New MD11 Weights

[EHM-1570 Bruce]

I have just completed a flight in our new MD11, however I had to reduce the cargo weights in order to get get sufficient fuel on board for the flight, even then I had to dump 35000lbs of fuel in order to get below the MLW of 430000lbs. The ZFW for this aircraft at the moment is 425400lbs and the MLW is 430000lbs this means that in order to be below the MLW you can only have 4600lbs of fuel on board when landing which is way too low as I believe you are supposed to have sufficient fuel on board for a further 1hr flying time ( this would require an extremely accurate fuel planner). The cargo weights are very high, the forward hold has 35000lbs and the rear hold 21000lbs, as this is a holiday  class aircraft the only cargo would mainly be Passenger baggage, and if we allowed 25kg per passenger and some extra weight for other bits and pieces, this would mean that the paylod would only be 18000lbs for baggage plus whatever small amounts of additional cargo. I feel that changes should be made to the aircraft.cfg file prior to downloading the aircraft in order to amend these weights rather than each individual amending the cfg file.

[EHM-1001 Robert]

Hi Bruce,

I am glad that at least somebody have any opinion on the aircraft ! Let me describe it:

As I see, the problem caused is the Cargo payload. The simple answer is: you do not need to take ANY cargo with yourself, simply set to zero those loads !

The heavy passenger airplanes are so big, that they can easily carry some cargo too next to the passengers baggage. The MD-11 for example have space for 16 pallet rows. With full airplane the baggage needs only 8 rows, so the half of the cargobay is empty. Also the aircraft structure allows to fill this space up to the Structural limit, which is 117 kLbs for the MD-11.

As a captain of a heavy aircraft, the first role before takeoff is to organize the payload you want to carry. You have several limits: the number of seats, the allowed structural payload, the available cargo room, MTOW, and the fuel required for the trip. Basically you need to distribute the payloads to be under MTOW, and to be under structural limit. But you decide: you can fly with full pax and baggages only, but also you can fly with half-empty plane, and 40 tons cargo on pallets. You can do both.

What you need to keep in mind is the aircraft range and MTOW. The aircraft range is ALWAYS given with full pax and baggages, and NO cargo ! This way you will be well below structural limit. With this amount of pyaload, and the available fuel amount you can fly the given range for sure ! Mostly with full pax, the heavies are able to filled with fuel up to 80-90% of the tank maximum volume. And this means if you fill max fuel, and less pax/cargo, you can fly even further than the given range.

Fuel useage of our aircraft is set also for the given range with max pax and no cargo, only baggage ! We give you 2 ranges for the MTOW weight, the normal (green) M[size=-1]LOAD[/size] and below it the 100% fuel range M[size=-1]FUEL[/size]



You can see, the range is given as the green line. If you fill more payload you can get less fuel and less range. If you fill less payload, you can maximally fill the tanks and you can fly much much longer !  If you go along the red line, from left of the break point you takeoff with MTOW, from right to the break point the fuel is always maximum, and the takeoff weight is less than MTOW !

I hope this will help selecting the proper loading

[EHM-1570 Bruce]

Hi Robert
   I have altered my aircraft.cfg file to reduce the payload, But I believe that there is a payload editor for this aircraft, but I do not know where to obtain it , do you know?

[EHM-1001 Robert]

Well, it was included in the Alain Capt panel package.

I will not alter the CFG for 1 simple reason: FS is prepared that it reads out maximum load for each fields in the CFG, and then the pilot can decide how much load he carries. The numbers in the CFG are only allowed maximums for each stations. You must decide before the flight if you really want to fill that station (pax/freight) or not.

To be honest I do not feel real those airplane models, where the CFG comes out with a payload model that can never exceed MTOW ! Aircraft are designed that there is much more room to fill than it can really carry as weight, and I do not like if somebody limits my possibilities. I want to decide how much and what kind of payload I carry on my flight within design limits, but for this the CFG must show what are the possibilities.

[EHM-1465 Dominic]

Bruce,

The original payload editor is on Alain Capt's site here if you can't find it