Is this a good way to burn off extra fuel
Joined: Feb 2013
Posts: 17
Likes: 1
From: 60 north
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.
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.
Joined: Mar 2012
Posts: 2,605
Likes: 154
From: Having a margarita on the beach
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.
Joined: Oct 2004
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From: LGW
Joined: Jan 2004
Posts: 3,247
Likes: 203
From: Here and there
Given "full take-off thrust required" one would assume the take-off is performance limited.
Joined: Jun 2007
Posts: 3,443
Likes: 39
From: Wanderlust
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.
Joined: Sep 2016
Posts: 937
Likes: 67
From: USA
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."
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."
Joined: Aug 2013
Posts: 30
Likes: 0
From: PA
500 kg need to be burned before takeoff is legal. No problem, just ride the brakes with a higher than normal thrust setting.
Joined: Dec 2003
Posts: 2,349
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From: Tring, UK
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.
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.
Last edited by FullWings; 22nd August 2017 at 21:48.
Joined: Aug 2013
Posts: 30
Likes: 0
From: PA
c) Who’s counting, anyway?
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.
Joined: Jan 2004
Posts: 3,247
Likes: 203
From: Here and there
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 
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.
There is another option you know? Just park somewhere and wait for the fuel to burn off.
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.
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!
Joined: Feb 2013
Posts: 17
Likes: 1
From: 60 north
Fullwings
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!
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!
Joined: Aug 2013
Posts: 30
Likes: 0
From: PA
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.
Well IMHO it depends WHY is TOW limited. Structural? Performance? Landing weight?
Last edited by underfire; 22nd August 2017 at 23:44.
Joined: Oct 2006
Posts: 658
Likes: 1
From: Ankh Morpork, DW
"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.
"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.
Joined: Jan 2004
Posts: 3,247
Likes: 203
From: Here and there
We certainly know if it is landing weight, structural, or performance. The performance people do the performance calculations, that is all.
Joined: Mar 2006
Posts: 2,633
Likes: 137
From: USA
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."
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."