Eurocopter Deutschland Gmbh EC 135 P2+ N226SA accident near Waukesha, Wisconsin

Probable cause

The separation and subsequent ingestion of the fenestron fairing cover into the fenestron blades for undetermined reasons.

NTSB analysis

After takeoff during an air medical flight, about 150 ft above ground level (agl), the pilot heard a "thump,” and the helicopter pitched up. The pilot immediately executed an emergency landing, and all occupants exited the helicopter uninjured. The helicopter sustained substantial damage to the fenestron blades.

Examination of the helicopter at the accident site revealed that the fairing cover was missing from fenestron assembly and was found fragmented about 600 ft in all directions. There was no evidence of a bird strike. The fairing cover fragments that were found showed damage consistent with ingestion into the rotating blades of the fenestron. All attachment hardware for the cover were accounted for and showed no evidence of preaccident failure.

The damage to the fenestron housing was consistent with object ingestion. No preaccident failures or malfunctions were found with the fenestron body, fenestron blades, gearbox, or fenestron drive.

The helicopter flew about 5.8 hours without incident after the most recent maintenance of the fenestron and no uncorrected maintenance anomalies were found in the maintenance logbooks. The reason for the separation and subsequent ingestion of the fenestron fairing cover into the fenestron blades could not be determined.

Text from the NTSB. Open the NTSB docket for CEN22LA258 for the full record.