A DA40-180 propeller governor failed in flight causing the engine RPM to over speed. An emergency wa...

Attributes
ACN	793660
Time
Date	200806
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 4000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	DA40 Diamond Star
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	climbout : intermediate altitude
Flight Plan	VFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : private
Experience	flight time last 90 days : 21 flight time total : 930 flight time type : 296
ASRS Report	793660
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : landed in emergency condition
Consequence	other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

We were climbing thru 4000 ft MSL out of airport. At that time the engine propeller developed an instantaneous over speed condition (greater than 3100 RPM) without any warning. Redline on this aircraft is 2700 RPM. I was able to regain control of the over speed condition by reducing the throttle (manifold pressure) control. Changing the propeller speed control had no effect on propeller RPM. By gradually increasing the throttle control and allowing the engine propeller to run at 2650 RPM we were able to maintain flying speed (about 80 KTS to 85 KTS) and altitude. We then diverted and declared an emergency with tower. The approach and landing was accomplished without any further difficulties and no damage to the aircraft or property on the ground. No one was injured during this event. The control system failure was caused by an improperly manufactured propeller governor that was installed on the aircraft during original aircraft manufacture in 2005. The aircraft had a total time in service since new of 300 hours.

Original NASA ASRS Text

Title: A DA40-180 PROPELLER GOVERNOR FAILED IN FLT CAUSING THE ENG RPM TO OVER SPEED. AN EMER WAS DECLARED WITH A LNDG AT A NEARBY ARPT.

Narrative: WE WERE CLBING THRU 4000 FT MSL OUT OF ARPT. AT THAT TIME THE ENGINE PROPELLER DEVELOPED AN INSTANTANEOUS OVER SPEED CONDITION (GREATER THAN 3100 RPM) WITHOUT ANY WARNING. REDLINE ON THIS ACFT IS 2700 RPM. I WAS ABLE TO REGAIN CTL OF THE OVER SPEED CONDITION BY REDUCING THE THROTTLE (MANIFOLD PRESSURE) CTL. CHANGING THE PROPELLER SPEED CTL HAD NO EFFECT ON PROPELLER RPM. BY GRADUALLY INCREASING THE THROTTLE CTL AND ALLOWING THE ENGINE PROPELLER TO RUN AT 2650 RPM WE WERE ABLE TO MAINTAIN FLYING SPEED (ABOUT 80 KTS TO 85 KTS) AND ALTITUDE. WE THEN DIVERTED AND DECLARED AN EMER WITH TOWER. THE APCH AND LNDG WAS ACCOMPLISHED WITHOUT ANY FURTHER DIFFICULTIES AND NO DAMAGE TO THE ACFT OR PROPERTY ON THE GND. NO ONE WAS INJURED DURING THIS EVENT. THE CTL SYSTEM FAILURE WAS CAUSED BY AN IMPROPERLY MANUFACTURED PROPELLER GOVERNOR THAT WAS INSTALLED ON THE ACFT DURING ORIGINAL ACFT MANUFACTURE IN 2005. THE ACFT HAD A TOTAL TIME IN SERVICE SINCE NEW OF 300 HOURS.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

A DA40-180 propeller governor failed in flight causing the engine RPM to over speed. An emergency was declared with a landing at a nearby airport.