Southwest Airlines Nose Gear Collapse at LGA

[Evan]

No wonder. That's what idling the engines does for sure in airplanes with engines well under the CG.

On the other hand, that's what happens in every flare, so to what extent this was a contributing factor is an open question at most.

I mean abruptly to idle rather than smoothly. If they were coming in long they might have flared high and yanked the thrust to idle. I expect Southwest SOP is to bring the engines smoothly to idle to avoid the stronger pitch-down issue. Just wondering if this may have been a factor leading to overcontrol.

[Joe H]

I mean abruptly to idle rather than smoothly. If they were coming in long they might have flared high and yanked the thrust to idle. I expect Southwest SOP is to bring the engines smoothly to idle to avoid the stronger pitch-down issue. Just wondering if this may have been a factor leading to overcontrol.

It was simply the Muppet show.....
We NEED to stop making excuses for these dumbos. Sack them and lock them up, or preferably lethal injections or old sparky - preferably drop them from a large height onto solid concrete.
Then recruit piots with an IQ in double digits who can fit into the seat comfortably.... (that rules out 78.6% !!)

[Gabriel]

I mean abruptly to idle rather than smoothly. If they were coming in long they might have flared high and yanked the thrust to idle. I expect Southwest SOP is to bring the engines smoothly to idle to avoid the stronger pitch-down issue. Just wondering if this may have been a factor leading to overcontrol.

I don't think it would make a big difference.
I'd say that the "smooth" idling takes less that 2 seconds, as opposed to the "abrupt" which is practically instantaneous. But these high-bypass engines make most of the thrust with the fan and have a spool-down lag.

I'd like to hear what our airline pilot buddies think about it.

Perhaps (and this goes beyond speculation and into creative imagination) if they added a good bunch of thrust, compensated the pitch-up tendency with a push in the column, and then idled them without compensating... I really don't think that this was a factor, but I am trying to make something of your theory.

[3WE]

It was simply the Muppet show.....
We NEED to stop making excuses for these dumbos. Sack them and lock them up, or preferably lethal injections or old sparky - preferably drop them from a large height onto solid concrete.
Then recruit piots with an IQ in double digits who can fit into the seat comfortably.... (that rules out 78.6% !!)

I asked if you had ever mis judged parking in a parking spot.

Your reply was that planes are different than cars.

That's correct, except that it's the exact same piece of equipment behind the wheel of both.

[BoeingBobby]

It was simply the Muppet show.....
We NEED to stop making excuses for these dumbos. Sack them and lock them up, or preferably lethal injections or old sparky - preferably drop them from a large height onto solid concrete.
Then recruit piots with an IQ in double digits who can fit into the seat comfortably.... (that rules out 78.6% !!)

Comments like this are why you will not get many responses from airline crews. Listen to what Gabriel is saying, though he is a light airplane pilot, he is just about as spot on as you can be!

[snydersnapshots]

I mean abruptly to idle rather than smoothly. If they were coming in long they might have flared high and yanked the thrust to idle. I expect Southwest SOP is to bring the engines smoothly to idle to avoid the stronger pitch-down issue. Just wondering if this may have been a factor leading to overcontrol.

While that is a good question, I doubt the pitch change due to an abrupt power change would be enough to cause this. I haven't heard what the experience level the crew had, after a few landings you get used to the pitch change and it becomes second nature to correct for it.

[snydersnapshots]

It was simply the Muppet show.....
We NEED to stop making excuses for these dumbos. Sack them and lock them up, or preferably lethal injections or old sparky - preferably drop them from a large height onto solid concrete.
Then recruit piots with an IQ in double digits who can fit into the seat comfortably.... (that rules out 78.6% !!)

I generally try to cut people slack on here and keep my arguments logical, informative, and to the point. I don't like to get personal and I think Gabriel and some of the others on here will attest to that. That being said, it's taking a lot of effort on my part to keep this post civil.

I don't know if you're trolling for a reaction, are uninformed, or are expecting more from pilots (who make mistakes just like every other human being in the world). I've been flying for over 34 years and have 20,000 plus hours, a large percentage of that in the very aircraft type we're talking about, and I take personal offense at your comment. It's taking all the willpower I have NOT to tell you to go do something with yourself that is physically impossible.

I guarantee you that the guys flying that airplane did not leave the house with the intention of landing on the nosewheel, wrecking the airplane, and injuring passengers. The vast majority of us take great pride in our work and try our best to do the job right. We try to get our passengers to their destination safely, comfortably, and on time. That being said, we ARE human beings and thus, make mistakes occasionally. And when we do make mistakes, be they large or small, we are usually harder on ourselves than others are.

