TKOF ABORTED AS PF THOUGHT ENG HAD FAILED. LANDS WHEELS UP AS GEAR HAD BEEN RETRACTED EARLY FOR A SHORT FIELD TKOF PROC AS REQUESTED BY INSTRUCTOR PLT.

Narrative

I WAS PREPARING FOR AN ATP CHK RIDE IN A PIPER SENECA I. MY INSTRUCTOR ASKED ME TO PERFORM A SHORT FIELD 50 FT OBSTACLE TKOF PROC JUST BEFORE TAXIING INTO POS. TO PERFORM THE PROC (AS TAUGHT BY THIS INSTRUCTOR); I WAS TO ACCELERATE TO 70 MPH; AND START ROTATION. THIS IS 10 MPH SLOWER THAN THE NORMAL ROTATION OF 80 MPH. I WAS ALSO TOLD TO USE 10 DEGS OF FLAPS. I WAS ALSO TAUGHT TO BRING THE GEAR UP AS SOON AS THE WHEELS LEFT THE GND; AND THIS IS EXACTLY WHAT I DID. AS SOON AS I ROTATED AND THE WHEELS WERE CLR OF THE GND I BROUGHT THE GEAR UP AND ALMOST IN THE SAME INSTANCE THERE WAS A MAJOR PWR REDUCTION ON THE R SIDE. MY IMMEDIATE REACTION WAS TO THROTTLE BACK AND LAND STRAIGHT AHEAD SINCE I HAD PLENTY OF RWY REMAINING. I WASN'T MORE THAN 15-20 FT OFF THE GND. WELL THE GEAR WAS ALREADY UP AND WHEN THE PWR WAS REDUCED TO 1 ENG THE PLANE SANK AND YAWED. TO THROTTLE BACK AND LAND STRAIGHT AHEAD WAS; I THOUGHT; THE ONLY DECISION TO MAKE. AS IT TURN OUT; IT WAS THE INSTRUCTOR WHO PULLED THE PWR ON THE R ENG; SOMETHING I WASN'T AWARE OF UNTIL AFTER I SKIDDED THE PLANE A COUPLE OF HUNDRED FT DOWN THE RWY. IF AN INSTRUCTOR IS GOING TO SIMULATE AN ENG FAILURE ON TKOF THAT CLOSE TO THE GND THEN HE NEEDS TO BE AWARE OF AIRPLANE'S CONDITION AT ALL TIMES. THE ONLY DAMAGE WAS TO THE PROPS AND 2 ANTENNAS ON THE BOTTOM OF THE PLANE. SUPPLEMENTAL INFORMATION FROM ACN 263817: WE STARTED THE TKOF ROLL AFTER WE ROTATED AND CLBED TO APPROX 50-75 FT AGL. I REDUCED PWR ON THE R ENG TO 2000 RPM (2700 RPM AT FULL PWR) TO TEST STUDENT'S ABILITY TO LAND OR CARRY ON WITH THE CLBOUT. THE STUDENT CORRECTLY CLOSED BOTH THROTTLES TO IDLE AND THE ACFT DSNDED TO THE RWY. ALTHOUGH WHEN LIFTED THE GEAR SWUNG DOWN INTO PLACE NORMALLY I AM UNABLE TO IDENT THE CAUSE OF THIS INCIDENT. THE STUDENT SAID HE DIDN'T RAISE THE GEAR. I DID NOT WITNESS HIM DOING SO. I TRAIN ONLY TO RAISE GEAR AFTER SUFFICIENT RWY FOR LNDG IS NOT AVAILABLE. WE HAD 2000- 2500 FT OF RWY LEFT; APPROX HALF THE RWY LENGTH AFTER WE CAME TO A STOP. ON INSPECTION THE MAIN GEAR TIRES HAD SCUFF MARKS ON THE SIDE WALLS INDICATING THE GEAR WAS IN TRANSIT (NOT UP; NOR DOWN). NO GEAR WARNING HORN WAS HEARD AT ANY TIME BY EITHER PLT.