ERA20LA192

NTSB accident investigation · Beech F90 · Knoxville, TN · May 18, 2020

Accident · No injuriesClass 3 · LimitedFinal report
Date
May 18, 2020, 11:10 local (15:10 UTC)
Place
Knoxville, TN
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N960VBeech F90
Defining event
Initial climb: Sys/Comp malf/fail (non-power)
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Eastern Region Aviation
Parties
FAA FSDO
FAA report
20200518006769A
Case key
101309

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

A failure of the left main landing gear scissors, which resulted in a landing gear collapse following a precautionary landing with the landing gear in an intermediate position..

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: landing gear actuatorAircraft › Aircraft systems · Damaged/degradedBeech F90: 1 caseAll aircraft: 54 casesProbable cause
Landing gear system: gear extension and retract sysAircraft › Aircraft systems · Damaged/degradedBeech F90: 1 caseAll aircraft: 416 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

Shortly after takeoff, the pilot moved the landing gear handle to the retract position, and the red “gear unsafe” light illuminated. The pilot conducted a low-altitude approach so that the tower controller could visually confirm the condition of the landing gear; the tower controller reported that the nose landing gear appeared “slanted.” The pilot then performed the unsafe gear checklist and attempted to manually lower the landing gear, but the red gear unsafe light remained illuminated. During a subsequent low-altitude approach, the controller indicated that the main gear appeared down but that the nose gear did not appear to be fully down and locked. The pilot performed a precautionary landing, and, shortly after touchdown, the main and nose landing gear collapsed, and the airplane skidded to a stop. Examination of the left main landing gear revealed that the landing gear scissors had fractured at the bolt attachment area and that the landing gear was twisted sideways and jammed against the main gear doors. The landing gear circuit breaker that controlled the landing gear motor had popped. The airplane manufacturer’s landing gear manual extension procedure required the emergency gear selector handle to be in the STOP detent. Postaccident examination of the airplane revealed that the handle was not placed in the STOP detent; however, it could not be determined, from the available evidence for this investigation, if the landing gear manual extension procedure could have been successfully accomplished with the landing gear system failure that occurred during the accident flight.

Factual narrative

On May 18, 2020, about 1110 central daylight time, a Beech F90, N960V, was substantially damaged when it was involved in an accident near McGhee Tyson Airport (TYS), Knoxville, Tennessee. The pilot and pilot-rated passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 corporate flight. According to the pilot, after takeoff from TYS, he moved the landing gear handle to the retract position; afterward, the red “gear unsafe” light illuminated. The pilot returned to the airport and conducted a low-altitude approach so that an airport tower controller could visually confirm the landing gear position. The tower controller reported that the nose landing gear appeared “slanted like it wasn’t down and locked.” The pilot performed the unsafe gear checklist and attempted to manually lower the landing gear, but the red gear unsafe light remained illuminated. During a subsequent low-altitude approach, the controller indicated that the main gear appeared down but that the nose gear did not appear to be fully down and locked. The pilot conducted another low-altitude approach and was told that the gear condition had not changed. He then elected to perform a precautionary landing. Shortly after touchdown, the main and nose landing gear collapsed. The airplane departed the left side of the runway and came to rest on a taxiway. Examination of the airplane revealed that several stringers and ribs were impact damaged, the nose landing gear actuator punctured the top of the fuselage, and the left aileron was impact damaged. Examination of the left main landing gear revealed that the landing gear scissors had fractured at the bolt attachment area and that the landing gear was twisted sideways and jammed against the main landing gear doors. The landing gear circuit breaker that controlled the landing gear motor had popped. Examination of the landing gear handle revealed that the emergency engage handle was not placed in the STOP detent, the position indicated in the landing gear manual extension procedures in the pilot’s operating handbook. A review of the operator’s maintenance records revealed that. on February 6, 2020, the airplane underwent a landing gear overhaul. At the time of the overhaul, the airplane had accumulated a total of 12,512 hours. At the time of the accident, the airplane had a total time of 12,533 hours During the 21 hours that the airplane flew between the landing gear overhaul and the accident, no reports of any mechanical irregularity were documented.

Aircraft

Registration
N960V
Reported as
Beech F90 (UNDESIGNAT)
Category
Airplane
Serial number
LA-31
Built
1980
Airframe hours
12,532
Engines
Pratt & Whitney PT-6A, 750 horsepower, turbo propPratt & Whitney PT-6A, 750 horsepower, turbo prop
Damage
Substantial damage
Flight
Executive/Corporate · Part 91
Operator
Empire Equipment Llc
Registered owner
Empire Equipment Llc
Airworthiness certificate
Standard, Normal
Last inspection
Annual · November 20, 2019 · 20 hours before
Departed
TYS · Knoxville, TN
Destination
HXD · Hilton Head Island, SC
Flight plan
IFR
Airport
TYS · Mc Ghee Tyson Airport, runway 24L, 9,000 × 150 ft, asphalt
Equipment
Electronic primary flight display, Auto-pilot, ADS-B, Stall warning system, Satellite tracking device, Onboard weather

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 · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
65
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, With waivers/limitations
Last flight review
August 14, 2019
Seat
Left
Restraint
3-point
Flight hours
5,411 total · 97 in this make and model · 5,100 as pilot in command · 36 in the last 90 days · 9 in the last 30 days · 0.4 in the last 24 hours
Role
Pilot-rated passenger
Age
49
Injuries
None
Certificates
Flight instructor, Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Seat
Right
Restraint
3-point

Weather

Conditions
Visual (VMC) · Day
Wind
300° at 4 knots
Visibility
10 statute miles
Lowest ceiling
3,700 ft broken
Temperature
75 °F, dew point 64 °F
Altimeter
29.84 inHg
Observed at
TYS, 1 nm away

Docket · 8

The files NTSB released with the investigation on May 16, 2022, on NTSB’s docket system: statements, records, photos and specialists’ reports. 62.3 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.

Other investigations on N960V · 1

Matched to the same aircraft by N-number and date.