Errors, myths, clangers etc would be avoided if only it dawned on folks that the FACTS are available through the Heritage society and even R-R itself rather than perpetuating some nonsense.
Agreed
enicalyth. To put to bed a couple here
Packard Merlins were just the same as their U.K-built counterparts, except that they used U.S. sized nuts, bolts, threads etc
The American engines used the very same British thread system. Packard had to produce all the taps and dies themselves, something they were not set up to do, and delayed actual engine manufacture for some period of time.
Lightning Mate, the Mossie props rotated in the same direction, irrespective of Mark. Your observation would be down to film frame rate as you say. You see the same effect in a film of a car wheel, at some point it will appear to be rotating in the reverse direction compared to its actual rotation. The clip you saw must have been on the very point where this effect takes effect, to coin a phrase. Slight difference in actual prop RPM would give the appearance of reverse rotation. Instructors used to use this strobe effect to determine if students had the RPM set correctly by flying astern and looking through their own prop disc at the students, and determining which direction the students prop appeared to be turning.