Total Runway Edge Light Disaster, [i]there[/i]

[3WE]

Quote=Bobieeee, there

https://www.flightglobal.com/safety/lan ... 21.article

Some runway lights did dieded.

This one bugs me...I ass-ume a competent pilot made a minor misjudgment.

Heavy rain, limited visibility and no centerline lights.

There, but for the grace of God (and the fact that I only TALK ABOUT IT), go I.

Would we have done a better job with control inputs? Or done a better job in determining that the landing was going south?

Sure, from the arm chair...

This one bugged me too- several procedures not_followed & go around SEEMS like a better choice, but what if spoilers had worked???

https://youtu.be/f9JGx6lROpY

Footnote: The BB razz and Evan black and white response was good, as expected...not sure I understood Gabieeee’s post. Hoping for a brief, but quality discussion, here.

[3WE]

3BS makes minor mistake with the controls while making an edit FROM THE ARM CHAIR, NO LESS!

[Gabriel]

Very hard to say without the view from the left seat. So I will withhold my judgement of the captain / PF this time but...
- The article makes it sound as if the captain realized of the lateral deviation before touchdown and tried to correct with rudder only, which changed the heading but not the flight path. That is exactly what is supposed to happen when you use rudder alone, so a pilot should not have the expectation of changing the flight direction using only rudder. But I don't know the real reason why the pilot used the rudder.
- Apparently the junior FO had a better awareness of the situation and said nothing due to cockpit gradient. That is a cultural issue that can be addressed (not necessarily easily).
- I disagree with your sarcastic comment that if it is going to end in an accident or incident, then go around, if not the go around is not necessary. That's not how risk management works at all, and it would be like saying "of you are going to crash wear a seat belt, if not it is not necessary". If the RISK of an incident or accident exceeds a certain threshold, then go around. It is hard to do an evaluation of the risk on the spot so the parameters are defined in atenacead. So if those parameters are exceeded, go around. Take the case of the Pakistan accident. If they had not left the gear up (or in fact retracted it after lowering it) most likely they would have gotten away with it, as most likely they did several times before. That doesn't make not going around any more acceptable.
- In this particular accident, whether the captain who was the pilot flying should have gone around depends on what information he had, which I don't know. But apparently the first officer did have a clearer picture and wanted to go around but was to shy to call for a go around. So the FO should have called "go around" and, if it works there as it does in most western airlines, the call for a go around by any flight crew member is executed, not judged, and analyzed later (unless of course the captain judges that it is unsafe to go around). So in the end, yes, they should have gone around.

[3WE]

... tried to correct with rudder only, which changed the heading but not the flight path. That is exactly what is supposed to happen when you use rudder alone, so a pilot should not have the expectation of changing the flight direction using only rudder...

Disconcur...ALL THE TALK THAT YOU HAVE MINIMAL BANK TO WORK WITH MEANS MOSTLY USE RUDDER...I get the inertia an no real lateral “lift” surfaces, but based on all the movies where many dudes actually slightly bank the wrong way (minor error) and all the talk of engine scrapes, etc.

No foul for a mostly rudder input...but apparently too little, too late.

- I disagree with your sarcastic comment that if it is going to end in an accident or incident, then go around, if not the go around is not necessary. That's not how risk management works at all,

Disagree all you want and admonish the stupid cowboy monkey pilots from your arm chair...my new mantra is that it’s easier said than done when you’ve made a bazillion perfect landings- INCLUDING SOME WHERE YOU HAD TO MAKE A LOT OF CONTROL INPUTS...the abort/go decision becomes VERY GRAY.

it would be like saying "of you are going to crash wear a seat belt, if not it is not necessary".

Yes, captain obvious, it is very analogous but it goes hand in hand with the concept of having completed a shit pot of landings, INCLUDING CHALLENGING ONES and NEVER (from the pilots frame of reference) pranging anything...I think there’s yet another way to express this- maybe you have heard it: “Hindsight is 20-20”.

Blah, Blah, Blah, go around

Great discussion that you wrote with a whole shitpot of hindsight...most notably that they ran over runway lights as opposed to a tiny bit more corrective rudder.

[Gabriel]

ALL THE TALK THAT YOU HAVE MINIMAL BANK TO WORK WITH MEANS MOSTLY USE RUDDER

Right. Because the only two options were to use rudder or dig a wing into the runway. False dilema.

apparently too little, too late.

Right, because a little more rudder a little earlier would have helped the plane turn like with no bank. Are you serious?

Disagree all you want and admonish the stupid cowboy monkey pilots from your arm chair...my new mantra is that it’s easier said than done when you’ve made a bazillion perfect landings- INCLUDING SOME WHERE YOU HAD TO MAKE A LOT OF CONTROL INPUTS...the abort/go decision becomes VERY GRAY.

