Is this a good way to burn off extra fuel

[JammedStab]

Widebody jet, 30 degrees C, full takeoff thrust required, max taxi weight but due to a runway change, the planned taxi routing runway is shorter than expected.

500 kg need to be burned before takeoff is legal. No problem, just ride the brakes with a higher than normal thrust setting. A parallel taxiway is available where we could stop and burn off fuel but when questioned, the captain says he has done this before. The other crewmembers don't seem concerned either when I ask about checking the brake temps. Saw one of them at 2 units a couple of minutes before takeoff.

Do I worry too much about this? Are carbon brakes so good that it is not an issue? Or is it poor airmanship?

[pa12 pilot]

How many years widebody experience does he have? How many years widebody experience do you have?

[Check Airman]

Never flown a widebody, so out of ignorance, I'll ask what the size of the plane has to do with it.

You said the brake temps were at 2 units. What's the maximum for takeoff? If there's still a good margin left, I don't see a problem. What would you have done?

[Intruder]

That is a TERRIBLE habit! Find a place to sit and burn it off.

[Airclues]

What would you have done?

I'd have asked to go to a quiet corner and then burn off the fuel. Look after your brakes, you never know when you might need them, especially at max weight.

How many years widebody experience do you have?

33 years

[jack11111]

That is intentional abuse of the brakes, in my opinion. If this pilot shows you he has no feeling for mechanical systems, I'd wonder what else he doesn't understand about stress on the aircraft.

[mutt]

JammedStab..... its a bad idea....

https://en.wikipedia.org/wiki/Nigeria_Airways_Flight_2120

IIRC, The report cites the long taxi with excessive braking as one of the causes.

[Check Airman]

The prevailing wisdom from the east side of the Atlantic seems to be that it was a bad idea. It's done from time to time on the western edge. Seems like there were 3 options:

1. Ride the brakes during taxi

2. Pull over somewhere with the power above idle

3. Pull over somewhere with the power at idle

1 & 2 will result in higher brake temps. The OP said 2 units. What's the maximum for takeoff? If it's 10, I hope it shouldn't be a problem.

Options 3 would keep the brakes cool, but may not have been feasible due to some time constraint.

[oldpax]

Is that correct?A widebody has to burn of 500kg of fuel before take off? So worldwide there are tons of fuel wasted,surely there must be a better way!What is the average burn from push back to take of with taxying and awaiting take of clearance?Passenger question!!!

[Vessbot]

The max takeoff weight is determined by the most limiting of about a dozen different factors, and the fuel loaded onto the plane is determined such that you are at your planned takeoff weight when you reach the end of the runway.

But sometimes things change after you push back from the gate (in this thread's first poster's case, they went to a shorter runway than planned) and you have to get rid of some of that weight, which you wouldn't have loaded onto the plane in the first place had you known how things were gonna go.

Edit: oops, I just re-read the first post and that's not what happened. But it just as easily could have.

Reminds me of the time I had to burn off the most fuel... In a short haul airplane on a short flight, MTOW was that flight was limited by max landing weight at the destination. Due to a rerouting for storm passage that drastically cut the flight plan distance, we had to lose 2000 pounds... which was a quarter of our fuel load! I wonder what the record is, percentage-wise. Maybe we hold it?

[wiedehopf]

@Check Airman

holding with whatever thrust set will NOT heat up the brakes.
you need friction + movement to create heat in the brakes. no movement = no heat.

so your option 2 will not result in higher brake temperatures.

still a long taxi might also raise brake temps, probably not as much as taxiing with higher thrust but still the question is how much fuel had to be burned off.

[megan]

Using the standard weights for pax, and seeing how much unweighed carry on they bring on board, I wonder how accurate the weights used for performance calcs actually are. 500kg for a fully loaded 747 represents a bit over 1kg per passenger after all.

[stilton]

Ask Atc where you can park and run up the
thrust.

Burn off the fuel.

Depart.

[Tu.114]

Lowly turboprop driver here.

On any type I have come across yet, fuel usage on ground has been a function only of engine power over time. Nothing else. Taxi speed, distance etc. seem to have only a minuscule or no effect at all, and seeing that OAT, pressure, wind etc. are a given when on the ground and cannot be influenced, I´d disregard their influence as well.

So the option to just sit somewhere out of the way, with the parking brake set and therefore not even having to ask the question whether the brakes will be abnormally heated or not, and increase engine power a little bit to a prudent value seems to have much merit. Also, if not already in use, starting the APU might speed up the desired reduction of fuel on board.

I´d therefore respectfully suggest asking ATC to hold in a quiet taxiway, the runway bypass or something like this (airfield dependent), obtain the approval to increase power to a setting e. g. for a crossbleed start, and just wait there until the MTOW is achieved.

If allowed in the company and not already done, is the use of alternate passenger weights an option?

Here is another accident (https://en.wikipedia.org/wiki/Swissair_Flight_306) that was caused by taxiing around while riding the brakes: a Swissair Caravelle that was taxied up and down the runway with high power settings in order to clear the fog, then took off and suffered a fire in the main wheel bay.

[Icelanta]

First of all, your fuel summation unit is often less accurate than 500 kg., especially on ground. Do not waste fuel. If you have to leave the gate with max. Ramp fuel, this also means you are dispatching with min. Flight plan fuel for your flight...

Secondly, some here do need to get into the books more and get an understanding on how carbon brakes work.
You will NOT overheat brakes when you are stationery and add thrust. You need FRICTION for brakes to heat up. Prolonged taxi is therefore more harmful than holding with thrust.
From all options, the best is to just ask to hold for a couple of minutes and burn the bloody 500 kg. If you insist. But do understand that ALL values on your loadsheet are estimates, and NOT absolute numbers, as is the onboard fuel displayed.

Ps. On B744, you need to look into the brake cooling schedule if your brakes temps. Are over 2 units. Nothing in the books on what the max. Brake units are for take-off but you do have to realize this. On Widebody, brake temp. Does rise very quickly.

[RAT 5]

Using the standard weights for pax, and seeing how much unweighed carry on they bring on board, I wonder how accurate the weights used for performance calcs actually are. 500kg for a fully loaded 747 represents a bit over 1kg per passenger after all.

Thanks Megan. I wonder how many out there would really do this, or just get on with it. Performance calculation is a dark art, not a precise science. It could be embarrassing if later on in the flight you needed that fuel. But cooking the brakes seems not a sensible idea.

[Basil]

If you are illegally overweight and have a totally unrelated incident which brings this to the attention of your regulating authority you may expect to have the book thrown at you.
The paperwork, and recorded data, must be legal.

