Are most airlines requiring fuel uplift calculations by crew

[JammedStab]

All the crew at my previous company were doing at least a rough calculation to add the uplift to fuel remaining to see if it equalled or was close to the new fuel load as a confirmation that the gauges are accurate.

5,000 litres was about 9000 lbs using a formula of double minus 10% and then adding it to the fuel remaining from the last flight which was in the logbook.

Then I got hired by an international airline and it does not seem to be done by the crew(although perhaps the fueller does it). Is it standard for most airlines to require the crew to do this?

[BOAC]

In my experience someone does it. Who fills in the tech log fuel section?5,000 litres was about 9000 lbs using a formula of double minus 10% and then adding it to the fuel remaining - stick with SG?

[B737900er]

My company Part A says uplift and planned uplift must be within 5%

[Denti]

A fuel quantity crosscheck has to be done each sector and has to be documented in the fuel part of the ACARS journey log (we dont have paper journey logs). The max allowable difference between calculated and indicated fuel is the higher of either 500kgs of fuel or 3% of the indicated fuel. Fuel density should preferrably be provided by the supplier, if that is unavailable a conversion table based on fuel temperature (temperature provided by the supplier) or 0.8 as standard value.

[TURIN]

Depends on the airline. Some flt crew take the uplift and sg direct from the refueller and calculate the discrepancy themselves. Others get the ground engineer/technician/mechanic to do the calculations and fill the log in. Either way the Captain or FO do a cross check.

[Mgggpilot]

Our company requires us to calculate the uplift. Then to find the difference btn the calculated and the actual uplift.

The only thing though they never told us is how much of this variance is acceptable.

How to calculate the uplift in kgs: (Total fuel required in tanks minus the remaining fuel in tanks before refill) divide by Specific gravity of fuel.

[sky9]

It would be prudent for the operating crew to do the calculation even if it isn't required. It is them not the engineer or refueller that has to live with the consequences of an incorrect uplift.

[Don Coyote]

For UK operators CAP 789 Chapter 9 Paragraph 1.15 has some guidance namely:

1.15 Fuel Uplift Reconciliation
1.15.1 Operators are to ensure that the instructions for the refuelling of aircraft specifically require the commander to reconcile the initial fuel contents, and the known added fuel quantity as per the refueller's written records, with the total contents indicated by the aircraft's fuel gauge at the end of refuelling. If the uplifted fuel is not delivered through a calibrated meter, other means of confirmation such as a visual check of fuel contents will be necessary, which may require the aircraft to be shut down.

This guidance was introduced in FODCOM 01/08 to implement a recommendation addressed to the UK CAA by the Irish Air Accident Investigation Unit (AAIU) in response to a serious incident

[BARKINGMAD]

The commonsense procedures which used to hold sway have probably been swamped by the beancounters obsession with carbon use and other exotica designed to employ otherwise useless administrators.

WHO in their right mind is going to allow the bowser driver to depart the aircraft without some form of gross error check on how many litres should equal the kg uplift??

Dan-Air and others practised it many years ago, but todays digitally obsessed airlines are not so much worried about whether the crew have enough motion lotion aboard than sweating about the SG and its calorific value and their place in the great carbon trading con which is screwing us all in our domestic fuel bills!

But not any longer, the fuel chit comes aboard, the bowser has :mad:'d off to the other side of the field and the SOP is now to fiddle with calculator changing litres BACK to KGs, using quoted SG figures to 3rd decimal place, then comparing before and after tank indications and then finding out too late that it's not quite right.

Can't see a pilot inventing that check, nor an engineer...................?

The question of discrepancy used to be answered by "oh it's 300kgs" til the respondent was challenged with "and what if we've only uplifted one tonne?". And that was from "qualified 737 engineers" who'd "used that figure on the 757"....................!

It's still a grey area in which a lot of airlines seem to have lost the plot. :ugh:

[Check Airman]

For what it's worth, at my airline, we never see the fuel slip. The bowser comes up, and fuel us, then goes off to the next plane.

