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Old 13th May 2006 | 19:21
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camlobe
 
Joined: Mar 2006
Posts: 262
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From: very west
VMAX range vs VMAX endurance

Mr Smiley, if we accept that VMAX range is the speed selected for the maximum distance possible (with or without diversion fuel) attainable for a given fuel load, and that VMAX endurance is the speed selected for the maximum duration possible (with or without diversion fuel) attainable for the same given fuel load, those speeds are a reflection of fuel flow (thrust selected) and drag. Both of these are already mentioned by barit 1.

In a basic answer to your question 'why is VMAX range greater than VMAX endurance' if you are aiming to stay aloft for as long as possible, you will be set up at a higher angle of attack than if you went for furthest distance. Although you have set a lower fuel burn for endurance, this is offset by the higher drag penalty and you will travel a shorter distance for the same fuel burnt.

Hope this helps.
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