As for this crew, I'm sure they are off flying status right now, very possibly without pay. They're being investigated by the airline, the NTSB, and the FAA. If it is proven that their negligence lead to the accident, they will probably be violated by the FAA to the tune of many thousands of dollars. They will be subject to re-training under the microscope of both the company and the FAA. It's possible that the FAA may suspend or even revoke their pilot certificates.

So I ask you. When was the last time you made a mistake in a car? Have you ever been in an accident? When was the last time you made a mistake at your job that could potentially cost you your career? How about the penalties for the mistakes you made? Should you be dropped from a great height on your head? Or given the electric chair?

I realize airline pilots are--as we should be--held to a higher standard, and I don't disagree with the penalties involved for the guys in this accident if it turns out they're warranted. These guys aren't idiots. They're professionals with thousands of hours and hundreds of uneventful landings in the 737. On top of that, we don't even know for sure they were at fault--that information will come out when the final NTSB report is released. Don't be executing them til the final verdict is in! I don't object to speculation, discussion, and honest debate, in fact I enjoy it. But until you can land a 737 (or any other airplane for that matter) with the same proficiency as I, or Boeing Bobby, or the guys in this accident, or any of the thousands of other pilots flying out there at this moment, I ask you to keep your outrageous and inflammatory comments to yourself.

[Gabriel]

Snyder,

Let me steer you away from this NVA discussion.
Maybe you can help me with my curiosity. I a previous post I've asked:

Just out of curiosity, how much does the Vref (or Vapp) diminishes with flaps 40 vs flaps 30 in the 37? My guess is that you can count the knots with the fingers of one hand, and maybe you still have a finger or two to spare.

And since you " 've been flying for over 34 years and have 20,000 plus hours, a large percentage of that in the very aircraft type we're talking about"...

[Evan]

While that is a good question, I doubt the pitch change due to an abrupt power change would be enough to cause this. I haven't heard what the experience level the crew had, after a few landings you get used to the pitch change and it becomes second nature to correct for it.

Thanks. I'm aware that pilots need to apply back-pressure for the thrust reduction pitch moment. Actually what I was referring to was not the pitch moment from normal thrust reduction but rather the more pronounced pitch moment from abrupt thrust reduction possibly being an exacerbating factor contributing to overcontrol and, I understand it, overcontrol is often the cause of such accidents.

I pulled this from the 1999 Boeing 737NG FCTM that I have on file (underlines are mine):

After the flare is initiated, smoothly retard the thrust levers to idle and make small pitch attitude adjustments to maintain the desired descent rate to the runway. Ideally, main gear touchdown should occur simultaneously with thrust levers reaching idle. A smooth thrust reduction to idle also assists in controlling the natural nose-down pitch change associated with thrust reduction.

So I'm speculating that in an attempt to get down in the landing zone thrust was abruptly reduced and that might have added to a slight overcontrol to correct for an early flare resulting in the -3° pitch down.

Or is the pitch moment not significantly different in this scenario (I assume it is if Boeing feels the need to mention it)?

[Gabriel]

Let me put it in this way:
As you might know, I have like 3 unofficial hours of 737 simulator, and I am not talking of MSFS but the real big iron 6DoF level D full flight simulator.

I don't remember how many landings I did in those three hours, maybe 4 or 5. In ALL of them I started the flare and retarded the thrust in one smooth but decided movement (less than 2 seconds probably).

I don't remember even noticing a change in pitch moment due to this thrust reduction. And I did land on the main legs on all the occasions. And that's with a background not of 20000hs with a large proportion in the 737, but 180hs in the plane in my avatar (my experience in the 37 was so low -zero, in fact- that I couldn't adjust the seat and it took me 15 minutes to figure out how to release the parking brakes!)

Not that that pitching moment didn't exist, but there are so many factors involved in the pitching moment and control forces and inputs at this time that it was absolutely masked.

You've probably seen some YouTube video of some hand-flown approach in a perfect day with little wind or turbulence. If so, you probably saw the column being moved fore and aft in what looks like a crazy way and what the pilots call "modulating" control inputs.

And that's during the stabilized portion of the approach. Add to that the flare itself (that as 3WE said is not one straightforward maneuver but rather a succession of trials and errors until you hit the ground), the decaying speed that generates a nose-down pitching moment, the increasing ground effect that generates another nose-down pitching moment, a bit of turbulence and variation in the wind speed/direction, and suddenly the control input needed to counteract the effect of the thrust reduction from the underslung engines becomes, let's not say negligible, but almost indistinguishable among all the control column movement that is already going on there.

And let's face it: It's not like you are shutting down the engine straight from TOGA. The approach thrust is not very high (well below 50% of TOGA thrust), and flight idle is not so close to zero thrust either, and that in a 737 that must be the airplane where the engines have the shortest moment arm among the airplanes with underslung engines (a heritage from the non-bypass, full turbojet era that so much headache caused and still causes in Boeing as they try to implement engines with ever-increasing fan diameter).