[BOAC]

Don't you have a tech log and if so who fills in the fuel uplift?

[nitpicker330]

We see the fuel receipt ( sign it ) then calculate the actual uplift and check it is within limits from the calculated uplift. Also checking grade of fuel and distribution in the correct tanks.....etc

Some Airlines don't do this????
Really?

[Capn Bloggs]

For what it's worth, at my airline, we never see the fuel slip. The bowser comes up, and fuel us, then goes off to the next plane.
Let me guess... Air Canada? :}

But not any longer, the fuel chit comes aboard, the bowser has 'd off to the other side of the field and the SOP is now to fiddle with calculator changing litres BACK to KGs, using quoted SG figures to 3rd decimal place, then comparing before and after tank indications and then finding out too late that it's not quite right.

Let's not get carried away. If you asked for 10,000kg and you got it on the gauges, there's a pretty good chance your "litres added" check will be OK. If the 3%/5% check subsequently doesn't work out, who cares? Ground the aeroplane until the engineers or your FO does a dip, and then launch!

PS: I was in 0A first! ;)

[catpinsan]

In my company, before the introduction of the 2 man cockpit, the Flight Engineers always did this cross-check. But it was (I'd say correctly) deemed to be too much for a 2man crew and hence it was discontinued.

It was reintroduced as a procedure for pilots after an allegation that "those at the other end of the ground interphone" were indulging in malpractice at a particular station. I do not think the company ever found genuine malpractice, but being abundantly careful, the fuel uplift calculation was added as a check to be done by pilots. Prior to this the Engineering offered us the airplane along with fuel and other fluids, and the Captain basically trusted those involved in fuelling etc. and the gauges.

Subsequently it was incorporated in detail into the Tech Log for the attending Engineer to fill, and hence the pilots no longer perform the conversion of the required fuel from volume to weight, but they can view it in the tech log sector release page.

Anyhow, have always been wondering about the possible gambit among those involved, e.g. what exactly could be done with the misappropriated Jet A-1?

Ideas anyone?

[Check Airman]

Don't you have a tech log and if so who fills in the fuel uplift?


If by tech log, you're referring to what we call simply the maintenance log, then yes we do. However, apart from maintenance items, the only thing in there is the Captain's signature and first flight of the day checks.

[BOAC]

Where is the record of arrival and departure fuel kept in your airline, CA? There appears to be none, which I believe to be illegal.

[Check Airman]

Blogs, touché.

Nope not Air Canada. Our OOOI ACARS message includes time and fuel. So there is a record of how much fuel was on board at arrival, but I've never seen anybody check that number. In any event, like I said above, we don't see the fueller anyway, so there's no way for us to know what volume was added.

[Onceapilot]

Part of the reconciliation process is a check against gauging errors. Not good to find you have not got as much fuel as you thought when you divert:uhoh:!

[Basil]

Part of the reconciliation process is a check against gauging errors.
. . and fraud. At a well known Italian airport I noticed that the uplift error always favoured the supplier.
I noted the figures for a few trips and filed a report. Tech manager said that they knew about the problem.
I guess if we'd made waves there would suddenly have been a lot of unexplained delays for our aircraft.
Please don't let the UK become like those places.

[mikedreamer787]

And quite a few places over here to Basil who'll push the
discrepancy limit close to the 3% boundary, and they are
smart - if they know the flight and the expected uplift they
will know how much to set on the truck to cheat and when
and when not to do so.

One screwed up once by 100kg requiring me to order a drip
done (refuelling truck was expecting flight AB123 but it was
suddenly changed on the spot to AB456 requiring much less
uplift) and a full investigation was done. Turns out the truck
was zeroed at 130L for 123 whereas 456 would've been 57L.
Truck bloke wasn't told nor could he see the panel change
and expressed surprise when the flow stopped short of what
he expected as the change occurred about a minute after the
refuelling started.

