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Thread: Engine RPM
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Old 1st February 2004 | 06:48
  #15 (permalink)  
SteveR
 
Joined: Sep 2000
Posts: 293
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From: Dorchester, Dorset
Good thread.

When I read this:
As for checking it, pre-flight, why not check it as you begin the take off run and still have time to abort.
I thought "D'oh! Of course, it's a ground roll check, so there's no point in it being written down, you were probably taught that in lesson #2"

Then I read:
Doing the engine run up into wind will get result accordind to the wind speed after all a 15kt headwind is more than 10% 0f the speed range of most fixed pitch light aircraft and will more than likely unstall the prop giving an over optimistic static RPM , with a tail wind the oposite would happen.
..and, after supplying my own punctuation , I realised the sense of doing pre-flight static tests crosswind.

A cruise prop is presumably changing from air shovel, through semi-airshovel, to very-draggy lift producer during the first 20-30 knots of takeoff roll, so full revs can't be expected until a time when eyes need to be outside the cockpit.

So obviously Timothy is right, you should never fly without full revs, but my question stands.

Why isn't a max static rev range, in a crosswind position, printed on written checklists? It seems an easy check with a definable expected result.

Steve R
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