Yes, THIS one MIGHT have been grey from the left seat. Have you noted me say basically that?

That doesn't mean that the landing should be judged only for the outcome. If you should have "clearly" gone around and you didn't and still got away with "a good landing" (like in 99.9% of the instances where pilots do that), it is NOT a good landing. Perhaps the result-oriented "good / perfect landing" definitions that we use (and that are supposed to be a joke) are making more damage than good.

Yes, captain obvious, it is very analogous but it goes hand in hand with the concept of having completed a shit pot of landings, INCLUDING CHALLENGING ONES and NEVER (from the pilots frame of reference) pranging anything...

Again, bad risk management. How many accidents occurred because of pilots decided to push a landing rather than to go around? You cannot take the pilot's frame of reference in isolation. You have to learn from the mistakes of the others because they are too many and too deadly to make them all yourself. 99.9% (i.e. one bad out of 1000) is a terrible "success rate" in aviation. Basically every airline pilot would be dead or about to die with that standard. In fact, it is not just the pilot but the whole industry who has to learn from the mistakes of others, and create policies, procedures (and systems too) to avoid that they happen again. The stabilized approach criteria is one of those.

Again, I don't know what picture the pilot flying had. So this case may not fall under that category for him. But apparently the FO had a more accurate picture and wanted to call the go around but was to shy (by his own admission). That means, almost by definition, the the FO HAD to call the go around and the PF HAD to execute it.

I think there’s yet another way to express this- maybe you have heard it: “Hindsight is 20-20”.

When you texted while driving during years and nothing bad happened yo you yet, and one day you miss clue or situation and end up under a truck that you didn't notice that was braking in time to avoid hitting it because you were distracted with non-critical multitasking, and I go and criticize you for driving while texting, you cannot rightfully come and reply "hindsight is 10-20, I did this hundreds of times and never had an accident before", because YOU KNOW that cellphone use (together with DUI) is one of the factors most frequently associated with accidents that happened to OTHERS.

Great discussion that you wrote with a whole shitpot of hindsight...most notably that they ran over runway lights as opposed to a tiny bit more corrective rudder.

Ok, I am quite bad at reading body language. Especially though text.
Are you frigging joking????

So, for the record, I never said any of that, rather what I am saying is that:
1) Rudder was obviously not effective to correct the trajectory of the flight, and it should not be expected be. Little less or little more and little later or little earlier doesn't matter. You don't turn airplanes with rudders simply because t doesn't work. It's an airplane, not a boat. Like a bike vs a go-cart, you know?
2) If (note the IF) the pilot applied rudder with the intention to deflect the direction of the flight, then we have couple of problems. First, see 1). Second, if (note another IF) in his mind a direction of the flight needed to be changed to achieve a safe landing (as opposed to just a "nice landing on the centerline") and the necessary amount of bank was not available due to proximity with the ground, THEN he should have GONE AROUND (not ADDED A LITTLE MORE OF RUDDER A LITTLE EARLIER)
3) If (another IF) the FO had a more clear picture that the plane was in a bad position to make a safe landing without hitting runway edge lights (as he apparently was), then he should have called a go around.
4) If (another IF) the FO called a go-around, then the PF has to go around and discuss later (if there is anything to discuss). But since the FO didn't call the go around this point does not apply to this case.

[flyboy2548m]

What?

[3WE]

What?

Some poor SOB took out some runway lights.

I’m sure you wouldn’t have, but I still feel bad for the pilot.

Hope that helps.

[3WE]

Gabriel:

I understand how rudders work.

It almost always requires some well coordinated aileron use.

I could be wrong, but I’m sure the pilot was working the stick too.

Again- since you have limited BANK because of engine scrape, adjusting your direction means a lot of rudder AND aileron to keep the wings “level”.

Indeed the plane skids a lot and you don’t get a great turn...and maybe there is a little bank.

Bottom line: I imagine the poor pilot here knows ALL this bank yaw skid dihedral stuff...

But I think the predominant effort and mindset is on the rudder. So he SAID the words “more rudder”.

But he probably did not “use rudder” ONLY, jus PREDOMINANTLY rudder and not enough of it.

[3WE]

Go around:

Yes, they should have...

But easy for you and me to say so.

[Gabriel]

Gabriel:

I understand how rudders work.

It almost always requires some well coordinated aileron use.

I could be wrong, but I’m sure the pilot was working the stick too.

Again- since you have limited BANK because of engine scrape, adjusting your direction means a lot of rudder AND aileron to keep the wings “level”.

Indeed the plane skids a lot and you don’t get a great turn...and maybe there is a little bank.

Bottom line: I imagine the poor pilot here knows ALL this bank yaw skid dihedral stuff...

But I think the predominant effort and mindset is on the rudder. So he SAID the words “more rudder”.