Riding the brakes to burn off fuel? I had to check the date ;)

[sonicbum]

Widebody jet, 30 degrees C, full takeoff thrust required, max taxi weight but due to a runway change, the planned taxi routing runway is shorter than expected.

500 kg need to be burned before takeoff is legal. No problem, just ride the brakes with a higher than normal thrust setting. A parallel taxiway is available where we could stop and burn off fuel but when questioned, the captain says he has done this before. The other crewmembers don't seem concerned either when I ask about checking the brake temps. Saw one of them at 2 units a couple of minutes before takeoff.

Do I worry too much about this? Are carbon brakes so good that it is not an issue? Or is it poor airmanship?

Take the parallel taxiway, set the parking brake, turn on the APU and wait. How long will it take to burn off 500kg of fuel on a widebody on the ground ? 30 min ? Well that's it not much you can do. Once you get to destination Your Cpt will write a nice report explaining what happened and eventually it will just be a lesson learnt for all. On the other hand pushing with non standard practices while increasing the threats (hot brakes) is something that could easily end up in the wrong way if Murphy decides to have a look at your flight on that specific day.

[dixi188]

I remember a BA 747-136 at Muscat that was much delayed, departing around 10am local.
Between getting the airfield data and start up the oat had gone up by about 10 degrees C.
He requested to sit on the end of the runway and burn off several tons of fuel. As he did this he kicked up a massive sand storm behind, but also the temp rose further and more fuel had to be burnt. It took about 20 mins to get down to RTOW. I think he refiled to tech stop on the way to London.

[gearlever]

Widebody jet, 30 degrees C, full takeoff thrust required, max taxi weight but due to a runway change, the planned taxi routing runway is shorter than expected.

500 kg need to be burned before takeoff is legal.


Well IMHO it depends WHY is TOW limited. Structural? Performance? Landing weight?

If it's the latter our SOP allow to assume a 50% burn off of contingency fuel, means increased trip fuel....

[BluSdUp]

Unless max structural TOW restricted : Start Apu and do a No Engine Bleed t/o?Gives me some 1300kg more on the 738.
Been field and or obstacle restricted a few times this summer.Good fun.

Have also had some backtracks to get headwind when ATC like to do Ils27 and 5 to 10 kts tailwind departures on 09 due to lack of taxiway.

I just love these local Kings in the tower telling me what I have to accept or not.

To cook the brakes to get legal is loosing the big picture, indeed.
The Dutch call it MirenNauken I think.

[sonicbum]

I just love these local Kings in the tower telling me what I have to accept or not.



These "local kings in the tower" might just want to offer you a favor with less taxi time and expedite air traffic flow on the airport. They don't know the performances of every single airplane every single day. Usually a nice "unable rwy 09 due performances" is all it takes.

[Flying Torquewrench]

The Dutch call it MirenNauken I think.

BluSdUp you mean Mierenneuken a.k.a. Nitpicker. However that is not the right expression in this context.


Just set the parking brake and burn the fuel off. No worries about brake tempratures increasing.

[AerocatS2A]

Well IMHO it depends WHY is TOW limited. Structural? Performance? Landing weight?

If it's the latter our SOP allow to assume a 50% burn off of contingency fuel, means increased trip fuel....

Given "full take-off thrust required" one would assume the take-off is performance limited.

[vilas]

It's not a good idea because break temperatures will peak after take off and could be hazardous and also wear and tear. If it was landing weight limited it could be burnt in the air otherwise as suggested by many just idle away those extra holding some where.

[Vessbot]

If it was landing weight limited it could be burnt in the air

Not necessarily. We can't do that.

[TurningFinalRWY36]

Why not? Cruise lower/fly faster will burn more

[Vessbot]

Well, if redispatched with the higher fuel burn to make it fit, then yes.

But "We'll just launch, and burn it off in the air" at higher than MTOW is a no-go. We only see limit codes for a few things, and this is not one of them; so we don't even know what the limiting factor is. While seeing that the LDW matches the MLDW is a good clue, something else could also be just as limiting at the same time, and we'd have no way to know.

Plus, we'd be violating 121.195: "No person operating a turbine engine powered airplane may take off that airplane at such a weight that (allowing for normal consumption of fuel and oil in flight to the destination or alternate airport) the weight of the airplane on arrival would exceed the landing weight set forth in the Airplane Flight Manual for the elevation of the destination or alternate airport and the ambient temperature anticipated at the time of landing."

[underfire]

500 kg need to be burned before takeoff is legal. No problem, just ride the brakes with a higher than normal thrust setting.

Feel sorry for the hold behind you inline, not to mention FOD issues for you and others...

[Skyjob]

500 kg need to be burned before takeoff is legal. No problem, just ride the brakes with a higher than normal thrust setting.

NEVER ride the brakes.
SET the brakes instead.

[FullWings]

I have to say it’s not something I would get really worried about (the marginal MTOW possible exceedance)?

a) On a widebody with a reasonable amount of airframe hours and a decent passenger load, I’d be surprised if the *actual* weight of the aircraft was within a couple of tons either way of what you thought it was.

b) What’s the worst that can happen? Even with a V1 cut is a couple of hundred kg either way going to make a difference? Just different line up and thrust setting techniques can affect things more if you’re RLL.

c) Who’s counting, anyway?

d) Even if I was worried, I certainly wouldn’t ride the brakes on an above-idle thrust setting. Just when you might need all of the braking performance, you deliberately remove some of it? Much rather take +500kg with cold brakes, thank you!

Betteridge’s Law applies here, I think.

[underfire]

c) Who’s counting, anyway?

Wow, incredible post!

What other things do you ignore?

a) you know the actual weight is a couple of tons either way, so whats another 500kg?
b) Whats the worst that can happen? (other than you driving?)
c) Whos counting? (Other than your conscious attempt to take off overweight) I suppose even you realize the standards that set that MTOW have a myriad of factors, none of which, the performance people who loaded the ac have calculated in loading the ac?
Go long, or screw up, and you will see who is counting.
d) I can see where you would be concerned about braking, especially when you dont care about DEP overweight.

kudos to the drivers who decide on ways to burn off 500kg, than simply violate the law.

[AerocatS2A]

c) Who’s counting, anyway?


The CAA after you've run off the end of the runway. Sure, you may have run off the end of the runway anyway at a max performance, max weight, take-off, with a max speed reject, but if you've knowingly taken off above the RTOW then you'd be in a deep :mad:


a) On a widebody with a reasonable amount of airframe hours and a decent passenger load, I’d be surprised if the *actual* weight of the aircraft was within a couple of tons either way of what you thought it was.

