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Performance reduction chart

Posted: Fri Mar 06, 2020 5:41 pm
by Richard Mole
I have just bought a copy of
Flight testing of production aircraft by JA Crosby-Warren, Pitman 1943

Fig 1 in appendix A is missing and I was wondering whether anyone else who had a copy of this book could scan it for me?

The text refers to fig 1 as a copy of Air Diagram No 1077 published by HMSO but a google search was unproductive.

Its hardly a matter of life or death but I would like to see the chart if anyone has access

Re: Performance reduction chart

Posted: Thu Mar 12, 2020 4:26 am
by Mark A
Looks like a table for performance loss vs density altitude (found on Ebay):
Image

Re: Performance reduction chart

Posted: Fri Mar 13, 2020 9:55 am
by Richard Mole
Mark, many thanks or this - excellent sleuthing by the way!

You are right in saying its about density altitude but only partly!
'Standard height' is the arithmetic mean of a corrected altimeter height {or mb setting, instrument error etc} and a 'full density height'.
In essence its a practical fudge between pressure and density notions of height.

I've since found another source with a better treatment of the underlying theoretical development in 'Aircraft performance testing' by Scott Hall & England Pitman ?1934 who were at Martlesham Heath where/when this work was being developed.

Its quite amazing how a £10 spent here & there opens up a window on our technological heritage!

Many thanks again

Richard