swarf in fuel tanks blocked the fuel filters

[nojh]

Swarf in fuel tanks blocked the fuel filters,on a B757 i was flying causing one of the RR Rb211 535e4 engines to fail on short final.We performed a single engined landing. Subsequently the engineers informed us the swarf contamination was so bad that we were minutes away from the other failing as well. We had flown across the atlantic ,and up and down to Sao Palo many times in this aircraft,were we lucky or what . I wonder if any one else out there has had engines failing due to SWARF.

[Tony Mabelis]

I know of a case of multiple fuel boost pumps failing due to FOD after modifications to the wing of a Gulf.IV. This caused the aircraft to imediately divert and land.

[Avman]

I'm ATC, presently working MADAP but soon to go to NFDPS. Does that mean anything to you pilots? :) So how about sharing what SWARF means please ;)

[FlyMD]

http://en.wikipedia.org/wiki/Swarf

[KUMOOZ]

On this occasion Swarf is not an acronym but an engineering term to describe the metal shavings that are produced during manuafacturing processes such as turning on a lathe or drilling holes in metal.
Now what do yours stand for? :bored:

[qwertyuiop]

Swarf is not an acronym it is a word. Swarf (or turnings) are shavings and chippings of metal—the debris or waste resulting from metalworking operations.

[a4fly]

Oxford concise dictionary reckons it's " fine chips or filings of metal "

can't find MADAP or NFDPS though !

[Avman]

:ok: Ok I was too lazy to check it out and just assumed it was an acronym.Putting my D cap on now. Got you all guessing about mine though :E

[Dream Land]

MADAP (http://en.wikipedia.org/wiki/EUROCONTROL) - Like this? :confused:

[ppvvmm]

swarf in fuel tanks blocked the fuel filters
Swarf in fuel tanks blocked the fuel filters,on a B757 i was flying causing one of the RR Rb211 535e4 engines to fail on short final.We performed a single engined landing. Subsequently the engineers informed us the swarf contamination was so bad that we were minutes away from the other failing as well. We had flown across the atlantic ,and up and down to Sao Palo many times in this aircraft,were we lucky or what . I wonder if any one else out there has had engines failing due to SWARF.


Any chance of a link to an official incident report?

or did you make it up?

pvm

[nojh]

Avman ,swarf are aluminium particles drill bit residues,etc which acumulates during the construction in the fuel tanks and is supposed to be removed before the delivery of your new multi million pound aeroplane In this case the aircraft flew for 6 months extensively over water before all the filters blocked up. This aircraft was UK Caa registered,makes you wonder does it not :D?

[tallsandwich]

So I guess the question has been asked as to which recent intervention on the aircraft created this swarf....? As it is a 757 I assume that this stuff did not just suddenly get dislodged (after spending many years stuck in a corner of a tank)?

[nojh]

No I did not make it up.

You want an official report try UK CAA

Or Boeing in Seattle,you could even phone them if you are so desperate.

[zerograv]

Nojh

If the aircraft flew for 6 months without a "issue", I would guess that the "junk" came, either, on the the fuel that was uplifted to the aircraft or, more sinister, the fuel pumps itself could be disintegrating to bits in its operation.:eek:

Just my five cents.

Safe flights always!
Zero

[relax.jet]

Not long ago our mechanics had to change one CFM-56 engines. The pieces of metal have been found in oil. In this case they had advice from FAA to check up this series of engines. (I think there was a manufacturer problem with one of the bearings on turbine shaft.) :ugh:

[Lowkoon]

So why didnt the filters bypass?

[Double Zero]

Zerograph,

your idea of disintegrating fuel pumps sounds most likely to me - and filters, unless very special, don't 'bypass' they either fail & let stuff through, or clog & stop flow !

Where are the filters in line re. the pumps ? Presumably after the pumps...uptaking fuel with swarf seems possible but I'd have thought there are several filters, in & outside the aircraft before the tanks to prevent that.

[slip and turn]

Can someone please provide the link to the AAIB reports on this one? At rik of understatement, it's important to know where the swarf came from. Personally speaking I am not desperate, but I do like to think I am sensible, and it seems slightly silly for someone to come here and report it happened to them, and then be reluctant to provide a link, and vaguely obtuse about it.

[Just an Engineer]

Zerograph,

your idea of disintegrating fuel pumps sounds most likely to me - and filters, unless very special, don't 'bypass' they either fail & let stuff through, or clog & stop flow !



