Fuel Dumped at Low Height over Los Angeles

[Evan]

Ok Gabriel, what about this one?

https://www.bbc.com/news/world-us-canada-51112630

Fuel dumped, obviously at too low of an altitude, yet still deemed necessary? Nothing yet on why. So what's going on here?

- Cannot climb to dump fuel?
- Dumping fuel during immediate return?
- Crew not aware of the minimum safe altitude for fuel jettison?
- Crew not aware that they can safely land overweight?

Certainly, if what you have been saying is true, the potential for some costly inspection and damage to the airplane is outweighed by the outrage of raining jet fuel on a bunch of school children.

[sjwk]

Looks like it was at about 2,400ft when it was roughly over the school, assuming that's when it was dumping.



More info to locate the school from here: https://www.nbcnews.com/news/us-news...round-n1115586

Delta Flight 89 to Shanghai experienced an engine issue that required it to return to LAX shortly after takeoff, the company confirmed in a statement.

"The aircraft landed safely after an emergency fuel release to reduce landing weight," the airline said.

Delta did not comment on where exactly the fuel was dumped.

[xspeedy]

They couldn’t fly level and get to the ocean to dump?

[TeeVee]

given what avherald is reporting about the incident, it is clear that there was NO emergency and dumping fuel was to avoid an overweight landing which simply costs $$$.

so, thank you delta for once again proving how little you care about people where your profits are concerned.

[Gabriel]

Ok Gabriel, what about this one?

https://www.bbc.com/news/world-us-canada-51112630

Fuel dumped, obviously at too low of an altitude, yet still deemed necessary? Nothing yet on why. So what's going on here?

- Cannot climb to dump fuel?
- Dumping fuel during immediate return?
- Crew not aware of the minimum safe altitude for fuel jettison?
- Crew not aware that they can safely land overweight?

Certainly, if what you have been saying is true, the potential for some costly inspection and damage to the airplane is outweighed by the outrage of raining jet fuel on a bunch of school children.

Unless there is something else that we don't know that would justify this, this is in my opinion unacceptable.
Any airplane is able to land on the runway it just took off with the weight it just took off. This plane landed in a runway that was 2000+ ft longer than the one they had taken off, they climbed to 8000ft before starting to return and they were over the ocean when they started to return. If you want to delay your return to dump fuel in an acceptable way, I am ok with that. If you want to return right away and land overweight instead of damping fuel, I am ok with that. Dumping fuel at 2000 ft over a populated area? I am NOT ok with that UNLESS there is a real need to do so, which doesn't seem to be the case here.

[klax_spotting]

Unless there is something else that we don't know that would justify this, this is in my opinion unacceptable.
Any airplane is able to land on the runway it just took off with the weight it just took off. This plane landed in a runway that was 2000+ ft longer than the one they had taken off, they climbed to 8000ft before starting to return and they were over the ocean when they started to return. If you want to delay your return to dump fuel in an acceptable way, I am ok with that. If you want to return right away and land overweight instead of damping fuel, I am ok with that. Dumping fuel at 2000 ft over a populated area? I am NOT ok with that UNLESS there is a real need to do so, which doesn't seem to be the case here.

Not quite sure the assertion that any plane can land with the weight it just took off is correct. Yes, it could land, but no guarantee that the aircraft won't overrun or sustain damage to the brakes and tires, starting a fire, and endangering the lives of those onboard.

[Evan]

I haven't seen a vertical profile but perhaps they had initiated the fuel dump above 6000ft and then neglected to terminate it while descending below that altitude. The reports show a non-critical engine surge situation on an ETOPS 330 aircraft, so I would think they would either choose to dump while holding over the Pacific or choose an immediate return without dumping fuel (Gabriel's preferred mandate). The report also states that there was no request or advisement with ATC regarding fuel jettison. Bad bad bad.

I think what we've got here is a failure to communicate...

[Gabriel]

Not quite sure the assertion that any plane can land with the weight it just took off is correct. Yes, it could land, but no guarantee that the aircraft won't overrun or sustain damage to the brakes and tires, starting a fire, and endangering the lives of those onboard.

I said the weight AND THE RUNWAY it just took off. Remember that runway was long enough to accelerate to V1 and then stop, Now you can approach with full flaps and have the whole length of the runway to stop.And this particular flight landed in a runway 2000 ft longer than the RWY it took off, almost 13000ft long at sea level in winter (i.e. the opposite of high and hot).

