Prop advice?

[foxmoth]

We had a prop strike on our aircraft which ended up with the engine being rebuilt - long story, but ended up as an o200 rather than the C90 it was before. We now need to sort out the prop - 2 choices, the correct one for the O200 (Evra D.11.28.7) or the C90 one (D.11.28.1) - It would seem obvious to go for the O200 one, but I am told this is a finer prop than the other which I think would give us better T.O. performance but not do much for the cruise - we do not really need a better T.O. (Landing is more limiting) so wonder if we should stay with a C90 prop.
Any comments from anyone that knows anything about this appreciated.

[foxmoth]

If it's a PFA type, I dunno, why not ask other owners of the same type?

Which is largely what I am doing now (aircraft is a Falconar F11-3, basically a Jodel). :rolleyes:

[PlasticPro]

If your aircraft is a PFA type, contact the engineering department at PFA HQ, Turweston. If its under CAA regs, contact Brinkley Light Aircrarft at Meppershall. They have a Prop Shop on site and will advise.
Best of luck
PP

[Windy Militant]

More Info here Changing Engines and Propellers (http://www.pfa.org.uk/Engineering%20pdfs/Mods%20and%20Repairs/TL%203.02%20Changing%20the%20Propeller%20or%20Engine.pdf) From The PFA web site Engineering section.

[shortstripper]

Ian, my email is buggering about again, so I've not been able to email direct. For the benefit of others as you've posted here, I'll give my opinion here too.

The Falconar F11-3 is basically a Jodel D11 variant with the wing crank one bay further in and a three piece spar (For those who don't know). Any prop/engine combination approved for the D11 will have a pretty smooth run getting approval from the PFA. Talking of smooth, Pete Smoothy of Airworld's advise re prop/engine combo is worth taking, as he deals with most of them. If the engine weight remains the same despite upgrade to 0200 (which it should), prop weight must be checked. A couple of lbs difference right at the front may not seem much but the lever arm is high so it's possible it could effect W&B although unlikely. If the prop is finer, then I'd be surprised if the diameter was the same or smaller? It would be a bit like putting a lower range gearbox on a more powerful engined car ... unless of course the original was way out of spec??? (wouldn't surprise me in our case!). Also, prop spec's, although the same, often have differing performance depending on manufacturer. As an example I had two props for my old VP2, a CL 57X32 and a RWG 60X29 The CL was theroretically a better cruise prop, but in reality made no difference to cruise, but didn't climb half as well as the RWG. Nice prop though with lovely inlaid brass leading edges ... 1.5 lbs heavier for it's loveliness.

SS