Narrative:

The flight started around XA40Z when we took off with an assigned altitude of 3000 ft and immediate left turn to 210 degrees after takeoff due to a thunderstorm to the north. After takeoff; we made the immediate turn to 210 degrees and were given further climb to 10000 ft. The captain performed the normal climb checklist and the first officer flew the aircraft. During the climb checklist; I pulled the condition lever to 900 and continued with the rest of the flow. Later in the climb; I brought the condition lever to 850 and pushed the 'mcl' button for climb power. With the immediate turn and my workload; it was easier to set 900 on the condition levers than go to 850's later when time permitted me to pick up the checklist. I had used that procedure before when flying an aircraft that fluctuated power settings in the 850 setting. I had heard either method was ok for use. After diverting around another thunderstorm and leveling off at 14000 ft; I asked the first officer if he wanted the cruise checklist. I started with the condition levers and started to pull them below the 850 gate. About 1 inch out from the gate I realized my mistake and advanced the condition levers back to 850. Immediately during the move; both engines went towards feather and then returned to 850 and kept going to 1060 RPM. Also; the master warning illuminated both the #1 and #2 propeller electronic control lights. After a moment; I asked the acm if he could find a checklist for our situation. At first we looked at the #1 or #2 pec failure and realized that wasn't our problem we moved on to the dual propeller overspeed. The checklist advised to land as soon as practicable and there was no other actions. Knowing that ZZZ was close by now and that there were thunderstorms at ZZZ1; I decided to continue to ZZZ. Both engines at this time were working properly besides the propeller speed and we were able to control the aircraft normally. I performed the normal PNF duties until we got to 4000 ft and I asked for the controls as I previously briefed I would be landing the airplane. After taking control (autoplt still on) and descending from 4000 ft to 3000 ft; the #1 engine started to fluctuate (or cycle between) feathered and overspeed. I advanced the power lever to see if it made a difference and it did not. Everyone in the flight deck agreed that it was an uncontrollable propeller or uncommanded feather. I asked for the acm to read the engine shutdown checklist while the first officer completed the items; also the first officer declared an emergency with ATC. At this time; approach handed us right over to tower since we were on a right base for ZZZ. Tower immediately cleared us to land and asked for the nature of the emergency. As I turned out on final and started to fly the visual approach (backed up by the ILS); I asked for the gear down; then flaps 15 degrees; and before landing checklist. The first officer completed the checklist and silently completed the single engine landing qrc. I noticed the gear was down and the flaps were set and I concentrated on the visual approach and made a normal landing with no reverse thrust and normal braking. We pulled off on high speed taxiway north and came to a stop using the parking brake. By this time the foot brakes were getting weak since the #1 engine was shut down. Emergency crews met us; I informed them everything was fine and we just needed a tug to the gate. After that; I briefed the passenger on the situation. We were pulled to the gate within 15 mins from landing and made a normal deplaning at gate. The event occurred because of nonstandard practices with the cruise flow with different aircraft as well as not focusing enough at the task at hand. Distrs from WX might have been a contributing factor. Supplemental information from acn 798930: I believe that the event occurred because the condition levers were set into a condition that was not correct. The airplane went to a safe mode; but was not able to maintain this for the time that we needed to make it to a safe and suitable airport. Returning to ZZZ1 was not an option due to the inclement WX. Further training and emphasis on what will happen if the condition levers are allowed to go below the 850 RPM gate on the condition lever quadrant.

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Original NASA ASRS Text

Title: Q400 FLT CREW REPORTS DUAL PEC FAILURE ON NUMBER ONE ENGINE AFTER CAPT RETARDS CONDITION LEVERS BELOW 850 DETENT.

