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fourgolds
19th Nov 2007, 19:32
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
This small point has been missed in the larger discussion:

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.

Rainboe
20th Nov 2007, 10:59
I think there are some dodgy decisions coming up here! Read your checklist! 'Land at nearest suitable airfield' is there for a reason. A twin on one and heavy- you are thrashing your remaining engine. Any runway you took off from, you can land on. If, for some reason, you can't, then you go to the next nearest. I would not be happy to blithely set off to a runway 50 miles away on one engine. Not that many aeroplanes have jettison systems anyway, and they are indeed slow. Far more important to get people back on the ground, overweight as required.

gatbusdriver
20th Nov 2007, 11:25
land
land
land

we have had this (or similar) discussion a few times this year, after the onur air, thomson, nationwide

it is simple, follow your QRH (or ECAM) Land at Nearest Suitable means just that.

Intruder
20th Nov 2007, 12:19
Don't forget that a "simple" engine failure may be for a "simple" but "global" reason -- fuel contamination! What may start out as benign may become catastrophic...

411A
20th Nov 2007, 12:25
Without getting into specifics, except to say that I don't fly a twin (perish the thought), some here might find this just a tad odd...

on the one hand So if we depart at max takeoff mass

whereas, later it is an overweight landing is the option otherwise,

Oh dear, the Europeans do have their knickers in a twist with takeoff mass and overweight landings.
Perhaps being on the same page of music would be helpful....:rolleyes:

As a side note, SV years ago had a problem with a brand new Saudi captain wherein he decided to steam around over the old RUH airport for one hour ten minutes so as to consume as much fuel as possibe after finding that his number two engine failed on rotation in his 737...weather CAVOK.
The respective fleet manager was not totally amused...:rolleyes:

Shiny side down
20th Nov 2007, 12:37
411A
I'm sure you mean well. And I'm all ears (or eyes) to learn something.

But do you have a view on the initial question, or simply wish to nit-pick the language used in the responses?

is this the right thread for discussing mass/weight, or can we all presume that for the purposes of the discussion at hand(original question), they refer to the same thing?

red rag dangling!

tristar 500
20th Nov 2007, 14:13
The worst incident I have come across was a SAA B733 on T/O from JNB enroute for LHR. Bird ingested in to #2 a fan blade exited via the intake & was swollowed by #1, I spoke to the crew later who said "we landed quickly"!!!!

Tristar 500

Ashling
21st Nov 2007, 17:22
Boeing recently published an excellant article on overweight landings in aero magazine. Its in 3rd quarter for this year. Its available online. Well worth a read.

In summary it says it should present no great problems. Certainly if you are in a twin its clearcut, lose 1 engine and you land ASAP. Overweight if necessary. ETOPS or no it doesn't matter, do not expose yourself your crew and your pax to more risk than necessary. This is justified as any degradation to the other engine will compromise safety of flight so you do not want to delay unecessarily before landing and dumping fuel would be an unecessary delay.

In a tri or 4jet then its a different story as losing 1 engine may not place you in a situation were the loss of a further engine would compromise safety of flight so there is more judgement involved. E.G. BA continueing trans atlantic on 3 engines having lost one on departure.

Anyway thats my take on things. Do read the article thoguh as its written by those much more knowledgable than me and has all the technical and legal detail involved.

zerozero
23rd Nov 2007, 01:10
Certainly if you are in a twin its clearcut, lose 1 engine and you land ASAP. Overweight if necessary. ETOPS or no it doesn't matter, do not expose yourself your crew and your pax to more risk than necessary.

Everyone is entitled to their opinion--and I've certainly never qualified on a heavy twin jet--but I'm wondering then, what's the point of installing a fuel dump system on a twin engine jet if not to dump down to landing weight?

I read that same Boeing article and I agree, it's very good. But I don't take that as carte blanc to perform overweight landings. If there's a system and a procedure surely it's meant to be used, no?

:cool:

Spooky 2
23rd Nov 2007, 01:38
Boeing has any number of models that have takeoff weights well in excess of their landing weight, but the aircraft are not provisioned with fuel dump systems. Many of the early 767-200ER's did not have any dump capability, yet had MLW many thousands of punds in excess of the MTOW, so I guess Boeing felt pretty comfortable with this concept.

