YAK52 FLT CREW HAS THE GEAR PARTIALLY RETRACT ON TOUCHDOWN; AND THE PROP STRIKES THE RWY AT 08A.

Narrative

WE WERE DOING A TRAINING RIDE FOR A 63 YR-OLD STUDENT; WHO HAD BOUGHT A YAK-52. HE NEEDED A CHKOUT AND A BIENNIAL FLT REVIEW. WE WERE ABOUT 9 HRS INTO HIS CHKOUT. HE HADN'T FLOWN FOR 18 YRS; AND ALMOST ALL OF HIS 7000 HRS WERE IN F-4'S AND F-15'S IN THE MIL. HE HAS VERY LITTLE TIME IN GA ACFT. I AM A 15000 HR PLT WITH EXTENSIVE EXPERIENCE IN AIRLINERS; MIL TRAINERS; FIGHTERS; AND TRANSPORTS; AND NUMEROUS GA ACFT. I'VE BEEN AN INSTRUCTOR AND EVALUATOR FOR 24 YRS. WE TOOK OFF AND WENT TO THE LCL PRACTICE AREA FOR SLOW FLT; STALLS; AND ROLLS. WE THEN RETURNED TO THE PATTERN FOR VISUAL APCH PRACTICE. THE STUDENT MOVED THE GEAR HANDLE FOR THE FIRST APCH. I HEARD THE SOUND OF AIR (YAKS USE AIR INSTEAD OF HYDS); SAW THE GEAR-UP LIGHTS EXTINGUISH; AND SAW THE GEAR-DOWN 'BARBER POLES' ON THE WINGS MOVE UP. I AM CERTAIN I SAW THE GREEN GEAR-DOWN LIGHTS FOR THE NOSE AND R MAIN (THE L MAIN LIGHT WAS BURNT OUT). I HAVE EXTENSIVE BACK-SEAT TIME IN T-38'S; YAKS; AND NANCHANGS. THE TOUCHDOWN WAS PERFECTLY NORMAL. AS THE STUDENT LOWERED THE NOSE; IN PREPARATION FOR ADDING PWR FOR THE TOUCH-AND-GO; THE ACFT LURCHED SLIGHTLY L. R RUDDER CORRECTED THE DRIFT; AND WITH PWR COMING UP; WE LEAPT AIRBORNE. THIS ACFT HAS A 400 HP M-14P; 9-CYLINDER RADIAL ENG AND PWR COMES ON WITH AN INCREDIBLE RUSH OF TORQUE AND NOISE. THE STUDENT RAISED THE GEAR AFTER THIS FIRST TOUCHDOWN; AND THE GEAR BANGED INTO THE UP POS. THIS WOULD BE NORMAL IF HE HAD ONLY LOWERED THE GEAR HANDLE TO THE CTR; NEUTRAL POS AS THE SUDDEN ONSET OF AIR PRESSURE SLAMS THE GEAR UP OR DOWN AS SELECTED. I REMINDED HIM THAT I HAD BRIEFED TO LEAVE THE GEAR DOWN FOR THE MULTIPLE PATTERNS; SINCE THERE IS NO GEAR WARNING SYS INSTALLED ON THESE ACFT. ON THE DOWNWIND; THERE WAS A LITTLE INCREASED AIRFRAME VIBRATION THAT DECREASED AS THE ENG RPM WAS DECREASED; SO I THOUGHT ALL WAS NORMAL. WE COMPLETED ABOUT 7 OR 8 MORE VISUAL PATTERNS THAT WERE ALL UNEVENTFUL. WE FULL-STOPPED AND TAXIED TO THE FUEL PIT. AFTER SHUTDOWN; WE NOTICED THE PROP BLADES HAD BEEN SHEARED OF ABOUT THEIR LAST 9 INCHES. I REVIEWED VERY CAREFULLY WHAT HAD HAPPENED. WITH THE FRONT GEAR HANDLE IN THE CTR; NEUTRAL POS; THE GEAR SYS WAS DEPRESSURIZED; THE 'PARROT HOOKS' RELEASED; AND THE GEAR FREE-FALLED TO THE DOWN POS. AS THE CFI IN THE BACK SEAT; I HAD AT LEAST 3; POSSIBLY 4 SIGHT AND SOUND INDICATIONS THAT THE GEAR WAS MOVING TO THE DOWN AND LOCKED POS. HOWEVER; WITH NO PRESSURE BEHIND IT; AFTER A NORMAL TOUCHDOWN; THE GEAR STARTED TO SETTLE. THE NORMAL MT 3-BLADE PROP FOR THIS ACFT AND ENG IS AN L250; BUT THIS ACFT HAD AN L260 MOUNTED. THE DIFFERENCE IS A LOSS OF 4 INCHES OF THE NORMAL 14 INCHES OF GND CLRNC. AFTER CAREFUL REVIEW; I AM ADDING THE FOLLOWING TO MY PREFLT BRIEFINGS AND INFLT PROCS: 1) THE LNDG GEAR WILL BE LEFT IN THE DOWN POS FOR MULTIPLE PATTERNS. 2) THE CFI IN THE BACK SEAT WILL LOWER HIS GEAR HANDLE AFTER THE STUDENT IN THE FRONT LOWERS HIS. (THE REAR HANDLE HAS OVERRIDE CTL.) ANY FURTHER RAISING OF THE GEAR WILL TAKE COORD. 3) BOTH PLTS WILL VERBALIZE; 'LNDG GEAR HANDLE DOWN; 3 GREEN LIGHTS; 3 POLES UP (NOSE 'BARBER POLE' ONLY VISIBLE TO FRONT SEATER); (AIR) PRESSURE UP.' THESE RUSSIAN AND CHINESE WARBIRDS ARE RUGGED; INEXPENSIVE; AND FUN TO FLY. WE WESTERNERS ARE STILL LEARNING THE STRENGTHS AND PITFALLS OF THESE ACFT. AS PER THE FAA ORDER 8020.11B DEFINITION OF 'ACFT ACCIDENT' AND 'SUBSTANTIAL DAMAGE;' THIS PROP STRIKE DOES NOT CONSTITUTE AN ACCIDENT. THEREFORE; I AM USING THIS FORM IN THE HOPE THAT THE YAK COMMUNITY CAN LEARN THE LESSONS OF THIS INCIDENT SO THAT NO ONE ELSE WILL BE LULLED INTO MAKING THE SAME MISTAKE.