Narrative:

While en route to hospital for an EMS interfacility patient xfer; aircraft had a bird strike to the main rotor system; while in cruise flight. Aircraft was en route from ZZZ airport to ZZZ1; night VFR with high light illumination; at 3250 ft MSL; 135 KIAS; in cruise flight; when aircraft apparently hit a large predatory bird severely damaging one main rotor blade; and minor damage on the horizontal stabilizer resulting in loss of right side position light assembly and strobe light assembly. These smaller components were missing on postflt inspection. During impact; aircraft shuddered momentarily after what sounded like a very loud 'thump' deep in the airframe. There was no noticeable loss of control or change in rotor dynamics. After a brief discussion by PIC with passenger; as to the possibilities of probable bird impact; PIC elected to abort the mission and return back to ZZZ; the airport of departure; which was the nearest suitable night landing area. Return flight was uneventful. A postflt inspection revealed significant damage to the stainless steel leading edge of one main rotor blade; at approximately 8 ft from the hub; 10-12 inches wide; 1 inch in depth. Leading edge was deformed and de-bonded; but still intact despite this deformation. PIC believes that the proven engineering and design was significant in the fact the blade did not disintegrate on impact. There was minor damage to the horizontal stabilizer on the right side; which resulted in a loss on components. The right side position light and strobe light were separated and departed on impact. No further damage was noted after a thorough postflt airframe inspection.

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Original NASA ASRS Text

Title: SIKORSKY S-76A PLT HAS A BIRD STRIKE; DECLARES AN EMER; AND RETURNS TO DEP ARPT.

Narrative: WHILE ENRTE TO HOSPITAL FOR AN EMS INTERFAC PATIENT XFER; ACFT HAD A BIRD STRIKE TO THE MAIN ROTOR SYS; WHILE IN CRUISE FLT. ACFT WAS ENRTE FROM ZZZ ARPT TO ZZZ1; NIGHT VFR WITH HIGH LIGHT ILLUMINATION; AT 3250 FT MSL; 135 KIAS; IN CRUISE FLT; WHEN ACFT APPARENTLY HIT A LARGE PREDATORY BIRD SEVERELY DAMAGING ONE MAIN ROTOR BLADE; AND MINOR DAMAGE ON THE HORIZ STABILIZER RESULTING IN LOSS OF R SIDE POS LIGHT ASSEMBLY AND STROBE LIGHT ASSEMBLY. THESE SMALLER COMPONENTS WERE MISSING ON POSTFLT INSPECTION. DURING IMPACT; ACFT SHUDDERED MOMENTARILY AFTER WHAT SOUNDED LIKE A VERY LOUD 'THUMP' DEEP IN THE AIRFRAME. THERE WAS NO NOTICEABLE LOSS OF CTL OR CHANGE IN ROTOR DYNAMICS. AFTER A BRIEF DISCUSSION BY PIC WITH PAX; AS TO THE POSSIBILITIES OF PROBABLE BIRD IMPACT; PIC ELECTED TO ABORT THE MISSION AND RETURN BACK TO ZZZ; THE ARPT OF DEP; WHICH WAS THE NEAREST SUITABLE NIGHT LNDG AREA. RETURN FLT WAS UNEVENTFUL. A POSTFLT INSPECTION REVEALED SIGNIFICANT DAMAGE TO THE STAINLESS STEEL LEADING EDGE OF ONE MAIN ROTOR BLADE; AT APPROX 8 FT FROM THE HUB; 10-12 INCHES WIDE; 1 INCH IN DEPTH. LEADING EDGE WAS DEFORMED AND DE-BONDED; BUT STILL INTACT DESPITE THIS DEFORMATION. PIC BELIEVES THAT THE PROVEN ENGINEERING AND DESIGN WAS SIGNIFICANT IN THE FACT THE BLADE DID NOT DISINTEGRATE ON IMPACT. THERE WAS MINOR DAMAGE TO THE HORIZ STABILIZER ON THE R SIDE; WHICH RESULTED IN A LOSS ON COMPONENTS. THE R SIDE POS LIGHT AND STROBE LIGHT WERE SEPARATED AND DEPARTED ON IMPACT. NO FURTHER DAMAGE WAS NOTED AFTER A THOROUGH POSTFLT AIRFRAME INSPECTION.

Data retrieved from NASA's ASRS site as of January 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.