# NTSB MIA94LA105: Wallace Thorp T-18, N215CK, Boynton Beach, FL, March 27, 1994 - Type: NTSB accident investigation - Classification: Accident · Fatal · Limited investigation · Final report - Date: March 27, 1994, 07:15 local (12:15 UTC) - Place: Boynton Beach, FL - Coordinates: 26.509338, -80.149665 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=26.5093&lon=-80.1497&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed, report November 18, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 37515 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA94LA105 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/37515/pdf - Page: https://openairdocs.org/ntsb/MIA94LA105 ## Probable cause THE PILOT IN COMMAND'S EXCEEDING THE DESIGNED STRESS LIMITS OF THE AIRCRAFT RESULTING IN OVERLOAD FAILURE OF THE LEFT WING OUTBOARD ATTACH FITTING. THIS RESULTED IN INFLIGHT SEPARATION OF THE OUTBOARD LEFT WING, AND SUBSEQUENT INFLIGHT COLLISION WITH THE TERRAIN DURING AN UNCONTROLLED DESCENT. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, maneuvering - design stress limits of aircraft - exceeded, pilot in command (cause) - wing,wing attachment fitting - overload - wing,wing attachment fitting - failure,total - wing - separation - In flight collision with terrain/water, descent - uncontrolled - aircraft control - not possible, pilot in command - terrain condition - water ## Analysis WITNESSES HEARD THE SOUND OF THE AIRCRAFT'S ENGINE INCREASE AND DECREASE SEVERAL TIMES. THEY THEN HEARD A 'LOUD POP' OR 'EXPLOSION' AND OBSERVED THE AIRCRAFT DESCENDING IN A SPIN WITH PART OF A WING MISSING. THE OUTBOARD LEFT WING WAS FOUND 1/4 MILE FROM THE MAIN WRECKAGE ALONG WITH THE LEFT AILERON AND DEBRIS FROM THE CANOPY AND CABIN OF THE AIRCRAFT. EXAMINATION OF THE LEFT WING INDICATED THE OUTBOARD WING SECTION SEPARATED IN A DOWNWARD DIRECTION DUE TO OVERSTRESS AT THE POINT IT ATTACHES TO THE INBOARD SECTION. ALL OTHER SEPARATIONS OF STRUCTURAL COMPONENTS AND FLIGHT CONTROL SURFACES HAD SEPARATION FEATURES TYPICAL OF OVERSTRESS. EXAMINATION OF THE ENGINE SHOWED NO EVIDENCE OF PRECRASH FAILURE OR MALFUNCTION. ## Factual narrative HISTORY OF FLIGHT On March 27, 1994, about 0715 eastern standard time, a Wallace Thorp T-18, N215CK, registered to Charles F. Kenny, crashed while maneuvering near Boynton Beach, Florida, while on a 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft was destroyed and the private-rated pilot received fatal injuries. The flight originated at Lantana, Florida, on March 27, 1994, about 0700. Witnesses reported hearing engine sounds from the aircraft which increased and decreased in power output several times. They did not visually observe the aircraft. They then heard a "loud pop" or "explosion." They looked toward the noise and observed the aircraft descending in a spin with part of a wing missing. PERSONNEL INFORMATION After the accident involving N215CK, the pilot's family was unable to locate a pilot logbook. Additional pilot information is contained in this report under Pilot Information. AIRCRAFT INFORMATION The pilot's son stated after the accident that he had custody of the maintenance records for N215CK. The son did not submit these records for examination as requested by NTSB on several occasions. Additional information on the aircraft is contained in this report under Aircraft Information. METEOROLOGICAL INFORMATION Visual meteorological conditions prevailed at the time of the accident. Additional meteorological information is contained in this report under Weather Information. WRECKAGE AND IMPACT INFORMATION The aircraft crashed in a swamp in the Loxahatchee Wildlife Refuge, near Boynton Beach, Florida. The aircraft's outboard left wing was located about 1/4 mile north of the main wreckage of the aircraft. The left aileron, debris from the canopy structure, and debris from the cabin area of the aircraft were located between the left wing and the main wreckage. All other components of the aircraft, except for the right horizontal stabilizer and elevator and the vertical stabilizer, were located on or around the main wreckage of the aircraft. The right horizontal stabilizer, right elevator, and vertical stabilizer were