nema From United Kingdom, joined Feb 2006, 647 posts, RR: 0 Posted (4 months 3 weeks 5 days 9 hours ago) and read 11190 times:
Just had an hours delay waiting for an inbound flight with Thomsons (TOM517) and when we eventually boarded the 737 aircraft the Captain explained the reason for their late arrival...
Apparently due to an instrument fault at EMA, when fuel was being loaded, too much was pumped in which then made the aircraft illegal to fly. He went on to say that, with there being no way to unload the surplus fuel, they had to wait around 45 minutes to burn off the surplus, hence the delay.
This is a new one on me but i wonder how this might happen. An instrument fault didn't really offer enough detail to understand how this actually happened, but it must have been costly for someone. Assuming the information as to how much fuel is being loaded is known by the fuel tanker operator as well as the crew, so at least one end of the operation gets it right unless a significant mis calculation was done which surely could have been noticed.
There isnt really a dark side to the moon, as a matter of fact its all dark!
dogbreath From United Kingdom, joined Mar 2008, 193 posts, RR: 0 Reply 1, posted (4 months 3 weeks 5 days 8 hours ago) and read 11052 times:
Nothing sinister here.
Fuel gauges can and will always fail, requiring the use of alternate procedures to refuel the aircraft (as approved by the MEL). Also sometimes the refuelling gauge on the wing is defective whilst the flight deck gauge is serviceable, and the refueller may overfuel the aircraft if unsupervised. I don't work for Thomson or know there SOP's, so have no idea how they refuel their aircraft. But in my airline the fuel figure is passed to the refueller via Operations, and the refuelling takes place before we even arrive at the aircraft. If a fuel gauge is MEL'd inop, the refueller will wait until we arrive, or a maintenance engineer will oversee the refuelling so that the correct amount of fuel is loaded.
Whatever the reason for the overfuelling in your case it's obviously an oversight (or error) by someone and the flight crew did the correct actions to prevent an overweight departure.
nema From United Kingdom, joined Feb 2006, 647 posts, RR: 0 Reply 2, posted (4 months 3 weeks 5 days 8 hours ago) and read 10928 times:
Quoting dogbreath (Reply 1): Whatever the reason for the overfuelling in your case it's obviously an oversight (or error) by someone and the flight crew did the correct actions to prevent an overweight departure.
Thanks for that, i guess to avoid any alarm, the 45 minute burn off would have just been a steady engine run, would be interesting to know how much fuel that would be though.
There isnt really a dark side to the moon, as a matter of fact its all dark!
antonovman From United Kingdom, joined Mar 2001, 705 posts, RR: 0 Reply 3, posted (4 months 3 weeks 5 days 7 hours ago) and read 10847 times:
Expensive mistake. A few times I have come across this and we were always told that there was no empty fuel truck to defuel the a/c. If it had been done it apparently can only be used again by same operator.
The only time it worked for us was in the USA and it seemed to be routine there
Umm , dunno about illegal, overweight I'm sure, but not illegal. The airline generally would BUMP bags and , god forbid, passengers to bring the aircraft within operational weights if they really wanted too.
That being said... it would be in the neighbourhood of 4000lbs or 2250 litres of fuel that had to be burned off on your particular flight for a 737-300/400/500 or as little as 3500lbs or 1967litres for the NG models.
Some fuelling operations do have the ability to defuel an aircraft, but it would have taken as long, if not longer!
In your particular instance TOM opted to do something to make sure everyone was accomodated with the least impact on operations and customer satisfaction.
BMI727 From United States of America, joined Feb 2009, 11546 posts, RR: 27 Reply 5, posted (4 months 3 weeks 5 days 6 hours ago) and read 10547 times:
Quoting antonovman (Reply 3): A few times I have come across this and we were always told that there was no empty fuel truck to defuel the a/c.
How would that process work at airports that have the underground tank system? Can the pump rigs put fuel back into the ground? Would that even be allowed, or would they have to put it into a tanker?