Rainboe
23rd Nov 2007, 10:02
zerozero,
But I don't take that as carte blanc to perform overweight landings.
What is carte blanche to perform an overweight landing is having a planeload of people depending for their lives on one engine. In larger airline ops, we just don't do that. The instruction is 'land at the nearest suitable runway'. you can add to that 'without delay' in brackets. Just remember you are thrashing that remaining engine

As an example- one of my colleagues was flying down to Madrid. Over northern Spain, he shut one down approaching top of descent. In view of his position at TOD, he elected to continue to MAD. Unfortunately he was over 'a suitable airport' (something beginning with 'V'). He was chewed out for it- he should have gone for the airport he was over. Another example- 767 out of Glasgow loses an engine- continues to Manchester. Another black mark in the record.

The problem is some people refuse to acknowledge the danger of a twin with one out, just as others don't recognise the safety built in to a 4 engine jet with one out. I would quite happily have flown the 747 from LAX to LHR with one out (I have flown a 747 from the Newfoundland coast to Chicago like that), but were I to lose one in my current 737, that thing would be on the ground so quick the cabin crew would still be serving coffee!

Ashling
23rd Nov 2007, 12:20
zerozero, Rainboe is quite correct.

I agree with you its not carte blanche to land overweight whenever and whatever the circumstances.

However there are situations that present an immediate threat to the safety of flight and an engine failure on a twin is one of them. Others might be fire/smoke, single electric or hydraulic source or multiple unrelated failures you judge to be a threat to safety of flight. A severe medical emergency is also justification to land overweight. In any engine fail scenario while you may suspect you have no real idea why your engine failed and while it is unlikely the other engine is also compromised it is possable (fuel contam, birds, sabotage/terrorism, FOD). If it was to fail then thats probably it for all on board so while you do not need to rush to the extent that doing so presents a hazard it is clearly prudent to land as expeditiously as you can. That may be several hours if your over the Pacific but only as little as 20 mins if you've just got airborne. Just because your ETOPS does not mean you are allowed to stooge around on 1 engine for 3 hours if you could have landed in 20 mins.

Clearly if the wether is poor the decision may be more complex but the maxim "if you can get airborne from it you can land on it" is true.

I believe Boeings article in Aero magazine was designed to demistify the whole overweight landing thing so that when this very scenario presents itself the correct decisions are made.

misd-agin
23rd Nov 2007, 14:54
zerozero (http://www.pprune.org/forums/member.php?u=34186)
Over 250 posts so far. Perhaps I should click here (http://www.pprune.org/ptorder/ptorder.htm) and order a Personal Title

Join Date: Jun 2001
Location: Anchorage, Alaska, USA
Posts: 323


So what's the point of the dump system?
Quote:
Originally Posted by Ashling
Certainly if you are in a twin its clearcut, lose 1 engine and you land ASAP. Overweight if necessary. ETOPS or no it doesn't matter, do not expose yourself your crew and your pax to more risk than necessary.

Everyone is entitled to their opinion--and I've certainly never qualified on a heavy twin jet--but I'm wondering then, what's the point of installing a fuel dump system on a twin engine jet if not to dump down to landing weight?


For reducing landing weight for less critical situations.

Delaying landing after an engine failure is not what the fuel dump system is for.

mutt
23rd Nov 2007, 15:10
How about to increase your takeoff weight?


Mutt.

Intruder
23rd Nov 2007, 20:44
what's the point of installing a fuel dump system on a twin engine jet if not to dump down to landing weight?
For FAA certification, the airplane must meet the requirement of FAR 25.1001. It starts with:

"(a) A fuel jettisoning system must be installed on each airplane unless it is shown that the airplane meets the climb requirements of §§25.119 and 25.121(d) at maximum takeoff weight, less the actual or computed weight of fuel necessary for a 15-minute flight comprised of a takeoff, go-around, and landing at the airport of departure with the airplane configuration, speed, power, and thrust the same as that used in meeting the applicable takeoff, approach, and landing climb performance requirements of this part."

zerozero
23rd Nov 2007, 21:06
Ok, ok, ok...

Don't dump it!

All this drama about flying around on one engine. Wow!

