PA18 PLT BEING CHKED OUT IN HIS NEW ACFT LOST CTL DURING A XWIND LNDG.

Narrative

DURING THE FINAL STAGES OF CHK-OUT IN THE PA18-135 I OWN; WE WERE WORKING ON XWIND LNDGS DUE TO THE FACT THAT WE HAD BEEN ASSIGNED RWY 3. THE WIND WAS APPROX 10-15 KTS DIRECT ACROSS THE RWY. I DID NOT QUESTION THE TWR ON THIS ASSIGNMENT; SINCE IT ENABLED US TO GET IN SOME PRACTICE. ON OUR THIRD LNDG; (A WHEEL LNDG) THE ACFT WAS CAUGHT BY A GUST AND STARTED TO VEER TO THE L OF THE RWY. I WAS IN THE BACK AND I APPLIED R RUDDER AND SOME BRAKE TO OVERCOME THE DRIFT AT THE SAME TIME THE PLT IN THE FRONT SEAT DID LIKEWISE. THIS CAUSED THE TAIL TO SWING DOWNWIND; AND THE AIRPLANE ROSE UP ON ITS NOSE WHERE IT STOPPED. THE SPD AT THE TIME OF THE EVENT WAS ONLY ABOUT 5 MPH AS WE HAD SLOWED ALMOST TO A STOP WHEN THE WIND PICKED US UP. MY IMMEDIATE REACTION TO PULL BACK THE STICK; ONLY EXACERBATED THE PROB SINCE THERE WAS NOW A TAILWIND AND ASSISTED IN THE NOSE OVER. THE PROP STRUCK THE RWY; AND WE BOTH CLBED OUT WITH THE PLANE ON THE NOSE. SINCE THE SPD WAS SO SLOW AND WE WERE WEARING BELTS AND HARNESSES; THERE WERE NO INJURIES. THINGS THAT WOULD HAVE HELPED: 1) ASK FOR RWY 1; AS IT WAS OPEN AND THE XWIND WAS NOT DIRECT. 2) CALL OUT TO THE PLT IN FRONT THAT I WAS ALSO APPLYING BRAKES. 3) APPLY PWR DURING VEER TO STRAIGHTEN PLANE AND GO AROUND. 4) USE PROPER XWIND/TAILWIND MOVEMENT OF ELEVATOR TO KEEP TAIL DOWN IN TAILWIND SIT.