Delta emergency @ LAX, dumps fuel on school playground.
Join Date: Jun 2001
Location: Rockytop, Tennessee, USA
Posts: 5,898
Likes: 0
Received 1 Like
on
1 Post
FWIW as a very rough ballpark/back of the envelope figure you can work on dumping at 2 tonnes a minute (it’s a different rate Centre tank vs. Wings but 2/min will do as a first approximation)..
Now all we need is to continue the Monday A.M quarterbacking is the Take off weight and the Zero Fuel Weight.....
Now all we need is to continue the Monday A.M quarterbacking is the Take off weight and the Zero Fuel Weight.....
An old B-772 FCOM gives these numbers in pounds:
One Or More Tank Quantity Indications Blank:
Determine jettison time using the following rates:
• Fuel in center tank: 5400 lbs./minute
• Center tank empty: 3100 lbs./minute
Determine jettison time using the following rates:
• Fuel in center tank: 5400 lbs./minute
• Center tank empty: 3100 lbs./minute
Join Date: Oct 2003
Location: Wadi Al Khoud
Posts: 41
Likes: 0
Received 0 Likes
on
0 Posts
This a bit of the bad habits pilots "learn" in the simulator and bring back to the line:
-We tend to rush things in the sim and any malfunction after take-off is a "come back and land" without much thinking involved.
In this scenario, time was never critical, time was never and issue, they could have gained some altitude, go over the water and hold somewhere, run all the abnormal checklist they needed, talk to operation, brief the cabin thoroughly, decide to dump or not to dump fuel and then land somewhere.
on top of that, I am always surprised why as professional we don't use the proper phraseology to declare an emergency and get everybody's attention.
-We tend to rush things in the sim and any malfunction after take-off is a "come back and land" without much thinking involved.
In this scenario, time was never critical, time was never and issue, they could have gained some altitude, go over the water and hold somewhere, run all the abnormal checklist they needed, talk to operation, brief the cabin thoroughly, decide to dump or not to dump fuel and then land somewhere.
on top of that, I am always surprised why as professional we don't use the proper phraseology to declare an emergency and get everybody's attention.
Join Date: Aug 2006
Location: norway
Posts: 71
Likes: 0
Received 0 Likes
on
0 Posts
Dave Reid said..." It's not immediately obvious what relevance that accident has to the Delta incident."
Now why on earth would you write something as supercilious as that?
Now why on earth would you write something as supercilious as that?
Join Date: Sep 2008
Location: Been around the block
Posts: 629
Likes: 0
Received 0 Likes
on
0 Posts
I assure you that most “deltoids” are capable of dividing by 2.2. I’ve got Boeing weights memorized in pounds and kilos. I’ll say this again, but if more than half the aircraft in the world are US registered, maybe pounds should be the standardized unit of weight in aviation. Sorry that QFE didn’t catch on, along with meters per second.
Join Date: Aug 2007
Location: Alabama
Age: 58
Posts: 366
Likes: 0
Received 0 Likes
on
0 Posts
I assure you that most “deltoids” are capable of dividing by 2.2. I’ve got Boeing weights memorized in pounds and kilos. I’ll say this again, but if more than half the aircraft in the world are US registered, maybe pounds should be the standardized unit of weight in aviation. Sorry that QFE didn’t catch on, along with meters per second.
Join Date: Jun 2001
Location: Rockytop, Tennessee, USA
Posts: 5,898
Likes: 0
Received 1 Like
on
1 Post
Join Date: Sep 2008
Location: Been around the block
Posts: 629
Likes: 0
Received 0 Likes
on
0 Posts
Unless a greater emergency occurred which prevented them either landing safely overweight or discontinuing the approach then this should not have happened. If you can accelerate to V1 and stop on a runway then you can land overweight on it. Ideally if you have time you go and dump fuel over the sea or above 10000ft, which also gives you time to plan a single engine approach. If you must land immediately then you can safely do so having actioned the overweight landing checklist which determines flap setting to ensure adequate go-around performance. If you land overweight then it requires an overweight maintenance check but as the aircraft had a faulty engine then not going to cause any delays to getting it back in service!
Spending more time problem solving rather than rushing into an approach would have prevented this (unless getting on the ground immediately was imperative).
The min height to jettison fuel to ensure it evaporates before hitting the ground is 7000ft in winter and 4000ft in summer.
Spending more time problem solving rather than rushing into an approach would have prevented this (unless getting on the ground immediately was imperative).
The min height to jettison fuel to ensure it evaporates before hitting the ground is 7000ft in winter and 4000ft in summer.
And I would put money on the fact that there was no issue that required immediate low level dumping.
All the evidence points to a crew that rushed into an approach and dumped at an inappropriately low level. Unless they had evidence of an impending problem with the remaining engine there was no need to hurry.
Rather like the Iran shoot down, if it looks like a duck, walks like a duck and quacks like a duck it probably is a duck.
LD
All the evidence points to a crew that rushed into an approach and dumped at an inappropriately low level. Unless they had evidence of an impending problem with the remaining engine there was no need to hurry.
Rather like the Iran shoot down, if it looks like a duck, walks like a duck and quacks like a duck it probably is a duck.
