The TO-360 on my Commander 112 TCA is getting very, very tired. I think I have another year in it, maybe two, but I'm definitely approaching "pushing my luck" territory.
Overhauling the TO-360 is cost prohibitive -- Lycoming wants this engine to have never existed, and overhaul quotes are coming in at much higher than a TIO-540 overhaul would be.
I was vaguely optimistic that the new MOSAIC standards would include the Commander, giving some freedom to play with ASTM standard engines, but the 58 kts Vs1 makes this exceedingly unlikely.
So, as I see it, I have four paths:
The ULPower UL520T is 220 hp @ 2700 rpm, "installed weight" 269 lbs. Critical altitude is 15k ft. With a correctly matched propeller (a bit shorter diameter), I'd expect similar climb and cruise performance (a bit more power at a bit less diameter); I'm okay with a slightly extended takeoff roll from the smaller prop. 100 lb weight reduction seems realizable; plus maybe a bit more from taking the hunk'o'lead battery and thick cables to it and throwing an EarthX up front.
Overall, based on my time flying the Commander, my limited knowledge of aircraft systems, and my discussions with ULPower, I suspect that the Commander 112TCA with a ULPower 520T would be a better aircraft than it currently is with the TO-360, even if the TO-360 was not approaching end-of-life...
So… how crazy is this idea? Should I really focus on option (3) instead of (4)? Other thoughts and ideas?
Overhauling the TO-360 is cost prohibitive -- Lycoming wants this engine to have never existed, and overhaul quotes are coming in at much higher than a TIO-540 overhaul would be.
I was vaguely optimistic that the new MOSAIC standards would include the Commander, giving some freedom to play with ASTM standard engines, but the 58 kts Vs1 makes this exceedingly unlikely.
So, as I see it, I have four paths:
- Buckle up at pay $80k+ for an overhaul of a TO-360. Cost prohibitive.
- Look at other existing engine options, either through TC or STC. The 112TCA is on the same type certificate (A12SO) as the rest of the 112 and 114 family, but is listed there with only the TO-360 engine, and has structural differences (e.g. longer wings!) than the rest of the family -- am I correct in assuming that there's no magic rule that would allow me to use other engines in the TC without going through the full STC process? There are STCs for different engine options (including a turbo-normalized IO-360 that would be a decent fit), but only for the 112/112A/112B -- and I assume these help me not at all. So I think this is not applicable.
- Go through the process to get a (one off?) STC for a certified engine. Significant engineering, expensive, and the best fit engine (probably a TIO-360) is still not amazing. More info requested from someone who has gone through this process.
- Take the Commander experimental (Exhibition?), and slap a non-certified engine on it. Just as much engineering as (3), but possibly cheaper, and possibly giving me a better result. Strongly request info from someone who has done this. (I accept that this would make reselling the aircraft in the future unlikely.)
The ULPower UL520T is 220 hp @ 2700 rpm, "installed weight" 269 lbs. Critical altitude is 15k ft. With a correctly matched propeller (a bit shorter diameter), I'd expect similar climb and cruise performance (a bit more power at a bit less diameter); I'm okay with a slightly extended takeoff roll from the smaller prop. 100 lb weight reduction seems realizable; plus maybe a bit more from taking the hunk'o'lead battery and thick cables to it and throwing an EarthX up front.
Overall, based on my time flying the Commander, my limited knowledge of aircraft systems, and my discussions with ULPower, I suspect that the Commander 112TCA with a ULPower 520T would be a better aircraft than it currently is with the TO-360, even if the TO-360 was not approaching end-of-life...
So… how crazy is this idea? Should I really focus on option (3) instead of (4)? Other thoughts and ideas?