That may be true. You may already be a couple of tonne overweight. There are some margins built into the take-off performance calculations to allow for unknown variations, I'm not about to intentionally use up those margins with a known variation.


d) Even if I was worried, I certainly wouldn’t ride the brakes on an above-idle thrust setting. Just when you might need all of the braking performance, you deliberately remove some of it? Much rather take +500kg with cold brakes, thank you!

There is another option you know? Just park somewhere and wait for the fuel to burn off.

[BluSdUp]

You remind me of a young lad I know.
Load her up until she starts sinking, toss ca 50lbs back on the dock and off you go, just 10% overload.
Oh, and that only worked with the one on CAP floats.
Allways carry a correct loadsheet.
And dont get caught!

[Vessbot]

Observation: inaccuracies in payload weight records

Problem: takeoff weight is possibly above limit

Conclusion: OK to add more weight

.... nice.

[underfire]

On a widebody with a reasonable amount of airframe hours and a decent passenger load, I’d be surprised if the *actual* weight of the aircraft was within a couple of tons either way of what you thought it was.

and you are a widebody driver?

Well IMHO it depends WHY is TOW limited. Structural? Performance? Landing weight?


You dont know why the performance people have calculated this, Did you think of what was taken into account? Their PROFESSION is to optimize the flight, your PROFESSION should NEVER second guess them.

[ImbracableCrunk]

"How do you plead?"

"Not guilty by reason of 'Widebody.'"

"Case dismissed. Clearly this man shouldn't be in any sort of legal trouble."

Seriously?

We put numbers on limits so we know when to say enough is enough. Why don't you leave the engineer business to Boeing and Airbus? They already account for the slop so you don't have to.

[AerocatS2A]

You dont know why the performance people have calculated this, Did you think of what was taken into account? Their PROFESSION is to optimize the flight, your PROFESSION should NEVER second guess them.

We certainly know if it is landing weight, structural, or performance. The performance people do the performance calculations, that is all.

[Bull at a Gate]

Seriously? You think that brake temperatures increase significantly when the wheels aren't turning?

[Check Airman]

Well, if redispatched with the higher fuel burn to make it fit, then yes.

But "We'll just launch, and burn it off in the air" at higher than MTOW is a no-go. We only see limit codes for a few things, and this is not one of them; so we don't even know what the limiting factor is. While seeing that the LDW matches the MLDW is a good clue, something else could also be just as limiting at the same time, and we'd have no way to know.

Plus, we'd be violating 121.195: "No person operating a turbine engine powered airplane may take off that airplane at such a weight that (allowing for normal consumption of fuel and oil in flight to the destination or alternate airport) the weight of the airplane on arrival would exceed the landing weight set forth in the Airplane Flight Manual for the elevation of the destination or alternate airport and the ambient temperature anticipated at the time of landing."

At my company, if we're landing weight limited, the paperwork will show it explicitly. A quick message to dispatch will have us on the way in minutes.

[DaveReidUK]

Seriously? You think that brake temperatures increase significantly when the wheels aren't turning?

No, that misconception was demolished about 30 posts back ...

[Sidestick_n_Rudder]

While I don't necessarily advocate taking off deliberately overweight...

I've seen people getting excited seeing a couple of kg's over MTOW on the a/c's weight display and doing some weird stuff, riding the brakes included. (BTW, has anyone mentioned additional FOD risk due to increased thrust during taxi?)

Now, the airplane's weight display (at least on the type I fly) calculates the gross weight by adding actual fuel weight to the ZFW entered into the MCDU. This displayed gross weight goes up and down as the fuel is sloshing around during taxi and its accuracy is limited. I think when legalities are concerned, the Loadsheet should be the basis of determining the TOW.

On one such occasion I have seen the CA burning the fuel during taxi. Then, when we stopped at the HP the ECAM weight indication stabilized and we ended up showing 2000lbs below MTOW... :ugh:

[Icelanta]

One other thing...

The take-off run itself, from brake release until rotation can consume almost 500 kg. On a widebody. So if pure performance allows it ( performance calculations can be capped of by structural limits, but the pure performance is higher) , you will still be legal when rotating 😆...Not that I recommend this obviously..
Once again: the loadsheet is the legal documentation. That one HAS to be correct. The actual taxi routing etc. can vary.

[mustangsally]

This threat has gone from maybe "what" to something much worse. The original post was about being 500 kg to heavy for the assigned runway. Now how to you kill 500kg, not do a re-dispatch or cruise at a lower level and fly at a higher cruise, to be legal for departing on the assigned runway. I'd never recommend riding the brakes on taxi out, who wants to abort with possible overheated brakes. 500kg or just over a 1000 pounds is nothing. On a wide body 500kg is maybe an extra ten seconds at a higher power setting prior to brake release. Next time you roll down the runway note the fuel burn and you will have your answer.

[RAT 5]

How to lose 500kgs on the load sheet = tippex. :ok:

[oceancrosser]

Looks kind'a awkward on an ACARS loadsheet...


Long time ago, in the mid-late 1980's after a very heavy DC-8 take-off somewhere in the Middle East, and barely making it (normal), the Captain tore the loadsheet into 3 pieces, passed on part to me and another to the F/E: "eat it!!!"

But then again we had some extremeists like the one that had 3 suitcases removed as he considered us overweight :ugh:

[vilas]

Legally there is no way to takeoff with that extra weight. Just park some where or go back and come back. Yes the temperatures may rise RTOW will further reduce but you are not expected to keep schedule by doing something stupid or illegal.

[overstress]

So you have dispatched below max ramp weight but you have used less than your flt plan taxy fuel taxying out? And you are worried you may be over MTOW? How do you know the accuracy of the ZFW anyway? Performance has margins, ignore the 'excess' taxy fuel and go, provided any exceedance is considered minor. (According to an Ops Manual near me).

It is NOT a requirement to burn all your taxi fuel before getting airborne, therefore you will be within your calculated performance criteria.

[oceancrosser]

IIRC in EASALand, OEW weighing and calculations have a 1% margin of error. On any widebody that is quite a bit. Also, using standard pax and bag weights is far from being always accurate.

[Band a Lot]

1) This pilot should be made to pay for all brake packs out of his salary. What a idiot for wasting money, and as implied before increasing rick due heat.

2) Was it actually required to burn the fuel? I assume the flight plan was correct, just the estimated taxi time changed on this 30 degree day.