[parabellum]

. . and fraud.


I got stitched up one night at Athens. My turn for walk round and refuelling.
Bowser came alongside and connected up, I noted that the gauges were at zero and gave the refueller the shut off amount so that he could dial up the correct number for auto shut off. Normally that was it, he would bring the fuel chit, collect his 20 fags and be gone. This night I noted the fuelling had stopped so went to see, got there in time to see another bowser hooked up and the numbers suggested he had been fuelling some time, not just started!

The story was that bowser #1 had 'run out' so they brought bowser #2 who had just come from the business jet apron. Final uplift, according to the drivers/refuellers was way, way above what it should have been.
An investigation revealed that driver/bowser #2 had fuelled an executive jet and taken cash, come straight to me and tried to get me to pay for the exec jet fuel! driver/bowser #1 was, of course, in cahoots. Cant believe they thought they would get away with it.

[TURIN]

Are some of you actually saying that you, as commander of your a/c, will depart from the gate with fare paying passengers on board, without cross checking that the fuel uplift is within tolerance.
I am shocked!

[BARKINGMAD]

And what happened to the recording in the Tech Log of the Totaliser readings after every sector?

Interesting to compare the actual burn with the CFP figure, a judicious tweak to the homebound figures might avoid an embarassing shortfall if no other reason can be found to account for overconsumption.

Some aircraft bias figures are possibly out of date, but by the time it passes under the noses of the deskpilots it may be too late to avoid that :mad:-puckering moment when one realises that all is not well?

Capt Bloggs, I cede the seat to you!

[JammedStab]

Thanks for the replies.

Several have said that they do a crosscheck but what exactly does that mean? Does this mean that you are taking your calculator out(or quickly using a formula in your head) and double checking that the uplift in terms of pounds based on before and after fuel guage readings is close to the amount of litres or gallons loaded.

We have a fuel sheet and both those numbers are listed(pounds uplifted based on before and after fuel guage readings along with litres delivered) but I don't see anyone doing some sort of calculation to ensure that they match or are near equivalent. I assume the fuel man does it but I don't know.

[Capn Bloggs]

Several have said that they do a crosscheck but what exactly does that mean? Does this mean that you are taking your calculator out(or quickly using a formula in your head) and double checking that the uplift in terms of pounds based on before and after fuel guage readings is close to the amount of litres or gallons loaded.

It's been a regulatory requirement here for decades: to the fuel remaining from the last flight, add the fuel loaded and make sure the new total on board (gauges or drip) equals the remaining+added plus or minus 3%. So yes, calculators/phones out. If not within 3%, start asking questions. Easier in the old bombs to use parallax to "adjust" by 50kg; bit harder to cheat now with digital displays! :{

That said, after a crew almost ran out of fuel due to a refuelling stuffup a few years ago, the regulator removed the regulatory need for a 3% check, deferring to the operators to make sure the fuel load was "correct".

[bubbers44]

Some central America countries, Panama, I was always slightly short on fuel so kept all receipts and went down and monitored the truck readings and recorded our fuel purchases. I took my findings to the chief pilot at Miami and they investigated. They found nothing so guess it was the cost of doing business. Obviously the truck gauges were rigged. What they put on vs what I parked with was always short.

[Dan Winterland]

One bowser I have encountered gave the same discrepancy every refuelling. It transpired it was the same as the capacity of the second diesel tank fitted to the vehicle which turned out not to be connected to the engine! I also saw a discrepancy of exactly 1000USG in the Philippines which was corrected immediately without question.

Fraud is endemic in aircraft refuelling.

[BARKINGMAD]

My own stay outa trouble technique, instilled by late great DanAir aeons ago, is to subtract what's left from what we want @ departure, divide by 4, add the result to the expected uplift kg figure, and then add some to the total if it's hot or a low SG fuel supplier.

Only applicable to KGs aircraft guages and LITRES delivery of course.

