How to adjust the pitch of a GA E-Props on Rotax 9xx ?

The ground adjustable pitch E-Props have a strong ESR effect. Their behavior is similar to that of an inflight variable pitch propeller: high efficiency of the engine-propeller combination over the whole speed range of your aircraft.

⇒ To obtain this ESR effect, the adjustment of the blade pitch must be subtle and precise

IMPORTANT:
The measurement of the ideal engine rpm is done in flight and NOT on the ground.
Fine-tuning the propeller pitch will vary from one aircraft to another, and from one engine to another. Each one has its own characteristics, which is why the setting measured in flight will be exactly that of each aircraft + engine combination.
During the first tests, this takes a little more time than static setting on the ground, but it’s so much more efficient !
And for ground adjustable pitch E-Props models, which have a strong ESR effect, static rpm measurement is not a significant data, because they are designed to reach their full traction or thrust just after the start of the take-off roll, not in static. In static, the blades of the E-Props are slightly stalled.

On Rotax 9xx series 4-stroke engines (912, 912S, 912iS, 914, 915iS), the pitch at which the E-PROPS propeller will give the best performance over the whole speed range of the aircraft is obtained :

5,500 rpm at full throttle level flight (at altitude about 2500 ft)

PROCEDURE:
1/  Adjust the pitch as recommended on the Propeller Identification Sheet (sent with the propeller)
See example of this Sheet here, for a RV-12 912iS => E-PROPS IDENTIFICATION SHEET
You can it on the description of the propeller on our CATALOG, or you may ask our team.

2/ On the ground, put full power on brakes or chocks.
✗  If you have between 5.000 and 5.800 rpm, you can go on with the flight tests.
✗  If this is not the case, adjust the blade pitch to have between 5.000 and 5.800 rpm on the ground.
Increasing the pitch by 0,6° reduces the rotation speed by 100 rpm.
Decreasing the pitch by 0,6° increases the rotation speed by 100 rpm.

3/ In flight, level off at an altitude of about 2500 ft.
✗  Apply full throttle.
✗  Note the number of rpm that appears on your tachometer.
✗  If you have 5.500 rpm (+/- 50 rpm), your setting is perfect.
✗  If not, land and redo the setting.

Example: in full throttle, the engine is running at 5,700 rpm, while the target is 5,500 rpm. The difference is 2 x 100 rpm, so the pitch must be increased by 2 x 0.6° = 1.2°
If you get this value of 5,500 rpm full throttle, then your propeller is optimally set for the full speed range of your aircraft. 😀

Now you know everything you need to know to effectively adjust the pitch of your E-Props ground adjustable propeller. Make a note of the resulting pitch for the next time you need to disassemble/reassemble your E-Props, and you’ll be set for many hours of flying (E-Props Durandal-3 has a TBO of 4,000 flight hours).

Data Sheet : E-PROPS 3-BLADE DURANDAL-3