FTW91LA117

NTSB accident investigation · Thorp T-18CW · Wimberley, TX · July 5, 1991

Accident · Minor injuriesLimited investigationFinal report
Date
July 5, 1991, 13:18 local (18:18 UTC)
Place
Wimberley, TX
Injuries
1 minor, 1 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N83MKThorp T-18CW
Weather
Visual (VMC) · Day
Status
Completed · report March 31, 1993
Report
Approved by Office Director
FAA report
19910705026429A
Case key
23362

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 failure of the airport personnel to maintain the airstrip in an operable condition and the pilots failure to maintain runway alignment on touchdown.

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.

On ground/water encounter with terrain/waterLanding - roll
Terrain condition - high vegetation
Proper alignment - not attainedPilot in commandFactor
Runway maintenance - inadequateAirport personnelCause
Loss of control - on ground/waterLanding - roll
On ground/water encounter with terrain/waterLanding - roll
Terrain condition - dirt bank/rising embankment
Ground loop/swerve - inadvertentPilot in command
Nose overLanding - roll

Analysis

During a landing on a grass airstrip the pilot failed to maintain runway alignment on touchdown and lost control when his left main wheel entered long grass. Left wing contacted 5 foot tall weeds adjacent to the 40 feet wide airstrip. The airplane veered left and struck a large ant mound resulting in the airplane ground looping to the inverted position. The pilot reported that touchdown occurred ten feet left of runway center.

Aircraft

Registration
N83MK
Reported as
Thorp T-18CW
Category
Airplane, amateur-built
Serial number
1367
Engine
Lycoming O-360, 180 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
James W. French
Registered owner
James W. French
Departed
T98 · San Marcos, TX
Airport
NONE · Woodbreck, runway 15, 2,200 × 40 ft, grass/turf

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
50
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 2, Valid Medical--w/ waivers/lim
Flight hours
2,594 total · 740 in this make and model · 2,502 as pilot in command · 40 in the last 90 days · 15 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
140° at 5 knots
Visibility
15 statute miles
Lowest ceiling
None
Temperature
-0 °F, dew point -0 °F
Observed at
AUS, 40 nm away

FAA reports on this event · 1

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