3) Max Take Off weights are common, when lined up on runway the temp is 2 degrees higher than planned - is a recalc carried out to see if more fuel needs to be burned before opening up the throttles?

[JammedStab]

Thanks for the replies. For those advocating that it is no big deal to takeoff a little bit overweight....I have done plenty of that in the old days and am well aware that there is likely to be little real world consequence.

But I now work for a company where a minor exceedence a limitation is a huge deal with serious consequences. So, the limits will be respected as things are closely monitored on these advanced aircraft. No need to discuss further.

As for the aircraft, the limit was max structural weight(I'm sure most figured that out as I stated we were at our max taxi weight). But we must have been close to runway limits at no derate or ATM was allowed.

There have been some accidents caused by excessive use of brakes prior to takeoff but those were steel brake. What about carbon brakes which supposedly like some heat.

I am not aware of any maximum brake unit heat prior to takeoff but I was also concerned that peak heat would happen after takeoff and we might end up having to extend the gear if we got a brake temp warning. Are these realistic concerns? 4 hours after takeoff when I returned from my crew rest, there was still some heat indicated on the brakes. That being said, I have noticed in the past that it does take a while for them to get down to zero.

[Check Airman]

So you have dispatched below max ramp weight but you have used less than your flt plan taxy fuel taxying out? And you are worried you may be over MTOW? How do you know the accuracy of the ZFW anyway? Performance has margins, ignore the 'excess' taxy fuel and go, provided any exceedance is considered minor. (According to an Ops Manual near me).

It is NOT a requirement to burn all your taxi fuel before getting airborne, therefore you will be within your calculated performance criteria.

Not sure where you fly, but in the companies I've flown for, it clearly states that the indicated weight at the start of the takeoff roll must not be more than the applicable maximum.

Which country issued the ops manual you're looking at?

[westhawk]

At least submit an ASAP or the equivalent safety reporting system at your airline. The company really should do an engineering assessment of this practice so an official policy can be developed and appropriate guidance made available to line crews. Since it's already known that most wear on carbon brakes occurs before they come up to operating temperature, excessive use of cold brakes will cause excessive wear. Besides, who wants smoking hot brakes tucked away in their wheel wells anyway?

[agg_karan]

1) This pilot should be made to pay for all brake packs out of his salary. What a idiot for wasting money, and as implied before increasing rick due heat.

2) Was it actually required to burn the fuel? I assume the flight plan was correct, just the estimated taxi time changed on this 30 degree day.

3) Max Take Off weights are common, when lined up on runway the temp is 2 degrees higher than planned - is a recalc carried out to see if more fuel needs to be burned before opening up the throttles?

Point 1 was just unnecessary.

[Check Airman]

@Jammed Stab

I'm unaware of your type, but assuming you were at 2 out of 10 units, I wouldn't be overly concerned with degradation of stopping performance, or brake cooling after takeoff.

I'm sure the engineers took those things into account when they determined the maximum temperature for takeoff. 8 out of 10 units would be a different matter though.

[Check Airman]

1) This pilot should be made to pay for all brake packs out of his salary. What a idiot for wasting money, and as implied before increasing rick due heat.

2) Was it actually required to burn the fuel? I assume the flight plan was correct, just the estimated taxi time changed on this 30 degree day.

3) Max Take Off weights are common, when lined up on runway the temp is 2 degrees higher than planned - is a recalc carried out to see if more fuel needs to be burned before opening up the throttles?

3) Our system allows us to send for new numbers when the temperature changes significantly. The performance paperwork that comes with the dispatch release covers a temperature range, and the associated max weights, so that information is readily available to the crew.

[Check Airman]

At least submit an ASAP or the equivalent safety reporting system at your airline. The company really should do an engineering assessment of this practice so an official policy can be developed and appropriate guidance made available to line crews. Since it's already known that most wear on carbon brakes occurs before they come up to operating temperature, excessive use of cold brakes will cause excessive wear. Besides, who wants smoking hot brakes tucked away in their wheel wells anyway?

Who said anything about smoking hot brakes?

[westhawk]

Who said anything about smoking hot brakes?I did! (sarcastically) But there is little doubt that the brakes will be some amount hotter after takeoff than they would have been without riding them on the taxi to the runway.

To me, the idea of riding the brakes with the thrust levers pushed up so as to burn off additional fuel seems unreasonable. I would be much more supportive of just taking a short delay to burn the extra fuel while stopped. While it might have very little effect upon actual aircraft performance, taking off when you know you are above the calculated limiting weight is practically indefensible from a regulatory viewpoint. In my experience, small amounts over various limits sometimes go "unnoticed" for this reason. Most of the time it doesn't make any difference, but once in awhile...

[Band a Lot]

Check Airman - show me 1 procedure for "Riding Brakes" in any manufactures manuals.

Any anyone intentionally caused excessive wear on anything - they should pay for it.

Hire a car and do a bunch of burnouts - expect to pay for it! The invoice will read something like " tires - excessive wear on rear (could be front).

regarding 3) So lets say temp range is 10-15C and it clicks over to 16C as you were about to go - what is your procedure? Not asking if information is readily available or not.

[agg_karan]

Digressing from the original post,
BAND A LOT - to answer your query point 3 is clearly stated in 'pilot guide to takeoff safety' of the FAA website pg 25/45 last para. How a pilots fulfills his responsibility of complying with last minute temp calculations is upto the pilot. I am sure there are many more legal documents putting the responsibility on the pilot to ensure compliance with last min temp/wind etc changes.

As far as the original post is concerned it has happened plenty of times where taxi fuel is catered for in greater quantities and RTOW (tow off weight) was restricted structurally & sometimes otherwise. Safest bet would be to hold with parking brake set.

I do not know about the brake energy consequences in a carbon brake so can't comment more than that.

[Band a Lot]

Thanks agg karan - so a last minute temp change is left to the pilot - good a hard fixed rule may least to rush and extra stress in the hot seat.

I would expect the same for a last minute taxi/runway change, that result in a time delay/advance would have the same result for the person in the hot seat - Once a plan is submitted, factors can change - but the plan has numerous built in contingencies including all weights of all kinds.

So I expect legally it is up to the pilot to decide if he wants 500kg less fuel or not - but to ride carbon fibre brakes at a higher power setting simply is wrong and due low temps and prolonged use massively increases the wear - and certainly not an official procedure that is approved by any manufacturer - hope this is recorded on the FDR.

[Check Airman]

Check Airman - show me 1 procedure for "Riding Brakes" in any manufactures manuals.