Why do Aerospace Engineering students have to turn things in on time?
AA737-823 From United States of America, joined Mar 2000, 4856 posts, RR: 13 Reply 7, posted (4 months 3 weeks 5 days 6 hours ago) and read 10428 times:
Quoting BMI727 (Reply 5): How would that process work at airports that have the underground tank system? Can the pump rigs put fuel back into the ground? Would that even be allowed, or would they have to put it into a tanker?
It's a nightmare. You cannot put fuel back into the hydrant system, no...
And, as someone else already mentioned, fuel that comes off of a plane cannot be put into another plane- at least, it belongs to THAT specific airline. It's a real headache.
All that AND there typically aren't any empty fuel trucks driving around.
I've been in this situation as a mechanic, who was supervising the fueling process for Heavies at the time. It's a very, very ugly situation to find yourself in, because all of a sudden, your plane can't fly, and no one really wants to help you with the problem. At all.
antonovman From United Kingdom, joined Mar 2001, 705 posts, RR: 0 Reply 8, posted (4 months 3 weeks 5 days 3 hours ago) and read 10002 times:
Quoting BMI727 (Reply 5): And, as someone else already mentioned, fuel that comes off of a plane cannot be put into another plane- at least, it belongs to THAT specific airline. It's a real headache.
All that AND there typically aren't any empty fuel trucks driving around.
Thats right, its classed as being "contaminated fuel" then.
So how did you get yourself out of the mess ? run ? LOL
grimey From Ireland, joined Jun 2005, 402 posts, RR: 5 Reply 10, posted (4 months 3 weeks 5 days ago) and read 8400 times:
I was told before that if your ever going to take off overweight make sure that its overweight with fuel and the only time your carrying too much fuel is when your aircraft is on fire.
Look on another bright side at least you didn't take off with less fuel then what was actually needed.
AAMDanny From United Kingdom, joined Apr 2008, 261 posts, RR: 0 Reply 11, posted (4 months 3 weeks 5 days ago) and read 8108 times:
Simular thing happened in MBJ to a VS 747 & a BA 777.
The Fueling truck's pump was faulty and was giving erratic readings, so a manual fuel count of each of the aircrafts fuel tankes had too be carried out, although the aircrafts tanks showed the correct ammount of fuel loaded you need two lot's of verification that it is correct (normally one from the fuel loader and one from the aircraft)
I've also seen a TCX 757 once at BHX have to do a simular thing when too much was loaded for a SSH sector and spent 40 minutes burning off th eexcess fuel as it was the quickest option, you also have too remember other factors such as crew hours and logistics of unloading pax, getting new crews and replacement aircraft etc, sometimes just literally burning it off is the quickest option.
tdscanuck From Canada, joined Jan 2006, 11037 posts, RR: 72 Reply 12, posted (4 months 3 weeks 5 days ago) and read 7992 times:
Quoting nema (Thread starter): This is a new one on me but i wonder how this might happen.
Many aircraft, including most models of 737, use automatic fulling shutoff. You program the fuel panel with how much fuel you want and the valves will close automatically when the indicator has the correct quantity in the tank. This is particularly helpful for large aircraft with complex fuel systems so that the fueler doesn't have to think as hard about how much fuel is in each tank, just on getting the right total.
If one of the indicators (or a downstream component like a tank sensor) goes bad the valves may not shut at the right time. If the quantity was close, like it sounds like it was in this case, you probably wouldn't notice until the fueler cross-checked the final uplift from the truck against what the aircraft says it has.
Quoting antonovman (Reply 3): A few times I have come across this and we were always told that there was no empty fuel truck to defuel the a/c. If it had been done it apparently can only be used again by same operator.
Yes. Normally no other airline will accept the liability of using it and no fueler will accept the liability of retesting it to put it back into their system for general use. It is a serious pain in the rear.
