I got a FAA field approval to install a 198cm 3 blade MT prop (that is 20 lbs lighter), the effect on approach when moved to full fine for landing is like throwing a chute out the back
Ah ha! Piperboy, that's a whole different situation! All bets are off for POH speeds and procedures having done that! We commend the FAA for giving that field approval, but a number of design requirements for certification were overlooked when that approval was issued (a fundamental flaw in the FAA field approval system). Email Martin Albrecht at MT, and review the situation, he may have some suggestions about adjusting the pitch stops to improve things, you simply do not need that braking affect for your flying.
In the mean time, if you have had an engine failure, do the following: Best glide speed*, prop selected to full coarse, select your forced landing place (closer being better), cause check (altitude permitting), and if you cannot get the engine running again at that time, mixture to ICO, and mags off then. Doing so forces you to follow through on a decent forced landing, rather than the engine spurting back to life, and luring you into passing up a decent forced landing opportunity for a worse/rushed one later and lower altitude, when it quits a second time.
I would advocate the POH best glide speed. That provides time and distance.
Yes, certainly. If you need the time and distance for you glide, fly at best glide speed. *However, if you can make a suitable landing area sooner/closer, do that and carry the extra speed to assure yourself a margin of reserve for a decent approach and landing. If you arrive to midway back final with too much speed/height, more flaps or sideslip, because you don't have airbrakes as the sailplane pilots do. Piperboy could select full fine again though!
I train this a lot when I'm doing advanced type training, and I regularly see really poor skills in terms of simply putting the plane back on the ground with a reserve of safety - pilots regularly overestimate their glide ability. Ultimately, if you're going to get it wrong as you cross the fence, you would much rather be too fast than too slow, and go off the far end at a few knots, than not cross the fence, and slam into whatever it is at flying speed!
This is extra important in drag changed planes, like floatplanes, skiplanes and float amphibians.
This should be practiced a lot. Every pilot I train and practice with seems to have an eye opener when we do this, so I'm thinking that other pilots could benefit from more practice too. That practice has most value only if it includes a touchdown - go arounds at 50 feet really don't show you that you could have landed and stopped.
Piperboy, I have installed an MT reversing propeller on my flying boat, and found the same characteristics you describe - a forced landing in fine pitch would be very challenging. I found similar, though less dramatic characteristics when I tested the MT reversing prop on the 182 amphibian. I have also flown the MT props during testing on 182, Lake Amphibians, Twin Comanche, and DA-42-L360. I really like them, but they're different, and sometime these differences are not well understood. Talk to Martin.