[David603]

Frontline fighter performance varied wildly. It especially departs from official factory and test pilot data.

and

I would agree that frontline fighter performance did differ substantially from data recorded by test pilots in factory fresh aircraft and prototypes,

Just wondering what these statements are based on..

Can you give me an example?

I can give you two just off the top of my head.

Clapped out Hurricane MkI's refitted for service late in BoB had substantially lower performance than factory fresh examples, in some cases as low as 305mph top speed.

Late in the P40's service life, many Allison engined models were modified in the field to run at 72" boost with a re-geared supercharger, giving an output of just over 1500hp at sea level, substantially boosting the P40's low level speed but exacerbating the power problems higher up.
[quote="ACE-OF-ACES"]Reason I ask is this 'idea' seems to be a common one

I myself have held the same 'idea' for years

But to be honest I don't have documentation to support that 'idea'

That and I think it means different things to differnt people

My 'idea' goes like this

Rolling off the assembly line, a Henry Ford type where variance is minimized you would have some variances

But they would most likely be small

So small that you probably wouldn