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?

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..

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]

Fuel specific gravity

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]

typos

Greetings
Between the fuel meter and your aircraft fuel tank there is a manifold, which contains the 100 kg missing, 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

[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 missing, 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

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 , it is simply succed back to the tanker.
Instead of being suspicous about what I have written, you would be better off investigating.

[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]

parabellum . . .

"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.