Quoting BMI727 (Reply 5): How would that process work at airports that have the underground tank system? Can the pump rigs put fuel back into the ground? Would that even be allowed, or would they have to put it into a tanker?
You have to pump it into a truck, which you are now the proud owner of until you pay the fueler to dispose of it or you come back to pick it up. In theory, if it was a really huge load (e.g. a full jumbo) you could flow it back through the piping to a dedicated storage tank but there aren't many airports with hydrant fueling that will want to dedicate an entire tank just to you.
This isn't such a big deal at many smaller airports where they like the revenue they get from renting fuel storage space to you, but anything of any size needs all their trucks a lot more than they want the incremental revenue of tying one up as temporary storage. And, as an operator, it's way more inconvenient because you now have to coordinate to make sure you get that specific truck when you come to pick up, as opposed to whatever's available.
ikramerica From United States of America, joined May 2005, 20630 posts, RR: 62 Reply 13, posted (4 months 3 weeks 5 days ago) and read 7992 times:
Quoting dogbreath (Reply 1): Whatever the reason for the overfuelling in your case it's obviously an oversight (or error) by someone and the flight crew did the correct actions to prevent an overweight departure.
It's not obviously and oversight or error if the gauge failed during the fill, is it? How is one to know? Until the flight crew checks as they do pre-flight and see they are overfull, all might seem fine if the wing gauge failed on that day.
Of all the things to worry about... the Wookie has no pants.
intsim From United States of America, joined Nov 2010, 81 posts, RR: 0 Reply 14, posted (4 months 3 weeks 4 days 23 hours ago) and read 7494 times:
Quoting ikramerica (Reply 13): It's not obviously and oversight or error if the gauge failed during the fill, is it? How is one to know? Until the flight crew checks as they do pre-flight and see they are overfull, all might seem fine if the wing gauge failed on that day.
Quoting tdscanuck (Reply 12): Many aircraft, including most models of 737, use automatic fulling shutoff. You program the fuel panel with how much fuel you want and the valves will close automatically when the indicator has the correct quantity in the tank. This is particularly helpful for large aircraft with complex fuel systems so that the fueler doesn't have to think as hard about how much fuel is in each tank, just on getting the right total.
If one of the indicators (or a downstream component like a tank sensor) goes bad the valves may not shut at the right time. If the quantity was close, like it sounds like it was in this case, you probably wouldn't notice until the fueler cross-checked the final uplift from the truck against what the aircraft says it has.
I am embarrassed to say I was the final nail of a human overfill error. Luckily it turned out well, it was on a Metro III. I was a green rampy 'helping' a fueler relay info when filling the other wing. I thought the little box on the meter meant 1/10s...nope it means gallons. The pumping went to like 124 gallons before the fueler halted to see what was going on. The flight crew was pretty pissed. Luckily they worked it out and the fuel could be tankered.
I agree but how can a plane with such a failure being allowed to take off.....????? what would happens if the failure indicates much more fuel than you got in the tank???
YYZALA From Canada, joined Nov 2009, 142 posts, RR: 0 Reply 16, posted (4 months 3 weeks 4 days 22 hours ago) and read 6755 times:
Interesting responses, but surely it is not the operator's fault but rather the contractor (in this situation). As such they either need to find an empty truck to store that fuel or compensate for the extra fuel loaded and associated headaches to the operator....
LimaFoxTango From Antigua and Barbuda, joined Jun 2004, 574 posts, RR: 0 Reply 17, posted (4 months 3 weeks 4 days 22 hours ago) and read 6407 times:
Quoting YYZALA (Reply 16): Interesting responses, but surely it is not the operator's fault but rather the contractor (in this situation). As such they either need to find an empty truck to store that fuel or compensate for the extra fuel loaded and associated headaches to the operator....