But he probably did not “use rudder” ONLY, jus PREDOMINANTLY rudder and not enough of it.

How much rudder would have been enough? Do you think that full rudder would have done much more than just changing the direction where you are looking (but not the direction where you are going)? (and that assuming that he would anti-coordinately use enough OPPOSITE aileron to avoid a severe yaw-induced bank, which in swept wings airplanes can be quite violent and at low speeds quite unarrestable with ailerons; does "crossover speed" ring a bell?)

[Gabriel]

Go around:

Yes, they should have...

But easy for you and me to say so.

The point is that it should have been easy for the Captain/PF to say so IF he was aware of the situation (which maybe he wasn't), and it SHOULD have been easy for the FO/PM to say given that by his own admission he was aware and wanted to go around but was too shy to call it.

[Gabriel]

Anyway, we had a couple of was a human factors triggered by weather factors and cockpit gradient and these kind of things can happen and that's why runways have safety zones around them and why the runway edge lights are frangible.

I am not too outraged by this incident and I would not sack any of these pilots just because of this or say that these pilot's don't belong there, as I did in other more outrageous cases (Air France and Colgan, for example).

More training for these two and more work on policies and culture for the airline could be in place though.

[3WE]

How much rudder would have been enough?

Given that he almost missed the lights; not too much- especially with a little bank...

Let me rephrase: Until you prove that the airline pilot had no phugoid clue about skidding and the interaction of bank, rudder and turn I CONTEND he just SAID “more rudder” AND WAS USING BOTH CONTROLS RATHER APPROPRIATELY, BUT NOT QUITE ENOUGH.

I doubt he was sitting there saying, let me stomp the pedals ONLY and be sure I have ZERO.zero degrees of bank.

Yes, I could be wrong...I’ll bet dibs on who goes first on Gabbiee’s 172 stall introduction.

[Gabriel]

How much rudder would have been enough?

Given that he almost missed the lights; not too much

I claim that he didn't apply enough volume to the radio. A little more more radio volume would have avoided hitting the lights because it was just a little more correction that was needed.

Yes, I did read the "especially with a little bank" part but the reality is that if he had used any bank that was enough to avoid the lights and not strike the wingtip or engine (if such a bank angle existed) then he would have avoided the lights regardless of whether the applied more or less rudder.

You keep talking as if rudders made planes turn so a little more rudder = a little more turn. That is not the case, hence my analogy with the radio volume.

[Gabriel]

Let's better wait for the final report.

Oh, wait a second, it is already out there.

The Commander applied several right roll inputs that led to a continuous right roll for approximately 8 seconds after the Aircraft crossed the threshold. The roll angle varied up to +4 degrees (right wing down). The sustained right roll angle led to an increase to the right in the Aircraft track and localizer, which resulted in the Aircraft deviating to the right of the runway centerline.

At about 15 feet AAL, the Commander realized that the Aircraft was on the right side of the runway.

The Commander progressively applied a left rudder pedal input of up to 2/3 full deflection. The left rudder pedal input led an increase in the drift angle from 1 to 8 degrees (Aircraft nose to the left of track). The Commander’s control inputs resulted in no significant change to the aircraft trajectory to cancel the lateral deviation.

On touchdown, the right main landing gear touched down first followed by the left main landing gear.
The Aircraft had 1 degree roll angle of right wing down, 8 degrees drift angle with the nose towards the left of track.

Causes
After crossing the threshold, the Aircraft drifted towards the right side of the runway due to a slight but continuous roll input to the right.

Contributing Factors to the Incident
(d) The several unintentional roll inputs to the right applied due to a subconscious action, since the pilot flying focused more on the Aircraft pitch attitude during the flare and the reduction in pilot flying situational awareness.
(e) Control inputs to re-align the Aircraft were not affirmative in that only incremental left rudder inputs were made without an associated left roll. A continuous increase in the Aircraft lateral deviation movement was a result of the ineffective flight control technique, and this was due to the existing high workload and the surprise effect of the unexpected Aircraft lateral deviation position such that the pilot flying overlooked the approved flight control technique before touchdown.
(f) The recovery action to take the Aircraft back to the centerline by applying right rudder input after touchdown, was relatively late due to the high workload. Initially the pilot flying applied an incorrect continuous left rudder input after touchdown.

It is clear than a little more of rudder input, that is a little more than 2/3 of full rudder deflection, would have fixed the situation. Not!

https://www.gcaa.gov.ae/en/ePublication ... Report.pdf

[3WE]

...
I claim that he didn't apply enough volume to the radio.
...
You keep talking as if rudders made planes turn
...

You have been spending way too much time with Evan and gone black and white.

The fuselage, winglets, engine nacelles will provide a small amount of “bite” to turn the direction of flight. Engine thrust will move the plane in the direction of the new heading...

