Copyright of RotorSport UK Ltd
Document number RSUK0060
Page 99 of 101 Page issue 5.1, dated 10.06.14
3. Propeller will not make pitch change (determined by no audible effect from engine when
at constant power setting). Probable cause: failed propeller mechanism, end-position
controller or cable fault. Follow the appropriate actions in 1. or 2. above and consider the
further scenarios in the table below:
Before take-off
Do not take-off
During take-off and climb
Try to keep climbing to a safe altitude, return
to the airfield and land. If the aircraft does not
climb, maintain altitude and plan to return in a
flat curve.
During cruise flight
Depending on the prop position, it should be
possible to find a speed and RPM to continue
the flight to the next possible landing area.
Depending on the prop position your descent
will look different and a go around is probably
not possible.
During descent
Depending on the prop position (in case of
coarse pitch), your descent will look different
and a go around will probably not be possible.
During Landing
Continue approach as planned. If the prop
changes to coarse pitch and the landing looks
too long, keep in mind to cut the engine.
4. A propeller blade pitch becomes different to the others. Probable cause, internal
mechanical failure. This will result in significant warning vibration. Reduce power and
assess vibration with consideration of a precautionary landing. If necessary turn off engine
& make immediate precautionary landing.
5. Loss of blade. This will result in severe vibration. Switch engine off and land
immediately.
6. Loss of blade tip. This will result in significant vibration. Switch engine off and land
immediately.
7. Loss of complete unit. This could result in destruction of the tail or other structural
damage. Switch engine off and land immediately.
8. Loss of LED indicator lamps. Probable cause; controller failure or fuse blown (25A).
Maintain aircraft speed and propeller pitch at around 80mph to prevent engine over-
speed.
9. 25amp panel fuse blows. This cannot be changed in flight. Loss of power supply to
propeller controller, hence propeller. No pitch change possible, prop will remain at last
pitch setting. Make precautionary landing if unsafe to continue the flight.
10. General Note – an increase in vibration from the engine area should always be
investigated at the earliest opportunity. Typical causes are (but not limited to): loose
engine mounting bolts to airframe or to the engine bearer, loose propeller, incorrect pitch
setting (blade to blade, as set or from jamming), or blade damage. After the instance of
such vibration the engine and airframe should undergo a detailed examination for
subsequent damage. Refer to RSUK for guidance.