You might be surprised to know that in some contracts between airline and fuel provider, the airline takes responsibility if the fuel provider accidentally (or deliberately for that matter) over fuels an aircraft. An expensive mistake yes, but the airline agrees to accept the liability. Most fuel providers do not defuel aircraft because 1. its considered contaminated fuel and thus cannot be placed in another aircraft, and 2. some fuel providers just don't have anywhere to put it.
You are said to be a good pilot when your take-off's equal your landings.
tdscanuck From Canada, joined Jan 2006, 11037 posts, RR: 72 Reply 18, posted (4 months 3 weeks 4 days 21 hours ago) and read 5903 times:
Quoting ferminbrif (Reply 15):
I agree but how can a plane with such a failure being allowed to take off.....?????
Most modern jets have the fuel quantity indication system on the minimum equipment list...you can have the entire system failed and it's OK to takeoff as long as the fuel quantity has been verified by other methods (often the dripsticks on the underside of the tank).
Quoting ferminbrif (Reply 15): what would happens if the failure indicates much more fuel than you got in the tank???
You repeat the Gimli Glider accident.
Quoting YYZALA (Reply 16): Interesting responses, but surely it is not the operator's fault but rather the contractor (in this situation).
The contractor has no control of the aircraft's fuel indication and fueling system; you can't hold them responsible for failures of the aircraft hardware, which is the most common cause of this type of problem.
jpax From United States of America, joined Aug 2006, 988 posts, RR: 0 Reply 19, posted (4 months 3 weeks 4 days 20 hours ago) and read 4958 times:
Quoting tdscanuck (Reply 18): you can't hold them responsible for failures of the aircraft hardware, which is the most common cause of this type of problem.
I entirely disagree. I've been over fueled quite a few times and not once was it hardware failure. It was all miscommunication, poor fueling practices, rushing, being cold, not paying attention, or any other human screw up. This goes for small FBOs in the middle of nowhere, to a 121 carrier aircraft being fueled at a major airport. And, of course, WHEN they screw up, it takes an hour to get the defueling equipment over, if even available, delaying the flight for no mistake of our own. In addition, I've never heard of any other of our pilots being overfueled due to faulty hardware. I'm sure it's happened, but its almost exclusively human error. The fuelers can be and ARE held responsible every single time.
nomadd22 From United States of America, joined Feb 2008, 1352 posts, RR: 0 Reply 20, posted (4 months 3 weeks 4 days 18 hours ago) and read 4318 times:
We had a few fuel mixups at Hobbs that resulted in unusable fuel. The Fire department was glad to take it as a donation to their training program. The USAF converted a couple of pistons to turbines once without changing the labels. 250 gallons of gas/jet mix wasn't good for much else.
dxing From , joined Dec 1969, posts, RR: Reply 21, posted (4 months 3 weeks 4 days 14 hours ago) and read 4241 times:
Quoting nema (Thread starter): Apparently due to an instrument fault at EMA, when fuel was being loaded, too much was pumped in which then made the aircraft illegal to fly. He went on to say that, with there being no way to unload the surplus fuel, they had to wait around 45 minutes to burn off the surplus, hence the delay.
I suspect the instrument fault was the fuelers head space timing gear. I've seen it happen plenty of times. Unless the aircraft was over take off weight, which pretty much limits you to defueling, and a lot of smaller airports can pump it but can't suck it (clear your filthy minds!), or deplaning pax, bags, cargo. The option they chose, to burn it off would be least desireable in most circumstances so I'm wondering what the limitation was. It must have been a take off weight deal as if it were en-route or landing you could just plan a longer-lower-faster route/speed to burn off the excess. Done that plenty of times.
Quoting tdscanuck (Reply 12): Many aircraft, including most models of 737, use automatic fulling shutoff.
Hmmm, I've fueled my share of B37-57-67-77 aircraft and it's always fill the wings, rest in the center tank. There's a couple of reasons for that one being that if the center fuel tank pumps go inop all that fuel has to be counted as part of the planes zero fuel weight which can put a nice ding on payload performance. The only think the auto shutoff really did for me was keep me from spraying fuel out the vent and all over the ramp. I've seen that happen on an MD80 and thankfully it wasn't me fueling.