It’s more than the radio volume...

Plus, the plane is going to WANT to bank into the turn.

For THIS incident, the dude did appear to bank right a bunch, and I will concede that as a primary factor- AND something that goes very STRONGLY against the rudder effects.

You also dismiss my contention that it wasn’t his knowledge the problem, but flying to allow the plane to bank right and struggle with visibility.

[Gabriel]

The fuselage, winglets, engine nacelles will provide a small amount of “bite” to turn the direction of flight.

Exactly.

Engine thrust will move the plane in the direction of the new heading...

The pilot retarded the throttles to idle at 20 ft and started applying rudder at 15 ft, AFTER the thrust was already to idle.
Idle thrust is still a thrust, which at 8 degrees of sideslip will give you a tiny component towards the interline, I give you that.
We can actually give a bound to that. Idle thrust is in the order of 2% of the airplane weight, sin (8 deg) is 0.14, so the lateral acceleration will be 0.0028g, that will bend your trajectory about 1/2 inch after the first second and 1 feet after 5 seconds.

It’s more than the radio volume...

Indeed, The torque reaction when you turn the volume knob is even smaller than the above.

Plus, the plane is going to WANT to bank into the turn.

Not in the A320. It won't roll unless you request roll with the sidestick, in the same way that it will "pull up" by itself and not drop the nose in the turn, unless you request so with the sidestick.

You also dismiss my contention that it wasn’t his knowledge the problem, but flying to allow the plane to bank right and struggle with visibility.

Oh, I agree with that. I simply don't understand what he intended to achieve when he increasingly deflected the rudder reaching 2/3 of full deflection. If it was to turn the plane's trajectory, it was a flawed expectation. And clearly it was not to de-crab.

[3WE]

The torque reaction when you turn the volume knob is...

ZERO

No decimal points cuz it’s ABSOLUTELY zero.

Please tell me you are trolling me!

The volume knob, pilot is a closed system within the aeroplanie.

The torque put into the radio results in counter torque through the pilots buttocks and sums to zero...

/Agronomic common sense and I can’t wait to
chem trail all of you with glysofate!

[Gabriel]

The torque reaction when you turn the volume knob is...

ZERO

No decimal points cuz it’s ABSOLUTELY zero.

Please tell me you are trolling me!

The volume knob, pilot is a closed system within the aeroplanie.

The torque put into the radio results in counter torque through the pilots buttocks and sums to zero...

/Agronomic common sense and I can’t wait to
chem trail all of you with glysofate!

Nope, not trolling you. Well, maybe I am, the knob volume thing is obviously a sarcastic joke because a volume knob is waaaaayyy too little to make any remotely measurable effect on an airplane, but your reasoning above is wrong.

I was writing a detailed Physics explanation involving the "angular impulse - variation of angular momentum" theorem. Let me know if you still wanted, but I thought that an example would be better.

Again, in this case, there is a super almost infinite massive difference of masses and moment of inertia between the knob and the rest of the airplane. But if the moments of inertia were more comparable, you would clearly see an effect.

Say that instead of an airplane you in space on board an EVA jet-pack, and you are holding a 18-wheeler's tire. Now turn the tire 1/4 of a turn. What will happen to you and your jet pack? Will turn in the opposite direction. Why? You can see it in 2 ways:

1) Two system: To start turning the tire you need to exert a torque on it, so the tire will exert an equal and opposite torque in the astronaut/jetpack system that will make it turn in the opposite direction. To stop the tire at the 1/4 turn mark, the opposite happens and both the tire and the astronaut/jetpack will stop turning. Both of them would have turned relative to the "fixed distant stars".

2) One system (tire+astronaut+jetpack all together): The system has zero angular momentum and there is no external torque applied on it, so the angular momentum is conserved (i.e. it will remain zero). When the tire starts turning in one direction, the rest of the system will start turning in the opposite direction because the angular momentum needs to remain zero. When the tire stops turning at the 1/4=turn mark, the rest of the system will stop turning too to keep the angular momentum at zero.

Another more real-life example. When you are in a car with a powerful engine and you press the gas in neutral to quickly rev-up the engine, you can see the car leaning to one side as a reaction. The only reason whey the car doesn't start turning in the opposite direction is because, by leaning, the springs of the shock absorber get more compressed on one side than on the other, which means that the wheels are pushing harder against the pavement on one side than on the other, which means that the pavement pushes on the wheels harder on one side that on the other, which is an external torque to the system. If the car was floating in space, when you rev up the engine the car would start spinning in the opposite direction. If you rev up the engine for 2 seconds and then return it to its original RPM, the car will stop spinning but it would have rotated from it original "bank" angle.

Again: The volume knob is like saying that when you jump both you and the Earth move away from their common center of mass. True, but ridiculously and undetectably small effect.