Question

A jet transport aircraft has fuel storage of 1200kg. It has completed taxi phase and preparing for take-off. At the end of the taxing, it has fuel fraction of 0.98. Determine how much fuel is available after taxing. Given take-off gross weight is 9000kg.

(a) 1020kg

(b) 180kg

(c) 1800kg

(d) 2240lb

This question was posed to me by my college professor while I was bunking the class.

My question is from Conceptual Sketch Sizing topic in section Conceptual Sketch Sizing of Aircraft Design

Answer 1

Correct choice is (a) 1020kg

The explanation is: Given,

Aircraft take-off gross weight W0 = 9000kg, Fuel storage = 1200kg

Fuel weight fraction after taxi = Wtaxi/W0 = 0.98

Here, there is no provision of reserved fuel is mentioned so, we are neglecting reserve fuel fraction.

Now, from fuel fraction method,

Used fuel weight fraction is Wf / W0 = 1 – (Wtaxi/W0)

= 1 – 0.98 = 0.02

Hence, fuel used during taxing mission = Wf = W0 * 0.02 = 180kg.

Now, remaining fuel weight = fuel storage – fuel used during taxi

= 1200 – 180 = 1020kg.