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-   -   single engine immediate return, large jet transports (https://www.pprune.org/tech-log/301102-single-engine-immediate-return-large-jet-transports.html)

fourgolds 19th Nov 2007 19:32

single engine immediate return, large jet transports
 
OK esteemed colleauges lets open this one up for a debate , and believe me there are going to be mixed feelings.

OK so I take off in my "big jet" the engine fails and I choose to return. I am very heavy and landing at this weight will cause melting of fuse plugs etc. So I decide to jettison down to a weight where this will not happen. However ATC tell me that the jettison area is 50 nm away from the airport. So my choices are
Land overweight at the nearest suitable airport in terms ot time and blow out a few tyres OR leave the airport enviroment to go and jettison ( for a long time )to ensure so the landing will not dammage any tyres.

If you land immediately and blow tyres , the arm chair warriors will say you should have jettisoned
However if you go and fly away to a remote area to jettison and the remaining engine fails , the arm chair warriors will have even more to say.

So to quote Keeanu Reeves in " Speed" , WHAT WOULD YOU DO ?

fourgolds 19th Nov 2007 19:36

Sorry folks
Wrong thread , was meant for tech log not terms and endearment. I am getting a little old.

fantom 19th Nov 2007 19:38

Easy: you land.

No_Speed_Restriction 19th Nov 2007 19:41

Planning to "land at the nearest suitable airport" doesnt always/usually mean fly away (50 nms) from a "suitable airport" you have just departed from.

Rainboe 19th Nov 2007 19:55

Foul! Unreal problem! Is it not accepted that you can always land back at the runway you took off from? It is within your performance. Twin, one out, land as soon as possible. you do not fly away.

Kit d'Rection KG 19th Nov 2007 20:02

For Fark's sake, just reassure me that the originator of this 'esteemed and worthwhile' thread doesn't turn left when he enters the aircraft, will you? :yuk:



vt. Person who tosses. :cool:

Pugilistic Animus 19th Nov 2007 20:29

Well, what if you have to fly to a TO alternate? you're not going to try below minimums approaches?
Operators in the US with certain equipment requirements met may now apply for RVR 3 TO minima as part of OpSpecs approval to certain suitably equipped airports this will put you below Cat II or IIIa approach minima

In the US that may be some uncomfortable waiting, for two-engined airplanes that can be up to an hour and that is for still air and normal cruise speed---if under the FAR 121 or 135

Kit d'Rection KG 19th Nov 2007 20:33

Very boring...

All accounted for by statistical analysis; that is: very unlikely to happen, thus acceptable.

Shiny side down 19th Nov 2007 22:03

If it's a dire, get on the ground asap, then surely the tyres are secondary, presuming a safe landing can be made in the space available? Lets face it, you might be wanting to evacuate once you land anyway.

If it's a situation under control, you can set things up to accommodate the conditions? Including weight.

On the B738, for what it's worth, we can't jettison. So if we depart at max takeoff mass, an overweight landing is the option otherwise, there's almost 13 tonnes to burn down on the B738, or 11.5 once you have executed the take off, emergency turn and handled the problem. Which means Hours of burning fuel. So it's a landing overweight decision, with available field performance in mind.

Short_Circuit 19th Nov 2007 22:17

It has happened.

I saw the aftermath of a 747 that SD 3 of 4 engines on rotate due to seagull strike.

It had no choice but to return ASAP as the last remaining engine was shaking violently.

The landing was successful. I doubt they would go limping around dumping fuel with that last donk about to expire.
:eek:

Admiral346 19th Nov 2007 23:54

Fourgolds, what are you talking about? Have you seen the rates at wich you can dump?

If you are only a few tons over your MLW, why dump? Put it down gently, not exceeding 360fpm, and there will be no problem! Not with braking, no fuse plugs blown.

If you are far over MLW, it will take you at least 30 mins to dump anyways (the A340 does around 1t/min, I tried it out) to get to an acceptable landing weight. If you have that time to spare, your problem can't be to pressing anyways.
If your Problem is so severe you need to go back immediatly, blow those tyres on overheated brakes, as long as they hold up during the landing... max brake temp is reached after about 15-20 min after brake application...
You will be a hero, and noone will ask questions about a few tyres...

