Classic British Flight Sim

independance.pl wrote:
Fuel calculations for BAC 1-11

500 version

First hour - 3000 kg/h
Each next hour - 2400 kg/h
Each 15min - 600 kg/h
Each 10 min - 400 kg/h
APU - 300 kg/h
Holding for 30min + 1 go around - 1600 kg
Divert to Alternate (each 60NM) - 500kg
TAS for fuel calculations - 385 kts

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400 version

First hour - 2900 kg/h
Each next hour - 2100 kg/h
Each 15min - 525 kg/h
Each 10 min - 350 kg/h
APU - 300 kg/h
Holding for 30min + 1 go around - 1500 kg/h
Divert to Alternate (each 60NM) - 500kg
TAS for fuel calculations - 385 kts


Example:

Flight LZTT / LYTV - 470NM, Altn LQSA - 125NM BAC 1-11-500

470 NM divided 385 kts gives 1.22h
1.22h means 1 hour and 0.22 min
0.22 multiplies 60 gives 13.2 min
Flight will take 1 hour and 13 min, rounding to the nearest one gives 1h15min
From above table:
Taxi fuel - 100kg, it covers APU running time + taxi for at least 20min.
For each 20 min add another 100kg.
First hour 3000kg and 15 min 600kg so it gives 3600kg.
For alternate:
Each 60nm gives 500kg , so for 125NM we will have 1050kg.
Holding plus go around gives 1600kg.

Total fuel TAXI+TRIP+ALTERNATE+HOLDING gives:

100Kg+3600kg+1050kg+1600kg=6350kg

6350kg is the minimum required fuel for flight.

After landing in LYTV, You should have 2650kg, which is the minimum fuel for the flight to alternate, so you can't land in LYTV with less than 2650kg. It is advised to have some extra fuel for unexpected delays. Paying close attention to Minimum Landing Weight (39500kg for 1-11-500) recommended extra fuel for at least 25min of flight is 1000kg.
Adding 1000kg to 6350kg gives 7350kg total fuel for the trip. After the flight in LYTV the plane should have 3650kg.

FLIGHT PROFILE:

Unless ATC restricted, climb at 250 IAS to FL100, then IAS 290 / 300 / 0.7 Ma to FL290 / FL300 / FL310, then with climb speed accelerate to cruise speed 0.72-0.74 Ma, then shallow climb to desired level.

cstorey wrote:I really don't understand how you have as your nominal cruise M0.72 which in most temperatures equates to approximately 430 kts TAS , and yet you use 385kts TAS for your fuel calculations