Any anyone intentionally caused excessive wear on anything - they should pay for it.

Hire a car and do a bunch of burnouts - expect to pay for it! The invoice will read something like " tires - excessive wear on rear (could be front).

regarding 3) So lets say temp range is 10-15C and it clicks over to 16C as you were about to go - what is your procedure? Not asking if information is readily available or not.

Show me where it says you can't ride the brakes. Like I said, it's not unheard of over here. Different philosophies I suppose. Filing a report would be seen as a gross overreaction to that technique.

Regarding the OAT, if the temp goes to 16, we simply request new data over ACARS. It shows up within a minute, we insert the uplink, and off we go. Is it much more complicated than that at your company?

And no, we can't just decide to go 500kg over MTOW. THAT would warrant 2-3 different reports. I find it curious that taking off above MTOW doesn't seem to bother you, as long as it's only a little, yet taking off with brakes in the green does. Where's your line when it comes to exceeding MTOW? 1000kg? 1500kg?

[agg_karan]

[QUOTE=Band a Lot;9874109]Thanks agg karan - so a last minute temp change is left to the pilot - good a hard fixed rule may least to rush and extra stress in the hot seat.

Yes compliance would be indeed stressful regardless of it being last min. But has to be done.

Unpractical but really necessary :)

[vilas]

Check Airman
Show me where it says you can't ride the brakes
Quoted below from FCTM:

TAXI SPEED AND BRAKING On long, straight taxiways, and with no ATC or other ground traffic constraints, the PF should allow the aircraft to accelerate to 30 kt, and should then use one smooth brake application to decelerate to 10 kt. The PF should avoid continuous brake applications.

[_Phoenix]

Show me where it says you can't ride the brakes
Show me where it says you can't taxi backwards on thrust reversers.

How about announcement "Flight attendants prepare the cabin for an imminent rejected take-off"

[vilas]

_Phoenix
Can you elucidate what you are saying?

[JammedStab]

_Phoenix
Can you elucidate what you are saying?

He is agreeing with you.

[Check Airman]

Check Airman

Quoted below from FCTM:

Touché

Agreed that it isn't preferred, but sometimes you gotta do what you gotta do.

[_Phoenix]

Just a joke Vilas, but technically correct how to burn more fuel before lift-up. Only a component of the reverse thrust acts on horizontal, therefore more fuel to burn. "Simulated" rejected take-off and an another line-up should deplete the extra fuel.

[RAT 5]

OMG: And I thought this was a chat forum for professional pilots. Where is this discussion going? Up the ring yang, me thinks..

[JammedStab]

Touché

Agreed that it isn't preferred, but sometimes you gotta do what you gotta do.

So if you gotta burn fuel, find a place to stop, add thrust and burn it.

[piratepete]

We are at the holding point at an actual weight exactly at RTOW.The tower advise(or we become aware) that the oat has risen by 3 degrees.I ask the copilot to re-check the RTOW."Sir we are 500kgs over our revised RTOW now".

SOLUTION: "Please hand amend the loadsheet to increase the TAXI FUEL BY 500kgs".Done this several times in the past 28 years of big jet PIC.......Never had a problem yet.

INSTRUCTOR: Alcohol is a dangerous drug for pilots.Its also addictive.
ME: Sir, ive been drinking alcohol every day of my life since I turned 18 and I have never found it addictive yet.....Pete.

[Check Airman]

This has got to be the most curios thread on pprune I've seen in a while. Some people seem to be more willing to knowingly depart overweight, than heat the brakes up a bit. Live and learn...

[westhawk]

And just as many prefer to stop and burn the excess fuel off before taking off. No unnecessary additional brake heat or wear and no overweight takeoff. Satisfactory?

[vilas]

From the answers it is clear that legally the fuel must be burned. Riding brakes with power will definitely cause more wear but short term rise in temperatures is uncertain and can affect breaking efficiency. Not a good choice. But what is the problem if you taxied for same amount time as originally planned by taking a longer route?

[overstress]

This is the weirdest thread in a while. :ugh:

Icelanta on P1 of this thread is correct.

The fuel does NOT have to be burned prior to t/o. If the flight plan and load sheet were legal on dispatch, in the outfit I work for, the taxi fuel usage need not be considered provided any exceedance is consider to be minor. 500kg in 396000kg is minor IMO.

In our SOP there is NO requirement to check any aircraft weight indication just prior to t/o, this would rely on fuel indications being dead accurate, which they aren't, and the ZFW being dead accurate, which it isn't. Using actual passenger weights are we? No! The legalities are covered by the load sheet, the performance is covered by the margin of error built in.

I would expect that any wide-body departure on any day is actually +/- 2000kg of what you think it is.

Anyone who deliberately increases their brake energy before a max TOW t/o in a wide body should be removed from the line for remedial ground school training.

The OP wrote: Widebody jet, 30 degrees C, full takeoff thrust required, max taxi weight but due to a runway change, the planned taxi routing runway is shorter than expected.

500 kg need to be burned before takeoff is legal. This last sentence is the incorrect assumption. Take the 500kg into the air with you as a bonus.

[FlyingStone]

In our SOP there is NO requirement to check any aircraft weight indication just prior to t/o, this would rely on fuel indications being dead accurate, which they aren't, and the ZFW being dead accurate, which it isn't. Using actual passenger weights are we? No! The legalities are covered by the load sheet, the performance is covered by the margin of error built in.

The thing is, you can't really check iz actual ZFW (as in actual cargo/pax weight, not loadsheet) is the within MZFW, but you can check if loadsheet ZFW + FOB is below MTOW, which I believe is legally binding. Otherwise if you are RTOW limited and wanted to take more extra fuel, you could just increase taxi fuel and still be legal? :rolleyes:

Same goes for the MLW limitation I guess, loadsheet itself isn't enough, but you have to check that ZFW (from loadsheet) + actual FOB on landing is less than MLW.

Fully agree on the brake point though, I think anybody using brakes against thrust before departure on any type of aicraft should get some extra training.

[Goldenrivett]

Hi overstress,
500kg in 396000kg is minor IMO.

The BEA would agree with you.
See accident report to Concorde July 2000, F-BTSC https://www.bea.aero/uploads/tx_elydbrapports/f-sc000725a.pdf See Conclusion, 3.1 Findings:

"Taking into account the fuel not consumed during taxiing, the aircraft’s takeoff
weight in fact exceeded the maximum weight by about one ton. Any effect on
takeoff performance from this excess weight was negligible."

