AN A1-B PILOT'S TAIL WAS BLOWN AIRBORNE BY A HELICOPTER'S DOWNWASH CAUSING THE PROP TO STRIKE AT HTO.

Narrative

AFTER A NORMAL L HAND PATTERN TO RWY 28 AT HTO; THE ACFT (HUSKY A1-B) WAS TURNED TO THE FINAL APCH LEG. AHEAD OF IT WAS A HELI. THE HELI WAS ON SHORT FINAL TO RWY 28; THE HELI PLT ANNOUNCED ON THE CTAF HIS INTENTION TO SIDESTEP TO THE PARALLEL TXWY TO THE R. THE TOUCHDOWN OF THE HUSKY WAS UNEVENTFUL; ON THE ROLLOUT IT PASSED THE HELI WHICH WAS STILL HOVERING AT LOW ALT; SOMEWHERE BTWN RWY 28 AND THE TXWY. AT THIS MOMENT; AND JUST BEFORE THE POINT WHERE RWY 10/28 INTERSECTS RWY 16/34; THE PROPWASH OF THE HELI LIFTED THE TAIL OF THE HUSKY; AND THE PROP STRUCK THE PAVEMENT. THE ENG WAS AT IDLE. THE AIRPLANE SETTLED ON ITS 3 WHEELS; ON THE RWY; SLIGHTLY R OF CTRLINE. A CONTRIBUTING FACTOR IS THE 'NOISE ABATEMENT RTES;' WHICH THE TOWN OF EAST HAMPTON 'STRONGLY RECOMMENDS FOR HELI OPS AT HTO.' IN THIS PRINTED DOCUMENT; IT LITERALLY STATES THAT 'HELI ARRS AND DEPS SHOULD BE TO AND FROM ACTIVE RWYS OR PARALLEL TXWYS.' INTEGRATING LARGER/FASTER HELIS WITH FIXED WING ACFT IS NOT IN ITSELF UNUSUAL; IT APPEARS HOWEVER THAT VERY LITTLE THOUGHT WAS GIVEN TO THE EFFECT OF ROTOR DOWNWASH; PARTICULARLY WHEN THE WT OF THE HELI IS AN ORDER OF MAGNITUDE LARGER THAN THE WT OF THE FIXED WING.