fuel truck guys cheating - any ideas?

[Skipping Classes]

Hello!

At one particular destination of our airline we always have a fuel difference of over 100kg between the amount re-fueled counted by the fuel truck (in liters) and the amount calculated by subtracting fuel remaining before refueling from ramp fuel after refueling.

This problem always happens at the same airport, on all aircraft. Compared to other airports, such a calculation gives an average difference of 30 kilograms.

The company is loosing a lot of money on this (3 times refueling - 330kg a day, 10 tons a month!)

We tried checking the fuel truck meters set to zero before refueling and the total meters differences but still get this difference every single time!

Any ideas what could be the problem? :ugh:

The guys are either cheating or have a faulty equipment.

But if they are cheating how do they do it?

Regards!

[spinnaker]

Temperature of the fuel? any other companies having the same problem?

[Opsbeatch]

Before signing for the fuel check the calibration sticker and seal. If it's in Europe then they are required to have one, no seal, no sign!

Watch how quick they'll get them calibrated if they don't get paid for an uplift!!!

OB

[powerstall]

well if it does happen at the same airport time and time again, you are definitely being cheated by the refueling company, they could pilfer a few liters here and there.. .add it up and voila.. you have a big can of jet fuel up for grabs... at a lower cost... maybe selling it to a few gen av planes.. :E

calibration might be an issue here but having the same problem and same amount of loss....

[Skipping Classes]

So the real questions here:

- How can we check if they are cheating?
- How do they manage to cheat?
- How can we prove they are cheating?

Any refueling personnel willing to shed the light?

[BelArgUSA]

Do they tell you what the specific gravity is...?
My table here indicates that Jet A-1 should be .812 at 15ºC temperature.
Try to get exactly a litre, and see if it weighs 812 grams...
Other possibility, the fuel you get is warm.
If fuel is constantly stored in a truck parked in the sun... that is the reason.
xxx
:)
Happy contrails

[Nightstop]

Airbus narrow body OEB Bulletin 808/1 (Subject: FQI Accuracy) gives a good explanation of what may be happening. To summarise:

FQI accuracy is +/- 1% of max tank capacity or of actual fuel quantity
Bowser quantity (volume tolerance +/- 0.50%) & density error (+/- 0.25%) accuracies are 0.75% combined
APU burn on a 30 minute turn approx 30 kgs
FU indication accuracy (which is an integration of FF) is +/- 1.5%

Both on-ground and in-flight discrepancies are generally due to FQI errors on Block Fuel.

Notice the maximum Bowser error of 0.75% is potentially significant and if combined with the other inherent errors may offer an explanation.

Hope this helps.

[kijangnim]

Greetings
Between the fuel meter and your aircraft fuel tank there is a manifold, which contains the 100 kg missing:eek:, because when they stop refuelling the fuel has already been trought the meter, but will remain is the fuel tanker manifold as he is disconnecting the bowser from your aircraft :}
Some airline have agreement with tankers to provide the manifold capacity (100 kg, 50 kg..) and to substract that quantity from the meter :ok:

[WHBM]

Old hands will remember the loss of an Alidair Viscount approaching Exeter many years ago, fortunately without injury, due to running out of fuel, where (though it was never conclusively proven) their gauges on board were u/s and they were substantially short-shiped for fuel at the start point; for the quantity signed for they could never have run out like this.

[criticalmass]

I have seen this in the marine environment when we were taking on bunker fuel in Korea from barges. The Chief Engineer noted over two tonnes discrepancy between what was on the paperwork and what his engineers calculated had been pumped onboard. He knew his engineers wouldn't make a mistake that big, so he got suspicious and came up on deck at the base of the accommodation-block where our bunker-tank manifold connection was. With him was the Second Engineer and the Agent from the shipping company who represented us in Korea.

The Chief refused to sign for the fuel. The Korean barge-master then said "maybe some stick to sides" and a pump started somewhere on the barge. 0.8 more tonnes of fuel-oil came aboard.

