NTSB Factual Report

HISTORY OF FLIGHT

On August 14, 1993, at 1930 eastern daylight time, a Cessna 182A, N5010D, owned and operated by Skydive Long Island, Inc., of Flanders, New York, dragged the left wing on the runway during a forced landing due to a power loss. The airplane was destroyed. The pilot was fatally injured and the four passengers received serious injuries. Visual meteorological conditions prevailed and no flight plan was filed for the flight operating under 14 CFR 105.

The onboard passengers (parachutists) reported the takeoff was normal. After the airplane was airborne, one reported hearing "backfiring", another reported hearing a "bang" and "...saw white smoke...plane began to descend...knew that left wing was going to hit first...", the Jump Master David Purinton reported "...Approximately, five seconds after I turned downwind, the engine quit abruptly...Immediately after the engine failed, I remember the pilot placing his right hand on the fuel valve..which was on..the mixture was okay..and ah..and that is all I remember of that. of him doing...."

Several witnesses saw the airplane takeoff and used various terms to report an engine that was running other than normal. Some reported seeing smoke coming from the airplane. All the witnesses agreed that the airplane continued to loose altitude on downwind and then turned toward the runway. Most agreed that the airplane contacted the runway on the left wing, while one said it contacted the runway on the right wing. The witnesses agreed that the airplane contacted the nose following the wing and then came to rest next to the runway.

The accident occurred during the hours of daylight at location 40 degrees, 49 minutes, 40 seconds north and 72 degrees, 44 minutes, 55 seconds west.

AIRCRAFT INFORMATION

The airplane was a 1958 Cessna 182A. It had been modified in accordance with Supplemental Type Certificate No. SA874CE. The modification removed all seats except the pilot seat, removed the right hand control yoke, and installed floor mounted seat belts for four occupants.

WRECKAGE AND IMPACT INFORMATION

The airplane was examined at the accident site on August 15, 1993. The examination revealed ground impact marks which originated on the approach end of runway 18 and headed 225 degrees. The marks terminated at the airplane wreckage. The distance between the first marks and the airplane was 70 feet.

The wing structure was torn loose from the fuselage. The left wing had impact damage on the leading edge back to the aileron. The right wing had minor impact damage to the outboard leading edge. The wing flaps, which are cable actuated, were found with the right wing flap was fully extended, and the left wing flap partially extended. The wing flap control lever in the cockpit was in the flaps retracted position

Approximately 5 gallons of fuel was found in each fuel tank, however, due to leaking fuel lines, the actual amount in the tanks at the time of takeoff was not determined.

The cockpit cabin was crushed, however, all seat belts were still attached to the floor. There was deformation on the left front side of the cockpit including the area where the pilot was seated. The throttle, mixture control, and propeller controls were found in the full forward position.

The engine, a Continental 0-470-L, serial number 67867-7-L, was last overhauled on December 8, 1980, at Weiss Aero Service, Inc, St. Louis, Missouri. No records of the overhaul were available for examination. Engine log book records disclosed the engine had 3369.2 hours total time at the time of the accident with 547.1 hours since engine overhaul.

Examination of the engine revealed no holes through the outside of the case. Pieces of metal were found in the accessory gear section on the rear of the engine, including one which was curved and had a grove similar in appearance to a piston ring grove. Several pieces of metal were found in the engine sump. Several small pieces of metal were found in the engine oil screen. All bearing surfaces were found to be free of distress.

The skirt of the number three piston was missing. Examination of the other pistons disclosed cracks which originated in sharp corners, on the inside of the skirt, approximately 90 degrees to the wrist pin. The cracks were orientated on the longitudinal axis of the pistons. On pistons #1, #2, and #4, the cracks were visible on both the inside and outside of the skirt. On pistons #5, and #6, the cracks were found only on the inside of the skirt.

The pistons carried the part number SA626992, and casting number SA632936. Due to the disintegration of the number three piston, the casting number was not visible, however, a small piece of metal with SA632 on it was found in the engine sump.

In a letter, Mr. Larry Shimbob, Vice President Business Development for Superior Air Parts stated:

1. Superior stopped selling the SA626992 piston in 1981 because that particular piston had been superseded by a new TCM [Teledyne Continental Motors] design.

2. Upon further review, it has been determined that Superior sold 8100 SA626992 pistons instead of the 5500 that had been previously reported.

3. The SA626992 piston was produced by Gould, Inc. located in Eastlake, Ohio.

The pistons were forwarded to the NTSB Metallurgical laboratory in Washington, DC for further examination. They were examined by NTSB metallurgist, Ms. Jean Bernstein. Her report 94-23 covered the examination of the pistons.

In her report, Ms. Bernstein stated:

...The presence of sharp casting recesses on the ID [inside diameter] surface of the piston in the lower skirt area was evident in all of the P/N 626992 pistons...A magnified inspection revealed a series of elongated surface shrinkage cavities along the recess line...The crack...appeared to be stemming from the shrinkage cavity. The stringers of surface shrinkage cavities in the sharp corners of the casting recesses were observed in all examined P/N 626992 pistons....

The crack on the number 4 pistons was opened up., According to the metallurgical report:

...Examination disclosed that the propagation of the crack occurred by a fatigue mechanism.

ADDITIONAL DATA/INFORMATION

Service Difficulty reports for Continental O-470 engines between January 1, 1986, and October 6, 1993, revealed two reports for the Superior SA626992 piston. One stated, "... the skirt was cracked all the way to the third ring grove, then radially to the oil drain holes. The crack was aligned with the very sharp mold recess on the inside of the skirt...The crack was perpendicular to the wrist pin." The other report stated, "...Piston on nr [number] 2 cylinder causing engine failure. During engine teardown remaining pistons all had cracks from oil control ring to the bottom of the piston. Total time unknown, Time since overhaul 1430.00 hours."

A weight summary of the accident flight was made based upon existing weights and the 10 gallons of fuel documented in the wings after the accident. The computed weight of the airplane 2692 lbs. The maximum allowable takeoff gross weight is 2650 lbs. Due to leakage in the fuel tanks, the actual takeoff weight could not be determined.

The fuselage was released to the owner on August 15, 1993. At the request of the registered owner, the engine was released to the law firm of Kananack, Murgatroyd, Baum & Hedlund, in Los Angeles, California.

NTSB Probable Cause

ENGINE FAILURE DUE TO A FATIGUE FAILURE OF THE NO.3 PISTON. THE FATIGUE FAILURE WAS A RESULT OF INADEQUATE MANUFACTURING. IN ADDITION, THE PILOT MADE AN IMPROPER DECISION DURING THE FORCED LANDING IN ATTEMPTING TO STRETCH HIS APPROACH IN ORDER TO REACH THE RUNWAY INSTEAD OF LANDING IN TERRAIN ADJACENT TO THE APPROACH END OF THE RUNWAY. AS A RESULT, THE PILOT LOST CONTROL OF THE AIRPLANE AND IT STALLED ONTO THE RUNWAY. A FACTOR WHICH CONTRIBUTED TO THE ACCIDENT WAS THE OVERGROSS WEIGHT OF THE AIRPLANE.