An Aircraft has following mission profiles with their respective mission weight fraction. There is 10% allowance of reserved fuel. Now, due to some reason loiter weight fraction has changed to 0.90. Now, with same amount of fuel as initial, will aircraft be able to perform loiter? Mission Weight fraction Engine start-up 0.975 Taxi 0.98 Climb 0.970 Cruise 0.989 Loiter 0.96 Landing 0.975

Question

An Aircraft has following mission profiles with their respective mission weight fraction. There is 10% allowance of reserved fuel. Now, due to some reason loiter weight fraction has changed to 0.90. Now, with same amount of fuel as initial, will aircraft be able to perform loiter?

Mission

Answer 1

To determine if the aircraft will still be able to perform loiter with the updated loiter weight fraction, we need to compare the aircraft's mission performance with the new weight fraction and the reserved fuel.

Given Data:

1. Original loiter weight fraction: Let's assume that initially the loiter weight fraction was provided, but since you only mentioned a change to 0.90, we'll assume that the original weight fraction was higher than 0.90.
2. 10% reserved fuel: This means 10% of the total fuel is set aside as reserve, which implies that the usable fuel is 90% of the total.
3. Mission weight fraction: This could refer to the weight of the aircraft after each phase of the mission (e.g., takeoff, climb, cruise, loiter, etc.).

Analysis:

• If the aircraft's loiter weight fraction has been reduced to 0.90, this means that the aircraft’s weight after the loiter phase is now 90% of the original weight.
• The loiter mission is heavily dependent on the aircraft's ability to carry enough fuel and maintain sufficient performance throughout the mission.

If the loiter weight fraction changes to 0.90, it indicates that the aircraft will be heavier (in terms of weight fraction), which could affect fuel consumption. However, whether the aircraft can still loiter will depend on:

1. The total available fuel after accounting for the 10% reserve: The amount of usable fuel will determine if the aircraft can sustain loitering at a higher weight fraction.
2. Fuel consumption rates during loiter: The aircraft's fuel consumption during loitering might increase due to the increased weight.

Conclusion:

• If the loiter weight fraction of 0.90 is higher than what was originally planned (and would require more fuel), it’s possible the aircraft might not be able to complete the loiter phase with the same amount of fuel as initially planned unless it has very efficient fuel consumption during this phase.
• To definitively determine if the aircraft can still perform the loiter phase, we'd need the exact values for the original loiter weight fraction, the total fuel capacity, and the rate of fuel consumption during loiter. With these values, a more accurate conclusion can be drawn.