MIA98LA084

NTSB accident investigation · Walter J Collie Cumulus · Hillsboro, TN · February 24, 1998

Accident · FatalLimited investigationFinal report
Date
February 24, 1998, 12:30 local (18:30 UTC)
Place
Hillsboro, TN
Injuries
1 fatal
Damage
Destroyed
Phase of flight
Enroute
Aircraft
N1171UWalter J Collie Cumulus
Weather
Visual (VMC) · Day
Status
Completed · report February 11, 2000
Report
Approved by Office Director
FAA report
19980224006049A
Case key
38461

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

Debonding of the leading edge to spar cap joint, which resulted in inflight separation.

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.

Airframe/component/system failure/malfunctionCruise
Wing,spar - debondedCause
In flight collision with terrain/waterDescent - uncontrolled
Terrain condition - grass

Analysis

The motorglider sustained an inflight separation of the left wing due to failure of a glue-bonded joint between the D-cell wing leading edge and the upper spar capstrip. The ballistic recovery system was fired, but the parachute's shroud lines were fouled around the propeller and shaft. The fuselage, minus both wings, impacted the terrain in a nose-down attitude.

Factual narrative

On February 24, 1998, about 1230 central standard time, a Collie Cumulus motorglider, N1171U, registered to a private individual, operating as a 14 CFR Part 91 personal flight, experienced a wing separation while in powered flight near Hillsboro, Tennessee. Visual meteorological conditions prevailed and no flight plan was filed. The commercial-rated pilot sustained fatal injuries, and the airplane was destroyed. The flight originated about 15 minutes before the accident.

An eyewitness stated he heard the aircraft takeoff from a nearby private airstrip, and shortly thereafter, it came into his view at about 400 to 500 feet altitude in straight-and-level flight. He then heard a loud "pop", looked up again, and saw a wing separated from the fuselage and the fuselage plunge earthward. The airplane impacted the terrain beyond the eyewitness' field of vision. He did not see a parachute deploy.

The fuselage crashed in a farm field, in a nose-down attitude. Both wings were found 200 to 300 yards from the main wreckage. A ballistic recovery system, BRS, was installed and had been fired, but the shroud lines had fouled in the airplane's pusher-type propeller resulting in nondeployment of the parachute's canopy. On-site examination of the wreckage by FAA personnel revealed that the left wing spar failed.

Subsequent inspection by representatives of the kit manufacturer, U.S. Aviation, and the FAA, revealed that the initial failure was the left wing spar due to improper bonding techniques. Specifically, the glue-bonded joint between the D-cell leading edge and the upper spar capstrip of the left wing failed. The findings were unanimous. ( See enclosed letter indicating inspection team's composition and findings.)

Postmortem examination of the pilot and toxicology testing were not accomplished. The protocol guidance given the FAA investigators on the scene, by the FAA Flight Surgeon's Office/ Southern Region, was to treat the accident as an ultralight accident, and therefore the testing was not ordered.

Aircraft

Registration
N1171U
Reported as
Walter J Collie Cumulus
Category
Airplane, amateur-built
Serial number
002
Airframe hours
100
Engine
Bombardier 447, 40 horsepower, reciprocating
Damage
Destroyed
Flight
Personal · Part 91
Registered owner
Walter J. Collie
Airworthiness certificate
Special, Experimental (Special)
Departed
TN24 · TN

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
Certificates
Flight instructor, Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Expired
Seat
Center
Flight hours
1,800 total

Weather

Conditions
Visual (VMC) · Day
Wind
260° at 12 knots
Visibility
10 statute miles
Temperature
66 °F, dew point 37 °F
Altimeter
30.00 inHg
Observed at
BNA, 66 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.