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-   -   Holding pattern and engine fire (https://www.pprune.org/tech-log/587269-holding-pattern-engine-fire.html)

Lantirn 21st Nov 2016 07:28

Holding pattern and engine fire
 
Assuming for the sake of conversation that you had an unnoticed serious fuel leak while you are on a standard holding pattern. Is there any real possibility of fire due to ingestion of own fuel in the engines? Any incident happened?

What about fuel dumping? I am flying the 320 so no fuel dumping. Are there other standard procedures for operators damping fuel other than entering a holding?

donpizmeov 21st Nov 2016 08:19

Fuel descends at 500 feet per minute. So in a hold, if you stay level you don't fly into your own dumped fuel.

Amadis of Gaul 21st Nov 2016 12:18

I don't think INGESTION would be an issue, but a leak somewhere in the pylon area that throws fuel onto some hot parts could cause a problem, I suppose. Of course, this is what managed NOT to happen to Air Transat...

I assume you're referring to fuel dUmping, not dAmping. I suppose you could descend, throw out some flaps, drop the gear. All that would increase fuel burn. I don't see why that's an issue, though, an overweight landing in an A320 is a relatively minor thing. The procedure is detailed in the QRH.

Lantirn 21st Nov 2016 12:47

Amadis of Gaul,

I meant ingestion and dumping you are correct, sorry for my bad English. I am correcting the initial post

I know what's in my QRH. :) My question was about fuel dumping procedures for aircrafts that are capable of. Are they allowed to dump fuel in a holding pattern? Or they have to fly other patterns like vectors from ATC.

Thank you

The question is done to ask for more opinions. It seems that some TRIs in my company love this, but I know it's :mad: stuff.

FE Hoppy 21st Nov 2016 12:54

In a previous life I often saw little chicks get a face full of Fuel. I was on the receiving end a few time too.

The most I ever saw was a very small rise in EGT for a very short time.

Don't lose any sleep over this.

lomapaseo 21st Nov 2016 13:14

extremely minimal risk to the engines to fly into dumped fuel. Mostly because it's dispersed over seconds in an airstream

A directed fuel leak is another story and if ingested directly into an engine core will cause the engine to surge/stall often emitting flames out the inlet. Military fighters with long inlets are spectacular in this case,

High-bypass engines on large jets are more likely to centrifuge the fuel out the bypass. Its a stretch of combinations but one is more likely to get into trouble sucking pooled fuel off a runway surface if going very slow.

MarkerInbound 21st Nov 2016 14:03

Some airports/ATCs have fuel dumping areas to send aircraft to if they are going to dump. And over here ATC will announce every 10 minutes or so "Fuel dumping in progress xx thousand feet at the ABC vor xxx radial xx DME."

CallmeJB 21st Nov 2016 22:33

Also you don't fly back through the same air parcels in a holding pattern unless there is zero wind, and that's rare.

Capt Quentin McHale 22nd Nov 2016 10:17

Lantirn,


Let's assume you are just above stall speed. Even at that speed there is no way that a fuel leak (assuming your leak is external to the engine) is going to make it's way forward against said airspeed airflow and be ingested by the engine. The fuel will be blown aft and atomised by the airflow and by the time you have completed a full holding pattern 360 the atomised fuel will have descended and evaporated.


With an undercowl fuel leak I doubt very much that even with undercowl airloads forcing the fuel forward it will not be ingested by the engine due to the inlet cowl to engine core bulkhead preventing it.

RAT 5 23rd Nov 2016 14:54

It's never been tested; I doubt, but Reverse Thrust might induce an interesting reaction. And I'm not volunteering. One would hope it WAS noticed and isolated.

Lantirn 23rd Nov 2016 16:24

It is supposed to be prohibited on ground when there is a leak!

RAT 5 23rd Nov 2016 19:43

It is supposed to be prohibited on ground when there is a leak!

Like I said, "if it was noticed." Human muscle responses are very difficult to resist. Very often in the sim, SE landings, I see the average pilots trying to pull both reversers.

Lantirn 23rd Nov 2016 19:56

Been there done that. On my first flights after line training my instructor told me non standard not to select reversers in a flight. He told me like 3 times during the approach.

Was very funny at the end, and never done it in the sim, it worked like charm.

schooner 24th Nov 2016 12:16

Well on the minibus at least, the average pilot is correct. The recommendation is to select reverse thrust on both engines if at least one reverser is operative, assuming no fuel leak.

lomapaseo 24th Nov 2016 13:02


Well on the minibus at least, the average pilot is correct. The recommendation is to select reverse thrust on both engines if at least one reverser is operative, assuming no fuel leak.
23rd Nov 2016 15:56
Why so?

If you have even a known reverser inoperative aren't you going to have steering issues?

I seem to recall a very high rate of runway excursion issues on the bus as well as other planes when some reversers were locked out if only because pilots were not experienced in this operation differing from everyday rote.

schooner 24th Nov 2016 13:22

At the risk of sounding flippant, because the FCTM and MEL say so!

I imagine it's to cater for mis-selection of the wrong reverser if one is out. The guidance says select both for RTO and landing.

RAT 5 24th Nov 2016 16:08

At the risk of sounding flippant, because the FCTM and MEL say so!
I imagine it's to cater for mis-selection of the wrong reverser if one is out. The guidance says select both for RTO and landing.


I'm always curious about these instructions by a manufacturer. This scenario is not a special technical difference to the type. It is a case of airmanship and judgement. I can not see what it has to do with an Airbus v Boeing v another type. If that is the case then I can not see the authority with which a single manufacturer makes that an FCTM issue.
If someone can enlighten me with sound reasoning I am open to discussion.
What I have seen, in the sim, is a pilot, in an already non-normal situation, who is a little nervous, try to select both reversers and become confused and concentrate on the blocked reverser and not focus 100% on completing what up till then was a successful landing.
IMHO, if in doubt, it is less risky to rely on TR's and just use auto brakes of size 11's.

gusting_45 24th Nov 2016 16:18

Did fuel dumping during post maintenance air tests, we allways flew orbits to check for the fuel trail and always flew a gentle climb to stay clear of ingestion area.

Yaw String 24th Nov 2016 17:01

Lantirn ,
2 minute legs in standard racetrack holding pattern.Minimum altitude 4000' but now in UK at least,FL100. Advise ATC,not near oil rigs,thunderstorms etc..

ShotOne 23rd Dec 2016 16:43

Regarding problems such as fire due to ingesting own fuel in a holding pattern I haven't heard of this happening ever in the history of aviation.

But somehow it seems to be a favourite of training departments and comes up (too) often as a sim discussion item


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