Narrative:

After a normal left hand pattern to runway 28 at hto; the aircraft (husky A1-B) was turned to the final approach leg. Ahead of it was a helicopter. The helicopter was on short final to runway 28; the helicopter pilot announced on the CTAF his intention to sidestep to the parallel taxiway to the right. The touchdown of the husky was uneventful; on the rollout it passed the helicopter which was still hovering at low altitude; somewhere between runway 28 and the taxiway. At this moment; and just before the point where runway 10/28 intersects runway 16/34; the propwash of the helicopter lifted the tail of the husky; and the propeller struck the pavement. The engine was at idle. The airplane settled on its 3 wheels; on the runway; slightly right of centerline. A contributing factor is the 'noise abatement rtes;' which the town of east hampton 'strongly recommends for helicopter operations at hto.' in this printed document; it literally states that 'helicopter arrs and departures should be to and from active runways or parallel txwys.' integrating larger/faster helicopters with fixed wing aircraft is not in itself unusual; it appears however that very little thought was given to the effect of rotor downwash; particularly when the weight of the helicopter is an order of magnitude larger than the weight of the fixed wing.

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Original NASA ASRS Text

Title: 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.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.