[klax_spotting]

I said the weight AND THE RUNWAY it just took off. Remember that runway was long enough to accelerate to V1 and then stop, Now you can approach with full flaps and have the whole length of the runway to stop.And this particular flight landed in a runway 2000 ft longer than the RWY it took off, almost 13000ft long at sea level in winter (i.e. the opposite of high and hot).

Even so, V1 is slower than approach speed of a full 772, and RTOs still risk hot brakes and fires.

[3WE]

Even so, V1 is slower than approach speed of a full 772, and RTOs still risk hot brakes and fires.

If RTO's risk hot brakes and fires, should we even be taking off?

It's an interesting question- with a good long runway, can you burn off enough speed with spoilers and reverse to keep from truly overheating the brakes.

[TeeVee]

hot brakes and fires are why the hose guys follow the plane down the runway. bottom line, based on the available facts, there was NO emergency so there was NO need to dump fuel. but some bean counter did some quick maths and decided it was cheaper to dump fuel than pay for the overweight check. or maybe, there's a pilot or two that need an ass whoopin...

[flashcrash]

They couldn’t fly level and get to the ocean to dump?

Seems they told ATC they didn't need to dump:

Pilot: "We've got it back under control. We're going to come back to LAX. We're not critical. We're going to slow to 280 knots, and uh, why don't you point us downwind at 8,000 feet (unintelligible) and we'll turn back to LA."
Tower: "OK, so you don't need to hold or dump fuel or anything like that?"
Pilot: "Uh, negative.

https://www.cnn.com/2020/01/15/us/de...day/index.html

[Gabriel]

Even so, V1 is slower than approach speed of a full 772, and RTOs still risk hot brakes and fires.

V1 with a takeoff-ish flaps setting is not that much slower than touchdown speed with full flaps.
But then, the plane will not touch down as far down down the runway as it was when it achieved V1 during the take off.t On the contrary, it will touch down in the first 1000 to 1500 ft of the runway, where during the take-off the plane was nowhere remotely close to V1. This means that the plane will have A LOT more runway to stop from the touchdown speed than what it would have had to stop from V1.

Then, what 3WE and TeeVee said: If you cannot accept the risk of hot brakes, flat tires due to fuse plugs, and possible tire fire as a result of a heavy braking, you should not attempt to take-off in the first place. When you come back to land overweight you will have the emergency services waiting for you next to the RWY and following you. They will be with you literally within seconds of you stopping. If any wheel fire develops at this point it will be put out in seconds, compared with minutes if you abort the take-off next to V1 when there is nobody expecting it. By certification standard, the plane must safely withstand wheel fire during 5 minutes. The plane is typically not even evacuated in case of wheel fire.

Finally, ok , you want to dump fuel to avoid the overweight landing, risk of hot brakes and wheel fire, etc????
No problem!!! You are already at 8000 ft over the ocean. Stay there, dump all the fuel you want, and then come back to land.

But dumping fuel at 2000 ft over a populated area is a big no-no unless it is a life-or-death situation, which we have no indication that it was (rather the opposite).

[Gabriel]

If RTO's risk hot brakes and fires, should we even be taking off?

It's an interesting question- with a good long runway, can you burn off enough speed with spoilers and reverse to keep from truly overheating the brakes.

Of course you can do the landing performance calculation to see how much margin you have.
If you don't have a really comfortable margin, or if you didn't do the landing calculation and want to be on the safe side, the good strategy is to apply max brakes (together with spoilers and reverses) until stopping on the runway is clearly assured, then release the brakes and continue with reverse and spoilers and use brakes only as necessary.

Doing the opposite (trying to bleed speed with spoilers and reverse first and ten, when you are slower, apply brakes) has 2 problems: 1) If you misjudge when you finally decide to apply brakes it can be too late to stop on the runway and 2) it is more effective to brake quickly with you are going fast than when you are going slow. For example, say that you touch down at 160 kts. If you loose 80 knots quickly (from 160 to 80) and then slowly (from 80 to 0), the stopping distance will be MUCH shorter than if you first loose speed slowly (from 160 to 80) and then quickly (from 80 to 0).

[Gabriel]

https://www.cnn.com/2020/01/15/us/de...day/index.html[/I]

There are maximum takeoff and landing weights for aircraft, so for a plane with full fuel tanks to land, it must dump the fuel to avoid potentially crashing upon landing, said CNN aviation safety analyst David Soucie.

I almost vomited when I read that.