Performance Question.. HELP

[spitfire747]

Have got this performance question in some feedback and wondered if anyone could explain why the answer is the one it is
and not answer B

How must an aeroplane be flown to achieve maximum possible speed ?

a. Flown at a speed corresponding to Vmp
b. Flown with maximum thrust and minimum drag
c. flown with maximum thrust and maximum drag
d. flown as the best lift : drag ratio speed

answer given = C

Cheers, Spitty

[FlyingForFun]

The answer lies in the drag curve. The faster you go, the more drag you have (assuming you are above Vmd, which is a safe assumption since we're trying to go fast). Or, to put it another way, the more drag you have, the faster you must be going.

In level flight, thrust=drag, so maximum drag requires maximum thrust. Answer: C.

There is an argument that Answer B could also be correct. If, by "minimum drag", they are refering to devices such as flaps, air-brakes, etc, then you would want the aircraft to be clean, i.e. minimum drag, if you were looking for maximum speed. The question would be much clearer if it specified whether configuration changes are being considered.

FFF
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[NineEighteen]

Here's a previous thread (http://www.pprune.org/forums/showthread.php?s=&threadid=96463) regarding the same question.

0918