The Chief now knew how the scam worked. There was a hidden tank on the barge and a small quantity of fuel was siphoned into it as the main body of fuel was pumped via the manifold into our bunker-tanks. He figured if there was 0.8 tonnes more that had just mysteriously "come down from sides" then the rest was still onboard the barge. So he still refused to sign the paperwork.

The Koreans began to get very unsettled. Twenty minutes of haggling between the barge-master, the Agent and the Chief Engineer and still we didn't have all the fuel. The Agent was getting some dirty looks from the barge-master, and the Chief was standing his ground, a smile grdadually developing as he saw the evident discomfort of the barge-master. Then the barge-master went below on his barge, came back a minute or so later and pressed a small piece of paper into the Chief's hand. The Chief turned away and looked at it, then signalled the Second Engineer over to have a look at it. Apparently it read (in English, surprisingly) "How about we give you little present?". A bribe was about to be offered.

Now the Chief's suspicions were concerned. It was a scam and the barge-master was probably going to be in trouble with Korean Customs (who would have to be in on the scam anyway) if the barge came back without the two tonnes of illicit fuel-oil.

The Chief asked the Agent to tell the barge-master in Korean "No Deal"...I want my fuel and I want it all, and I want it all now." We weren't sure if the Agent was also in on the scam, but he did as he was asked and the barge-master scuttled away, muttering in Korean. The asthmatic pump ground into action on the barge again, and a further 1.1 tonnes of fuel-oil arrived onboard.

By now the Korean barge-master knew he had been out-stared by the Chief and all he had for his trouble was maybe a couple of hundred pounds of fuel-oil instead of the couple of tonnes he was hoping to spirit away. The Agent stayed aloof, the Chief signed the paperwork and the barge departed.

I watched a little of the drama but was called away. The full story was related to me that evening in the smoke-room by the Chief Engineer, who still had the little piece of paper. We all had a good laugh about it, but there is a good chance the barge-master got his backside kicked royally by the Customs guys with whom he was probably hoping to split the profits from selling the purloined fuel. I guess those Korean Customs guys could kick pretty hard, especially one of their own.

So, such scams are alive and well. All it needs is a way to siphon off a small volume as the main load of fuel is transferred, and a hidden tank in which to store it so it can be taken for subsequent "re-sale". I don't think that would be all that hard to do on a fuel-truck.

As Clarkson says "How hard can it be?"

[Brian Abraham]

Some times works to ones advantage, a particular airport was a favourite refuelling stop for oceanic ferry of light aircraft because fuel delivered into the tank was more than appeared on the fuel truck meter.

[spannersatKL]

10 tonnes a month...clearly not a B747 operation?

Is the SG you are given correct/ Is it checked shipside with a hydrometer along with the temerature of the uplift fuel? This is the best way to check this? I suspect that this is the issue here? Most fuel companies will do this for you and you can do this yourselves too...

Whilst stated above that the SG of AVTUR is .812....never seen that in my years....seen from 0.785 to 0.820 and every day is different....in USA have seen the highest SGs and in Middle East the lowest (well it is hot!). So check the SG you are using to convert the VOLUME you uplift to a MASS is correct for the location, day, temperature of uplift fuel etc. If you want to do it properly you also need to allow for the SG of the cold fuel in the tank as well....remember this will be colder and therefore heavier and be covering the densitometer in the bottom of the tank thus giving a false reading on the gauge. Some years ago Air New Zealand used to have a graph on the back of their fuel sheet to give an average SG from fuel in tank after fuelling taking in to account the SG/MASS of the fuel in the tank before fuelling, to the Uplifted SG to MASS uplifted so you could give an accurate fuel MASS onboard when checking the actual fuel on board with the fuel sticks.