Narrative: THE FLT STARTED AROUND XA40Z WHEN WE TOOK OFF WITH AN ASSIGNED ALT OF 3000 FT AND IMMEDIATE L TURN TO 210 DEGS AFTER TKOF DUE TO A TSTM TO THE N. AFTER TKOF; WE MADE THE IMMEDIATE TURN TO 210 DEGS AND WERE GIVEN FURTHER CLB TO 10000 FT. THE CAPT PERFORMED THE NORMAL CLB CHKLIST AND THE FO FLEW THE ACFT. DURING THE CLB CHKLIST; I PULLED THE CONDITION LEVER TO 900 AND CONTINUED WITH THE REST OF THE FLOW. LATER IN THE CLB; I BROUGHT THE CONDITION LEVER TO 850 AND PUSHED THE 'MCL' BUTTON FOR CLB PWR. WITH THE IMMEDIATE TURN AND MY WORKLOAD; IT WAS EASIER TO SET 900 ON THE CONDITION LEVERS THAN GO TO 850'S LATER WHEN TIME PERMITTED ME TO PICK UP THE CHKLIST. I HAD USED THAT PROC BEFORE WHEN FLYING AN ACFT THAT FLUCTUATED PWR SETTINGS IN THE 850 SETTING. I HAD HEARD EITHER METHOD WAS OK FOR USE. AFTER DIVERTING AROUND ANOTHER TSTM AND LEVELING OFF AT 14000 FT; I ASKED THE FO IF HE WANTED THE CRUISE CHKLIST. I STARTED WITH THE CONDITION LEVERS AND STARTED TO PULL THEM BELOW THE 850 GATE. ABOUT 1 INCH OUT FROM THE GATE I REALIZED MY MISTAKE AND ADVANCED THE CONDITION LEVERS BACK TO 850. IMMEDIATELY DURING THE MOVE; BOTH ENGS WENT TOWARDS FEATHER AND THEN RETURNED TO 850 AND KEPT GOING TO 1060 RPM. ALSO; THE MASTER WARNING ILLUMINATED BOTH THE #1 AND #2 PROP ELECTRONIC CTL LIGHTS. AFTER A MOMENT; I ASKED THE ACM IF HE COULD FIND A CHKLIST FOR OUR SITUATION. AT FIRST WE LOOKED AT THE #1 OR #2 PEC FAILURE AND REALIZED THAT WASN'T OUR PROB WE MOVED ON TO THE DUAL PROP OVERSPEED. THE CHKLIST ADVISED TO LAND AS SOON AS PRACTICABLE AND THERE WAS NO OTHER ACTIONS. KNOWING THAT ZZZ WAS CLOSE BY NOW AND THAT THERE WERE TSTMS AT ZZZ1; I DECIDED TO CONTINUE TO ZZZ. BOTH ENGS AT THIS TIME WERE WORKING PROPERLY BESIDES THE PROP SPD AND WE WERE ABLE TO CTL THE ACFT NORMALLY. I PERFORMED THE NORMAL PNF DUTIES UNTIL WE GOT TO 4000 FT AND I ASKED FOR THE CTLS AS I PREVIOUSLY BRIEFED I WOULD BE LNDG THE AIRPLANE. AFTER TAKING CTL (AUTOPLT STILL ON) AND DSNDING FROM 4000 FT TO 3000 FT; THE #1 ENG STARTED TO FLUCTUATE (OR CYCLE BTWN) FEATHERED AND OVERSPEED. I ADVANCED THE PWR LEVER TO SEE IF IT MADE A DIFFERENCE AND IT DID NOT. EVERYONE IN THE FLT DECK AGREED THAT IT WAS AN UNCTLABLE PROP OR UNCOMMANDED FEATHER. I ASKED FOR THE ACM TO READ THE ENG SHUTDOWN CHKLIST WHILE THE FO COMPLETED THE ITEMS; ALSO THE FO DECLARED AN EMER WITH ATC. AT THIS TIME; APCH HANDED US RIGHT OVER TO TWR SINCE WE WERE ON A R BASE FOR ZZZ. TWR IMMEDIATELY CLRED US TO LAND AND ASKED FOR THE NATURE OF THE EMER. AS I TURNED OUT ON FINAL AND STARTED TO FLY THE VISUAL APCH (BACKED UP BY THE ILS); I ASKED FOR THE GEAR DOWN; THEN FLAPS 15 DEGS; AND BEFORE LNDG CHKLIST. THE FO COMPLETED THE CHKLIST AND SILENTLY COMPLETED THE SINGLE ENG LNDG QRC. I NOTICED THE GEAR WAS DOWN AND THE FLAPS WERE SET AND I CONCENTRATED ON THE VISUAL APCH AND MADE A NORMAL LNDG WITH NO REVERSE THRUST AND NORMAL BRAKING. WE PULLED OFF ON HIGH SPD TXWY N AND CAME TO A STOP USING THE PARKING BRAKE. BY THIS TIME THE FOOT BRAKES WERE GETTING WEAK SINCE THE #1 ENG WAS SHUT DOWN. EMER CREWS MET US; I INFORMED THEM EVERYTHING WAS FINE AND WE JUST NEEDED A TUG TO THE GATE. AFTER THAT; I BRIEFED THE PAX ON THE SITUATION. WE WERE PULLED TO THE GATE WITHIN 15 MINS FROM LNDG AND MADE A NORMAL DEPLANING AT GATE. THE EVENT OCCURRED BECAUSE OF NONSTANDARD PRACTICES WITH THE CRUISE FLOW WITH DIFFERENT ACFT AS WELL AS NOT FOCUSING ENOUGH AT THE TASK AT HAND. DISTRS FROM WX MIGHT HAVE BEEN A CONTRIBUTING FACTOR. SUPPLEMENTAL INFO FROM ACN 798930: I BELIEVE THAT THE EVENT OCCURRED BECAUSE THE CONDITION LEVERS WERE SET INTO A CONDITION THAT WAS NOT CORRECT. THE AIRPLANE WENT TO A SAFE MODE; BUT WAS NOT ABLE TO MAINTAIN THIS FOR THE TIME THAT WE NEEDED TO MAKE IT TO A SAFE AND SUITABLE ARPT. RETURNING TO ZZZ1 WAS NOT AN OPTION DUE TO THE INCLEMENT WX. FURTHER TRAINING AND EMPHASIS ON WHAT WILL HAPPEN IF THE CONDITION LEVERS ARE ALLOWED TO GO BELOW THE 850 RPM GATE ON THE CONDITION LEVER QUADRANT.

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.