Narrative:

2 qualified pilots were in the front seats. 1 pilot (the owner) is multi engine land certificated and a single engine land CFI. The other (me) a multi engine land instructor. The flight was being conducted to increase proficiency in the piper apache and to satisfy the owner's insurance requirements. The crew had flown together previously, 4 previous flts in the PA23 and a few other flts in single engine airplanes. The instructor believes the owner to be a good pilot. After flying to stk, an uneventful landing was made with a simulated engine out (by using zero thrust on the engine deemed to be inoperative). A takeoff with both engines was made and another landing was being prepared. As the owner set up the controls for the next simulated engine out landing, the instructor verbalized that the speed was going below blue line (vyse) and the owner acknowledged. Speed was still above red line (VMC). The owner made a few more control inputs and started a left crosswind to downwind turn, exact sequence of events is unknown, then the apache rolled to the left nose down from pattern altitude. Both pilots immediately took corrective action: power off, ailerons neutral, rudder opposite, elevator forward then aft. Controled flight was regained 200 ft AGL. Lessons learned by the instructor: do not become complacent with the controls when one is flying with another that the instructor believes to be good. Keep a hand on the throttle quadrant to make sure the controls are being positioned properly. We had a thorough debriefing after this incident. Callback conversation with reporter revealed the following information: reporter advises that the aircraft in use was the lower pwred 150 hp version and, although equipped with turbo chargers, they were not in use at the time. He also advised that although they were flying a l-hand pattern, he chose to simulate failure of the left engine which necessitated either turns into the dead engine, the proximity ultimate cause of the stall/spin, or a request to the tower to maneuver so as to utilize only r-hand turns to align with the runway.

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Original NASA ASRS Text

Title: INST PLT AND STUDENT PRACTICING SINGLE ENG APCHS TO STK IN A PA23 STALL, SPIN AND RECOVER AT 100 FT.

Narrative: 2 QUALIFIED PLTS WERE IN THE FRONT SEATS. 1 PLT (THE OWNER) IS MULTI ENG LAND CERTIFICATED AND A SINGLE ENG LAND CFI. THE OTHER (ME) A MULTI ENG LAND INSTRUCTOR. THE FLT WAS BEING CONDUCTED TO INCREASE PROFICIENCY IN THE PIPER APACHE AND TO SATISFY THE OWNER'S INSURANCE REQUIREMENTS. THE CREW HAD FLOWN TOGETHER PREVIOUSLY, 4 PREVIOUS FLTS IN THE PA23 AND A FEW OTHER FLTS IN SINGLE ENG AIRPLANES. THE INSTRUCTOR BELIEVES THE OWNER TO BE A GOOD PLT. AFTER FLYING TO STK, AN UNEVENTFUL LNDG WAS MADE WITH A SIMULATED ENG OUT (BY USING ZERO THRUST ON THE ENG DEEMED TO BE INOP). A TKOF WITH BOTH ENGS WAS MADE AND ANOTHER LNDG WAS BEING PREPARED. AS THE OWNER SET UP THE CTLS FOR THE NEXT SIMULATED ENG OUT LNDG, THE INSTRUCTOR VERBALIZED THAT THE SPD WAS GOING BELOW BLUE LINE (VYSE) AND THE OWNER ACKNOWLEDGED. SPD WAS STILL ABOVE RED LINE (VMC). THE OWNER MADE A FEW MORE CTL INPUTS AND STARTED A L XWIND TO DOWNWIND TURN, EXACT SEQUENCE OF EVENTS IS UNKNOWN, THEN THE APACHE ROLLED TO THE L NOSE DOWN FROM PATTERN ALT. BOTH PLTS IMMEDIATELY TOOK CORRECTIVE ACTION: PWR OFF, AILERONS NEUTRAL, RUDDER OPPOSITE, ELEVATOR FORWARD THEN AFT. CTLED FLT WAS REGAINED 200 FT AGL. LESSONS LEARNED BY THE INSTRUCTOR: DO NOT BECOME COMPLACENT WITH THE CTLS WHEN ONE IS FLYING WITH ANOTHER THAT THE INSTRUCTOR BELIEVES TO BE GOOD. KEEP A HAND ON THE THROTTLE QUADRANT TO MAKE SURE THE CTLS ARE BEING POSITIONED PROPERLY. WE HAD A THOROUGH DEBRIEFING AFTER THIS INCIDENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR ADVISES THAT THE ACFT IN USE WAS THE LOWER PWRED 150 HP VERSION AND, ALTHOUGH EQUIPPED WITH TURBO CHARGERS, THEY WERE NOT IN USE AT THE TIME. HE ALSO ADVISED THAT ALTHOUGH THEY WERE FLYING A L-HAND PATTERN, HE CHOSE TO SIMULATE FAILURE OF THE L ENG WHICH NECESSITATED EITHER TURNS INTO THE DEAD ENG, THE PROX ULTIMATE CAUSE OF THE STALL/SPIN, OR A REQUEST TO THE TWR TO MANEUVER SO AS TO UTILIZE ONLY R-HAND TURNS TO ALIGN WITH THE RWY.

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.