Delaware City, DE, USA
N6432X
Beech V35B
The airplane was in cruise flight at 4000 feet msl, at night, when the pilot reported a partial loss of engine power. Air traffic control provided a vector to the nearest airport, about 8 miles north of the airplane's position. About 7 miles from the airport, at an altitude of approximately 1,000 feet, the pilot reported that he was not going to reach the airport. The airplane subsequently impacted terrain about 6 miles from the airport. Examination of the wreckage revealed an approximate 4-inch diameter hole on the top section of the crankcase, near the number two cylinder. Further examination of the engine at the manufacturer's facility revealed that a silicone sealant consistent with RTV was observed along mating surfaces where the cylinders attached to the case. The substance was also found on the through-bolts. The number two cylinder was found backed-off from the case. The engine case exhibited marks consistent with rubbing between the number two cylinder and the case. The number two piston ring had shattered. The number two piston skirt exhibited impact marks consistent with the skirt striking the case. The number two connecting rod exhibited elongated holes, consistent with an overstress failure, and the rod cap was not recovered. The top of the case exhibited two holes in the vicinity of the magnetos. A mechanic stated that he completed a top overhaul of the airplane engine about 3 months prior to the accident. The overhaul included the installation of six new cylinders. The mechanic reported that he added Permatex RTV (part number 27B) to the cylinder bases during engine assembly. The mechanic further stated that he had referred the manufacturer's service information letter regarding sealants, but it did not list RTV either pro or con. The mechanic stated that he did not refer to the manufacturer's service bulletin SB96-7B. That bulletin stated that the use of sealants or lubricants other than those specified by the manufacturer on mating threads and between mating surfaces can cause incorrect torque application and subsequent engine damage or failure.
HISTORY OF FLIGHT On January 26, 2003, at 1736 eastern standard time, a Beech V35B, N6432X, was substantially damaged during a forced landing to Pea Patch Island, near Delaware City, Delaware; following a total loss of engine power during cruise flight. The certificated private pilot and passenger sustained fatal injuries. Night visual meteorological conditions prevailed at the time of the accident, for the flight that departed Wings Field (LOM), Philadelphia, Pennsylvania, destined for Columbia Metropolitan Airport (CAE), Columbia, South Carolina. An instrument flight rules (IFR) flight plan was filed for the personal flight conducted under 14 CFR Part 91. Review of Federal Aviation Administration (FAA) air traffic control (ATC) data revealed that the flight departed about 1710. At 1712, the pilot contacted Philadelphia Departure Control and advised he had an IFR flight plan on file. The controller acknowledged the transmission and provided the pilot a clearance, which included a climb to an altitude of 4,000 feet msl. At 1717, the pilot reported that he had reached 4,000 feet. At 1730, the pilot declared an emergency, and stated that he was experiencing a terrible vibration, possibly an engine or propeller problem. The ATC controller suggested the pilot divert to New Castle County Airport (ILG), Wilmington, Delaware, which was 8 miles behind the airplane. The pilot agreed, and the controller provided a vector to the airport. At 1731, the pilot reported that the airplane lost engine power. The controller stated that ILG was at the pilot's "eleven o'clock" position and 7 miles away. At 1732, the pilot stated that he did not think the airplane would reach ILG. The controller then advised of an alternate airport 7 miles west. The pilot reported that the airplane had some engine power and asked for a recommendation. The controller replied that ILG was the closest airport at a "twelve thirty" position and 7 miles away. At 1734, the pilot reported that he was at 1,000 feet and descending, and not going to reach ILG. The controller replied that emergency equipment would be notified to respond to the landing area. About 1 minute later, the controller reported that radar contact was lost. The airplane impacted a wooded area about 6 miles south of ILG. The accident occurred during the hours of darkness; located about 39 degrees, 35.74 minutes north latitude, and 75 degrees, 34.47 minutes west longitude. PERSONNEL INFORMATION The pilot held a private pilot certificate, with ratings for single engine land and instrument airplane. His most recent FAA third class medical certificate was issued on January 10, 2003. At that time, the pilot reported a total flight experience of 2,960 hours. The pilot's logbook was not recovered. AIRCRAFT INFORMATION The aircraft logbooks sustained fire damage, and were partially legible. According to a mechanic that worked on the airplane, the most recent annual inspection was performed on March 1, 2002. The mechanic estimated that the airplane had flown approximately 200 hours from the time of the annual inspection, until the accident. The airplane was equipped with a Continental IO-520 engine. During November 2002, the mechanic completed a top overhaul of the engine, which included the installation of six new cylinders. METEOROLOGICAL INFORMATION The reported weather at ILG, at 1751, was: wind from 290 degrees at 11 knots; visibility 7 miles with light snow; a scattered cloud layer at 2,300 feet, a broken cloud layer at 4,900 feet, and an overcast cloud layer at 6,000 