ERA18LA154

NTSB accident investigation · Cessna 421 · Sandersville, GA · May 21, 2018

Accident · No injuriesClass 3 · LimitedFinal report
Date
May 21, 2018, 13:10 local (17:10 UTC)
Place
Sandersville, GA
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N427JMCessna 421
Defining event
Landing-landing roll: Landing gear collapse
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
20180521005709A
Case key
97353

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 nose landing gear collapse for reasons that could not be determined based on the available information.

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.

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 pilot reported that the flight was uneventful and during the approach for landing, he placed the landing gear handle in the down position and observed three green landing gear lights, indicating that the gear was down and locked. Shortly after touchdown, the nose landing gear collapsed into the retracted position. The airplane’s nose impacted the runway and the airplane skidded to a stop, resulting in substantial damage to the airframe. After the airplane stopped, the landing gear position lights indicated that all of the landing gear were extended and locked into position. A mechanic who saw the landing and assisted in removing the airplane from the runway after the accident reported that, during the attempt to move the airplane, they lifted the nose off the ground and tried unsuccessfully to move the nose landing gear into the down and locked position. Postaccident testing of the nose landing gear actuator revealed no discrepancies. Although the green safe switch remained illuminated during the entire testing cycle, indicating a defective switch, this did not directly contribute to the collapse of the nose landing gear. Review of maintenance records showed no nose gear discrepancies over the previous 18 months. The reason for the nose landing gear collapse could not be determined based on the available information.

Factual narrative

On May 21, 2018, about 1310 eastern daylight time, a Cessna 421-C, N427JM, was substantially damaged when it was involved in an accident near Sandersville, Georgia. The commercial pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that the flight was uneventful; during the landing approach, he placed the landing gear handle in the down position and received three green landing gear lights, indicating that the gear was down and locked. He stated that, after the main landing gear touched down, “he didn’t feel any resistance from the nose nosewheel” when it settled onto the runway. The airplane continued to settle, and the nose impacted the runway. The pilot maintained directional control and attempted to maneuver the airplane off the runway onto a taxiway with differential braking as it skidded to a stop. After the airplane stopped, the landing gear position lights indicated that all gear were down and locked. A mechanic saw the landing and reported that the airplane looked “normal” on final approach. He heard the main landing gear touch down, followed by “something dragging.” After the airplane came to rest, he checked on the condition of the pilot, then attempted to remove the airplane from the runway. During the attempt to move the airplane from the runway, they lifted the nose off the ground, tried unsuccessfully to get the nose landing gear into the down and locked position, and ultimately strapped the landing gear in place to move the airplane. Examination of the airplane by a Federal Aviation Administration maintenance inspector revealed substantial damage, including buckling of the airframe on both sides of the nose landing gear well, and abrasion through to the airframe on the bottom of the nose and fuselage. The nose landing gear actuator was removed for detailed examination. The actuator was tested in the locked and unlocked position at the correct pressures with no leaks or discrepancies noted.; however, the green safe switch remained illuminated during the entire test, indicating a defective switch. The switch was brittle and appeared “very old.” A review of the airframe maintenance logbook revealed that, during the most recent annual inspection on July 10, 2017, a landing gear retraction test was conducted per the manufacturer’s service manual with no defects noted. On April 27, 2018, a logbook entry showed a main landing gear irregularity that was corrected. The landing gear was cycled 10 times with no defects noted with the nose landing gear.

Aircraft

Registration
N427JM
Reported as
Cessna 421 (C)
Category
Airplane
Serial number
421C0103
Built
1976
Airframe hours
4,437.2
Engines
Continental GTSIO520L4B, 375 horsepower, reciprocatingContinental GTISO520L4B, 375 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Mabb Transport LLC
Registered owner
Mabb Transport LLC
Airworthiness certificate
Standard, Normal
Last inspection
Annual · July 11, 2017
Departed
CTJ · Carrollton, GA
Destination
OKZ · Sandersville, GA
Flight plan
IFR
Airport
OKZ · Kaolin Field, runway 13, 5,016 × 75 ft, asphalt
Equipment
Stall warning system, Auto-pilot, Electronic multifunction display, Onboard weather, Satellite tracking device

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
64
Injuries
None
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 2
Last flight review
January 15, 2018
Seat
Left
Restraint
Lap only
Flight hours
22,697 total · 948 in this make and model · 22,690 as pilot in command · 141 in the last 90 days · 44 in the last 30 days · 3 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
3,700 ft broken
Temperature
73 °F, dew point 70 °F
Altimeter
29.70 inHg
Observed at
OKZ

Docket · 6

The files NTSB released with the investigation on November 3, 2021, on NTSB’s docket system: statements, records, photos and specialists’ reports. 22.8 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.