[Check Airman]

The thing is, you can't really check iz actual ZFW (as in actual cargo/pax weight, not loadsheet) is the within MZFW, but you can check if loadsheet ZFW + FOB is below MTOW, which I believe is legally binding. Otherwise if you are RTOW limited and wanted to take more extra fuel, you could just increase taxi fuel and still be legal? :rolleyes:

That's what I don't understand about the EU system. We all know that we're using assumed weights here, but under the FAA, you're required to use the best available information regarding your actual weight.

Our ops manual specifically states that if actual taxi burn is less than planned, the fuel must be burned prior to commencing the takeoff roll if we are above MTOW. No wiggle room.

The NTSB report would open with "The PIC attempted to depart with an overweight aircraft..."

[Band a Lot]

This is the weirdest thread in a while. :ugh:

Icelanta on P1 of this thread is correct.

The fuel does NOT have to be burned prior to t/o. If the flight plan and load sheet were legal on dispatch, in the outfit I work for, the taxi fuel usage need not be considered provided any exceedance is consider to be minor. 500kg in 396000kg is minor IMO.

In our SOP there is NO requirement to check any aircraft weight indication just prior to t/o, this would rely on fuel indications being dead accurate, which they aren't, and the ZFW being dead accurate, which it isn't. Using actual passenger weights are we? No! The legalities are covered by the load sheet, the performance is covered by the margin of error built in.

My posts also had a filed flight plan as being ok with this "minor" change - BUT never wit ridining brakes

I would expect that any wide-body departure on any day is actually +/- 2000kg of what you think it is.

Anyone who deliberately increases their brake energy before a max TOW t/o in a wide body should be removed from the line for remedial ground school training.

The OP wrote: This last sentence is the incorrect assumption. Take the 500kg into the air with you as a bonus.


My posts also had a filed flight plan as being ok with this "minor" change - BUT never with ridining brakes and the manual from past post seems to agree - bar a fool that thinks longer taxy time = brakes applied. Now honestly I hope he/she is not a real pilot or has plans to be.

[JammedStab]

Once again...I work for an airline where an exceedance is taken very seriously including exceeding a max taxi weight(they had a big letter about it once) or the max takeoff weight. So no need to tell me about how the performance won't be affected. I don't care. I care about not being demoted.

So...is this a good way to burn off excess fuel?.....Which has been answered straight from the FCTM and now from FAA world as well.

Thanks

[piratepete]

When I was a line Captain on (big jet) with xxxx, I used to carry an extra 2000 kgs more than the CFP/NFP required to cater for known extra BURN on the regular 9 hour flight.All line pilots knew this, and did this, because we knew that inspite of best intentions at this very professional outfit, the ZFW was always understated, mainly from the Nigerian PAX who carried massive amounts of cabin bags.
When the fleet CP harrassed me about this practice, I told him if you look at the FMC target thrust in cruise, it is much lower that ACTUAL THRUST, meaning we are heavier than we think.To work out how much heavier, just keep increasing the ZFW number on your performance page until the ACTUAL THRUST and the TARGET THRUST are the same.The result is scary.All your V speeds are thus too low for take off and landing.

Funny thing was, the same CP had an engine failure at 500 feet agl from the same airport on the same route and couldnt climb away, in fact his bigjet started to descend!!! Eventually he managed it, but upon landing a re-weigh indicated they were 6000 kgs over the stated ZFW, so I have to take most of the comments posted here with a large pinch of salt.....Pete.

[overstress]

I agree, Pete, there are so many inaccuracies involved the only way you could know for sure is weigh the aircraft at the departure holding point. All those outraged types on here saying they would never take off overweight may already have done that on many occasions without knowing it!

Having said that, read your ops manuals, don't break any rules and never ride carbon brakes.

[JammedStab]

don't break any rules and never ride carbon brakes.

The question is....why not. Is there a particular reason for this type of brake not to, or is it for the same reason as steel brakes?

[RAT 5]

To be pedantic and not condone any dubious practices, but....

Many on here say it is illegal, not a good idea, etc. to take off overweight. What they really mean it is not a good idea etc. to take off with a load sheet showing you are overweight.

The two are not the same. If you can alter the load sheet, sensibly, you can solve the latter scenario. If you want to ensure the former you'd better be prepared to cancel your slot time, expect to use discretion after having checked all the pax & bag actual weights, incur the wrath of CP for all of the above. Anyone who takes off at load sheet'd MRTOW is taking a blind but legal leap of faith.

[overstress]

awair, all very well, but if your company ops manual says you can disregard unburned taxi fuel, (as mine does) then that's what I will continue to do. I can hardly be committing a wrong if the manual says you can do it.

[JammedStab]

Ops manuals are typically approved by the governing authority. Could you please tell us which country you work in so we are aware of what country approves this.

Will we get an answer?

[Band a Lot]

The question is....why not. Is there a particular reason for this type of brake not to, or is it for the same reason as steel brakes?

Why not! - there is no approved procedure to ride carbon brakes or steel brakes - do they react differently YES!.

Now if this pilot is riding brakes for an extended period he is going into an area of brake use that has no data and thus the usefulness of the brakes is now un-known, in what we now know is not an empty aircraft but an over weight one for this flight.

Friction creates heat - over time heat is transferred further and further and other items can get hot, possibly to hot if the heat period is very long. Think something melting or boiling!

Aircraft are tested to procedures max braking no reverse, consecutive braking and other tests and from this limits are obtained - there is no test for riding brakes, so the parameters of this use are un-known in future performance. So no braking performance can be planed or expected.

* Carbon brakes work best and have good wear characteristics at an optimum temp that is quite high, and no doubt designed to fit the normal braking requirements of the aircraft type. Below this temp they have a much faster wear rate and if the temp get too high they become warped.

I think we can all agree that in aircraft, the brakes are solely designed for stopping an aircraft and not designed for stopping an aircraft accelerating.

We could always use a touch of flap to trim the aircraft - but that is un-known data and that is why the elevator is trimmed.

[sonicbum]

awair, all very well, but if your company ops manual says you can disregard unburned taxi fuel, (as mine does) then that's what I will continue to do. I can hardly be committing a wrong if the manual says you can do it.

