SEA98LA073

NTSB accident investigation · Aero Commander 500-A · Billings, MT · May 9, 1998

Accident · No injuriesLimited investigationFinal report
Date
May 9, 1998, 11:05 local (17:05 UTC)
Place
Billings, MT
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N9382RAero Commander 500-A
Weather
Visual (VMC) · Day
Status
Completed · report February 15, 2001
Report
Approved by Office Director
FAA report
19980509015569A
Case key
42784

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

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Probable cause

Failure of the main landing gear strut outer-body to inner-body needle bearing from the lack of lubrication and the development of corrosion. An inadequate manufacturer's inspection program was a factor.

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/malfunctionTakeoff - initial climb
Landing gear,main gear - corrodedCause
Maintenance,lubrication - not performedCompany maintenance personnelCause
Maintenance,aaip/progressive program - inadequateManufacturerFactor
Gear collapsedLanding - roll

Analysis

The pilot reported that, after takeoff, the left-main landing gear would not fully retract. The pilot stated that he then extended the landing gear and performed various emergency procedures in an attempt to fully extend the left-main. The pilot was unable to get the left-main to lock in the down position and elected to land the airplane with the right-main and nosewheel extended. During the landing roll, the left-main gear collapsed and the airplane slid to a stop. Inspection of the left-main landing gear revealed that the upper-main landing gear strut's outer-body to inner-body needle bearing had failed, and the lower needle bearing was near failure. The lack of lubrication in this area was noted, along with evidence of severe corrosion development. The Manufacturer's Inspection Program for this model aircraft does not address a calendar and/or time inspection interval, or lubrication interval for the upper and lower needle bearing.

Factual narrative

On May 9, 1998, at 1105 mountain daylight time, an Aero Commander 500-A, N9382R, registered to and operated by Corporate Air as a 14 CFR Part 91 positioning flight, landed at the Billings Airport, Billings, Montana, with the left-main gear in the unlocked position. The left main gear collapsed during the landing roll. Visual meteorological conditions prevailed at the time and an instrument flight rules flight plan was filed. The aircraft was substantially damaged and the commercial pilot, the sole occupant, was not injured. The flight had departed Billings at 0810, and was destined for Minot, North Dakota.

The pilot reported that after takeoff from Billings, the left-main landing gear would not fully retract. The pilot extend the landing gear and performed various emergency procedures for about three hours in an attempt to fully extend the left-main. The pilot was unable to get a down-and-locked indication on the left-main gear and elected to land the airplane with the right-main and nosewheel extended. During the landing roll, the left-main landing gear collapsed and the airplane slid down the runway.

Inspection of the left-main landing gear by an inspector from the Federal Aviation Administration Flight Standards District Office, Helena, Montana, revealed that the upper-main landing gear strut's outer-body to inner-body needle bearing had failed and the lower needle bearing was near failure. The lack of lubrication in this area was noted, along with evidence of severe corrosion development.

The right-main landing gear was also inspected, and during the disassembly, similar conditions existed for the right gear as was found for the left.

The Manufacturer's Inspection Program for the 500 series aircraft does not address a calendar and/or time inspection interval, or lubrication interval for the upper and lower needle bearings. The manufacturer's inspection program maintenance manuals for the 600 and 700 series aircraft, which have the same design landing gear assemblies, identify procedures to overhaul and lubricate the landing gear at a five year or three thousand hour interval.

Aircraft

Registration
N9382R
Reported as
Aero Commander 500-A
Category
Airplane
Serial number
500A-899-8
Airframe hours
15,233
Engine
Lycoming IO-540-E1A5, 290 horsepower, reciprocating
Damage
Substantial damage
Flight
Positioning · Part 91
Registered owner
Corporate Air
Airworthiness certificate
Standard, Normal
Last inspection
AAIP · April 19, 1998 · 30 hours before
Destination
MOT · Minot, ND
Flight plan
IFR
Airport
BIL · Billings, runway 28R, 10,528 × 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
32
Certificates
Flight instructor, Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
1,420 total · 215 in this make and model · 700 as pilot in command · 180 in the last 90 days · 60 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
310° at 4 knots
Visibility
10 statute miles
Lowest ceiling
3,000 ft broken
Temperature
46 °F, dew point 39 °F
Altimeter
29.00 inHg
Observed at
BIL

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.