Narrative:

Shortly after takeoff (approximately 600 ft MSL) from lax, we experienced an autofeather on the right propeller. I was the PF for the leg. My initial actions were to maintain aircraft control and to continue our climb. Yaw forces were mild and our climb rate was good but the amount of noise was startling. We retracted the flaps. The tower gave us some instructions but the first officer told them to 'stand by.' at about 1800 ft MSL, we confirmed the problem to be on the right side. The right engine appeared to still be operating, but I felt it best to retard the power lever and place the propeller lever in the manual feather position. I confirmed the first officer's hand placement as he moved the levers. We informed the tower of our need to return to lax. We declared an emergency and requested the equipment from socal approach. We then requested a long downwind and told the controller that we would let him know when we were ready to proceed inbound. We then continued to analyze the problem. We consulted the QRH for an inadvertent autofeather or similar checklist. At that time we were unable to locate such a procedure. (I have since spoken with a company instructor and have been told there is no written procedure.) we then discussed a precautionary engine shutdown but decided to leave it running since the engine itself appeared to be operating satisfactorily. It should be mentioned that earlier in the day we had observed a momentary decrease on the right torque indicator immediately after rotation. I did not feel any power loss or yaw. We did not observe further fluctuation so we continued to our destination where the indicator was replaced after I wrote up the indication. We observed no fluctuations on the next 3 legs and thought the problem was fixed. Apparently, it was not. We strongly suspect that a faulty torque indication activated the autofeather. The torque must drop below 23.6% +/-2.5% with the autofeather armed to trigger an autofeather. Anyway, we did not consider taking the propeller out of feather since our performance was fine on 1 engine and we felt it best to get on the ground in a timely manner. We completed the after takeoff, descent, single engine approach and landing and single engine missed approach checklists. The first officer briefed the flight attendant who briefed the passenger. We also contacted our company on the appropriate frequency. We performed a visual approach (followed ILS profile) and landed without incident. I would like to see a written procedure in our QRH for an autofeather not associated with an engine failure. Callback conversation with reporter revealed the following information: the reporter questioned the air carrier's training department and learned that the QRH did not contain an autofeather procedure. It was his impression that this was an error of omission. As a result of his telephone call, the reporter felt that the autofeather procedure would be included in the QRH in the very near future.

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Original NASA ASRS Text

Title: AN EMB120 EXPERIENCED AN AUTOFEATHER ON TKOF FROM LAX. THE QRH DID NOT INCLUDE A PROC FOR THIS EVENT.

Narrative: SHORTLY AFTER TKOF (APPROX 600 FT MSL) FROM LAX, WE EXPERIENCED AN AUTOFEATHER ON THE R PROP. I WAS THE PF FOR THE LEG. MY INITIAL ACTIONS WERE TO MAINTAIN ACFT CTL AND TO CONTINUE OUR CLB. YAW FORCES WERE MILD AND OUR CLB RATE WAS GOOD BUT THE AMOUNT OF NOISE WAS STARTLING. WE RETRACTED THE FLAPS. THE TWR GAVE US SOME INSTRUCTIONS BUT THE FO TOLD THEM TO 'STAND BY.' AT ABOUT 1800 FT MSL, WE CONFIRMED THE PROB TO BE ON THE R SIDE. THE R ENG APPEARED TO STILL BE OPERATING, BUT I FELT IT BEST TO RETARD THE PWR LEVER AND PLACE THE PROP LEVER IN THE MANUAL FEATHER POS. I CONFIRMED THE FO'S HAND PLACEMENT AS HE MOVED THE LEVERS. WE INFORMED THE TWR OF OUR NEED TO RETURN TO LAX. WE DECLARED AN EMER AND REQUESTED THE EQUIP FROM SOCAL APCH. WE THEN REQUESTED A LONG DOWNWIND AND TOLD THE CTLR THAT WE WOULD LET HIM KNOW WHEN WE WERE READY TO PROCEED INBOUND. WE THEN CONTINUED TO ANALYZE THE PROB. WE CONSULTED THE QRH FOR AN INADVERTENT AUTOFEATHER OR SIMILAR CHKLIST. AT THAT TIME WE WERE UNABLE TO LOCATE SUCH A PROC. (I HAVE SINCE SPOKEN WITH A COMPANY INSTRUCTOR AND HAVE BEEN TOLD THERE IS NO WRITTEN PROC.) WE THEN DISCUSSED A PRECAUTIONARY ENG SHUTDOWN BUT DECIDED TO LEAVE IT RUNNING SINCE THE ENG ITSELF APPEARED TO BE OPERATING SATISFACTORILY. IT SHOULD BE MENTIONED THAT EARLIER IN THE DAY WE HAD OBSERVED A MOMENTARY DECREASE ON THE R TORQUE INDICATOR IMMEDIATELY AFTER ROTATION. I DID NOT FEEL ANY PWR LOSS OR YAW. WE DID NOT OBSERVE FURTHER FLUCTUATION SO WE CONTINUED TO OUR DEST WHERE THE INDICATOR WAS REPLACED AFTER I WROTE UP THE INDICATION. WE OBSERVED NO FLUCTUATIONS ON THE NEXT 3 LEGS AND THOUGHT THE PROB WAS FIXED. APPARENTLY, IT WAS NOT. WE STRONGLY SUSPECT THAT A FAULTY TORQUE INDICATION ACTIVATED THE AUTOFEATHER. THE TORQUE MUST DROP BELOW 23.6% +/-2.5% WITH THE AUTOFEATHER ARMED TO TRIGGER AN AUTOFEATHER. ANYWAY, WE DID NOT CONSIDER TAKING THE PROP OUT OF FEATHER SINCE OUR PERFORMANCE WAS FINE ON 1 ENG AND WE FELT IT BEST TO GET ON THE GND IN A TIMELY MANNER. WE COMPLETED THE AFTER TKOF, DSCNT, SINGLE ENG APCH AND LNDG AND SINGLE ENG MISSED APCH CHKLISTS. THE FO BRIEFED THE FLT ATTENDANT WHO BRIEFED THE PAX. WE ALSO CONTACTED OUR COMPANY ON THE APPROPRIATE FREQ. WE PERFORMED A VISUAL APCH (FOLLOWED ILS PROFILE) AND LANDED WITHOUT INCIDENT. I WOULD LIKE TO SEE A WRITTEN PROC IN OUR QRH FOR AN AUTOFEATHER NOT ASSOCIATED WITH AN ENG FAILURE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR QUESTIONED THE ACR'S TRAINING DEPT AND LEARNED THAT THE QRH DID NOT CONTAIN AN AUTOFEATHER PROC. IT WAS HIS IMPRESSION THAT THIS WAS AN ERROR OF OMISSION. AS A RESULT OF HIS TELEPHONE CALL, THE RPTR FELT THAT THE AUTOFEATHER PROC WOULD BE INCLUDED IN THE QRH IN THE VERY NEAR FUTURE.

Data retrieved from NASA's ASRS site as of July 2007 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.