Frankly having done Fuel Farm / facility audits in a number of places I have found the overwelming majority of the supply companies to be very honest in their dealings and very open to audit of their operations. In fact most are very proud of their operation and wish to demonstrate how compliant with the requirements they are.

[12 twists per inch]

I've had it quite a few times in Africa where every now and again during the refuel they pump air - with the bowser gauge still counting.....and you still paying! Much gesturing occurs when you catch them at it, nearly 4 tonnes discrepancy once! But yes very common in my world.

[Speedbird48]

Many years ago Palma was a place where they had a good scam going. The trucks all had trailers, and as the truck pumped into the aircraft a valve was partialy opened to the trailer and fuel was fed back to the trailer after it had been counted by the meter.

Not all thieves are loaders.

[mitzy69]

a false S.G. of delivered fuel is a good way to fiddle refueling to get the figures correct.
used to refuel B747 in KUL to LHR and uplift was over 200,000 litres, so the forth sigificant figure of the S.G. being inaccurate would give a 100kgs discrepancy.
and it is very hard to get an accurate reading on the hydrometer on the forth sig figure, as the hydrometer sticks to the side of the glass jar and the meniscus of fuel on the scale trying to be read.
if the S.G. of delivered fuel is supplied by the refueling company and not measured by an airline employee, then will get fiddled.
An old tale when company aircraft were refuelled in New York and always got a descrepancy, was that refueling was started before the pilots arrived at the aircraft, so would not know if the numbers had been zeroed before delivery.
At certain airport the local mechanics were over zealous with draining the water out of tank and could fill a 45 gallon drum with waste fuel.
If a discrepancy always happens at the same airport to all aircraft then suspect a scam.

[CAT1 REVERSION]

Greetings
Between the fuel meter and your aircraft fuel tank there is a manifold, which contains the 100 kg missinghttp://static.pprune.org/images/smilies/eek.gif, because when they stop refuelling the fuel has already been trought the meter, but will remain is the fuel tanker manifold as he is disconnecting the bowser from your aircraft http://static.pprune.org/images/smilies/badteeth.gif
Some airline have agreement with tankers to provide the manifold capacity (100 kg, 50 kg..) and to substract that quantity from the meter http://static.pprune.org/images/smilies/thumbs.gif


kijangnim,

Surely the 100kg which has been left in the manifold downstream of the meter (ie after the meter) will sit there for the next aircraft thus the first 100kg are delivered un-metered and the last 100kg not delivered is metered = No descrepency!!????

The only exception I can think of is if the last 100kg left in the manifold is somehow removed from the manifold before every delivery!

Which Airlines deduct this 100kg figure from their uplift?

[kijangnim]

Greetings,

No my dear, 100 kg dont stay in the "tube" (sorry English is not my first language) and pushed in the next customer''s fuel tank :ouch:, it is simply succed back to the tanker.:}
Instead of being suspicous about what I have written, you would be better off investigating.:hmm:

[spannersatKL]

kijangnim......what tank on a hydrant fuelling stand? There ain't one....only the dispenser.....plugged in to a manifold in the ground and plugged in to the aircraft.....In the case of a tanker (Bowser) the fuel cannot go back up the pipe either.....

[parabellum]

Athens pulled a scam on me one night by switching bowsers mid refuelling and eventually getting us to sign for nearly a ton more than delivered. Turned out they were selling it to executive jets passing through and paying cash for fuel! (We always checked the bowser counter before start but by changing mid way when we were not there the second bowser was arriving with the counter already showing at least a ton of delivery, being suspicious we caught them at it, it seems it was a big money maker for them!).

[GlueBall]

"We always checked the bowser counter before start..."

Wow! If you're a pilot, then you are very maintenance dedicated. Do you double check tire pressures as well?

We normally have maintenance reps "downstairs" overseeing the fuelling. :ooh:

[ChrisLKKB]

I doubt the fuel from the manifold would bet sucked back into the bowser. Once it leaves the bowser it should be assumed to be contaminated and a one way valve fitted to ensure there's no risk of back flow which could contaminate the enitre contents.