Quoting intsim (Reply 14): The flight crew was pretty pissed. Luckily they worked it out and the fuel could be tankered.
I'm surprised to hear this as I have never had a capt call and say "Hey they gave us too much gas, we can take it but we want it taken off!".
Quoting nomadd22 (Reply 20): The Fire department was glad to take it as a donation to their training program.
I've heard of this happening before as well. In addition if the fueler has a spare truck they keep just for defueling, most hub operators do, and they also service the ground equipment and it is diesel, then there's your gas station for the next few days.
tdscanuck From Canada, joined Jan 2006, 11037 posts, RR: 72 Reply 22, posted (4 months 3 weeks 4 days 13 hours ago) and read 4205 times:
Quoting dxing (Reply 21):
Quoting tdscanuck (Reply 12):
Many aircraft, including most models of 737, use automatic fulling shutoff.
Hmmm, I've fueled my share of B37-57-67-77 aircraft and it's always fill the wings, rest in the center tank.
That's normal for three-tank twins. You want to keep weight in the wings as long as you can to get maximum benefit out of the relieving stress on the wings (better fatigue life). It's more complex for something like a 747 (7 or 8 tanks) or an A380 (12 tanks, I think).
Quoting dxing (Reply 21): The only think the auto shutoff really did for me was keep me from spraying fuel out the vent and all over the ramp
If it's working properly and in use, it should also prevent you from filling the center above the target quantity. The thing protecting the main tanks from overflow is the volumetric topoff switch, which is a different function (and different sensor) than the automatic quantity shutoff.
dxing From , joined Dec 1969, posts, RR: Reply 23, posted (4 months 3 weeks 4 days 9 hours ago) and read 4130 times:
Quoting tdscanuck (Reply 22): It's more complex for something like a 747 (7 or 8 tanks) or an A380 (12 tanks, I think).
The reason I didn't list them. Same thing on a ER1J45XR, they are the only ones in that series that have a center tank. You had to be careful not to overfuel them as they were even more weight critical than the larger jets. Then you have the B19's with the aux tanks.
Quoting tdscanuck (Reply 22): If it's working properly and in use, it should also prevent you from filling the center above the target quantity.
In reality if you try and pump all three at once for some reason it bogs every thing down. I used to close the center tank and do the wings first opening the center tank as the wings neared full to keep the flow going. Usually I would open and close the 2 wing tanks independently for the last 500 pounds or so while letting the center tank run. Only did a few 747's and you are correct, they are more complicated and require too much brain power on a cold or cold and rainy night.
troubleshooter From Germany, joined Feb 2005, 423 posts, RR: 5 Reply 24, posted (4 months 3 weeks 4 days 5 hours ago) and read 4052 times:
Quoting tdscanuck (Reply 12): Many aircraft, including most models of 737, use automatic fulling shutoff. You program the fuel panel with how much fuel you want and the valves will close automatically when the indicator has the correct quantity in the tank. This is particularly helpful for large aircraft with complex fuel systems so that the fueler doesn't have to think as hard about how much fuel is in each tank, just on getting the right total.
Never seen that function on the B737 I´ve been working on. Must be optional. The only auto shut-off function in the B737 fuel system I know is the volumetric shut-off, which closes the fuel valve if the related tank is full to prevent an overflow situation.
I´ve worked on B757/767 - they had a fuel quantity pre-selction installed. A320´s as well.
This job sucks!!! I love this job!!!
25 Mender: What I'm about to say my not have happened in this case but I've known the pre-selected fuel quantity to go blank due to a power transfer glitch when
26 tdscanuck: It was optional on the 737-300/400/500 (they had multiple FQIS supplier options). The 737NG has only one FQIS system but the quantity selectors on th
27 troubleshooter: It´s always a good practice to select power for refueling from the batteries.
