FTW93LA184

NTSB accident investigation · Cessna 172 · Canyon Lake, TX · June 9, 1993

Accident · Minor injuriesLimited investigationFinal report
Date
June 9, 1993, 11:12 local (16:12 UTC)
Place
Canyon Lake, TX
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N6446BCessna 172
Weather
Visual (VMC) · Day
Status
Completed · report September 13, 1994
Report
Approved by Office Director
FAA report
19930609017689A
Case key
18771

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

The movement of the pilot's seat aft which resulted in his loss of control, his inability to regain control, and the ensuing inadvertent stall. A factor was the inadequate inspection of the airplane.

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.

Loss of control - in flightTakeoff - initial climb
Fuselage,seat - disengaged
Stall - inadvertentPilot in commandCause
Remedial action - not possiblePilot in commandCause
Maintenance,annual inspection - inadequateOther maintenance personnelFactor
In flight collision with objectDescent - uncontrolled
Object - tree(s)

Analysis

The pilot stated that during the run up, he moved his seat back to secure one of the doors and then readjusted his seat to its original position. Shortly after liftoff, the seat traveled aft and the pilot lost control of the airplane. It subsequently impacted trees in a nose down attitude off one side of the runway. Examination of the seat latching mechanism revealed that it was intact, as were the seat tracks. Examination of the latching holes indicated that they were elongated and scrape marks were evident between the holes. The end of the latching pin was rounded. The seat latching mechanism subsequently operated normally. The seat latch AD inspection had last been performed two years prior to the accident.

Factual narrative

On Wednesday, June 9, 1993, at approximately 1112 central daylight time, a Cessna 172, N6446B, was substantially damaged when it collided with trees following a loss of control on initial climb out from the Canyon Lake, Texas, airport. The airplane, owned and operated by the ATP rated pilot, was departing on a local personal flight. There was no flight plan filed and visual meteorological conditions prevailed. The pilot, the sole occupant, received minor injuries.

The pilot stated that during the engine run up, he noticed that one of the doors was not properly secured and he adjusted his seat in order to reach the door. He stated that after securing the door, he readjusted his seat to its original position and took off. He further stated that shortly after liftoff, the seat pin broke and the seat traveled aft. He lost control of the airplane and it subsequently impacted the trees off the left side of the runway in a nose down attitude. The airplane remained suspended in the trees.

Examination of the airplane revealed that the seat latching mechanism was intact, as were the seat tracks for the pilot's seat. Examination of the latching holes indicated that they were elongated and scrape marks were found between the holes. The end of the latching pin was worn and rounded. Following the examination, the seat was re-installed and the seat locking mechanism operated normally. A review of the airplane's maintenance records indicated that the recurring seat latch airworthiness directive (AD 87-20-03) had last been performed on January 1, 1991.

Aircraft

Registration
N6446B
Reported as
Cessna 172
Category
Airplane
Serial number
17229646
Airframe hours
6,161
Engine
Continental O-300A, 145 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
Beal, Thomas W.
Airworthiness certificate
Standard, Normal
Last inspection
Annual · May 13, 1993 · 1 hours before
Departed
34TS
Destination
34TS
Airport
34TS · Canyon Lake, runway 19, 2,600 × 45 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
72
Certificates
Airline transport, Flight instructor
Airplane ratings
Single-engine land, Single-engine sea, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
20,505 total · 360 in this make and model · 15,012 as pilot in command · 48 in the last 90 days · 43 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
130° at 12 knots
Visibility
15 statute miles
Lowest ceiling
3,400 ft broken
Temperature
82 °F, dew point 63 °F
Altimeter
29.00 inHg

Docket · 3

The files NTSB released with the investigation on June 3, 1995, on NTSB’s docket system: statements, records, photos and specialists’ reports. 2.2 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.