Hi all,suppose I took a short flight (e.g. 70 NM) with full pax and 50% fuel.and the Maximum Gross Landing Weight of 747-400 is 630.000 lb.what If I land it with 700.000 lb of gross weight, will it be damaged?what about the real world????? (what kind of damages)Fuel jettison is required in this situation, isn't it?ok, how to know the amount of fuel that will be burned during the flight to avoid MGLW ????the last thing is related to this..........my GPU is not powerful enough to show me fuel jettison on wings..........is it modeled?neither smoke that comes from engine while there is a fire.............is it modeled too?Abraham .R

i believe that damage to engines/ fire used to be modeled? i saw it once, but your realism settings need to be put on real or something like hard. as for fuel jettison, they do not model the visual jettison per se.as for real world... i am sure they wouldn't land over the gross landing weight. i could be wrong. they would probablly need to jettison fuel.tomax

There are circumstances in the real world where you have no time to dump fuel and you might indeed land ABOVE the MLW.Cargo fire comes to mind. If you got one of those you might land regardless of being overweight as an open fire in the cargo bay is one of the worst possible things that can happen to you inflight. Remember it can take up to 20 minutes to dump fuel to reach MLW. In some emergencies you just don't have time for that.So IF you decide to land above MLW you can do that. Provided a smooth landing can be done there's a good chance you don't get any damage. However after an overweight landing the aircraft MUST be checked by maintenance before it is allowed to fly again. That check is rather time consuming and is not something you can do in 5 minutes at the stand.Regards,Markus

The biggest problem would be (RW), if you decide to land with more than the MLW, that you gear and the whole gear structure could suffer on this. One could try to compensate this with a very smooth landing, but I doubt an airline would try this voluntary! ;-)

Rules are rules, but in terms of damage, this wil vary greatly. Keep in mind that the MLW is the a legal limitation and is likely significantly less that the actual physical limitation of the aircraft (not that one should treat the limit casually). Any damage that occurs will depend upon: A. How much over weight you are. Landing at 640,000 lbs is not the same as landing at 800,000 lbs.B. Your vertical speed at touchdown. Again a hard landing will multiply the force on the gear by several times and significanly increas the risk factor. Remeber that this is not entirely under the pilot's control. Light wind shear on short final is very common and has the same effect and sloppiness by the pilot.C. Crosswind component. If there is a cross wind, this my put additionly levels of force on the gear, and being overweight makes thsi riskier5 as well.Andrew

Additionally at the weight you mention of 700,000 lb you will exceed the weight at which you can deploy landing flap (25 and 30) so you would require a flap 20 landing. Lots of extra landing distance....there will be a trade off between smooth landing and eating up valuable runway. The approach speed and rate of descent on approach will also be higher than normal (as well as nose attitude at flap 20).CheersSteve

Okthank you very much captains.but there is one thing :how to know the amount of fuel that will be burned during the flight? ? ?

Here, see attachment:From the Boeing manual..JohanA LITTLE LESS CONVERSATION, AND A LITTLE MORE ACTION PLEASE!HELP:http://support.microsoft.com/?kbid=238882

I think it's in the FMC, isn't it?But where?

"I think it's in the FMC, isn't it?"Unlikely... During Fuel Jettison, the FMC switches from "Calculated" to "Totalizer" values to enable it to make more accurate fuel predictions."Calculated" is engine fuel flow x time. Obviously you can't use this value for fuel usage predictions as fuel is also coming out the wing jettison nozzles.Cheers.Q>

An old and bold 747 pilot told me that when you use an average of 24000 lbs you can safely use it as an good estimate on fuel burn. (per hour)This includes takeoff, climb, decend and landing.Try it and you see it works..JohanA LITTLE LESS CONVERSATION, AND A LITTLE MORE ACTION PLEASE!HELP:http://support.microsoft.com/?kbid=238882