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Old 1st Jun 2006, 19:11
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Bealzebub
 
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Ok so if I understand you correctly you are planning to land with minimum fuel ( diversion plus 5 % + 30 minutes holding ), however by not consuming the trip fuel 5% contingency element you will hopefully have an additional 2500-3000kg at the time of landing ? I am not familiar with the aircraft type or operation, but am guessing it is a large widebody airliner and possibly a cargo freight operation. From what you say it also would seem that the Max zero fuel weight is fairly close to the maximum landing weight ? This is on the assumption that a reasonably close diversion plus the holding and say 3000kg of excess arrival fuel moves you significantly from one limit to the other ? that does seem a little odd ? On the 757 the difference is 6500kg and on the 767 it is around 11,300kg and both of these are obviously smaller aircraft than your example. In these two examples the aircraft could arrive at a typical European destination with standard reserves plus 3000kg (757) and 7000kg (767-300) before the max landing weight was superceded by the max zero fuel weight limitation.

If indeed this is the case then it would seem there are a number of choices. Obviously you need to carry sufficient fuel to satisfy the planning requirement. This may be subject to adjustment to allow for actual weights and expected winds etc. Additionally it may transpire that the alternate airport on the plan can be substituted with a closer one. You could consider using an en-route alternate procedure which would reduce the fuel contingency fuel to 5% of the onward trip fuel from over or abeam the en-route alternate to the destination.

If (as you suggest) experience is proving that on certain trips the contingency fuel is not being used, then simple common sense would suggest reducing the payload to compensate for the fact. If this is commercially frowned upon then you are left with the choice of either seeking a flight level that is worse than optimum, increasing drag in the descent ( spoilers ), or holding at the destination until the maximum landing weight is achieved. Given that you may indeed need to use any of these methods it is quite appropriate and indeed necessary to include the additional fuel used in the trip fuel box of the loadsheet. Why this would be commercially beneficial I do not know, but it might be.

Contigency fuel is carried to allow for deviations from standard fuel consumption data for an individual aircraft, deviations for forecast met' conditions, and deviations from planned routings or cruising levels etc. This since not all the factors which might have an influence on the trip fuel consumed to the destination can be foreseen.

Again increasing the fuel burn on the paperwork is not a falsification of the paperwork since clearly you intend to do that and consequently need to do so to get down to your max landing weight. Neither can I see why it is morally devious ? I still maintain that the sensible thing is to reduce the payload and I am sure many airports would be less than impressed if you flight plan to have take up a hold to burn off excess fuel, however if that is the only option you feel is open to you then that is what you would have to do.

You say that there have been many overweight landings because Captains have found it impractical to increase the burn to arrive at the maximum landing weight. Then that presumably is their choice. There are circumstances when it may be unavoidable to make overweight landings and that would no doubt be reported as appropriate, however the responsibility for the safety of the flight lies with the crew and ultimately with the captain, and it is they who should consider all the known and likely factors when deciding on the fuel requirement. It is also incumbant upon them to take a course of action that in the ordinary course of events does not result in any of the weight limitations being exceeded. Any overweight landing requires engineering checks and in all likelyhood an air safety report, so I am a bit surprised that you suggest you and your Captains are routinely accepting such occurences ?

Finally a Captain cannot sign a loadsheet that shows the aircraft landing 3000kg overweight since he would be declaring an intention to do so at the planning stage. That is why we have had the discussion on increasing the trip fuel figure. He can land at any weight he likes provided the limiting weights and speeds are not exceeded and the runway length permits the performance figures used.

You seem to be suggesting that because the trip fuel does not in some cases consume the contingency (and contingency by definition is hopefully not consumed unless such contingencies actually arise) that the aircraft must be landed overweight ? This is simply not the case. You also ask "are you going to ask for a lower level to increase the burn off". My answer would be in the latter stages of the flight if this scenario is looking very likely then yes why not ? Are you going put the gear down with 100 miles to run ? My preference would be to increase the drag with spoilers, but if the gear usage is within limitations and practical, then again yes why not ? As long as the methodology satisfies the requirement to be down to your landing weight and your required fuel reserves are intact there are many choices open to you.
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