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six-sixty
29th Oct 2004, 19:02
Evenin all, I know it's a lot to ask on a Friday night (or any night) but any takers for the following?

In the climb an aircraft has a thrust to weight ratio of 1:4 and a lift to drag ratio of 12:1.
While ignoring the slight difference between lift and weight in the climb, the climb gradient will be??

(ans 16.7%)

I know that gradient is (T-D) / W but apart from that I'm totally stumped however I rearrange these numbers!

Alex Whittingham
29th Oct 2004, 19:59
lift to drag = 12:1, assume lift = 12 bananas, drag = 1 banana, where a banana is an arbitrary unit.
thrust to weight = 1:4, assume thrust is 3 bananas and weight 12 bananas (this done so that lift= weight, which is what the question assumes)
If this is the case the (Thrust - Drag) ÷ weight = (3 bananas - 1 banana) ÷ 12 bananas = 2/12 or 1/6.
1/6 = 0.16666 recurring

six-sixty
29th Oct 2004, 20:32
I was blind but now i can see...

Thanks Alex. Another victory for the underrated yellow crescent shaped fruit.

or as I should say... - thanks a "bunch"

S-S