Can be done in the remains of my brain as I sally forth to examine the 'frame to see what's dropped off, and I impress upon the bowser operator that that litres figure is roughly what I expect to see on the bowser meter.

Subsequent calculator bashing is to keep the carbon trader fraternity happy as, if my gross error is within 3%, then I'm happy to close up and push off homewards.

Simples or not? :)

[flyboyike]

Are some of you actually saying that you, as commander of your a/c, will depart from the gate with fare paying passengers on board, without cross checking that the fuel uplift is within tolerance.
I am shocked!


If the gauges show what the release says they should show, we're good to go. We also don't start the engines by hand any longer, nor check the oil in each engine prior to departure.

Shocking indeed, although nowhere near as shocking as the kind of money we do this for.

[FlightDetent]

If the gauges show what the release says they should show, we're good to go. We also don't start the engines by hand any longer, nor check the oil in each engine prior to departure.

Shocking indeed, although nowhere near as shocking as the kind of money we do this for.

Seconded. Twice.

[JammedStab]

If the gauges show what the release says they should show, we're good to go. We also don't start the engines by hand any longer, nor check the oil in each engine prior to departure.

Shocking indeed, although nowhere near as shocking as the kind of money we do this for.

So what is your method to discover a faulty fuel quantity system and if you had been captain of this flight, would you have ended up in the same situation?

On August 5 Quinter's ATR-72 TS-LBB arrived at Tunis with 790 kgs of fuel left in the fuel tanks. During maintenance the Fuel Quantity Indicator (FQI) was changed. Erroneously the FQI for ATR-42 aircraft was installed. The normal operation of the FQI is to processes the signal coming from the capacitance probes installed in the tanks with an algorithm typical for each aircraft, depending on tank shape, size and number of probes installed. The indication of the amount of fuel on board the airplane now read 3050 kgs instead of 790 kgs. On August 6 the airplane was prepared for flight 152F to Bari. An amount of 465 kgs fuel was added for the flight (total fuel: 1255 kgs, with 3800 kgs indicated). Upon landing at Bari only 305 kgs were left in the tanks. Normally this should have triggered a 'LO LVL' warning, but the FQI read 2300 kgs, which made the crew believe they had plenty of fuel left. In preparation for the flight to Djerba, just 265 kgs of fuel was added. The flight departed with 2700 kgs of fuel indicated by the FQI (actual amount: 570 kgs).
En route, at 15:24 the crew contacted Palermo for an emergency landing. They had run out of fuel and both engines had quit. Their FQI nevertheless showed 1800 kgs of fuel. They did not make it to Palermo and ditched in the sea around 15:40.

ASN Aircraft accident ATR-72-202 TS-LBB Palermo-Punta Raisi Airport (PMO) (http://aviation-safety.net/database/record.php?id=20050806-0)

[CONF iture]

So what is your method to discover a faulty fuel quantity system and if you had been captain of this flight, would you have ended up in the same situation?
After the airplane was released by the maintenance, nobody could have catch the erroneous indication ... Would you have JammedStab ?

[Capn Bloggs]

After the airplane was released by the maintenance, nobody could have catch the erroneous indication ...
This has happened to me before (not ditching in the drink!). Got a fright when the fuel low level light for a tank came on with what should have been enough fuel on board to not trigger the warning. Did a dip after landing and the main gauges were quite a bit out.

Unless a dip or full-tank refuel is done on a regular basis (or the aeroplane runs out of fuel, or more likely the separate-pickup low-fuel lights illuminate if fitted)) a dodgy FQI system won't be picked up by the normal 3% check. A dip/full tank check should be mandatory after a FQIS servicing.

[BARKINGMAD]

Agreed Capt Bloggs, but such a procedure costs money and would leave a frame with absolutely full tanks with no flight to earn bucks to follow.

Can't see the engineers getting that past the beancounters.

