# NTSB CEN22LA258: Eurocopter Deutschland EC 135 P2+, N226SA, Waukesha, WI, June 18, 2022 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: June 18, 2022, 17:10 local (22:10 UTC) - Place: Waukesha, WI - Coordinates: 43.039627, -88.239269 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.0396&lon=-88.2393&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Airbus Tech Advisor to BFU, Metro Aviation, BFU Accredited Representative, FAA FSDO - NTSB case key (mKey): 105286 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN22LA258 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105286/pdf - Page: https://openairdocs.org/ntsb/CEN22LA258 ## Probable cause The separation and subsequent ingestion of the fenestron fairing cover into the fenestron blades for undetermined reasons. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Tail rotor](https://openairdocs.org/ntsb-findings/01046400): Aircraft › Aircraft propeller/rotor · Unknown/Not determined (probable cause); cases with it: [Eurocopter Deutschland EC 135 P2+, 3 cases](https://openairdocs.org/ntsb-findings/01046400/cases.md?model=5620030), [All aircraft, 23 cases](https://openairdocs.org/ntsb-findings/01046400/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) (defining event); cases with it: [Eurocopter Deutschland EC 135 P2+, 3 cases](https://openairdocs.org/ntsb-events/338/sequence.md?model=5620030), [All aircraft, 563 cases](https://openairdocs.org/ntsb-events/338/sequence.md) ## 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. ## Factual narrative On June 18, 2022, about 1710 central daylight time, a Eurocopter Deutschland Gmbh EC-135 P2+ helicopter, N226SA, sustained substantial damage when it was involved in an accident near Waukesha, Wisconsin. The pilot and 3 passengers were not injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 135 air medical flight. According to the operator, the pilot received a flight request for an inter-facility transfer flight. The intended route of flight was from the aircraft's primary base at Waukesha County Airport (UES) to pick up a patient at Aurora Lakeland Medical Center, Elkhorn, Wisconsin, and transport them to Children's Hospital of Wisconsin, Milwaukee, Wisconsin. After departing from UES when the helicopter about 150 ft 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 pilot had full control of the helicopter during the emergency landing. The helicopter sustained substantial damage to the fenestron blades. The accident site was situated over a large area adjacent to a concrete ramp and taxiway. The fairing cover was missing from fenestron assembly. Debris was found about 600 ft in all directions. The debris consisted of fenestron fairing (hub cover) fragments, composite fragments from the fenestron body, attachment bolts, and brackets. Some debris was found on top of a one-story hangar rooftop. Small fragments of the fairing cover were found scattered on the ramp and the top of the one-story hangar. Larger fragments of the fairing cover were found wedged between the fenestron housing and the fenestron blades. The fairing fragments that were found showed damage consistent with ingestion into the rotating blades of the fenestron. There was no evidence of a bird strike present. After an extensive search of the accident area, investigators were unable to identify any foreign debris that might have come into contact with the cover before its separation. Other than the fenestron fairing cover and fenestron housing, the entire helicopter (airframe and engine) had no other damage or missing hardware/components. The fenestron blades within the fenestron housing were found attached with no evidence of malfunction. The fenestron blades and the inside of fenestron housing were impact damaged, consistent with ingestion of the fragments from the fenestron fairing cover. No evidence of preaccident malfunctions of the fenestron housing, blades, gearbox, or drive were found. No improper maintenance anomalies were found with the fenestron assembly. Along with multiple fragments of the fenestron fairing cover, five of the fenestron fairing cover attachment bolts were found attached to their respective brackets, and all were torqued. A sixth bolt was not found; however, a portion of the sixth bolt’s bracket was found embedded in a faring cover fragment, consistent with the bolt being attached before the accident. Allfaring cover attachment hardware was accounted for and showed no evidence of preaccident material failure. On an exemplar fenestron assembly, a security test of the fenestron fairing cover was conducted with various combinations of retaining bolts and clips. The fairing cover was attached to the exemplar fenestron assembly with six attachment bolts, brackets, and anchors. The hub cover was secure. Two of the bolts were removed, and the fairing cover remained secure. Two more bolts were removed, and with only two bolts remaining, and the fairing cover remained secure. The helicopter flew about 5.8 hours without incident after the most recent maintenance of the fenestron. Since the fenestron maintenance, numerous daily maintenance checks and pilot prefights were conducted, with no unresolved items or anomalies. No uncorrected maintenance anomalies were found in the maintenance logbooks. There were six historical events involving the fenestron faring cover separating from the same model helicopter. All six events were related to FOD ingestions that caused the fenestron fairing cover to separate. ## Aircraft - Registration: [N226SA](https://openairdocs.org/aircraft/N226SA), registered now, S/N 0559, built 2007 (OpenAirDocs) - Reported make and model: EUROCOPTER DEUTSCHLAND GMBH EC 135 P2+ - Registry model: [Eurocopter Deutschland EC 135 P2+](https://openairdocs.org/model/eurocopter-deutschland-ec-135-p2-plus) (registry code 5620030) (OpenAirDocs) - Registry engine: [Pratt & Whitney Canada PW206B](https://openairdocs.org/engine/pratt-whitney-canada-pw206b) (registry code 52204, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 0559 - Year built: 2007 - Airframe hours: 5538 - Engines: P&W Canada PW206B2 431 horsepower turbo shaft; P&W Canada PW206B2 431 horsepower turbo shaft - Damage: Substantial damage - Flight: Other work use, Part 135 - Operator: Metro Aviation INC - Registered owner: Bennett Aviation LLC - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, June 17, 2022, 5.8 hours before - Departed: Wauksha, WI - Destination: 0W13, Elkhorn, WI - Flight plan: Company VFR - Airport: UES, Waukeska County Airport - Equipment: Video recording device, Satellite tracking device, Onboard weather, Electronic multifunction display, Electronic flight bag or handheld device, Auto-pilot, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: none; commercial, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane, helicopter; medical: class 2, with waivers/limitations; last flight review March 23, 2022; seat: right; restraint: 4-point; flight hours: 6,390 total, 663 in this make and model, 12 in the last 90 days, 3 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 80° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 66 °F, dew point 36 °F - Altimeter: 30.28 inHg - Observed at: UES ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20220618021819A](https://openairdocs.org/incident/20220618021819A), Jun 18, 2022: Eurocopter Deutschland Gmbh EC 135 P2+, Waukesha, WI, Substantial damage. The crew received an air ambulance flight assignment to pick up a patient from the local hospital. The pilots began their assignment by performing an aircraft… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.