SEA07LA133

NTSB accident investigation · Beech B-99 · Billings, MT · May 19, 2007

Accident · No injuriesLimited investigationFinal report
Date
May 19, 2007, 04:00 local (10:00 UTC)
Place
Billings, MT
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N950AABeech B-99
Weather
Visual (VMC) · Night
Status
Completed · report February 28, 2008
Report
Approved by Office Director
Parties
FAA FSDO
Case key
65845

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

The total failure of the nose landing gear actuator and the subsequent nose gear collapse during landing.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Airframe/component/system failure/malfunctionCruise - normal
Hydraulic system,actuator - failure,totalCause
Nose gear collapsedLanding - 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
Reported as
Beech B-99
Category
Airplane
Serial number
U-159
Airframe hours
34,613
Engines
Pratt & Whitney PT-6A, 680 horsepower, turbo propPratt & 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

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
51
Injuries
None
Certificates
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