The performance on our Eaglet with its original GT Tonini prop has been very satisfactory with a take off roll (approx 120-130m at MTOW - 600kg); climbout approx 1000fpm; cruise approx 105-108 at 18lph. To be perfectly honest, although I had flown with CSU's on other aircraft, I was quite happy with the performance of our fixed pitch prop and the simplicity of it in terms of operation and maintenance (ie very little).
I had a flight with a friend with an Eaglet and Airmaster CSU with Sensenich 2-blade prop and I liked the improved cruise speed and commented so to husband. Unknown to me, he ordered the same CSU/prop combination. It arrived and I had reservations as to whether this was all a good idea - "why fix something that's not broke!" My fixed pitch prop did a great job!
So we fitted the prop and were amazed how well it was all set up at the factory...just a case of following the manual with all the pre-set pitch settings already in place....I took it for a circuit and was very happy with the fitment. Very smooth.
A week later we toured around Qld and SA so I was able to make comprehensive comparisons, and noted them for accuracy. Conditions were winter. I couldn't be happier:
At MTOW we were off the ground quicker (approx 90-100m); our climbout is now approx 1500fpm (I often now don't use take-off flaps for take-off); cruise settles in at approx 115kts at 18lph around 2500'.
The set pitch settings from TAKE-OFF (5600rpm) to CLIMB (5400rpm to CRUISE (5000rpm in log book but mine is sitting at this stage 4900rpm according to instrument) are very definite and the performance change is noticeable as unit transitions from one mode to the other.
Using HOLD we have had it set to 4000rpm for turb conditions and get 93kts (Va) at 15lph.
Or, setting HOLD at 5200rpm, I get approx 120kts at 20lph. Approach is more stable than the fixed pitch although the two blade prop does not appear (to me) to give the same "breaking feel" as the three blade.
Also, the system is so simple to operate; and the maintenance schedule is very straight-forward with no parts being limited to a time-life. And the looks of the prop....really stunning! Have to say, much prefer it to the three blade.
Having flown our Tecnams for 8 years with many trips all around Australia, the performance of the GT fixed pitch prop has always been extremely satisfactory - the CSU with Sensenich 2-blade is certainly "icing on the cake". Whilst I had absolutely no intentions of buying a CSU, now that we have one, I am absolutely delighted. This was indeed a situation where I loved being wrong!
Cheers, and thanks,