CEN16LA354

NTSB accident investigation · North American Navion · Monett, MO · August 29, 2016

Accident · No injuriesLimited investigationFinal report
Date
August 29, 2016, 09:30 local (14:30 UTC)
Place
Monett, MO
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N91488North American Navion
Defining event
Landing-landing roll: Landing gear collapse
Weather
Visual (VMC) · Day
Status
Completed · report May 1, 2017
Report
Approved by Office Director
NTSB office
Central Region
Parties
FAA FSDO
FAA report
20160829015439A
Case key
93955

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

Maintenance personnel’s failure to properly rig the right main landing gear locking mechanism, which resulted in a gear collapse during landing.

Findings · 2

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Landing gear system: gear extension and retract sysAircraft › Aircraft systems · Incorrect service/maintenanceNorth American NAVION: 1 caseAll aircraft: 416 casesProbable cause
MaintenancePersonnel issues › Task performance · Maintenance personnelNorth American NAVION: 1 caseAll aircraft: 143 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The commercial pilot stated that, during the landing roll following a normal landing, the airplane began pulling to the right. The airplane departed the right side of the runway and traveled down an embankment and through a barbed wire fence. When the pilot inspected the airplane, he noted that the right main landing gear (MLG) had collapsed. An examination of the landing gear found that the locking mechanism had been improperly rigged. Several weeks before the accident, the airplane's right MLG was damaged in an incident and had been replaced with a serviceable unit. A review of maintenance records noted that a gear retraction test was conducted after the replacement and described as satisfactory. It is likely that during this maintenance, the landing gear was improperly rigged, which resulted in its collapse on the accident flight.

Factual narrative

On August 29, 2016, about 0930 central daylight time, a North American Navion airplane, N91488, departed off the side of the runway at the Monett Regional Airport (KHFJ), Monett, Missouri. The pilot was not injured and the airplane was substantially damaged. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The flight originated from the Gimlin Airport (18MO), Ozark, Missouri, and was landing at KHFJ.According to the pilot, he landed the airplane on runway 18 at KHFJ about 0930. Weather was clear and he estimated the wind at 120° at 4 knots. Following a normal approached and landing, he noticed the airplane's right wing was lower than the left wing, and the airplane began a pull to the right. The airplane departed the right side of the runway, went down an embankment and run through a barbed wire fence. When the pilot inspected the airplane, he noted that the right main landing gear (MLG) had collapsed. During recovery of the airplane, the airplane was lifted and the right MLG was extended manually and locked. The airplane was examined by inspectors from the Federal Aviation Administration. A landing gear swing test was conducted and the landing gear had been improperly rigged. A review of the airplane's history revealed that several weeks prior to the accident, the airplane's right MLG scissor was damaged during a high speed turn. A review of maintenance records revealed that on July 22, 2016, the airplane's right MLG scissor was replaced with a serviceable unit. A gear retraction test was conducted and described as satisfactory.

Aircraft

Registration
N91488
Reported as
North American Navion (A)
Category
Airplane
Serial number
NAV-4-119
Built
1946
Airframe hours
1,611
Engine
Continental IO-520-BA, 285 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Utility; Standard, Normal
Last inspection
Annual · October 26, 2015 · 40 hours before
Departed
18MO · Ozark, MO
Destination
HFJ · Monett, MO
Airport
HFJ · Monett Rgnl, runway 18, 5,000 × 75 ft, concrete

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
70
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 3, With waivers/limitations
Seat
Left

Weather

Conditions
Visual (VMC) · Day
Wind
120° at 5 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
81 °F, dew point 72 °F
Altimeter
30.19 inHg
Observed at
KHFJ

Docket · 3

The files NTSB released with the investigation on March 29, 2017, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.2 MB in all.

FAA reports on this event · 1

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