Wouldn't have thought disintegrating fuel pumps on both sides.... If it was 6 months off delivery it will probabally be build up of swarf over the period

As for filter bypass being 'special'...are you sure now ? ;)

[Fake Sealion]

Come on now fellow Ppruners....the journos may be watching, ready to put 2 and 2 together to make...."BA 777 brought down by iron filings"

You heard it here first!

:ok:

[alright_pal]

swarf to be found through fuel uplift highly unlikely, fuels pumped on through filters on bowser either moniters which are like giant tampons trap fod and swell and block at the 1st sign of water, or coallescers then the final defence are cone end filters in the actual coupling which as it says is a cone of very fine mesh, which should be checked monthly, if its a decent oil company.....:ok:

[airsupport]

Around 40 odd years ago now, as an Apprentice at the time, often used to have to work inside the fuel tanks on Aircraft undergoing major checks and overhaul, we had to wear special clothing and footwear so as to not leave anything behind in the tanks.

You would not believe some of the things we found in tanks, including on one Lockheed L188 Electra one day, not 1 but 2 heels from someone's shoes.

This is as well as the filings you are talking about, and rivet heads etc etc............ :sad:

[broadreach]

I'm trying to remember who operated 757s to Sao Paulo. Think Varig did for a while, cant remember anyone else.

[nojh]

My B757 s engines died on fial approech SWARF FROM BOEING She was built in Seattle brand new.
She was built duiring the Boeing Strike.
Did someone SABOTAGE our plane.
If there is no explanation from Boeing,
Watch ITN NEWS I am pissed off with the Caa ,D Mclelland Caa party boy I am going on TV.
Caa hide too much
British Medical Association flew Blue Planes dangerous Fk27s rudder trim tab fell off in flight

Too many cover ups.

Too much builying Thanks Pablo Mason.you stood tall and true.

I am about to vent the wrath of my SPLEEN on the Authorities

[moggiee]

nojh - that must be the most rambling, incoherent post I've ever seen on PPRUNE. Try again when you've calmed down/sobered up/flushed the pills out of your bloodstream.

[Andy_S]

My B757 s engines died on fial approech SWARF FROM BOEING

This is contradictory to the story you gave yesterday, in which you said

Swarf in fuel tanks blocked the fuel filters,on a B757 i was flying causing one of the RR Rb211 535e4 engines to fail on short final.We performed a single engined landing.

Am I the only person having trouble taking you seriously?

[nojh]

Exactly why I wrote the thread,metallic swarf caused our engines to fail so why not a 777.

It is time to stop covering up mistakes by the whole industery.

Tis time for transparency and the truth,so let us tell the media what aviation is realy like,

[mavrik1]

When drilling holes off or reeming holes from outside of aircraft in, you should have someone on the inside of fuel tank with a vacuum cleaner held over the hole to contain the swarf as the hole is being drilled!, for example.
These's days due to time and careless these little details are not incorporated into a lot of todays maintenance practices. In every maintanence task there is many ways of carrying out the job, (unlike the boys flying em) the long way or the short dodgy way. No airline wants to pay for good maintenance. You will see a lot more of these sort of occurances in the future.

[moggiee]

nojh: if you are genuine, give us some facts

Airline
Aircraft registration
Date and time of event
Location
Links to AAIB reports or media reports.

[blue up]

I couldn't find anything on the AAIB site.

[broadreach]

nojh,

Lack of any sort of evidence makes your posts sound just a bit suspect. And swarf contamination would be a first on long flights, it seems.

Come clean.

[208]

When I worked for the late lamented MANX/British regional/ba connect it was company policy to change/inspect fuel filters 25 flying hours after any in tank work no matter how minor to catch any swarf/fod debris.

[nojh]

Aruba carribean Light blue 757 1990 UK reg.

[nojh]

Try Aruba Dutch Netherlands 1990

[nojh]

Blueup no accident hence no report,An incident is not an accident

[nojh]

Dear Mavrik 1

At last an intelligent post ,thank you very much for that one.

We were told that what you described was exactly what happened duiring construction. (this aircraft was built duiring the Boeing strike,and was severly delayed,and seemed to lack continuity of construction and procedures)

Boeing went into Ostrich Mode

Strange but many years later An RB211535E4A disintegrated over Greece RR had not torqued up the nuts and bolts on the LP turbine. This was also strike related,! Worse still I had flown that one the day before .

Thanks for your suportive post.

[moggiee]

Now what evidence would you like ,should I send you the photographs ? I would if I knew your address

Go to www.photobucket.com , sign up for a FREE account, upload the evidence to that account and then post the links to those photos on this thread.