Surely adequate recording of guage figures, cross-checked by volume checks and finally a space in the tech log to record and compare how much the engines have guzzled, a figure which would also be included as part of the verification, would be more likely to be implemented by the psycho corporations of today?

Obviously APU running, ground running post-wash, MCDs etc has to be accounted for, but hopefully a drift out of tolerance will be picked up by those in Eng Records?

The ATR suffered from inadequate Tech Log entries which was one of the holes in that cheese, illustrating how important it is to accurately record the regular uplifts. :hmm:

[JammedStab]

After the airplane was released by the maintenance, nobody could have catch the erroneous indication ... Would you have JammedStab ?



I hope I would have caught it as I did a check on every uplift I ever had on the ATR. In Bari, the required fuel uplift was 400 kg. This means about 900 pounds required. Total liters uplifted was 340 litres.

For a quick check, 340 times 2 equals 680 minus 10% equals about 600 pounds uplifted compared to 900 required. That is around a 30% error. Actually, they had a known uplift their point of origin as well that was off by over 30%. Their fuel burn for the first leg was 37% high.

Isn't that what the intention of a fuel check is all about?

[TURIN]

Quote:

Originally Posted by Turin

Are some of you actually saying that you, as commander of your a/c, will depart from the gate with fare paying passengers on board, without cross checking that the fuel uplift is within tolerance.
I am shocked!

If the gauges show what the release says they should show, we're good to go. We also don't start the engines by hand any longer, nor check the oil in each engine prior to departure.

Shocking indeed, although nowhere near as shocking as the kind of money we do this for.

When you say "release" do you mean the log book or the receipt from the bowser? The log book record will have the cross check entry surely.

Most large transport a/c I am familiar with will have the oil checked before departure. Either a physical check or gauge.

I agree with the shocking amount of money "we" do this for too but I'll bet you wouldn't trade your wage for mine.

[flyboyike]

TURIN, I don't know what your background is, but if I have to explain to you what a dispatch release is, I fear we won't get far.

And no, "most transport" category airplanes don't have the oil checked before departure, that's utter nonsense. There is an oil quantity indication on the EICAS. If it's in the green, that's all I care about.

[sjm]

Fuel on gauges/ required fuel - fuel remaining(previous sector) = required uplift in kgs

Converted into litres and recorded as required uplift in litres

actual uplift in litres then converted into kgs and recorded then,

added to fuel remaining (previous sector)

Total in tanks, to equal within tolerance of 300kg, the calculated fuel:ugh::ugh:

= ball ache:rolleyes:

[flyboyike]

So what is your method to discover a faulty fuel quantity system?


PFM and lots of prayers, I suppose.

[BOAC]

TURIN, I don't know what your background is, but if I have to explain to you what a dispatch release is, I fear we won't get far. - a moment's looking would show you Turin claims to be from the UK where we have no such thing, so no, we will not get far.

[flyboyike]

Regrettably so.

[TURIN]

The only dispatch release I know of is the one sent by acars to the a/c with the MEL items added. I take it this also has your fuel requirement on it.
However, surely, someone will cross check the uplift against pre-refuelling fuel on board to ensure the gauges and calculations tallies?

As for an oil check. Not nonsense at all. Every transit check I know of, whether it be an N, G, 9V, A6, A7, D or F registered someone, whether it be maintenance or flt crew, will check the oil level. That includes you chief when you glance at the EICAS.

[EGPFlyer]

In easyland we note the arrival fuel, expected uplift in KG, actual uplift in litres, actual uplift converted to KG and the departure fuel in the tech log. The oil quantities are also noted before every departure. All very sensible and takes all of 30 seconds, provided you are proficient in your 0.8 times table. :ok:

[CONF iture]

JammedStab, thanks for the reply, interesting.
I initially thought the error between the fuel quantity indication and the real fuel quantity on board was a constant whatever the real fuel quantity.
There was a possibility, for a very alert crew, to hopefully investigate further the unusual fuel burn or the little fuel added in liters versus in kg according to the FQI.

