NTSB Factual Report

HISTORY OF THE 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.

NTSB 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.