Nic

Ok, I overlooked the problem of the twin - but if you are flying a large twin, aren't you ETOPS approved, able to count on that other engine? Or are you suspecting contaminated fuel as a cause for eng fail, and that is why you have to return? Hey, then take it back, as Rainbow wrote, if you can take off on it, you can land on it. Blow those tyres after heat dissipation from the brakes to the rims to the tyres (it will happen while you are stopped), and you are safe. You will have solved the problem.

lomapaseo 20th Nov 2007 00:17


It has happened.

I saw the aftermath of a 747 that SD 3 of 4 engines on rotate due to seagull strike.

It had no choice but to return ASAP as the last remaining engine was shaking violently.
The last time I saw such a confirmed report was in the early 70's, QF out of Sydney. Of course if this is just a postulation, carry on.

zerozero 20th Nov 2007 00:36

The crux of the matter.
 
This small point has been missed in the larger discussion:


Originally Posted by fourgolds
If you land immediately and blow tyres , the arm chair warriors will say you should have jettisoned
However if you go and fly away to a remote area to jettison and the remaining engine fails , the arm chair warriors will have even more to say.

Assuming it's safe to dump, you should dump.

But I wouldn't rule out dumping on the infintessimal chance that the remaining engine *might* fail.

As for Monday morning quarterbacks: to hell with them.

:ok:

Intruder 20th Nov 2007 02:10

If you have the time to dump fuel, you have the time to fly 50 km or 50 miles to do it. If the time to fly 50 miles and back exceeds the time to dump, then just land -- or fly in circles for a few minutes before you land.

bflyer 20th Nov 2007 04:00

go back...set it gently on the runway...accept brakes overheating and tire loss...better be on the ground wishing you took the time to dump ful than beign in the air wishing to have made an overweight landing

gas-chamber 20th Nov 2007 04:11

Does it not depend a bit on the severity of the engine failure? There are failures - as in dud FCU's etc - and then there are catastrophic failures with blades being chucked through windows, fire warnings, fuel pissing everywhere etc etc.
A benign failure is no reason to rush back home. The odds of a second engine failing on the same flight are very very remote - or at least ETOPS tells us so ! As for the nasty ones, minima and limitations can go to buggery - this old (and in the past bold) Captain will dump the airplane on the nearest runway where he reckons he can get it stopped. If it is really severe - like uncontained fire - the only checklists I would run would be the immediate recall items and the engine inoperative landing ; and in really dire situations even the latter would be actioned from memory if time was running out. All the other stuff would have to wait for the next simulator ride when the armchair experts in mahogany row called for my remedial training.

cribble 20th Nov 2007 05:16

The important thing is to be there for the court of enquiry. If you are in severe straits this probably means land overweight.
What if you need an autoland, and your jet is not certified for an overweight autoland?
See sentence 1, above, IMHO.

Short_Circuit 20th Nov 2007 05:24

Lomapaseo
You got it, 747-200 JT9D’s
somewhere in the 70’s:ok:

fourgolds 20th Nov 2007 05:39

Thanks ladies and gents. Kinda my sentiment and it would depend on the day. Lets put it like this. ( maybe I should write stories)

You take off from say Birmingham( short runway) in your big jet. The engine fails. Mr Boeing says if you take off from it you can land on it. OK so this time the rwy is contaminated ( standing water). Your stopping distance at the highest possible take off weight for the conditions is only giving you a fewhundred metres spare.( you will have to fly just like the test pilots). Its not in question if you have had a fire ( it will bring the test pilot skills out in you). However if it has just flamed out , what about the possibility of flying down the road to say MAN and jettison enroute ( if its allowed) reducing your weight slightly before you arrive and have a longer runway as well. You might argue that the time it took to get there was required to ensure the safest operation and that Manchester was more suitable from a performance point of view. Therefore you did land at the nearest suitable airport.

Bearing in mind too that if you were to check the actuall figures by opening the manuals in flight. This would no doubt also take a few minutes to check ( perhaps those same valuable minutes you could use whilst enroute to Manchester).

or do we not approach this with so much detail and simply land on it because we took off on it ? if there are any incident investigation types out there , how about your take on it. It would be interesting to see what the regulators might think.

PS. taildraggers still rule.

Capn Bloggs 20th Nov 2007 10:45

If there's no fire, I'd be inclined to head on down the road to a longer runway. No point in stacking things up against you by doing a limit landing on a contaminated runway ie not "suitable". The other one's supposed to run for a (at least short) while so it should carry you to MAN OK.


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