28 dogbreath: Refuelling an aircraft is not just simply just filling up the tanks and relying solely on the fuel quantity indicating system. On every flight (regar
29 intsim: Sorry. They took the fuel. There were several calls to ops. It seems like the fueler had to match the wing quantities but i do not recall how it exac
30 DarkSnowyNight: The 737s I work with (Most NG types as well as the 4xxs & 5xxs) will indeed auto-shutoff, but only when you are about to hit the VTO. I've not se
31 tdscanuck: The VTO shutoff is a float switch in the high point of the tank that severs power to the refuel valve. It is completely independant of the fuel quant
32 HAWK21M: Out here the fastest a de-fuelling ops can be accomplished will be not less than 1-2hrs.the reason being that due to heavy ATF refuelling demand, the
33 josekmlb: with Delta we had 4 different ways to refuel the airplane for an MD-88, The magna sticks, truck meter, cockpit gauges, and fuel transfer. With the 737
34 KELPkid: When I was an FBO line boy, fuel left over from defuelling operations was used for ground equipment. Diesel engines will burn Jet-A, and anything with
35 HAWK21M: Some GSE are configured to run on ATF....considering the heat generated it would not be advisible to run every GSE on ATF
36 canoecarrier: That I can remember, I've never had to defuel a single point capable aircraft before, but in smaller GA aircraft it wasn't that uncommon for us to pu
37 HAWK21M: What about quality control of that fuel before reuse?..... The trick is to shut off a little prior as the refuelling valve closure Time delay allows
38 darksnowynight: You just get to know your types and remember which ones tend roll up by how much, etc... I stay away from using the gallons meter on the hydrant for
39 HAWK21M: If the Sp gravity is calculated accuratly, the variation should not be much unless the FQIS needs calibration.
40 vc10: In my day [ I know poor old devil ] we would subtract the amount on board from the required amount for the the next flight , and convert that to gallo
41 DiamondFlyer: In the quantities involved in defueling a GA airplane, it probably isn't used in an aircraft again. -DiamondFlyer
42 HAWK21M: Out here refuelling ops need to be supervised/handled by company personnel at all times. What in case of Unscheduled Mx needing tank entry/repair &am
43 DiamondFlyer: Been there, done that. Really on most GA airplanes, the volumes involved aren't big enough to make it worth finding a way to store the fuel. -Diamond
44 HAWK21M: Storage is NOT the issue here....Defuelling requires a seperate Container by the refuelling agency,this needs to be quality cleared before Refuelling
45 darksnowynight: The SG can also easily be off if the fuel in question comes from a different tank at the Fuel Farm. I've noticed that it really is the gallons that v
46 DiamondFlyer: Maybe you misunderstood me. The fuel isn't used again, in my experience. It goes into GSE for their use. -DiamondFlyer
47 Maverick623: Not only does that make zero sense (the sum of everything is the weight).... When you crash because you're overweight there's gonna be a huge fire!
48 HAWK21M: That would have its sp gravity stated to assist in calculation. Thats optional, but there is a need to record the same.some operators sell it to the
49 DiamondFlyer: Might be that I'm having trouble understanding your English, but I've never once recorded de-fueling an aircraft. Mind you, these are not airline air
50 canoecarrier: Although I can't specifically remember what we did with that fuel after we took it out of the tanks, if supervised by an A&P and the containers y
51 HAWK21M: Exactly.....But out here apart from Accounting purpose,its the certification of that action to ensure no misuse of the same Fuel & accountability
52 canoecarrier: And, I can appreciate that attention to safety. No one here is implying there would be a misuse of the fuel taken from the tank. I only asked why if
53 HermansCVR580: I totally have to disagree with this statement!!!! I have fueled everything from a Cessna C-208 to the Antonov AN-225 and while I have seen mistakes
54 HAWK21M: What about paperwork....for the records of the Action undertaken.
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