TBM 700/TBM 850
Flight Crew Sea; Flight Crew Instrument
Flight Crew Last 90 Days 60; Flight Crew Total 1900; Flight Crew Type 500
Distraction; Confusion; Training / Qualification; Human-Machine Interface; Workload; Troubleshooting
Aircraft Equipment Problem Critical; Deviation - Altitude Excursion From Assigned Altitude; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance
Flight Crew Returned To Departure Airport; Flight Crew Landed in Emergency Condition; Flight Crew Took Evasive Action; General Declared Emergency; General Maintenance Action
Aircraft; Human Factors
I received my clearance from Clearance; to climb via the SID. I loaded 10000 ft in my altitude pre-selector and armed it. The Tower gave me an immediate departure and a vector of 240. During the takeoff roll my torque gauge didn't seem quite right but I verified everything was in the green and continued the takeoff with torque at 100%. After takeoff I cleaned up the gear and flaps; then I noticed that my torque was at 60% this is not normal so I pushed the throttle forward and could only get 80%. Normally you can over torque a TBM so I knew something was up. Tower gave me a new heading of 270 so turned to 270; I was climbing at around 1800 FPM. Going through 8000ft my torque gauge started bouncing all over from 20-85%; next thing I know it went to 0%. Then my prop went to zero; oil pressure zero; oil temp was gone. I declared an emergency and was given 8000ft. I entered 8000 in my autopilot and armed it. During all the action on the radio I was looking in my trend monitoring equipment to see if I had torque there and it might just be a gauge. I was blowing through ten thousand and was almost on the right page in my trending unit. I continued until I found the right page and saw that it also was at zero; by then I was at 10300. I then disconnected the autopilot and hand flew down to 8000ft. We were on downwind by then; Tower had me fly a right base to 16R. We landed and taxied back to the FBO. Looking back on this; my autopilot was confused it hadn't reached 10000 yet but was above 8000 when I tried to reprogram it. I think that is why it continued to climb; I should have just hit the altitude hold button or hand flew the plane. I thought it was better for me to continue to let the autopilot fly the plane why I talked on the radio and tried to diagnose the problem.
The Reporter stated that the propeller torque transducer shorted and because associated electrical/electronic items are on a common circuit breaker those were disabled also. He knew during this event that the powerplant was functioning but did not know if he was pumping oil out or what else may have been malfunctioning. After the transducer was replaced and the circuit reset all systems returned to normal.
A TBM-700 pilot declared an emergency and returned to the departure airport after the propeller torque transducer shorted during climb and because other engine condition indications are on the same buss he was unable to monitor the engine.