Here is the NACA Report on Control Characteristics of Spitfire VA specifically stating that the CG of the Spitfire was estimated:
Crumpp can argue black and blue that NACA accurately calculated the cg properly - the report specifically states this was not the case:
Quote:
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Because no accurate drawings of the Spitfire were available, the calculated location of the mean aerodynamic chord may be somewhat in error....The center-of-gravity location with full military load is not known....center-of-gravity location 31.1 inches behind the leading edge of the wing.
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and a Spitfire I CG diagram:
Datum point 19.5 in aft of wing leading edge
Maximum aft location of cg was 7.6 in (MiG-3U 7.9 to 8.6 in) aft of datum point, 19.5 in aft of the wing leading edge = 27.1 in aft of leading edge (up to 28.1 in) - NACA calculations = 31.1 in aft of leading edge, enough to make a difference in the longitudinal stability (slightly tail heavy).