All this to say, I don't think that this factor was much of a factor in this accident, be the thrust reduction smooth or abrupt.

Let's see what the real big-iron pilots think about it.

[TeeVee]

I generally try to cut people slack on here and keep my arguments logical, informative, and to the point. I don't like to get personal and I think Gabriel and some of the others on here will attest to that. That being said, it's taking a lot of effort on my part to keep this post civil.

I don't know if you're trolling for a reaction, are uninformed, or are expecting more from pilots (who make mistakes just like every other human being in the world). I've been flying for over 34 years and have 20,000 plus hours, a large percentage of that in the very aircraft type we're talking about, and I take personal offense at your comment. It's taking all the willpower I have NOT to tell you to go do something with yourself that is physically impossible.

I guarantee you that the guys flying that airplane did not leave the house with the intention of landing on the nosewheel, wrecking the airplane, and injuring passengers. The vast majority of us take great pride in our work and try our best to do the job right. We try to get our passengers to their destination safely, comfortably, and on time. That being said, we ARE human beings and thus, make mistakes occasionally. And when we do make mistakes, be they large or small, we are usually harder on ourselves than others are.

As for this crew, I'm sure they are off flying status right now, very possibly without pay. They're being investigated by the airline, the NTSB, and the FAA. If it is proven that their negligence lead to the accident, they will probably be violated by the FAA to the tune of many thousands of dollars. They will be subject to re-training under the microscope of both the company and the FAA. It's possible that the FAA may suspend or even revoke their pilot certificates.

So I ask you. When was the last time you made a mistake in a car? Have you ever been in an accident? When was the last time you made a mistake at your job that could potentially cost you your career? How about the penalties for the mistakes you made? Should you be dropped from a great height on your head? Or given the electric chair?

I realize airline pilots are--as we should be--held to a higher standard, and I don't disagree with the penalties involved for the guys in this accident if it turns out they're warranted. These guys aren't idiots. They're professionals with thousands of hours and hundreds of uneventful landings in the 737. On top of that, we don't even know for sure they were at fault--that information will come out when the final NTSB report is released. Don't be executing them til the final verdict is in! I don't object to speculation, discussion, and honest debate, in fact I enjoy it. But until you can land a 737 (or any other airplane for that matter) with the same proficiency as I, or Boeing Bobby, or the guys in this accident, or any of the thousands of other pilots flying out there at this moment, I ask you to keep your outrageous and inflammatory comments to yourself.

Hint: forum "ignore" function...

[snydersnapshots]

Snyder,

Let me steer you away from this NVA discussion.
Maybe you can help me with my curiosity. I a previous post I've asked:



And since you " 've been flying for over 34 years and have 20,000 plus hours, a large percentage of that in the very aircraft type we're talking about"...

Gabriel... Scratching my head over "NVA".... last time I read that acronym it meant "North Vietnamese Army", though your usage is probably very obvious if I ponder it long enough.

You are correct--the speed difference between flaps 30 and 40 is in the neighborhood of 5 knots give or take depending on the weight.

[snydersnapshots]

Hint: forum "ignore" function...

Yeah...You're right. Usually I don't let them get under my skin, but I read this after a long day and minimum sleep and I guess I had a short fuse this afternoon...

[Joe H]

As for this crew, I'm sure they are off flying status right now, very possibly without pay. They're being investigated by the airline, the NTSB, and the FAA. If it is proven that their negligence lead to the accident, they will probably be violated by the FAA to the tune of many thousands of dollars. They will be subject to re-training under the microscope of both the company and the FAA. It's possible that the FAA may suspend or even revoke their pilot certificates.

so, they may be fined a few grand, wow !. or, gosh, lose their jobs ....what if they had killed people ?
Why not fine the airlines a billion or 2, or 10, or shut them down completely, that might cause changes to the lax training and recertification and poor safety culture.

The asiana fiasco brought volatile comments from 'some' of these amazingly high houred people ... however, when it's one of your own, you close ranks...

Well done, you ARE a product of that system. I am sure a lot of the regional pilots thought South Korea was when their job prospects looked bad...

ps, I wouldnt really want them to be 'killed by the state'... (Yanks often have no sense of irony or humour) - just sacked and made to work menial, low paid, boring, repetative jobs needing minimal intelligence .... ooops.. that might not work as they would have been sacked in the first place from that...

[3WE]

Way to have absolutely no acknowledgement whatsoever of valid points made by other posters.

Please carry on with your one sided omnipotent dismissive judgement from your keyboard which is not traveling at 135 knots hauling 150 people, because that is so easy to do.