Good, so let's say your structural MTOW is 300t and your Max Ramp Weight is 302t (random figures). You're well packed today, long flight so no MLW issues and you pushback at 302T. Your loadsheet has a 2t taxi fuel. ATC now changes runway in use to a runway that is just less than 2 min taxi from your current position. Happy days ! Setup, no problems with performances (long big runways sea level no obstacles lovely temperature etc..) quick rebrief and off we go, we've saved 30-45 min taxi and we are about to takeoff at 301t (1t above your MTOW). So your Company manual says you can disregard unburned taxi fuel, hence who cares ? We're super legal, let's exceed a limitation. You happily takeoff and a few hours later people working in your flight safety office get a nice red flag on the OFDM and call you for tea and biscuits. From there you learn to read the manuals, read the SOP and also "think" about what you are doing.

[FlyingStone]

Setup, no problems with performances (long big runways sea level no obstacles lovely temperature etc..)

How do you check the performance in this case? Most tools will not allow entering weight above MTOW as even the AFM doesn't have data to support it.

[Band a Lot]

Good, so let's say your structural MTOW is 300t and your Max Ramp Weight is 302t (random figures). You're well packed today, long flight so no MLW issues and you pushback at 302T. Your loadsheet has a 2t taxi fuel. ATC now changes runway in use to a runway that is just less than 2 min taxi from your current position. Happy days ! Setup, no problems with performances (long big runways sea level no obstacles lovely temperature etc..) quick rebrief and off we go, we've saved 30-45 min taxi and we are about to takeoff at 301t (1t above your MTOW). So your Company manual says you can disregard unburned taxi fuel, hence who cares ? We're super legal, let's exceed a limitation. You happily takeoff and a few hours later people working in your flight safety office get a nice red flag on the OFDM and call you for tea and biscuits. From there you learn to read the manuals, read the SOP and also "think" about what you are doing.

If your approved company manual says you can do 20% over any weight or even fly inverted .

Trust me it is legal and approved - they have given details and data to have it approved ( by what ever means inc rough weights of pax and carry on) by a governing body.

[sonicbum]

Band a Lot,

I am pretty sure that You have given a wrong interpretation to some wording of your ops manual. If you are aware of being overweight by looking at your fmc or whatever other system shows your current GW it is your responsibility to do something about it (hopefully not by riding the brakes please). The load sheet is a plan of how your aircraft is loaded prior to start your flight and how, based on the expected flight plan data, it is going to evolve. Should figures significantly change because of any change such as a reclearance you still have to ensure you are complying with the aircraft and performance limitations.

[RAT 5]

Every Ops manual I've worked with has used standard pax weights; all approved. Standard baggage weights as well. You have to be kidding if you think theses are realistic. Approved? Yes. Accurate? No. You go figure. So messing about for 500kgs on a large jet. It's all about paperwork not reality, surely.

[sonicbum]

RAT5 you are missing the OP point I believe. There is no doubt that as standard weights are used, the 300t or whatever weight your load sheet shows you for departure will most likely be different that the actual current weight of the airplane. You don't know by how much, you would need a scale, but industry standards are built in such a way that you will be covered. What we are talking about here is the fact that if you know that you are currently overweight because if you are supposed to burn a certain amount of taxi fuel as per your load sheet and you actually burn much less, then you know you are overweight, it is simple maths and the load sheet has nothing to to with it as it will still show the correct figures. Taking off above MTOW be it structural or regulated is simply not legal.

[wiggy]

Given many of us may here be quoting from the same book but I'm another one whose company ops manual quite clearly states that there is no requirement to ensure all taxi fuel is burned prior to commencement of the take off roll provided any possible weight exceedence is "considered minor" (not defined).

I haven't quoted the two line rule verbatim apart from the two words in quotes but nevertheless the policy is clearly worded and as far as I see not really open to being misunderstood or misconstrued. Now how the company squares that statement with the requirements likes of EASA, and the numbers Boeing and Airbus publish I will leave for further discussion.......

[Vessbot]

What I've learned is that there's nothing that isn't open to being misunderstood or misconstrued, no matter how simple. Never underestimate the ability of a lazy or inattentive pilot to understand something as the direct opposite of what it says. Or, when given an inch of discretion, to take a mile instead.

[Band a Lot]

If a aircraft manufacturer states that the MTOW is 225,000 kg in it manual.

and a Regulator (FAA/CAA/CASA) states that a flight shall not be planned to take-off above MTOW.

And the Regulator has approved the company operations manual to plan a flight.

The Regulator will over rule the manufacturer in every country.

So if approved, that unused but planned taxi fuel weight need not be deemed excessive then that aircraft can legally fly above the manufactures listed limit - in this case it can take off at 225,500kg.

Key word/s are planned & deemed excessive - excessive should be described in the company approved manual.

[pineteam]

Taking off overweight... A big no no in most airliners including the one I fly. With QAR data, we would be called by the safety department immediately. And in the other hand it's a common acceptable praticse in other small airlines. No need to mention any countries; I can not recall any colleagues who had flown in Africa who never took off overweight. Surely any aircraft can do it. We all know that. And noone will question you as long as everything is normal. But then if something bad happens, good luck to explain to the authorities why you accept to take off overweight. I guess it's a question of knowing and accepting the risks... A bit like driving slightly over the speed limit.
it's kinda annoying when people say: " if this happens or that happens... blablabla." Well if you lose one wing, guess what you will surely die. But sometimes, we have to relax, assess the risks going with flying and do what you have to do. Having saying that, I'm not saying we should take off overweight. Especially when it's due to extra fuel, it does not hurt anyone except the environment to wait few minutes on a taxiway to burn that extra fuel.

[riff_raff]

Why not! - there is no approved procedure to ride carbon brakes or steel brakes - do they react differently YES!....Friction creates heat ....* Carbon brakes work best and have good wear characteristics at an optimum temp that is quite high, and no doubt designed to fit the normal braking requirements of the aircraft type. Below this temp they have a much faster wear rate and if the temp get too high they become warped....I think we can all agree that in aircraft, the brakes are solely designed for stopping an aircraft and not designed for stopping an aircraft accelerating....

Actually, the brakes only stop the wheels/tires. It's the tire contacts with the runway surface that stops the aircraft. You can estimate the amount of heat energy that would need to be rejected by using up 1100 lbs (500 kg) of jet fuel, assuming the LHV of jet fuel is approx 18,500 Btu/lb.

[Band a Lot]

The brake is attached to the rim, not the tire!

So the tyre can slip (very rare) or the tyre can skid - anti skid will assist here if not effected by excessive heat.


Now is this with cold brakes or hot ones?

I can work out what "x" weight aircraft will need for braking distance on "un-used " or first brake application, possibly a 0 temp indication.

But at a 2 indication, how does that effect my brake performance at MTO? or shall I wait for a zero reading before takeoff?