[BARKINGMAD]

sjm "Total in tanks, to equal within tolerance of 300kg, the calculated fuel":=

PLEASE don't continue with this mythical figure of 300kgs!

It might apply to very large aircraft with very large uplifts, but what if one only uplifted 1 tonne? I leave it to you to work out the % error in that?

The 737 quotes guage tolerance of +/- 2.5% at FULL in each tank, so let's stay with that form of tolerance and the quoted maker's figures for any type.

The 300kgs figure has been bandied around too long by those who haven't thought it through, even engineers, so can we bury it in the fairy tales book once and for all time???? :ugh:

[ahramin]

At my airline the written SOP is to check the fuel uplift, but that's it. Doesn't matter what the check shows, there is no guidance on what discrepancy is acceptable.

Probably why the prevalent SOP is to skip the check.

[Capn Bloggs]

Barking,

You're being a bit harsh there. He did say:

Total in tanks, to equal within tolerance of 300kg, the calculated fuel
, not the uplift within 300kg.


At my airline the written SOP is to check the fuel uplift
I'm glad about that! :p :D

[BARKINGMAD]

Cap'n Bloggs, harsh but fair.

I presume we are discussing a variety of types, with greatly varying tankage.

If the ATR off Palermo permitted 300kgs of error tolerance, then that accident could have happened without the wrong guages.

"Total in tanks, to equal within tolerance of 300kg, the calculated fuel", is a plain statement, which I have obviously misinterpreted, so I wait for clarification and education.

Can we have your understanding of this FIXED figure amongst the enormous variety of uplifts every day by a multitude of crews?

Keeping the fuel exhaustion accidents in mind, Alidair Viscount @ Ottery St Mary in UK in 70s, the lbs/kgs Canadian (A300?) deadstick landing, the Tunisian ATR off Palermo and others, I am concerned that in the absence of ones own company quoting HARD tolerance figures that someone reading this thread may go off into the blue accepting the 300kg figure as a useful guideline.

I blame the companies for not specifying this figure in their OMs, strange given the understandable obsession with crew fuel uptakes and the reasons for taking any extra above the CFP figure.

Now I am :confused:!!, but put it down to age and too many sectors at night..................

[root]

Normally you would calculate how many liters roughly you are expecting before the fueller has even connected. This is just common sense, regardless of what your SOP may be.

[BARKINGMAD]

"Can be done in the remains of my brain as I sally forth to examine the 'frame to see what's dropped off, and I impress upon the bowser operator that that litres figure is roughly what I expect to see on the bowser meter." BM Posting # 28?


"Normally you would calculate how many liters roughly you are expecting before the fueller has even connected. This is just common sense, regardless of what your SOP may be." Root Postin # 49

We may be straying into that dangerous area which used to be known as "airmanship", since replaced by "where does it say that in the book?".

Hopefully some companies' managements are following this thread and might just respond with some firm guidance for those of us not previously indoctrinated in the mysteries of fuel reconciliation.

Until then I will carry on doing what has prevented me and others from converting our expensive toys into gliders for want of some simple maths.

And as in the other thread, I shall continue to practise gliding in the expensive toy by way of performing CDAs where possible, but with juice in the tanks to keep me outa the smoking hole, though if there's no fuel, then there would not be too much smoke.....................................? :confused:

[JammedStab]

JammedStab, thanks for the reply, interesting.
I initially thought the error between the fuel quantity indication and the real fuel quantity on board was a constant whatever the real fuel quantity.
There was a possibility, for a very alert crew, to hopefully investigate further the unusual fuel burn or the little fuel added in liters versus in kg according to the FQI.

The best plane I ever flew for having an accurate fuel check was the HS-748. At our home base, the fueller would be told the flightplan fuel. He would hook up the fuel hose, then pull the fuel dripsticks out to the appropriate fuel quantity level(which stick was pulled depended on how much fuel was required) and then pumped away until fuel started dribbling out. If our gauges matched what was required on the flight plan(which is the amount given to the fueller) or was close, then it was accurate.

