# NTSB MIA98LA084: Walter J Collie Cumulus, N1171U, Hillsboro, TN, February 24, 1998 - Type: NTSB accident investigation - Classification: Accident · Fatal · Limited investigation · Final report - Date: February 24, 1998, 12:30 local (18:30 UTC) - Place: Hillsboro, TN - Coordinates: 35.46083, -86.080314 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.4608&lon=-86.0803&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed, report February 11, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 38461 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA98LA084 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/38461/pdf - Page: https://openairdocs.org/ntsb/MIA98LA084 ## Probable cause Debonding of the leading edge to spar cap joint, which resulted in inflight separation. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, cruise - wing,spar - debonded (cause) - In flight collision with terrain/water, descent - 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](https://openairdocs.org/deregistered/N1171U-2000-03-16), registration cancelled 2000-03-16, S/N 002 (OpenAirDocs) - Reported make and model: WALTER J COLLIE CUMULUS - Registry model: [Collie Walter J U S AVIATION CUMULUS](https://openairdocs.org/model/collie-walter-j-u-s-aviation-cumulus) (registry code 056038A) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 002 - Airframe hours: 100 - Engines: Bombardier 447 40 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Registered owner: Walter J. Collie - Airworthiness certificate: Special, Experimental (Special) - Departed: TN24, TN ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; 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 (OpenAirDocs). - [Accident 19980224006049A](https://openairdocs.org/incident/19980224006049A), Feb 24, 1998: Amtr CUMULUS, Hillsboro, TN, Destroyed, 1 fatal. Narrative: on February 24, 1998, about 1320 central standard time, an experimental airplane called a Cumulus, N1171U, registered to an individual, operating as… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.