I agree that the what you loose in the manifold, you get back by receiving what the last guy lost. That is unless the company is on the fiddle and kijangnim is right. Sounds like a potentially dangerous practice if it is.

[hugeb]

About 20 years ago we used to have a similar problem in Malta where we found that half way through the refuelling the refueller pulled a lever for a couple of minutes. When asked what it did there was no answer, but we suspected (but never proved) that it pumped fuel into the trailer it was towing. The only answer we found was to carefully monitor the bowser operator for the whole refuel time.

[kijangnim]

Greetings,
If the manifold contains 100 kg of fuel plus the weight of the manifold we can talk around 120 kgs, do you think one man can lift it and unplung it :confused: so if you see that happening be a little suspiscious :hmm:

[parabellum]

Maybe you have never worked for a UK charter airline? I was with Air Europe at the time and the PNF for the return sector did the walk round and supervised the fuel when away from base. Engineering support was there from the local carrier if needed.

[Fuel Boy]

Morning All,

As usual blame the fuellers.......

The S.G is most commonly the problem, we will always give a pilot or engineer the S.G if asked ( which is rare!) but even when we do and the sums don't quite look right, they normally walk off muttering I'll change it for a better one.

If you calculate your uplift in litres to compare whats been delivered, why not give Us fuellers the fuel figure in litres then, then there would be no discrepancy, but no we have to work with pilots who give us figures like,
" Can I have a GOOD 14T" :confused: what sort of figure is that !!!!!!
or
" A generous 25 Thanks"

so we are left to decide what you think these figures are, not very good is it?

On the litres thing AF and KM both used to give their fuel figures in Litres when flying 737's, and on the odd time the S.G would mean even their maths was wrong.

And lastly our meters are calibrated twice a year to prevent this kind of problem.

Fuel Boy

[DBate]

All it needs is a way to siphon off a small volume as the main load of fuel is transferred, and a hidden tank in which to store it so it can be taken for subsequent "re-sale".

Gentleman be aware when refueling in ALA. There is one fueler usually driving the same modified fueltruck. Part of the fuel is siphoned back into the truck. This regularly leads to a difference of around 500kg during each refueling. :eek:

Someday one of our engineers found out and informed all station personell involved around our aircraft. Since then, this special fueler and truck is not allowed to refuel our aircraft. :=

Thinking about notifiying the officials about this? Probably a good idea, but sometimes things work differently in those parts of the world. I think our company officials even did that - to no avail. In all likelyhood it's a bigger scam going on around there, so just prohibiting that guy and truck to refuel the aircraft is the easier way...

So, watch out in ALA.

[Chille Con Carnie]

Bring back the F/E

[spinnaker]

Crikey! Looks like more money can be saved by monitoring the fuel loading, than by company fuel policy

Fuel Boy

" Can I have a GOOD 14T" I would take that to mean as close to 14t as you can get without being under.

I take your point though.

[Desert Diner]

At one particular destination of our airline we always have a fuel difference of over 100kg between the amount re-fueled counted by the fuel truck (in liters) and the amount calculated by subtracting fuel remaining before refueling from ramp fuel after refueling.

This problem always happens at the same airport, on all aircraft. Compared to other airports, such a calculation gives an average difference of 30 kilograms.

It must be an S.G. problem. The source may hydrotreat their kero as opposed to just merox treat it which results in a slightly lower SG and therefore less mass for the same volume.

[Pilot Pete]

If you calculate your uplift in litres to compare whats been delivered, why not give Us fuellers the fuel figure in litres then, then there would be no discrepancy We do.;)

PP

[WHBM]

To give a link to the incident at Exeter referred to earlier :

"Meter indications on the refuelling vehicle at Santander, which cannot have reflected the quantity of fuel delivered, are also considered to have been a probable contributory factor."

