CAP 697 Table
2.2.3
OAT is +13ºC, ISA at 8000ft = -1ºC,
so Temperature condition is 'ISA +14ºC'
Therefore, we need to interpolate
between 'ISA' and 'ISA +20ºC' on the Table
TAS .... this is the
same, 160 kts
Fuel flow:
8000ft, ISA, fuel flow 71.1 PPH
8000ft, ISA +20ºC, fuel flow 68.5 PPH
Our condition 'ISA +14ºC', so
(71.1-68.5) x (6/20) = .78, so fuel flow = (68.5 + 0.78) = 69.28 PPH