Which Engine flew....

[meleagertoo]

Which engine flew the most types? Types, that is....

My guess is it would be one of the smaller Lycomings or Continetals. Probably in the 65Hp class if you're going to count homebuilts.

But I fear the PT6, with it's vast array of variants might trump the deal.

So let's re-ask the question - which piston engine powered the most types?

And which turbine?

[Octane]

For military aircraft, the RR Merlin?

[Pypard]

For military aircraft, the RR Merlin?

R-1340, R-1830 or R-2800 I'd venture.

[DaveReidUK]

I agree with the OP - almost certainly one of the small HOAs.

[Jhieminga]

I guess that the O-360 and derivatives should end up near the top of the list. Although perhaps we should not discount the de Havilland Gipsy (Major) and its various incarnations.

[Dave Gittins]

The answer depends on how you add up the various sub sets of each type. Is Cessna172 just one ? or is it 172 S, 172 R and so on. And is the O-360 one type or is it injected or normally aspirated, different horse ratings etc as two or more..

Could maybe make a claim for the Dart if you allow 4 per Viscount and 2 per 748.

All in all I'd be inclined to the O-360 (assuming it's only one engine) when looking on here Lycoming O-360 - Wikipedia (https://en.wikipedia.org/wiki/Lycoming_O-360#Specifications_(O-360-A1A))

[DaveReidUK]

Could maybe make a claim for the Dart if you allow 4 per Viscount and 2 per 748.

The OP specified number of type applications, not number of units built.

[Self loading bear]

Merlin all types 41 applications according Wiki.
Pratt & Whitney R-985 Wasp 44 applications acc Wiki.
Pratt & Whitney R-1340 Wasp 56 applications
Continental C90/O-200 also 56 applications

[TCU]

Rotax 912 (all variants).

According to Wiki an incredible 380 types....but my eyes were getting so bleary reading the list, I may be 10 or so out!

The type range includes ultra lights, gyros through to proper aeries such as the Katana and Tecnam P2006T.

[DaveReidUK]

Merlin all types 41 applications according Wiki.
Pratt & Whitney R-985 Wasp 44 applications acc Wiki.
Pratt & Whitney R-1340 Wasp 56 applications
Continental C90/O-200 also 56 applications

I would expect Wikipedia's list of applications for those P&W radials and the Merlin to be pretty comprehensive.

But if we're going to include homebuilts/experimentals/one-offs (and I don't see why we shouldn't) then I would suggest that a full list of C90 applications over the last 75 years (many undocumented and/or lost in the mists of time) would run into several hundreds.

[dduxbury310]

Alternatively, another useful list might be the number produced of each of the more prolific aero engines which would have to prove SOMETHING. Of the bigger piston engines, I believe that the P&W R-1830 Twin Wasp would be very hard to beat (some 173,618, I believe, and do not know if this includes Australian production). Licensed production has been pretty popular from the beginning, and there were quite a few engine types obviously inspired by successful ones, but not necessarily acknowledged as direct copies. As to number of Merlins? About 150,000 I believe, give or take, bur does this figure include Australian production? (Note, I am not Australian!)

[Self loading bear]

But if we're going to include homebuilts/experimentals/one-offs (and I don't see why we shouldn't) then I would suggest that a full list of C90 applications over the last 75 years (many undocumented and/or lost in the mists of time) would run into several hundreds.

I think your right about this. Could run in the hundreds.
(Btw. Wiki already states some one-offs)
But also very grey area.
Would you call it a successful application when an experimental does not come further than a one-off because it shows to be underpowered?

[ChrisVJ]

Don't know about USA of European countries but in Canada an experimental (Home Built) is labelled by its builder rather than actual type of kit. eg. My Searey was registered as a "Vernon-Jarvis." Might distort the reality somewhat.

[ATNotts]

The answer depends on how you add up the various sub sets of each type. Is Cessna172 just one ? or is it 172 S, 172 R and so on. And is the O-360 one type or is it injected or normally aspirated, different horse ratings etc as two or more..

Could maybe make a claim for the Dart if you allow 4 per Viscount and 2 per 748.

All in all I'd be inclined to the O-360 (assuming it's only one engine) when looking on here Lycoming O-360 - Wikipedia (https://en.wikipedia.org/wiki/Lycoming_O-360#Specifications_(O-360-A1A))

Thinking of the Dart obviously the Viscount, Herald, F27, Andover, HS748, Gulfstream 1, DC3 (Conroy and Basler conversions) and the NAMC YS11. Quite a few types, actually more than I had originally thought. Other British built engines used on fewer types would be the Avon (Caravelle and Comet), Conway (707-400 and VC10), Spey (BAC1-11, F28, Trident) and Tyne (Vanguard, CL44, and Transall). The Dart is perhaps the most widely fitted British engine in terms of types it was applied to.

[DaveReidUK]

Thinking of the Dart obviously the Viscount, Herald, F27, Andover, HS748, Gulfstream 1, DC3 (Conroy and Basler conversions) and the NAMC YS11. Quite a few types, actually more than I had originally thought.

Also on the Argosy, of course, and 80-odd examples of the French Alizé.

But in terms of applications, still a few hundred short of those small HOAs used by homebuilders.

[dduxbury310]

I imagine that the Rotax 912 powers a lot of one offs and kit-set aircraft types because it is (I am presuming here!) one of the more reliable engines in this class, and has been in production for quite a long time. The fact that it has been produced in some numbers (does anybody know how many?), and used by so many "types" is probably quite noteworthy, but the financial investment in each engine is comparatively tiny when compared to the investment in each big reciprocating engine. That is why I think the question of greatest number of aircraft types using any particular aero engine (piston or turbine) is of rather less consequence than the rather simpler question (number of each engine type actually manufactured).