It is an interesting example, but it isn’t strictly a case of ‘tolerance’…..more one of surface finish.

I can understand exactly how such a ‘failure’ in an air-cooled cylinder could occur if the surface finish is ‘too good’ and has no imperfections to retain lubricating oil and that leads to increased wear, overheating and, ultimately, to a piston seizure.

At one time ‘cylinder honing’ was done to remove imperfections; now honing is mainly used to introduce them!

I take your point Creaking Door, but if the bore was that perfect, you would glaze bust it before service, for the rings to bed in?.

Yes all the best Edgar

That’s really nice, thanks ever so much for posting.

I see there is a Pitts 12 on there as well. anyone know where in South Wales that this stuff is?

In-cockpit video and audio were running throughout the flight, and were recovered from the crash site, so the NTSB had a pretty clear idea of exactly what went on in the cockpit.

My point exactly, if it was a loss of situational awareness the pilot would have crashed regardless even if he hadn’t let his passenger have a go

Replic’Air will build 2 (two) D.551.

Let’s hope one of the magazines takes note and does an in depth report on this project. I for one would be keen to see it