Narrative:

En route, VFR in a helicopter from dallas to austin, I observed wildlife moving along a large stream. I slowed to approximately 40-50 KTS and descended. The stream was located in a small ravine. My altitude was above the highest point of each side of the ravine. The area was covered with thick vegetation and trees (mostly large oaks). Several large birds suddenly came into my flight path. To avoid the birds, which were both above and directly in front of me, I lowered collective pitch and pitched the nose down. I lost approximately 20-30' of altitude and went just under the birds. A wire suddenly became visible directly in front of me. This wire went across the ravine. No poles were visible due to dense vegetation. I pulled up on the collective and pitched the nose up in attempt to avoid the wire. The wire struck the nose of the helicopter. The wind shield shattered and the wire was cut by the installed wire strike protection system (wsps). The aircraft was in a nose high, left yaw attitude after the strike. I regained control and saw a small clearing about 150 yds ahead. I landed the helicopter in the clearing and shut down to check for other damage. No other significant damage was found. I phoned my maintenance facility to begin recovery operations. In order to prevent recurrent, I will allow an extra margin of altitude above the highest side of a ravine to allow for unanticipated bird movement. This method will allow for maneuvering yet still provide a safety margin above any unseen wires. The wsps worked as advertised, and prevented significant damage.

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Original NASA ASRS Text

Title: PLT OF PLT HELICOPTER DESCENDING TO GO UNDER A FLOCK OF BIRDS STRUCK WIRE STRETCHED ACROSS A RAVINE.

Narrative: ENRTE, VFR IN A HELI FROM DALLAS TO AUSTIN, I OBSERVED WILDLIFE MOVING ALONG A LARGE STREAM. I SLOWED TO APPROX 40-50 KTS AND DSNDED. THE STREAM WAS LOCATED IN A SMALL RAVINE. MY ALT WAS ABOVE THE HIGHEST POINT OF EACH SIDE OF THE RAVINE. THE AREA WAS COVERED WITH THICK VEGETATION AND TREES (MOSTLY LARGE OAKS). SEVERAL LARGE BIRDS SUDDENLY CAME INTO MY FLT PATH. TO AVOID THE BIRDS, WHICH WERE BOTH ABOVE AND DIRECTLY IN FRONT OF ME, I LOWERED COLLECTIVE PITCH AND PITCHED THE NOSE DOWN. I LOST APPROX 20-30' OF ALT AND WENT JUST UNDER THE BIRDS. A WIRE SUDDENLY BECAME VISIBLE DIRECTLY IN FRONT OF ME. THIS WIRE WENT ACROSS THE RAVINE. NO POLES WERE VISIBLE DUE TO DENSE VEGETATION. I PULLED UP ON THE COLLECTIVE AND PITCHED THE NOSE UP IN ATTEMPT TO AVOID THE WIRE. THE WIRE STRUCK THE NOSE OF THE HELI. THE WIND SHIELD SHATTERED AND THE WIRE WAS CUT BY THE INSTALLED WIRE STRIKE PROTECTION SYSTEM (WSPS). THE ACFT WAS IN A NOSE HIGH, LEFT YAW ATTITUDE AFTER THE STRIKE. I REGAINED CTL AND SAW A SMALL CLRING ABOUT 150 YDS AHEAD. I LANDED THE HELI IN THE CLRING AND SHUT DOWN TO CHK FOR OTHER DAMAGE. NO OTHER SIGNIFICANT DAMAGE WAS FOUND. I PHONED MY MAINT FAC TO BEGIN RECOVERY OPS. IN ORDER TO PREVENT RECURRENT, I WILL ALLOW AN EXTRA MARGIN OF ALT ABOVE THE HIGHEST SIDE OF A RAVINE TO ALLOW FOR UNANTICIPATED BIRD MOVEMENT. THIS METHOD WILL ALLOW FOR MANEUVERING YET STILL PROVIDE A SAFETY MARGIN ABOVE ANY UNSEEN WIRES. THE WSPS WORKED AS ADVERTISED, AND PREVENTED SIGNIFICANT DAMAGE.

Data retrieved from NASA's ASRS site as of July 2007 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.