# NTSB SEA07LA133: Beech B-99, N950AA, Billings, MT, May 19, 2007 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 19, 2007, 04:00 local (10:00 UTC) - Place: Billings, MT - Coordinates: 45.807777, -108.542778 - Nearby events: https://openairdocs.org/map.md?lat=45.8078&lon=-108.5428&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report February 28, 2008 - Report: Approved by Office Director - Parties: FAA FSDO - NTSB case key (mKey): 65845 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA07LA133 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/65845/pdf - Page: https://openairdocs.org/ntsb/SEA07LA133 ## Probable cause The total failure of the nose landing gear actuator and the subsequent nose gear collapse during landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, cruise - normal - hydraulic system,actuator - failure,total (cause) - Nose gear collapsed, landing - roll - terrain condition - runway ## Analysis The pilot reported that about 40 nautical miles into the flight, he heard a "clunk" and the red unsafe light in the gear handle came on. He verified that all systems were functioning normally, and he cycled the landing gear up and down to see if that would solve the problem. The unsafe light remained illuminated. The pilot returned to the departure airport and circled for several hours to burn his fuel load down. He said that at one point he flew low over the runway so the company mechanic, with the aid of a light from an airport vehicle, could visually check the nose gear position. It was hanging out of the wheel well at approximately a 45-degree angle. Upon landing, the airplane settled to its nose during landing rollout. Examination of the airplane revealed that the nose gear actuator mount bracket area was bent and wrinkled. The nose gear actuator shaft had fractured just above the clevis bolt, which attaches to the drag brace. The failed actuator had been installed on July 26, 2006. The Beech B-99 maintenance manual states that the hydraulic actuator needs to be overhauled or replaced every 10,000 hours; maintenance records indicate that this one had 231.4 hours on it at the time of the accident. Metallurgist examined the failed actuator and concluded that all of the fractures were overstress, and no preexisting fatigue signatures were evident. The airframe had accumulated 34,613.2 hours of flying time, at the time of the accident. ## Factual narrative On May 19, 2007, at 0400 mountain daylight time, a Beech B-99, N950AA, was substantially damaged when the nose wheel landing gear collapsed during landing roll at Billings Logan International Airport (BIL), Billings, Montana. The airline transport pilot, the sole occupant in the airplane, was not injured. Alpine Aviation Inc., Provo, Utah, was operating the airplane under Title 14 CFR Part 135. Night visual meteorological conditions prevailed for the cross-country flight, which had originated at 0100. The pilot was flying on an activated instrument flight rules (IFR) flight plan, which had an intended destination of Kalispell, Montana. The pilot said that he had departed from Billings, Montana, and had climbed to 12,000 feet. About 40 nautical miles northwest of Billings, he heard a "clunk" and the red unsafe light in the gear handle came on. He verified that all systems were functioning normally, and he cycled the landing gear up and down to see if that would solve the problem. The unsafe light remained illuminated. The pilot returned to Billings and circled for several hours to burn his fuel load down. He said that at one point he flew low over the runway so the company mechanic, with the aid of a light from an airport vehicle, could visually check the nose gear position. It was hanging out of the wheel well at approximately a 45-degree angle. Upon landing at Billings, the airplane settled to its nose during landing rollout. Examination of the airplane by an FAA inspector revealed that the nose gear actuator mount bracket area was bent and wrinkled. The nose gear actuator shaft had fractured just above the clevis bolt, which attaches to the drag brace. The failed actuator had been installed on July 26, 2006. The Beech B-99 maintenance manual states that the hydraulic actuator needs to be overhauled or replaced every 10,000 hours; maintenance records indicate that this one had 231.4 hours on it at the time of the accident. Metallurgists from both the National Transportation Safety Board and Hawker Beechcraft Corporation examined the failed actuator. Both concluded that all of the fractures were overstress, and no preexisting fatigue signatures were evident. The airframe had accumulated 34,613.2 hours of flying time at the time of the accident. ## Aircraft - Registration: [N950AA](https://openairdocs.org/aircraft/N950AA), registered now, S/N U-159, built 1974 (OpenAirDocs) - Reported make and model: Beech B-99 - Registry model: [Beech B-99](https://openairdocs.org/model/beech-b-99) (registry code 1154004) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52032, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: U-159 - Airframe hours: 34613 - Engines: Pratt & Whitney PT-6A 680 horsepower turbo prop; Pratt & Whitney PT-6A 680 horsepower turbo prop - Damage: Substantial damage - Flight: Part 135 - Registered owner: Alpine Aviation Inc. - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, April 1, 2007, 130 hours before - Departed: BIL, Billings, MT - Destination: GPI, Kalispell, MT - Flight plan: IFR - Airport: BIL, Billings Logan Intern Arpt, runway 10L, 10,518 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; injuries: none; flight instructor, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review March 1, 2007; seat: left; flight hours: 11,360 total, 2,490 in this make and model, 11,053 as pilot in command, 240 in the last 90 days, 79 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night - Wind: 20° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 54 °F, dew point 46 °F - Altimeter: 29.98 inHg - Observed at: BIL 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.