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## Factor affecting endurance

• Posts: 62

### MissSoph created the topic: Factor affecting endurance

Afternoon everyone...could someone please just help me out with this one....
I understand that flying into say a headwind means that you will have to fly faster than the speed which gives you min drag to counter act the headwind... but why then does the wind not affect your endurance...
I’m trying to imagine my plane flying along into a headwind... so I have to adjust the power setting to make sure I actually get somewhere..but with a higher power setting now...I’m taking more bites out of the fuel... so wouldn’t that affect how long my fuel would now last ?

• John.Heddles
• Offline
• ATPL/consulting aero engineer
• Posts: 415

### John.Heddles replied the topic: Factor affecting endurance

Range - you would like actually to get somewhere useful. As the wind has a direct influence on G/S, the specific ground range (SGR) (which is the relevant parameter for real world range) varies with wind, as you clearly are aware.

When it comes to endurance, the only goal is to stay aloft for as long as is possible/practicable and wind is irrelevant to that goal. (If the wind is of sufficient strength that you are having trouble staying in the hold, then you probably are going to have a world of hurt when it comes to landing anyway).

I’m trying to imagine my plane flying along into a headwind.... so wouldn’t that affect how long my fuel would now last ?.

It sure will but you would not be increasing your speed if endurance were the concern on the day. Your problem here is that you are trying to mix and match range and endurance - they really are two quite different considerations. Yes, you gain a bit of range if you increase speed a little into a wind, but that has naught to do with flying for endurance where the speed chosen is that for minimum fuel flow.

Engineering specialist in aircraft performance and weight control.