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iainsmith

747-400F for FS9 - insufficient fuel???

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So here I am approaching my destination EDDL Dusseldorf and on the downwind leg prior to being vectored on to final, so less than 50 miles to t/down with just under 10000 lbs of fuel remaining. The FMC then says "insufficient fuel". Surely it's joking? Is this normal?(a great sim model by the way).Iain Smith

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It's not joking. The insufficent fuel message means that it has calculated you are going to reach destination with less than the number of pounds of fuel you have input for reserves. You can decrease your reserves or ignore the message.

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No it is not at all joking, you ARE short of fuel, SERIOUSLY... If you are on downwind in a 747 with just 10'000lbs fuel on board and this is NOT your alternate airport nor have you done a 30 minute holding or a go around then you are seriously unsafe... When doing the fuel planning you need to consider all the necessary alternate and reserve fuel requirements.Regards,Markus

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Its not uncommon to have what 20,000- 37,000 lbs. of fuel. Right?

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When flying the 747-400 you have what is called a "minimum landing fuel" and this can vary depending on the nature of the flight.. but 10,000lbs is way way WAY too low, that's 5 tonnes, at some airfields you'll might use 1 tonne during your taxi! I would expect to land with at the very least triple that.. I would aim realistically for 37,000lbs really as a minimum when landing.The way to set up the reserves is to work out what you minimum landing fuel (MLF) is.. then add onto it your alternate/holding fuel, contingency fuel.... (CF)... This is like your real "reserve".. for holding, weather, diversion etc.. The MDL is something you're EXPECTED to have really at the gate.. It's a minimum safety requirement for 747-400 operations.So.. MDF + CF = The fuel you'd have in the tanks at the gate (give or take 2,000lbs for taxi) if you were to just come straight in on your approach with no hold ups..For the FMC reserve entry, I think it's good practice to enter MDF + 50% of CF... into the RESERVE entry then when I get the "INSUFFICIENT FUEL" notice, I know I've used half my normal reserve... and it's time to get down..Example (just plucked these numbers out the air I can't remember the proper numbers without getting my paperwork out)25,000lbs MDL + 25,000CF = 50,000lbs (25 tonnes)FMC RESERVE ENTRY25,000lbs MDL + 50% of 25,000CF = 25,000lbs MDL + 12,500lbs = 37,500lbs = ENTRY 37.5With that entry, when you're holding and you're waiting for your landing slot, when the FMC chimes with "INSUFFICIENT FUEL" you know you've only really got 12,500lbs to play with.. and if you're not on your way down.. you want to be shouting out to ATC to let them know your fuel situation means it's time to land now..I am sure someone can correct these figures..CheersCraig

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Thank you all for the info. How can you tell that I'm new to the 747? :-) Iain Smith

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i read somewhere ( i forgot where though ) that Boeing requires a certain amount of fuel in all tanks at all times. they made this a standard for all 747's after the TWA800 incident. before you taxi out to the runway on the departure airport, check the FMC progress page 1. it will tell you an estimated figure on how much fuel youll have left when you get to the destination airport.

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You're probably refering to AD 2001-12-21 which states that if Center Wing tank fuel is to be used during flight there must be no less than 17,000 lbs. of fuel in the take prior to engine start. If CW tank fuel is less than 50,000 lbs., the CW Override pumps cannot be used until the cruise phase of flight; and if there is more than 50,000 lbs. of fuel in the CW tank, then the fueling system can be used normally. This also prohibits the use of the Horizontal Stabilizer tanks for any reason, they must be empty. However, all this is null and void if the fuel pumps have been replaced with later models.Also, there is a minimum fuel load for each of the four main tanks for hydraulic fluid cooling. On the "classics" it's 2,000 lbs. in the outboards and 5,700 lbs. in the inboards (if my memory serves). I'm not sure what the minimums are for the -400.Ryan

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yeah thats what i was referring to. i think the restrictions are a little lighter for the 744 verses the 742.but they still require a minimum of 2000LBS in the CTR tank.and if im not mistaken they have restrictions on the 767 also. i think its 1200LBS of CTR tank fuel.

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