:{

Happy landings!

:8

Ashling
23rd Nov 2007, 21:48
well done zerozero

Old King Coal
24th Nov 2007, 09:07
Wrt an engine failure in a twin-jet, the phrase "Land at nearest suitable airport" implies that operations on a single engine represent a significant increase in risk and therein Mr Boeing / Airbus want you to get it on the ground asap. Or putting it another way, they want you on the ground asap in order to limit your time-exposure to operations on just a single engine.

'Risk' is a normally referenced to statistical probabilities of certain events occurring, wherein for aviation purposes the following are normally assumed:
Frequent (Up to 1 per 1000)
Reasonably probable (1/1,000 to 1/100,000) Unlikely to occur frequently but may occur several times during the life of each aeroplane, e.g. Engine Failure.
Remote (1/100,000 to 1/10,000,000) Unlikely to occur to each aeroplane during its life but may occur several times during the life of the fleet. e.g. Low speed over-run; Failure to achieve NTOFP.
Extremely remote (1/10,000,000 to 1/1,000,000,000) Unlikely to occur in the life of the fleet but still possible. E.g. High speed over-run; Ditching; Hitting an obstacle in the NTOFP; Double engine failure in twin engine aircraft
Nb. The use of ‘Fleet’ in the above refers to all the aircraft of a particular type, i.e. as produced by the manufacturer (and not to a particular airline’s fleet of that type).

Whilst the above suggests that a double engine failure in a twin-jet has an 'Extremely Remote' probability of occurring, that does not mean that it can't happen! :eek:

Therein I'll agree with Rainboe et al and the the old adage that it's much better to be down here wishing you were up there, than up there wishing you were down here.
That said, I would not promote rushing drills and / or approach briefing & set up / flying, etc, in order to get it on the ground asap, as we all know that rushing exacerbates the level of risk.

Intruder
24th Nov 2007, 18:57
I would not promote rushing drills and / or approach briefing & set up / flying, etc, in order to get it on the ground asap, as we all know that rushing exacerbates the level of risk.
Rainboe's anecdote above (engine failure at TOD) illustrates this concept very well. The Captain decided to continue on a NORMAL, PREPLANNED arrival at the destination airport, rather than scrambling with an UNPLANNED, possibly UNFAMILIAR "emergency" approach at a different airport. The time difference might have been a few minutes at most. I would agree with the Captain at the time that continuing with the preplanned arrival was much SAFER.

Rainboe
24th Nov 2007, 21:45
I think the problem with the decision was that a normal 2 engine TOD would have been say 3 x Alt in thousands. Once on one engine, that TOD pulls forward when you consider a second failure, to something like 2 x Alt in thousands. So a 2 eng TOD becomes a long drag on one engine, then the destination becomes unachievable if at any time the second engine fails from TOD, even single engine TOD, and that was what hung the pilot involved. The difference could be 40 miles or more. It is accepted practice in simulator training that on one engine, you do not rush, but you do try and get it on the ground without undue delay. Then with a chuckle, the trainer makes you go around!

hoggsnortrupert
25th Nov 2007, 01:45
Not in the same league as you heavy metal chappies:
I had a PT6 suffer a "hiccup" en-route Nasuori Rotuma, some miles out over "the Big Blue Wet Thing"
Hitting "Nearest" on the "PFM" thingy, gave me Nadi as closest, by 5+Nms, my F/o wanted to go into Nadi:
However with the wind on track " being a more or less direct tail wind" I elected to return to Nasouri?
I was asked to explain my actions for 5 Nm's and I guess rightly so!
When I explained it was 1:28 seconds closer, to return to Nasouri, the "Owner" of the "Airline" "stopped short of saying BS" and asked me to prove my concise answer, I asked for the Pax Manifest handed in after every days Flt?
If I can digress a tad here: I was taught to always do a Hdg/As/Tk/Gs computation in cruise: and record the Wv/Dir!
Having it written on the back of the Pax manifest (my flt log for every flt)
It was rather simple to answer.
In saying this : today I find it common place that F/o's dont even carry a "Kane" yep call me pedantic an old Fuddy duddy: but I thank the Chaps that taught me how to become a Fuddyduddy?
I guess at the end of the day Pucker factor is Pucker factor::(:(

hoggsnortrupert
25th Nov 2007, 02:25
Sorry! thats meant to be 1min 28sec's:
Chr's
H/Snort:ugh:

Rainboe
25th Nov 2007, 08:57
Quite. But what's a Kane?

haughtney1
25th Nov 2007, 10:27
Yeah, whats a Kane?