not located after the accident. No parachute was found in the wreckage or on the pilot. Examination of the left wing indicated the outer wing section from the point the flap and aileron meet separated downward. The complete bottom portion of main spar fitting pulled loose from were it attaches to the bottom of the outboard wing section. The top portion of the main spar fitting separated within the fitting. The fitting fracture surface was typical of overstress separation. The rear spar separated when the sheet metal tore loose between the inner and outer wing sections. There were no impact marks on the outer wing panel. The left aileron separated from the outboard left wing panel and was found near the outer left wing panel. The aileron had separated when the outboard hinge pulled loose from the wing panel and the sheet metal to which the inboard aileron hinge was attached pulled loose from the rear wing spar. The aileron control rod separated with fracture features typical of overstress. Examination of the separation points of the left and right horizontal stabilizers and the vertical stabilizer indicated fracture features typical of overstress separation. Examination of the flight control systems indicated that all separation of flight control surfaces or separations within the flight control linkages were typical of overstress separation. Examination of the engine from N215CK indicated the engine rotated normally and continuity was established within the crankshaft, camshaft, valve train, and accessory drives. Each cylinder produced normal compression and each spark plug had coloring typical of a normally operating engine. Each magneto operated normally. The carburetor float operated normally and all jets were free of obstructions. The propeller was in the low pitch or high rpm blade angle. The engine-driven fuel pump operated normally and automotive fuel was found in the carburetor and fuel pump. MEDICAL AND PATHOLOGICAL INFORMATION Post-mortem examination of the pilot was performed by Dr. Stephen J. Nelson, M.D., Associate Medical Examiner, Palm Beach County, Florida. The cause of death was attributed to multiple blunt force traumatic injuries. Post-mortem toxicology testing on specimens obtained from the pilot was performed by F. Thomas Carroll, Chief Toxicologist, Palm Beach County Sheriff's Office and by Barry Levine, PhD., Chief Forensic Toxicology Laboratory, Armed Forces Institute of Pathology, Washington, D.C. The tests were negative for ethanol, basic, acidic, and neutral drugs. For additional medical and pathological information see Supplement K and the toxicology reports attached to this report. ADDITIONAL INFORMATION The aircraft wreckage was released on March 27, 1994 to a refuge officer at the Loxahatchee Wildlife Refuge. On April 6, 1994, components retained by NTSB for examination were released to Lilian Brochard, Murphy's Towing, West Palm Beach, Florida. ## Aircraft - Registration: [N215CK](https://openairdocs.org/deregistered/N215CK-2012-10-18), registration cancelled 2012-10-18, S/N JSW310, built 1969 (OpenAirDocs) - Reported make and model: WALLACE THORP T-18 (THORP T-1) - Registry model: [Wallace Thorp T-18](https://openairdocs.org/model/wallace-thorp-t-18) (registry code 89510UT) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: JSW310 - Engines: LYCOMING O-360-F1A6 180 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Registered owner: Charles F. Kenny - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, September 13, 1993, 26 hours before - Departed: LNA, LANTANA, FL ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 69; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 2,100 total, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 17 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 70 °F - Altimeter: 29.00 inHg - Observed at: PBI, 13 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 19940327007829A](https://openairdocs.org/incident/19940327007829A), Mar 27, 1994: Amtrth THORPT18, Boynton Beach, FL, Destroyed, 1 fatal. Wing and tail surfaces separated in flight. Observed spinning to impact. Overstressed airframe. Possible aerobatics 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.