Question ID: 330269

[mbrosnan]

(Refer to the image or Flight Planning Manual MRJT 1 Figure 4.3.1c)
For a flight of 2400 ground nautical miles the following apply : Tail wind component 25 kt Temperature ISA -10 Cruise altitude 31000ft Landing mass 52000kg The (a) trip fuel and (b) trip time respectively are :

Could someone please explain why the red line in the magnified box is closer to the 37 line than the 10 and why its not equally in between the 37/10 blue lines.
I can see how the 2 blue lines are created but not why the red is nearer the 37 line.

Thanks in advance!

[Mac]

The blue line labelled 10 is the guide line for 10 000 ft and the blue line labelled 37 is the guide line for 37 000 ft. The spread of altitude between them is 37 - 10 = 27 000 ft; half of that would be 13 500 ft.
Half way between the blue lines would be 10 000 + 13 500 ft = 23 500 ft
The question states the aircraft altitude is 31 000 ft so the line for fuel must be closer to 37 (37 000 ft) than 10 (10 000).

[mbrosnan]

Perfect! Thanks Mac.