170. Inspection!

Today we had no less than three experts looking over our handiwork to see if there was anything stopping it being allowed to fly.

Mike Smartt has been our inspector throughout the build, and his signature is needed on the paperwork to show that all the necessary stage inspections had been done. For a kit-built aircraft where there have been other identical ones built before, this would usually be sufficient to complete the process. The papers would go off to the Light Aircraft Association (LAA) and their Chief Engineer, Francis Donaldson, would sign the Permit to Test, which would allow the test flying to be completed, after which a Permit to Fly is issued, at which point the aircraft becomes fully signed off.

But since this is pretty unusual, Francis himself wanted to come and have a look, and so he turned up as well. But because of the particular and unusual engine, he  asked that Jean Munn, Chief Engineer of the Shuttleworth Collection be present as well, since he knows more about rotary engine installations than anyone else in the UK.

In fact, all three of them went right through the airframe as well as the engine, and came up with some very constructive comments.

Francis Donaldson (L) and Jean Munn (R) discuss the finer points of the aileron circuit.

Only one possible issue may need a certain amount of rethinking and reorganising which isn’t as straightforward as it would have been before we covered the fuselage, but we’ll wait to see what the outcome of Jean’s research is on that. Otherwise, the things that need doing, while they aren’t trifling, are relatively easy and quick to fix, and generally everybody was very complimentary about our work.

Once the static inspection was complete, we rolled 1264 out into the sunshine and started the engine, and here Jean’s experience was supremely valuable. We proved that our 1915 tachometer was working, and – by comparing it with Jean’s optical tacho, which counts the propeller blades whizzing past – that it was very accurate.

We also showed that Jean’s concerns about the enclosed cowling and the possible overheating that might occur, during ground running were justified, but that it was possible to run it for about three minutes without doing any harm.

He also established that the needle in the fine control valve may not be completely appropriate, and if we can take some measurement,s he’ll have a root through their collection and see if he can find something more appropriate.

The issue that might take a little longer to fix (if it is a problem) is that we’ve fitted the mixture valve a different way up from the normal installations. If we can find a suitable justification for this,, it may be possible to leave it where it is. If not it will have to be turned over, and this will take rather more work to achieve. We’ll wait for Jean’s final verdict before taking any action, however.

Mike signed up the necessary pages of the inspection book, and these will be sent off to Francis, who will write us a letter detailing all the various points raised, and when we’ve convinced him that we’ve satisfactorily closed them out, he will issue a Permit to Test, together with a test schedule for the test pilot(s) to complete.

In the meantime, the aircraft is dismantled and back in its trailer and waiting to be brought back to Milson so that we can get on with the work more easily.