# NTSB DFW05CA181: Messerschmitt BK-117 B-2, N440HH, Houston, TX, July 14, 2005 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: July 14, 2005, 08:10 local (13:10 UTC) - Place: Houston, TX - Coordinates: 29.52111, -95.242225 - Nearby events: https://openairdocs.org/map.md?lat=29.5211&lon=-95.2422&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report October 27, 2005 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 61972 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DFW05CA181 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/61972/pdf - Page: https://openairdocs.org/ntsb/DFW05CA181 ## Probable cause The separation of the left passenger door due to worn attaching hardware. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, approach - vfr pattern - downwind - door,passenger - worn (cause) - door,passenger - separation (cause) - In flight collision with object, approach - vfr pattern - downwind - rotor system,main rotor blade - foreign object damage - Forced landing, approach - vfr pattern - downwind ## Analysis While on an extended downwind for an approach to runway 14L, the crew requested to open the left sliding passenger door. The 7,135-hour pilot approved the request and at an altitude of approximately 100 feet above ground level (agl), and while at 55 knots indicated airspeed, the left sliding passenger door exited the helicopter and made contact with all four main rotor blades. The pilot immediately descended to a three-foot agl hover and with no indication of control problems, proceeded approximately 1,800 feet to a helipad and landed. An examination of the sliding door and attaching hardware, by a Federal Aviation Administration inspector, revealed that the lower door guide rail had worn sufficiently enough to allow the door to exit the helicopter when the door handle was placed in the open position. ## Factual narrative On July 14, 2005, about 0810 central daylight time, a Messerschmitt BK 117 B-2 twin-turbo-shaft powered helicopter, N440HH, was substantially damaged following an airframe component failure while on approach to the Pearland Regional Airport (LVJ) near Houston, Texas. The commercial pilot and two crewmembers were not injured. The helicopter was registered to and operated by Memorial Hermann Hospital Systems Incorporated. Visual meteorological conditions prevailed and a company flight plan was filed for the 14 Code of Federal Regulations Part 91 positioning flight. The local flight originated from the company's refueling farm near Fresno, Texas. According to the 7,135 hour pilot, while on an extended downwind for runway 14L the crew requested to open the left sliding passenger door. The pilot approved the request and at an altitude of approximately 100 feet above ground level (agl), and while at 55 knots indicated airspeed, the left sliding passenger door exited the helicopter and made contact with all four main rotor blades. The pilot immediately descended to a three-foot agl hover and with no indication of control problems, proceeded approximately 1,800 feet to a helipad and landed. An inspection of the helicopter by a Federal Aviation Administration inspector revealed that the leading edge of all four main rotor blades sustained structural damage that would necessitate their replacement. An examination of the sliding door and attaching hardware revealed that the lower door guide rail had worn sufficiently enough to allow the door to exit the helicopter when the door handle was placed in the open position. ## Aircraft - Registration: N440HH (not matched to a registry record) - Reported make and model: Messerschmitt BK-117 B-2 - Category: Helicopter - Serial number: 7238 - Airframe hours: 7923.5 - Engines: Lycoming LTS101-750B-1 turbo shaft; Lycoming LTS101-750B-1 turbo shaft - Damage: Substantial damage - Flight: Positioning, Part 91 - Registered owner: Memorial Hermann Hospital Systems - Airworthiness certificate: Standard, Transport - Last inspection: AAIP, July 1, 2005, 15.2 hours before - Departed: Fresno, TX - Destination: LVJ, PEARLAND, TX - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 66; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, with waivers/limitations; flight hours: 7,135 total, 2,785 in this make and model, 44 in the last 90 days, 25 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Visibility: 9 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 75 °F - Altimeter: 29.94 inHg - Observed at: LVJ ## 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 20050714015059A](https://openairdocs.org/incident/20050714015059A), Jul 14, 2005: Bolkms BK117B2, Houston, TX, Substantial damage. (-23) On July 14, 2005, at approximately 0810 CST, an MBB-BK117-B2 helicopter serial number 7238, registered as N440HH, was being operated by hermann life… 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.