feet; temperature 34 degrees F, dew point 25 degrees F; altimeter 30.04 inches Hg. The pilot telephoned the Anderson, South Carolina flight service station (FSS) about 1540 on January 26, 2003. He received a standard weather briefing for an IFR flight from LOM to CAE, with a proposed departure time of 1640. The briefing including an Airman's Meteorological Information (AIRMET) for occasional moderate rime or mixed icing in clouds and precipitation below 14,000 feet, from the departure airport to the Virginia-North Carolina border. The pilot was also advised of an AIRMET for IFR conditions from the departure airport to the Maryland-Virginia border. The IFR conditions included ceilings less than 1,000 feet, and visibility less than 3 miles with fog, mist, and snow shower activity. The pilot telephoned the Williamsport, Pennsylvania FSS about 1655. He filed an IFR flight plan from LOM to CAE, with a proposed departure time of 5 minutes after his telephone call. He requested an initial altitude of 3,500 feet to stay under the cloudbank, and then a cruising altitude of 4,000. The pilot noted that the flight would be 3 hours and 15 minutes with 5 hours and 10 minutes of fuel on board. WRECKAGE AND IMPACT INFORMATION The wreckage was located in a wooded area, on the northeast side of Pea Patch Island, about 6 miles south of ILG. The cockpit, cabin, and left wing were destroyed by fire, but all major components of the airplane were accounted for at the scene. The wreckage was oriented about a 210-degree heading, and situated about 15 from a tree that sustained several impact marks. Flight control continuity was established from the right aileron to the cockpit area, and from the ruddervator to the rear cabin area. Ruddervator trim control continuity was established from the tabs to the control arm at the aft fuselage section. Due to fire damage, continuity could not be established for the left aileron. The right wing remained intact, exhibited fire damage, and sustained impact damage to the leading edge. The right aileron was deflected upward, and the right flap was found near the retracted position. The right main landing gear was also found near the retracted position. The empennage remained intact, and sustained minor impact and fire damage. Two propeller blades were bent aft, and one remained straight. No s-bending or chordwise scratches were noted on the blades, and the spinner did not exhibit any rotational damage. The cowling was removed from the engine for inspection. The left rear cylinder (number two) was found partially separated from the crankcase. Additionally, an approximate 4-inch diameter hole was found on the top section of the crankcase, near the number two cylinder. The engine was retained for further examination. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the pilot by the Office of the Chief Medical Examiner, Wilmington, Delaware. Toxicological testing was conducted on the pilot at the FAA Toxicology Accident Research Laboratory, Oklahoma City, Oklahoma. TESTS AND RESEARCH The engine was examined at the manufacturer's facility on February 25 and 26, 2003. The magnetos had separated from their respective mounts in the vicinity of the number one and number two cylinders, but they remained attached to the ignition leads. The magnetos, fuel pump, vacuum pump, Freon pump, starter, and spark plugs were removed from the engine. Approximately 3-4 quarts of oil was drained from the engine. The cylinders were removed from the engine, and a silicone sealant consistent with RTV was observed along mating surfaces where the cylinders attached to the case. Additionally, the substance was on the through-bolts. The number two cylinder was found backed-off from the case. The engine case exhibited marks consistent with rubbing between the number two cylinder and the case. The number two piston ring had shattered. The number two piston skirt exhibited impact marks consistent with the skirt striking the case. The number two connecting rod exhibited elongated holes, consistent with an overstress failure, and the rod cap was not recovered. Additionally, the top of the case exhibited two holes in the vicinity of the magnetos. A through-bolt was recovered from the number two cylinder. Both ends of the through-bolt had separated from the bolt, and the respective nuts were still attached to the separated ends. Examination of the fracture surfaces of both ends revealed beach marks consistent with cycle fatigue. Teledyne Continental Motors (TCM) Service Information Letter (SIL)99-2A related to current authorized sealants, lubricants, and adhesives. The SIL did not list RTV as an approved sealant on the mating surfaces of the crankcase halves or cylinders to crankcase. Additionally, review of TCM Service Bulletin (SB)96-7B, which related to torque values for fasteners on all TCM engines, stated: "WARNING THE USE OF SEALANTS OR LUBRICANTS OTHER THAN THOSE SPECIFIED BY TCM ON MATING THREADS AND BETWEEN MATING SURFACES CAN CAUSE INCORRECT TORQUE APPLICATION AND SUBSEQUENT ENGINE DAMAGE OR FAILURE." In a written statement, the mechanic reported that he added Permatex RTV (part number 27B) to the cylinder bases during engine assembly. The mechanic further stated that he had referred to SIL 99-2A, but, "RTV is not mentioned either pro or con." During a telephone interview, the mechanic stated that he had not referred to SB96-7B. ADDITIONAL INFORMATION The wreckage was released to a representative of the owner's insurance company on January 27, 2003.
The mechanic's improper engine overhaul. A factor was the night condition.
Source: NTSB Aviation Accident Database
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