Easy.

[N1 Vibes]

nojh

to go way back to your original question - yes - I have seen an engine contaminated by swarf, though not from the tanks, but from a failed engine driven fuel pump.

And just to put peoples terminology into perspective shouldn't we be referring to this material as DOD not FOD. Since you are suggesting the material was from inside the tanks. If someone had taken something from outside the tank, left it in there - that would be FOD. DOD - Domestic Object Damage, i.e. from inside the system.

Further to your questions, would you be better asking what procedures are in place to replace engine LP fuel filters at a set period after fuel tank repairs. I thought this was common-practice, if not in-fact an AMM requirement?

Brgd's

N1 Vibes

[nojh]

Air ARuba engs said it was SWARF

Boeing Engs said it was SWARF

[straightfeed]

Had a donk run down on a 707 over Germany , enroute to LHR. Wouldn't relight either.
Aircraft had a history of hot starts or late light offs.

Turned out to be sludge caused by the foam backing from a carpet left in a wing tank during maintenance. Filters didnt touch it till it blocked the burners.

Seemed that in investigating the starting problem, the ground guys drained the suspect tank BUT didnt tank it off as waste merely put it in the centre tank.

The manual allowed feeding from the centre to all engines with one other tank as a back up. Wouldnt have worked well as a back up with all engines blocked!

[N1 Vibes]

nojh,

wasn't criticising your use of the word SWARF. Only other posters use of the term FOD, which is a loction for the source of swarf, suggesting the swarf came from outside the a/c. Sorry if it gave the wrong impression.

Brgd's

N1 Vibes

[Tankrat Charles]

how successful have you been? I hope you see my thread created under fuel tanks.

[CY333]

On the CFM 56 you can find MCDs and CDs which have a job of indicating an engine part that is failing, on the oil system of the engine.
I dont know the 757 at all but do they use MCDs in fuel or not?
I personally have never seen them on fuel lines.
Oh sorry CD stands for Chip Detector and MCD for Master Chip Detector.
My question is that if it was SWARF it must have been a booster pump structure failure because in my opinion if it was failing slowly slowly you would have had a decrease in pressure of the fuel.
On the other hand if it failed at once you would get booster pump low pressure in my opinion.
Did you have any of the above indications or it just failed out of the blue?
I dont believe it was fuel tank SWARF due to the fact that fuel tanks are integrally sealed with sealants to avoid any leaks and to stop any SWARF been dragged down the pipes.
But on the other hand we have seen cases of aircraft parts and systems failing whne they should not.

[CY333]

FOD=foreign object damage or foreign object debri must not be confused with Bird Strike or by damage caused by aircraft parts to the aircraft (SWARF for example).
Is not considered FOD as it is not foreign to the ac.
I believe some n the indstry cal it LOD (local object debri) but I have seen it under other names also.

[RMC]

Swarf contamination of engine fuel feed lines happened on Airbus A300s 25 years ago. It was picked up in the flight testing stage though. There are a few bits of information missing. I fly the 737 and am assuming that (like Airbus) the design philosophy of Boing fuel systems is essentially the same across the product range.

(1) Did the associated fuel pump low pressure light come on (indicative fuel low pressure filter blockage)?
(2) Did the filter bypass light come on (indicative of high pressure filter bypass).

If the engineers are clear that the contamination came from swarf in the tanks then this rules out fuel pump break up.

In UK engineering speak Swarf normally refers to corkscrew shaped strands of metal (or broken pieces of the same strands...large chips which are measured in milimeters). Swarf comes from drilling operations during manufacture or repair.

If your HP filter was blocked by much smaller chips (dust measured in microns rather than millimeters) this would come from reaming operations of high tolerance assemblys such as the wing/tank undercarridge support structure...or from pump break up. It Should not be referred to as swarf.

The fuel filters on all bowsers are huge (and very expensive). The only way swarf could be introduced from a bowser was if the filters had been removed and not replaced during maintenance. Possible but very very unlikely.

Just to clear up the intended function of aircraft sealant ...it is to seal not as someone said to stop swarf being dragged into the pipes.

That said during manufacture swarf can stick to wet sealant ...much later this swarf can be dislodged and settle at the lowest point in the tank.

Without exteremely dilligent inspection swarf will end up making its way down to the fuel pumps during the early weeks and months of an aircrafts life (or following a major repair).

The only thing I find odd is that your engine failed at low power. Both fuel filters have a bypass (although this is achieved in different ways). The only time you should get fuel cavitaiton is at high altitudes..with high power settings?