LD
Join Date: Mar 2007
Location: USofA
Posts: 1,235
Likes: 0
Received 0 Likes
on
0 Posts
Agree with the simulator assessment, but the way to works is there is just so much time to get all the "required
maneuvers" completed in the allotted time and in this case an immediate return was pre-ordained into the process.
maneuvers" completed in the allotted time and in this case an immediate return was pre-ordained into the process.
Join Date: Apr 2015
Location: Under the radar, over the rainbow
Posts: 788
Likes: 0
Received 0 Likes
on
0 Posts
Ex Non-pilot aircrew here.
I have experienced compressor stalls on B727 climb outs after which our erstwhile flight engineer would explain this away as being attributed to the fuselage creating a shadow during high angle climb outs. It certainly felt like we launching a rocket at times from some short fields and this was then sometimes followed by a 'boom boom' in quick succession.Indications on the flight deck always found No 2 was the culprit.
But what causes a compressor to stall on a T7? Is it a function of heavy TO weight and high alpha on climb out and if so, would not both engines suffer in that case? Or is it related to steep climbing turns where the engine turning in might suffer some airflow shadow affect?
I have experienced compressor stalls on B727 climb outs after which our erstwhile flight engineer would explain this away as being attributed to the fuselage creating a shadow during high angle climb outs. It certainly felt like we launching a rocket at times from some short fields and this was then sometimes followed by a 'boom boom' in quick succession.Indications on the flight deck always found No 2 was the culprit.
But what causes a compressor to stall on a T7? Is it a function of heavy TO weight and high alpha on climb out and if so, would not both engines suffer in that case? Or is it related to steep climbing turns where the engine turning in might suffer some airflow shadow affect?
). Inlet separation at high angles of attack used to be a big issue resulting an a surge or stall, particularly with Pratt engines. But those days are pretty much behind us.Now days, inlet and engine designed has improved to the point that an engine surge is nearly always the result of some sort of engine or engine control problem or fault.
I don't know if this Delta crew had any reason to suspect fuel contamination as a potential cause, but if they did that would a good reason to want to land ASAP.
Join Date: Jul 2011
Location: Planet Earth
Posts: 29
Likes: 0
Received 0 Likes
on
0 Posts
The center engine on the 727 was rather notorious for surging/stalling (the only time I've ever experienced a surge on a commercial flight was on a 727 during takeoff). It was the combination of the center "S" duct and an engine (JT8D) that wasn't very tolerant to inlet distortion. It didn't take much to make that "S" duct inlet separate, and once it did the JT8D would almost invariably surge. The good news was that the JT8D was a robust engine and a surge would seldom do damage. It used to be that Pratt engines surged all the time (the JT9D was at least as bad as the JT8D), but it rarely did damage, while GE engines almost never surged, but if it did it, you had to throw it away and install a new one (insert GE light-bulb joke here ). Inlet separation at high angles of attack used to be a big issue resulting an a surge or stall, particularly with Pratt engines. But those days are pretty much behind us.
Now days, inlet and engine designed has improved to the point that an engine surge is nearly always the result of some sort of engine or engine control problem or fault.
I don't know if this Delta crew had any reason to suspect fuel contamination as a potential cause, but if they did that would a good reason to want to land ASAP.
). Inlet separation at high angles of attack used to be a big issue resulting an a surge or stall, particularly with Pratt engines. But those days are pretty much behind us.Now days, inlet and engine designed has improved to the point that an engine surge is nearly always the result of some sort of engine or engine control problem or fault.
I don't know if this Delta crew had any reason to suspect fuel contamination as a potential cause, but if they did that would a good reason to want to land ASAP.
Join Date: Apr 2015
Location: Under the radar, over the rainbow
Posts: 788
Likes: 0
Received 0 Likes
on
0 Posts
Join Date: Jul 2009
Location: Asia
Age: 62
Posts: 131
Likes: 0
Received 0 Likes
on
0 Posts
but if there was no need in the pilots mind at that time hence a circuit to the east and the surprise to us all on the ground when the fuel dumped after they turned back from the east of the field ?
Seems like by now the pilots have been debriefed and the Feds at least must know what really happened in the cockpit
Seems like by now the pilots have been debriefed and the Feds at least must know what really happened in the cockpit
Join Date: Dec 1998
Location: UK
Posts: 289
Likes: 0
Received 0 Likes
on
0 Posts
Anyone know how many pax? Could then work out roughly how heavy they were and how much dumping would have been needed to get below MLW.
Out of interest, did they shut the engine down or leave it running at lower thrust setting that was surge and stall free?
An approach speed of 157 (Vref 152) is only just above MLW for F20. Doesn’t seem right if they had 95T of fuel - they must have been empty for that to tie up.
Out of interest, did they shut the engine down or leave it running at lower thrust setting that was surge and stall free?
An approach speed of 157 (Vref 152) is only just above MLW for F20. Doesn’t seem right if they had 95T of fuel - they must have been empty for that to tie up.
Last edited by Propellerhead; 17th Jan 2020 at 06:09.
If I might sound a note of realism here....
The only people who actually know what was going on were those on the flight deck yet we have 160 posts pontificating...
The only people who actually know what was going on were those on the flight deck yet we have 160 posts pontificating...
