Given the following information, determine the quantity of barrels of 45 gallons required, considering the actual fuel at the destination for the Commercial flight. Assume the Basic Fuel Scheme WITHOUT variations applies.
Assume that the actual fuel consumption is maintained at the same rate.
Total distance from A to B: 320 NM
Fuel remaining after 1 hour 15 minutes: 859 US gal
Distance travelled after 1 hour 15 minutes: 119 NM
Average TAS: 115 kt
Wind component: 20 kt headwind
Trip Fuel: 1280 US gal
Planned average fuel flow: 380 US gal/h
Extra fuel: 0 gal
Discretionary Fuel: 0 gal
IMPORTANT NOTE: The modifications resulting from the updated fuel policy regulations, which came into effect on October 30, 2022, are only changes in wording but nothing really new. The terminology "extra fuel" has been replaced with "discretionary fuel." EASA has clarified that the calculations and procedures pertaining to fuel calculations will remain unchanged, and there will be no new questions regarding the new "extra fuel" concept.
 extra fuel, include anticipated delays or specific operational constraints that can be predicted
 discretionary fuel, include a quantity at the sole discretion of the commander
For reference, additional information can be found in EASA's AIR OPS documentation.
1) Determine the actual fuel consumption (US gal/h) during the first 1 h 15 min:
After 1 h 15 min the fuel remaining equals 859 US gal. The planned trip fuel is 1280 US gal. Therefore, after 1 h 15 min, 1280  859 = 421 US gal of fuel were consumed.
Fuel flow (FF) = 421 US gal / 1 h 15 min = 336.8 US gal / h
2) Determine the distance remaining after 1 h 15 min:
Total distance from A to B: 320 NM
Distance covered in 1 h 15 min: 119 NM
Distance remaining = 320  119 = 201 NM
3) Time taken to cover 201 NM:
Average TAS: 115 kt
Wind component: 20 kt headwind
Therefore, the Ground Speed = 95 kt
Flight time = 201 NM ÷ 95 kt = 2 h 7 min
4) Determine the fuel consumed during 2 h 7 min (to cover 201 NM):
Fuel flow (FF) = 336.8 US gal/ h
Fuel consumed = 2 h 7 min x 336.8 US gal/ h = 713 US gal
5) Calculate the actual fuel at the destination:
Total fuel consumed = 421 US gal + 713 US gal = 1134 US gal
Actual fuel at destination = 1280 US gal  1134 US gal = 146 US gal
Number of barrels = 146 US gal/ 45 US gal = 3.3 ≈ 4
Note: The fuel referred to as trip fuel in this question is apparently the total fuel on board.
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