[RMC]

ASFKAP - Agreed this would not have happened if everything had been done by the book (either during manufacture or repair).In the Airbus case inspection of tanks was not done properly.
I am assuming that the description of swarf from the wing tanks is correct. Unless there has been widespread driling out of bolts (unlikely on a relatively new aircraft) the swarf will be aluminium and won't be picked up by the magnetic chip detector.

[CY333]

I said the main purpose is to seal but also to stop swarf due to the fact that the inside of the tanks are not fine surface but have a few rough ends.
I personally disagree that sealant would not stop SWARF as sealant can be up to 10 mm thick.
I am sure some gets away but ae are talking about amounts that could block fuel here so I am sure hat the SWARF did not come form the tanks walls.

At least this is what i was taught at uni doing my B1 lisence.....but i see we agree on the low pressure indication....

[Fark'n'ell]

Avman ,swarf are aluminium particles drill bit residues,etc which acumulates during the construction in the fuel tanks and is supposed to be removed before the delivery of your new multi million pound aeroplane In this case the aircraft flew for 6 months extensively over water before all the filters blocked up. This aircraft was UK Caa registered,makes you wonder does it not ?

Swarf is metal shavings,aluminium or otherwise.

[RMC]

The reason there could have been enough swarf from the wing tanks is that I understood this to be a relatively new aircraft. To give you an idea of the amount of swarf generated during manufacture there are just over 1,000,000 holes to be drilled and filled in each A300 wing.(I spent 16 years working as an engineer at the Airbus wing manufacturing site in Chester). If you think the guy who put that stat together had a sad job have some sympathy for the Boeing guy who calculated that a 747 has a total 45 million parts.

Having applied gallons of sealant inside Airbus wing tanks of during my apprenticeship I can assure you that cured sealant (if applied correctly) will not trap swarf. It has to be applied in a way which ensures there is a free flow of fuel to the pump box area. If fuel (and therefore swarf) starts collecting in pockets (and the unusable fuel level goes up) then the aircraft will fail its critical tank capacity check.

Fark'n'ell - Swarf is generated by drilling holes...the only material in a 757 primary wing box (tank) structure is aluminium so the only drill swarf that can be in a wing tank is aluminium (unless, as I said, someone has been drilling out lots of high tentile steel bolts during a massive repair.

The notes of caution here are:-
1. We had a prolonged strike during my time at Airbus (got a 35 hour week out of that one) and the management and some non unionised workers kept some production going. There are a number of problems with this...in relation to this thread you have people working areas they are not familiar with. If you dont follow the designers instructions on sculpting sealant and ensuring rib drain holes are clear of sealant etc then you could end up with pocket situation mentioned by CY333. Also management in particular were reluctant to go into tanks and do the dirty work necessary to properly remove the mass of swarf. It is not just from cured sealant but the coolant used for drilling the bigger holes keeps smaller swarf particles stuck to the inside surface.
2. Whilst not wanting to start yet another Boeing / Airbus debate there is no question that this would be more likely to happen on a new Boeing than an Airbus. My engineering apprenticeship was five years (too long to be fair)...the majority of Boeing hole drillers and fillers have around that many months. Airbus product build quality is far superior to Boeing. Again the CY333 situation is more likely to occur with what is effectively a semi skilled workforce. This is particularly true when build rates start to increase and you have to take a semi skilled guy off a job he has done all his life ...and put him in a new area which requires tacit knowledge obtained during years of training. As I said in my first post I am now a Boeing driver so this is not an anti American/Boeing post...just the facts.

[ARINC]

Following fuel problems we removed a wing from a Harrier in Germany many moons ago...only to find the main fuel line full of kimwipe.:ugh:

Nothing new under the sun....

[RMC]

We used to use kimwipe (industrial kitchen roll) ....to get swarf out of tanks without leaving fibre traces left by rags! Works better if the kimwipe is taken out afterwards though :-)

[glad rag]

Sheeties NEVER, NEVER clean up after themselves, industry standard.:ugh:

[MMEMatty]

Was once the safety man for a chap working in the fuel tanks of an aircraft in our hangar... he counted everything out (bolts, screws, washers etc.) out before he went into the tank, then counted it all again when he came out.

Said he had found some strange things in these tanks over the years, including, once, a plastic coffee cup... (Though not at the same company, I hasten to add)

Matty

[HAWK21M]

The B757 does not have MCDs in the Fuel system.

Are there details on Date/time/Registration of the Aircraft available.

regds
MEL