ASN Aircraft accident Vickers 708 Viscount G-ARBY Ottery St. Mary (http://aviation-safety.net/database/record.php?id=19800717-0)

[Intruder]

Gentleman be aware when refueling in ALA. There is one fueler usually driving the same modified fueltruck. Part of the fuel is siphoned back into the truck. This regularly leads to a difference of around 500kg during each refueling.

Someday one of our engineers found out and informed all station personell involved around our aircraft. Since then, this special fueler and truck is not allowed to refuel our aircraft.
Any way to identify that truck at ALA in advance?

[aguadalte]

First of all, it all depends on the type of aircraft they're refueling. (300kg of fuel on a large aircraft is not as important as on a smaller one). In my case A340/330.
In my company, we write the amount of fuel needed in Lts in the technical log book, that has to be signed by the commander (having in mind the fuel density provided by the refueling company) and that amount added to the fuel over destination has to be consistent with the one required on your OFP.
Further, when you add, lets say, 40 Tons (at a mean temp of 24ºC) to 15Tons of Fuel remaining in the tanks, that is at a temperature of -36ºC, (after 8 or 9 hours of flight), you will get a lower weight than expected, but the required amount in liters will be as predicted. Since most aircrafts give you a "weight figure", that has a fixed .800 "cadensicon" fuel weight determination, you may then find a different figure on your FQI. That summed to, at least, a 1% (depending on aircraft) FQI margin will probably give that amount of misreading.
Anyway I must tell you that, using the fuel density liter/Kgs determination procedure we have found that some of our refueling companies in Africa were cheating us...:bored:
Regards,
VF

[tescoapp]

Old hands will remember the loss of an Alidair Viscount approaching Exeter many years ago, fortunately without injury, due to running out of fuel, where (though it was never conclusively proven) their gauges on board were u/s and they were substantially short-shiped for fuel at the start point; for the quantity signed for they could never have run out like this.

Sorry to hijack for a bit but as a bizarre turn I actually spoke to the Captain of that flight last week (unless more than one viscount has run out of fuel and ditched). He was a pax and came up to the front for a chat, was quite forward with the fact his takeoff versus landing count was out by 4. Wish i could have chatted to him for longer.

Just read the accident report must have been a different one.

[mona lot]

Please can someone explain why fuel is still dispensed in units of volume whereas aircraft fuel guages display the mass of the fuel. The volume of fuel is completely irrelevant because the amount of internal energy it contains depends on the mass of the fuel and not the volume. Most modern aircraft have an instrument that measure the mass flow rate of fuel to the engines so why can't modern fuel bowsers also measure the mass flow rate being delivered to the aircraft? This would negate the problem of temperature errors/variable specific gravities.

[kijangnim]

Greetings
Fuel is sold in volume, because the Crude oil unit is Baril i.e. Volume :E

[DBate]

Any way to identify that truck at ALA in advance?

I have no idea. I am on holidays at the moment, back at work in about three weeks. Will try to find out then...

[BigShip]

Hi, just wanted to mention. I had the same problem in Almaty and in Astana.

I did not have enough fuel after refueing was done. Fuel just disappeared after fueling stopped. Very strange but happens all the time there and everybody knows and adds some hundreds on the refueling.

Now after refueling a ton or so we start the engines and at the T/O position we suddenly got a ton more in fuel indication. Lucky we did calculation with some air for the speeds.
It all appeared suddenly.

Investigation is still going on.

But something else: The fuel used is not a Jet A-1 or A. It is a russian production and some "K" stuff. Almost like Jet A-1 but not all the way.

Maybe they just pumped the stuff with too high pressure and it generated foam and concluding wrong indications ?

I do not believe the fueltruck story, seems also just a problem with one aircraft type.

[HAWK21M]

We calculate the uplift required & cross check by confirming the refuellers S.G.
The calibration dates are noted too of the equipment used.
regds
MEL