BLOOMINGTON, IN, USA
N6FN
Beech BE-35V
The airplane impacted a wooded area during a forced landing following a total loss of engine power. Examination of the engine revealed sealant was used on the cylinder bases and the cylinder base O-rings of the Teledyne Continental Motors (TCM) engine. A step was present at one of the thru bolt parting surfaces located at the cylinder base. The TCM overhaul manual, service bulletin and service letter do not specify the use of sealant on cylinder bases and cylinder base O-rings. Engine logbook records indicated that Blue Ash Aircraft Services performed a major overhaul of the Teledyne Continental IO-520-BA engine, serial number 249748-R, on March 24, 1998 at a tachometer time of 2,930.0 hours. Engine logbook records also indicated that a 100-hour inspection of the airplane was performed by the same maintenance facility on November 2, 1999 at a tachometer time of 3,668 hours. The tachometer at the accident site indicated 3,766.02 hours. The engine accumulated a total time since major overhaul of 836 hours.
On February 27, 2000, at 1045 central standard time, a Beech 35V, N6FN, operated by the Flying Neutrons, Incorporated, was destroyed on impact with trees and terrain during a forced landing into a field located approximately 9.5 miles east of Bloomington, Indiana. There was a total loss of engine power during cruise flight. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was operating on an instrument flight rules flight plan (IFR). The commercial pilot sustained minor injuries and the passenger sustained serious injuries. The flight departed from Blue Ash, Kentucky, at 1040, en route to the Monroe County Airport, Bloomington, Indiana. In a written statement the pilot reported the following, "On February 27, 2000 at approximately 14:15Z, I received at my home a standard briefing from and filed two IFR flight plans with Dayton Flight Service, Dayton, Ohio for a 15:30 departure from ISZ, Cincinnati-Blue Ash to BMG, Bloomington, Indiana (calculated GTE/Duats flight time of 54 minutes), and for the return trip. Weight and balance had been reviewed prior to arrival at the airport and was within limits. After arriving at the airport, I noted any current problem items in the Nuetron's squawk book for that airplane. Problems noted were the autopilot working in heading mode only and required check for one fuel tank cap for secure fit after fueling. We loaded baggage and I preflighted N6FN for standard items, including but not limited to visual full fuel check of each wing tank and fuel cap operation, wing drains and sump for contamination/proper fuel, flight controls, lights, pitot static ports and pitot heat and Bonanza specific landing gear items. I checked oil which showed 10 quarts and added 1 quart." "After starting the airplane, standard engine/systems checks revealed no abnormalities or problems. Run-up revealed no abnormalities or problems with engine, mags, or prop, nor was there a problem with flight controls, instruments, radios or GPS." "I was cleared as filed and released by CVG Clearance/Delivery at approximately 15:40Z and we departed ISZ, Cincinnati-Blue Ash Runway 24 immediately. I was cleared to my filed altitude of 4,000 and was in a broken cloud layer shortly after departure vectoring and then somewhat later I was cleared Direct BMG." "At about 16:35Z, there suddenly appeared in the cockpit a thin haze and a smell not unlike that which comes from an electrical short, along with a burning irritation of the eyes. About 10 seconds later the engine began running rough for about 15 seconds with a substantial loss of power, even having moved mixture to full rich, followed by a complete stop. The prop was not windmilling but completely stopped. The GPS distance to BMG showed about 13+ miles, as I recall. I immediately switched fuel tanks, throttle and prop full forward and tried for a restart without success. I switched tanks again, giving some boost pump and tried for another restrart. I did get what seemed like some wind up from the engine but no restrart. I located a somewhat short but the only nearby possible crash landing site which was a clearing at what appeared to be about 3 miles and started the turn attempting to maintain best glide speed. I checked circuit breakers with none feeling tripped. I called Indianapolis Center and declared an emergency/engine out. I received a brief acknowledgment with heading and distance to BMG but then lost all electrical power, as all the nav/comm equipment and GPS equipment went off." "As I approached the tree line short of the clearing, a gliding impact with the trees became certain. I went to landing flare just prior to impacting the treetops. After forward motion stopped, the plane inverted during the approximately twenty-five foot fall to the ground. Aviation fuel from ruptured tanks was spilling into the cockpit when we came to rest. I immediately checked for all switches off which were difficult to find because of my disorientation and the plane wreckage. I pushed open the main door and dragged my wife clear of the airplane and then examined my wife's condition which seemed not to be critical. Shortly thereafter, a woman, who apparently lives nearby, appeared at the crash site and advised emergency personnel had been notified and were on the way." The pilot also stated, "Flying Neutron's Regulations require an annual checkout with a flight instructor for any aircraft to be flown by a club member. Flying time in the Bonanza is required every ninety days or a flight instructor checkout is required before flying the airplane". On-scene inspection of the engine by the Federal Aviation Administration (FAA) revealed that there was a 3-inch diameter hole in the right side crank case adjacent to the number 3 cylinder crankshaft connecting rod journal with no connecting rod attached. Examination of the engine at Teledyne Continental Motors, under the supervision of the National Transportation Safety Board, revealed that a silicon sealant was present on the cylinder bases and on the cylinder base O-rings. A "step" was present on one of the cylinder base parting surfaces located at the thru bolt. The crankshaft was fractured at the number 2 main bearing and at the number 3 main journal. Photos of the examination are included in this report. Service Bulletin SB96-7B, addresses torque values for fasteners utilized on all Teledyne Continental Motors (TCM) engines. SB96-7B includes a warning, which states, "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 damage or failure". SB96-7B also cautions under cylinder torque procedures, "Failure to torque through bolt nuts on both sides of the engine can result in a loss of main bearing crush, main bearing shift and engine failure". Service Information Letter SIL99-2, addresses the current listing of sealants, lubricants, and adhesives authorized by TCM. SIL99-2 does not mention the use of any sealant on cylinder bases or cylinder base O-rings. Engine logbook records indicate that a major overhaul of the Teledyne Continental IO-520-BA, serial number 249748-R, engine was performed by Blue Ash Aircraft Services on March 24, 1998 at a tachometer time of 2,930.0 hours. Engine logbook records also indicate that a 100-hour inspection of the airplane was performed by the same maintenance facility on November 2, 1999 at a tachometer time of 3,668 hours. The tachometer at the accident site indicated 3,766.02 hours. The owner of Blue Ash Aircraft Services reported the following, "...My procedures for overhauling and assy. Of Cont. IO-520 BA6B S/N 249748R engine. Owner: Flying Neutrons, Inc. These procedures are per Teledyne Continental Overhaul Manual: IO-520 engines: section assembly of subassemblies and final assembly sections - these sections are followed page by page - par. by par. letter by letter, - figure by figure...". The FAA and TCM were parties to the investigation.
the improper major overhaul of the engine by company maintenance personnel. The tree was a contributing factor.
Source: NTSB Aviation Accident Database
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