Travel Secret #372

We posed this question to an experienced airline pilot. Here’s what he had to say:

Not just speed, even the fuel consumption at higher altitude is less. BUT there are a number of reasons why we choose to fly lower :

At times, the altitude is not available due to traffic i.e. some other aircraft on the same route has already been allotted the higher altitude.

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There could be very strong head winds at a higher altitude as compared to a lower altitude wherein the advantage in terms of speed and fuel consumption is lost.

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Sometimes, when you have full load, the aircraft may be incapable of flying at say 40000 ft (due aircraft performance) and so you maintain a much lower altitude.

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