Of course the greenies don't like the idea of a bit of fuel going on the ramp as can be seen at some European airports. But then again it is going to come out of the aircraft one way or the other.

[TURIN]

I blame the companies for not specifying this figure in their OMs, strange given the understandable obsession with crew fuel uptakes and the reasons for taking any extra above the CFP figure.



Every, and I mean every, commercial aircraft I have worked over the last 30 years or so has carried a refuelling manual onboard. It details the refuelling procedures, lists allowable refuelling discrepancies and pages of stick conversion tables based on differing SGs and aircraft attitudes.


From what I am reading on this thread it comes as a surprise, to me at least, that the above is not the norm.

[BARKINGMAD]

Yes, Turin, there used to be a Noddys guide to refuelling aboard, but now that we're not allowed even to carry a screwdriver for "minor maintenance tasks", presumably because some EASA desk pilot considers us unfit for such duties, I suspect it's been removed.

Even worse, it's been hidden or lost in the maze of EFB or e-manuals which are all the rage with de management, but as a recent CHIRP demonstrates, are not necessarily the answer to the task of staying abreast of changes.

As part of my inflight occupational therapy, I will on my next trip scour the flight deck for such a publication, but without much hope of success.

I might even discover the source of the magic 300kgs figure....................? :confused:

[flyboyike]

Every, and I mean every, commercial aircraft I have worked over the last 30 years or so has carried a refuelling manual onboard. It details the refuelling procedures, lists allowable refuelling discrepancies and pages of stick conversion tables based on differing SGs and aircraft attitudes.


I've never even heard of a refueling manual. On ANY aircraft, commercial or otherwise.

[ahramin]

I've never seen a refuelling manual either.

For those that calculate your expected uplift beforehand as a matter of airmanship, what would you do if the uplift was 1000 litres less than what you expected? Delay departure and investigate, or go anyway?

[Capn Bloggs]

For those that calculate your expected uplift beforehand as a matter of airmanship, what would you do if the uplift was 1000 litres less than what you expected? Delay departure and investigate, or go anyway?

Obviously, you'd check it out. Either the tanker gauges are wrong or the aircraft FQIS has developed a fault. Tanker? You could be paying big dollars when you didn't get the fuel. FQIS? Good thing you picked that up; do a dip to verify actual FOB.

[TURIN]

I've never seen a refuelling manual either.

For those that calculate your expected uplift beforehand as a matter of airmanship, what would you do if the uplift was 1000 litres less than what you expected? Delay departure and investigate, or go anyway?


This is where your refuelling manual comes in. It will show whether or not the 1000 ltrs is within the allowed discrepancy for that type / fuel load.

EG.
The 747 classic used to have arbitary allowable discrepancy figures of +2% and -1% of the fuel load.
So, for a fuel load of 130,000 KG, the allowable discrepancy was +2600kg and -1300KG.

Except, its not that simple. There was also a graph showing an upper limit to the discrepancy. I can't remember off hand what that was. 1200KG rings a bell but to be honest its such a long time since I refuelled a 747 the grey matter is struggling.
However, the figure of 300KG quoted previously may have been the upper limit for a smaller type such as a 737.

[BARKINGMAD]

As per Turin, were it a VERY large 'frame where I'd uplifted 100,000 litres, then the discrepancy is +/- 1% which should be well within the makers fuel guage tolerance figure.

If it's my current 73NG mount, or a small 'bus, then everything will stop for tea whilst dip checks are carried out.

I still can't understand why FIXED litreage/kgs/lbs figures are still being bandied about when it surely must be a percentage of any uplift to be meaningful and accurate?

The principle of working out an accurate volume expected is not just good airmanship (that word again!) to make sure you have enough/not too much and that the FQIS is working properly, but sensible practice before you release the bowser to disappear elsewhere on the airfield and then need to call for top-up.