P.S. the tires will be pre heated by riding brakes of a extended period.

[Vessbot]

I already posted the FAA reg, and it says "No person operating ... may take off ..."

Not "no person may plan to take off" and, oopsie daisy!, things didn't go according to plan..

[sonicbum]

Band a Lot,

Honestly I do not really understand how a regulator can allow to deliberately exceed an aircraft limitation or performance, it seems really odd.
Can You give us some examples of operational situation where Your employer/regulator will allow You that and under what regulations You are operating (EASA, FAA, etc..) ?
Thanks !

[solomanflyer]

we are living in a world where people trying to save energy and fuel,, but here fuel has been burnt to reduce the TOW...

[DaveReidUK]

Post #1 details the circumstances under which it was necessary to do so.

[overstress]

Ops manuals are typically approved by the governing authority. Could you please tell us which country you work in so we are aware of what country approves this.

Will we get an answer?

EASA. There you go.:eek:

[overstress]

if you know that you are currently overweight

How do you know? Did you put the aircraft on a scale at the holding point?

Key word/s are planned & deemed excessive - excessive should be described in the company approved manual.

It isn't in mine!

So your Company manual says you can disregard unburned taxi fuel, hence who cares ? We're super legal, let's exceed a limitation. You happily takeoff and a few hours later people working in your flight safety office get a nice red flag on the OFDM and call you for tea and biscuits. From there you learn to read the manuals, read the SOP and also "think" about what you are doing.

You work to your Ops Manual. I'll work to mine. What's an OFDM? And I DO read my manuals thanks, and think what I'm doing, or else I wouldn't be posting this stuff on here, would I? :ugh:

[sonicbum]

How do you know? Did you put the aircraft on a scale at the holding point?

Let's try again. I give you a load sheet, you have a current ramp weight of 302t and a take off weight of 300t all based on a taxi fuel of 2t. 300t is also your structural MTOW. You start taxi, and uh uh ! Happy days you get to go first in sequence having burned 500kg of fuel. Now 302t-0.5 = 301.5t. You are 1.5t above Your MTOW. You don't need a scale here, You need a 6 years old maths skills.

You work to your Ops Manual. I'll work to mine.

I will:E

What's an OFDM?

Onboard flight data monitoring.

[wiedehopf]

the driving point here is: it does not matter if the airplane is actually above MTOW.

you can't accurately calculate your current weight so you calculate a weight governed by certain rules ... which is the weight you compare to your MTOW.

if all the weights would be vs actual weights you could always say:
but i didn't have a scale so i didn't know for sure i was overweight so i packed two elephants more.

[overstress]

You don't need a scale here, You need a 6 years old maths skills.

I get it, no need to patronise. OFDM, as you put it, can only monitor based on inputted ZFW. As we both know, this is highly likely to be inaccurate anyway. My ops manual says minor exceedance is OK. Your example is flawed, it's unlikely for 2T taxi fuel, more likely to be burning contingency. I see no point in discussing this further as you don't work for the same company as me and I don't have to answer to you! :hmm:

[sonicbum]

no problem:)

[JammedStab]

Apparently, Overstress is just making stuff up. He won't name the country or quote the manual where he says this is allowed. It is more like, he is just taking off a bit overweight. Probably not a worry as it is not monitored.

[Ozgrade3]

i would think that any skipper who sat on a taxiway or moved slowly with high thrust set would quickly attract the ire of airfield operations. Most taxiways are do not have re enforced shoulders. I have seen quad jets rip up long stretches of grass just at idle thrust.

[wiggy]

.Apparently, Overstress is just making stuff up. He won't name the country or quote the manual where he says this is allowed

He might be, he might not...

But FWIW and as I mentioned earlier our EASA compliant Ops manual allows it, and it is monitored.

[Band a Lot]

I think you will find it is the regulator that sets the "standard weights" of pax not the aircraft manufacturer.

So it wont even take a smart pilot walking past his passengers to notice if many/most or all pax are over weight.

Lets say 90% appear to be a bit fat as the pilot walked down the isle - no problem here it is perfectly legal. Because it has been approved by the regulator and data had been given to average weights on certain things - this case passengers.

Now I know many companies that run extensions, on engines ( I know it not a weight thing) that are approved because a company has developed a method that has been deemed acceptable (this can be trend testing and overhaul limit checks), The regulator also has approved methods to test colour blind pilots - but that's a different story.

Now it is certainly possible to have a approved system in place to handle small overweight conditions (so may just need to be recorded) - the over weight landing checks for instance depend on by how much over weight was the landing, a very small amount requires a very small inspection, a large amount is a different story.

FYI I have worked FAA, EASA, CASA and a few of the CAA's

[JammedStab]

He might be, he might not...

But FWIW and as I mentioned earlier our EASA compliant Ops manual allows it, and it is monitored.

But you won't write down the wording for us. I think then that it is a made-up story. Or not discovered during the audit.

[falconeasydriver]

Taking off overweight... A big no no in most airliners including the one I fly. With QAR data, we would be called by the safety department immediately.

Easy way around this, just input the zfw as 500kg lower into the FMC/FMS etc :E

Not that I'm an advocate of course :}

[pineteam]

Haha!! I never had a overweight take off situation but I have been a couple of time close to MLW due to tankering and I was thinking about what you just said. lol

[Band a Lot]

Do not remember if this is the one but RAM had an increased gross weight approved by FAA and a STC issued simply by re mark of the ASI + a flight manual suplement.

Serviceable ( non-TAS ) airspeed indicators - remarked
[ If TAS indicator is currently installed, consult with your RAM representative. ]
<li class="Body-Copy">Gross Weight Increase STC and Flight Manual Supplement
T310 P [ + 270 lbs. Useful load ] [ GW from 5,400 up to 5,670 lbs. ]
T310 Q [ +170 lbs. Useful load ] [ GW from 5,500 up to 5,670 lbs. ]

[JammedStab]

Easy way around this, just input the zfw as 500kg lower into the FMC/FMS etc :E
The problem is...the documents are kept for a year and the CAA auditors where I fly are good at finding minute details.

[overstress]

JammedStab, thanks for questioning my integrity. My employer has a social media policy which I'm not about to break here just so you can know where I work. And I have never taken off overweight, I simply quote a company ops manual which is not available online except if you have a company login! To be clear, I'm not cutting and pasting, I paraphrase. Why would I make stuff up, life's too short.

If you don't like alternative views, why spend time on an aviation forum? Why not just accept that different operators in different countries have different policies and interpretations?