Daher-Socata TBM 900 Pilot's Information Manual page 116

SECTION 3
EMERGENCY PROCEDURES
EASA Approved
Indicates :
- a propeller governor failure
In that case, the propeller overspeed limiter will limit initially the rotation speed to 2100 RPM approximately.
- or a propeller governor and overspeed limiter failure
In that case, only the torque limiter operates to limit the power.
However, the pilot intervention is necessary to maintain Np ≤ 2000 RPM.
The propeller reducer is designed for a max. Np of 2200 RPM.
1 - Reduce the power and the airplane speed to avoid propeller rotation speeds higher than 2000 RPM.
2 - Land as soon as possible.
3 - Do not perform a go-around.
A go-around would damage the engine reduction gearbox
The airplane repair is mandatory before any other flight.
Page 3.4.4
EXCESSIVE PROPELLER ROTATION SPEED
PILOT'S OPERATING HANDBOOK
Edition 0 -- October 31, 2013
Rev. 1