ERA17LA130

NTSB accident investigation · Socata TB20 · Melbourne, FL · February 25, 2017

Accident · No injuriesLimited investigationFinal report
Date
February 25, 2017, 11:15 local (16:15 UTC)
Place
Melbourne, FL
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N2519TSocata TB20
Defining event
Landing-landing roll: Landing gear collapse
Weather
Visual (VMC) · Day
Status
Completed · report August 10, 2020
Report
Approved by Office Director
NTSB office
Eastern Region Aviation
Parties
FAA/FSDO, Daher Aircraft inc.
FAA report
20170225001129A
Case key
94864

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

Improper installation of the circlip within the nose gear strut, which resulted in the strut overextending in the wheel well and preventing the nose landing gear from extending 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.

Maintenance: repairPersonnel issues › Task performance · Maintenance personnelSocata TB-20 TRINIDAD: 1 caseAll aircraft: 99 casesProbable cause
Landing gear system: nose/tail gear strut/axleAircraft › Aircraft systems · Incorrect service/maintenanceSocata TB-20 TRINIDAD: 1 caseAll aircraft: 36 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

During a personal flight, the airplane's alternator warning light flashed and the battery began to discharge, so the pilot conducted a precautionary landing. The nose landing gear did not fully deploy, and the pilot performed a gear-up landing. Examination of the landing gear system revealed the nose landing gear was jammed within the wheel well because the nose strut had overextended. Further, the circlip that held the strut inside the gear assembly was dislodged from the groove. Paint was identified on the outer portion of the circlip. Review of the maintenance records revealed that the nose landing gear was disassembled and repaired more than 2 years and 75 flight hours before the accident flight. The airplane was fully painted after that maintenance. According to the airplane maintenance manual, the circlip should have been fully installed in the groove, and the landing gear should be rotated several times to confirm proper installation. If the circlip had been properly installed inside the nose strut housing groove at the time paint was applied, paint would not have been on the outer surface of the circlip. It is likely that the circlip was improperly installed when the nose landing gear was repaired; it eventually became dislodged sufficiently to cause the internal strut to overextend and the gear to become jammed within the wheel well.

Factual narrative

On February 25, 2017, about 1115 eastern standard time, a Socata TB20, N2519T, was substantially damaged during a gear up landing at Melbourne International Airport (MLB), Melbourne, Florida. The private pilot was not injured. The personal flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the flight, which departed Key West International Airport (EYW), Key West, Florida, about 1012.The pilot reported that during his cross-country flight he noticed the alternator warning light flash and the battery began to discharge. He contacted air traffic control, but did not declare an emergency, and began a slow descent while initiating the emergency gear extension. After multiple unsuccessful attempts the pilot performed a gear up landing. An examination of the airplane by a Federal Aviation Administration Inspector revealed that the main landed gear was extended but not fully locked. The nose landing gear did not extend and remained in the wheel well. Examination of the airframe revealed that the bottom forward bulkhead was damaged during landing sequence. An examination of the nose gear assembly revealed the circlip on the nose landing gear strut was dislodged from the nose landing gear leg assembly, which allowed the strut to extend further than usual. The circlip used to retain the nose gear strut inside the nose gear assembly had paint on the outer portion of the circlip, which should have been fully set inside the groove used to keep the circlip in place. An examination of the circlip groove revealed that it was in serviceable condition with no corrosion or other deformation within the groove. A review of the maintenance records showed that the nose strut was disassembled and repaired on July 15, 2015, and the airplane was completely repainted on April 5, 2016. Further review of the maintenance records revealed that since the disassembly of the nose gear, a total of 75 hours of flight time had accumulated since the maintenance. According to the airplane's maintenance manual the, nose landing gear strut retaining circlip should have been fully installed in the groove. After it is installed, the landing gear should be rotated several times to confirm proper installation.

Aircraft

Registration
N2519T
Reported as
Socata TB20
Category
Airplane
Serial number
949
Built
1989
Airframe hours
73
Engine
Lycoming IO-540-C4050, 250 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · July 25, 2016 · 2,983 hours before
Departed
EYW · Key West, FL
Destination
DAB · Daytona Beach, FL
Flight plan
IFR
Airport
MLB · Melbourne Intl, runway 27R, 6,000 × 150 ft, asphalt
Equipment
Stall warning system, Angle of attack indicator, Auto-pilot

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
66
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 3, With waivers/limitations
Last flight review
August 26, 2016
Seat
Left
Restraint
3-point
Flight hours
2,858 total · 1,849 in this make and model · 2,700 as pilot in command · 22 in the last 90 days · 17 in the last 30 days · 3 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
240° at 6 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
73 °F, dew point 68 °F
Altimeter
29.93 inHg
Observed at
MLB

Docket · 5

The files NTSB released with the investigation on June 8, 2020, on NTSB’s docket system: statements, records, photos and specialists’ reports. 6.6 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.