I totally agree Hogsnort BTW......although, mayby the Ops department could produce a CFP with a couple of ETP's on it...:E

"plan to land at the NEAREST suitable airport" is what mr Boeing says....whats so hard about that?

Intruder
25th Nov 2007, 15:26
What's "hard" is:

An airport that is "nearest" in straight-line distance may not be "nearest" in time.

An airport that may be "suitable" may be marginally so.

A "diversion" at TOD may cause significant additional safety risk to many other airplanes and people as ATC tries to reshuffle traffic to accommodate your emergency. Priority handling on the anticipated arrival to your original destination will cause much less disruption. Fuel contamination (the other major cause of multiple engine failure besides fuel starvation) is unlikely near the end of the flight if there are no indications (e.g., Filter Bypass warning) prior to the first engine failure.

An interruption to normal routine always carries additional risk. It is up to the Captain to decide how much additional risk is appropriate for the situation, and to balance offsetting risks.

Intruder
25th Nov 2007, 15:32
I think the problem with the decision was that a normal 2 engine TOD would have been say 3 x Alt in thousands. Once on one engine, that TOD pulls forward when you consider a second failure, to something like 2 x Alt in thousands. So a 2 eng TOD becomes a long drag on one engine, then the destination becomes unachievable if at any time the second engine fails from TOD, even single engine TOD, and that was what hung the pilot involved. The difference could be 40 miles or more. It is accepted practice in simulator training that on one engine, you do not rush, but you do try and get it on the ground without undue delay.
The simulator scenario MAY be appropriate if you know or suspect the cause of the first failure to be something that may also affect the second engine (fuel contamination, volcanic ash...). However, 40 miles at cruise speed equates to about 5 minutes. It might take that much longer to find all the appropriate approach plates and get the ATC coordination for the diversion!
Again, the Captain must assess the situation and make a reasoned decision. It's not quite as simple as haughtney seems to think.

Aspen20
25th Nov 2007, 16:55
Some years back a SAA B747 took off out of Frankfurt close to MTOW. They lost 3 & 4 engines and came straight back to land. No problem. as a previous post said melted fuse plugs a lot less serious than a hull loss.

hoggsnortrupert
25th Nov 2007, 16:56
Yeah, whats a Kane?
I totally agree Hogsnort BTW......although, mayby the Ops department could produce a CFP with a couple of ETP's on it...

Yes we ended up getting Co Fp's, but as for getting ETP's on this route, or its parent one Nadi Rotuma, was deemed to be pointless????
Note that "I" did try to get it so!
Don't know what they do now 12 yr's later.
A "Kane: It a type of bamboo, shaped like a sheep crook" commonly called a "walking stick" its an aid to walking for those that need it!:}
For those of you surrounded with PFM thingy's!:ooh:
A Kane or is it Cane! :)
A Little circular plastic thing, fits in your breast pocket, has numbers on it! very useful, especially when the power goes "off" due to "double Generator failure" ( but thats another war storey) helps keep the "Grey Matter" fuctioning.:}
The other thing I recently got upset about was the relience of "CREW" upon the ships flash lite? :hmm:I carry my "own", always have, Maglite & Kane go every where with me! have done for 25 years.:ok::ok:
Chr's
H/Snort

haughtney1
25th Nov 2007, 21:09
What's "hard" is:

An airport that is "nearest" in straight-line distance may not be "nearest" in time.

An airport that may be "suitable" may be marginally so.

Intruder.....and?

The points you make are part and parcel with operating a medium/heavy twin either ETOP's or over some of the more remote area's of the globe in every sense of the word.....like I said...its not THAT hard.
Its why at the route planning stage an airline is required to produce detailed and specific area and aerodrome briefs to enable its operating crews to become familiar with the various suitable/adequate/nearest alternate airfields.

I'm sure you are well aware of this, but perhaps its important to enlighten those who aren't aware.