Try this at Majorca on a busy summer weekend day and you can forget about ATC slots and start looking at your duty hours?!

[TURIN]

While googling for an example fuel manual I found this...

Pprune Archive 2010 (http://www.pprune.org/tech-log/417886-fuel-sg-bowser-uplift-vs-calc-uplift.html)

Bit more info and a few post from yours truly that I have no memory of. :uhoh:

[flyboyike]

The best plane I ever flew for having an accurate fuel check was the HS-748. At our home base, the fueller would be told the flightplan fuel. He would hook up the fuel hose, then pull the fuel dripsticks out to the appropriate fuel quantity level(which stick was pulled depended on how much fuel was required) and then pumped away until fuel started dribbling out. If our gauges matched what was required on the flight plan(which is the amount given to the fueller) or was close, then it was accurate.


Dripsticks, refueling manuals....God, my life is easy.

[BARKINGMAD]

"Dripsticks, refueling manuals....God, my life is easy."

Relax, that was the old days when men were men and had sheep for breakfast, hopefully not in the biblical sense.........................................:)

[Paul Wilson]

To give an idea of what you do with a bit of fuel, an example from my dad's first job as a petrol station attendant. (Same principle applies)
Local cement firm had an account, ran about 40 cement lorries. They had 50 gallon tanks. Standard chit chat when driver comes in, followed by "one for you, and one for me?" 48 gallons delivered. Dad writes out chit for 50 gallons, gives driver the price of a gallon, he now has 2 gallons "in the tanks" - repeat as necessary.
Private driver comes in later in the week, "10 gallons" he says, dad duly pumps "his" 10 gallons in, and collects the cash from the driver, goes into pocket.
Everybody's books look right, with the exception of the cement firm, who may have sharp words with the lorry supplier, as they use about 4% more fuel than advertised. But b cement tricks spend a lot of time idling, and don't do to much long distance work, so they probably never noticed.

Anybody remember a "shot of redex, for upper cylinder lubrication" if you were paying cash at a serviced petrol station, the cash went in the pocket of the attendant, and the redex never went in your tank.

These are just 2, and don't need the involvement of the management. Imagine what you can do if you own the place?

[MD83FO]

could they cheat by giving you a higher SG?
how can i get proof of the real specific gravity, as they just bring a hand written paper.

[emmanuel_tabilon]

can you tell me what is fuel discrepancy?

[Capn Bloggs]

can you tell me what is fuel discrepancy?
If the fuel remaining from last flight + the fuel added exceeds (or is less than) 3% of the fuel now on board, that's a discrepancy; >3%.

[TURIN]

can you tell me what is fuel discrepancy?

Depends on the airline.

It could be the difference between the actual uplift of fuel and the calculated uplift. (A volume EG Litres)

EG. If you start with 3000KG of fuel on board, and you actually need a block fuel figure in tanks of 11000KG then you will need to add 8000KG which with an SG of say .800 is 10000Litres.
If you uplift 10300 Litres to achieve a fuel indicated gauge reading of 11000KG then your discrepancy is +300 litres or 3% of the uplift (or 2.72% of the Gauge Total)

Or it could be the difference between what the aircraft fuel gauges are showing and the calculated sum of fuel uplift and fuel remaining before fuelling.

EG As above, gauges at start show 3000KG. When you finish they may show 11300KG.
If you have added say 10000Litres of fuel (8000KG) then the difference between the sum of 8000KG & 3000KG and 11300KG on the gauge gives you a discrepancy of 300KG. Or 2.65%

Some companies have the most bizarre ways of working out discrepancies. Some logical, some not so.

[SP01L3R]

My Company uses a simple table
00000kgs> 30000kgs +/- 1000kgs
30001kgs > 70000kgs +/- 1500kgs
70001kgs > 100000kgs +/- 1800kgs
100001kgs > Full Tanks +/- 2100kgs