikely that this was knowable at the time, and unlikely that knowing it now would translate into useful knowledge for future flights.

[Jeroen Hoppenbrouwers]

Maybe it would be nicer if we could publish "could have NOT" statements instead of "could have". Like, simming to Teterboro...