HILLSBORO, OR, USA
N199JM
Cessna T210N
The pilot-in-command reported a power loss on approach to the runway. The aircraft passed through the tops of trees approximately 150 feet beyond, and entered a stall/spin maneuver, impacting a power line and the ground approximately 2,800 feet short of the runway threshold. The flaps and landing gear were in a retracted position. Post-crash examination revealed the crankshaft separated in fatigue which originated from a circumferential gouge mark on the aft face of the #2 cheek at an area located outboard of the forward radius of the #1 rod journal. The circumferential gouge mark on the crankcheek was consistent with the connecting rod shifting forward during engine operation. The rub marks on the cheek walls of the #1 connecting rod were consistent with tight piston pin bushing to piston pin clearance. Additionally, the bushings for all the connecting rods were undersize. Airframe/engine logs revealed a top overhaul of the engine approximately 23 hours prior to the crankshaft failure, during which the piston pins were replaced but the connecting rod bushings were not. No dimensional check of the bushings was made or required at that time. The engine was overhauled 515 hours previous to the top overhaul. The manufacturer's overhaul manual specifies that the new bushings should be reamed to the specified (inside) diameter. Post-crash examination of the engine revealed non-standard connecting rod cotter keys and light fretting between the engine case halves.
HISTORY OF FLIGHT On June 9, 1998, at 1253 Pacific daylight time, a Cessna T210N, N199JM, registered to and being flown by a private pilot, was destroyed during an uncontrolled descent into power lines and terrain following impact with trees. The pilot had just radioed that he had lost his engine and was attempting to land at the Portland-Hillsboro Airport, Hillsboro, Oregon. The pilot and passenger sustained fatal injuries. Visual meteorological conditions existed and no flight plan had been filed. The flight, which was personal in nature, was to have been operated under 14CFR91, and had departed Sun River, Oregon, earlier on the morning of the accident. According to family members, the pilot and his wife departed Sun River, Oregon, late on the morning of the accident destined for Hillsboro, Oregon, where they planned to meet friends for lunch and then drive to the Oregon coast. There was no record of a flight plan being filed nor a weather briefing being obtained for the Sun River-Hillsboro flight. The first known radio contact with the aircraft was at 1252:19, when the pilot contacted the Federal Aviation Administration's (FAA) Hillsboro air traffic control tower (ATCT) advising "about two miles north landing Hillsboro." The tower controller acknowledged and instructed the pilot to "report right downwind runway three zero." At 1252:29, the pilot radioed "we got an emergency here, we need to land immediately," and the tower controller responded six seconds later inquiring "do you want a straight in two zero?" At 1252:37, the pilot responded "that's affirmative" and the tower controller immediately advised "roger, report on final for two zero, do you need equipment?" At 1252:42, the pilot responded "no, that's uh no equipment, we'll make it." Between 1252:50 and 1253:21, the tower controller coordinated with three other aircraft in the vicinity, and at 1253:21, the controller inquired "centurion niner juliet mike, how far north are you and what's the nature of the emergency?" The pilot responded seven seconds later advising "juliet mike we lost our engine." At 1253:31, an unknown aircraft radioed Hillsboro tower reporting "tower, he's uh coming in three zero, he's in the trees (pause) south of the airport and he's overhead, I'll go check for injuries and fire, you got fire north of the (power outage occurs)." No further radio transmission were received (refer to ATTACHMENT ATC-I). The three tower controllers on duty observed the aircraft and/or the fireball from the impact slightly southeast of the Hillsboro airport (refer to ATTACHMENTS T-I, II and III). A number of ground witnesses observed the aircraft. One witness reported observing "a thin trail of smoke coming from the plane, and the landing gear was up. The plane came from the east." Another witness also reported observing the aircraft "flying low with a faint trail of light black smoke trailing" and that "the plane then hit the trees." A third witness reported that the "motor [was] running but not running strong" and that "as he made his way through the trees, he clipped a tree." A fourth witness reported that "it sounded to me that the plane's engine was under throttled or under powered." Two additional witnesses reported seeing the "single engine plane with landing gear up heading for (north) the PGE 115 KV line," and that "the plane's rt. wing clipped a tree" (refer to ATTACHMENTS W-I THROUGH W-V). PERSONNEL INFORMATION No pilot flight logs were found at the accident site. The pilot's flight time was estimated on the basis of the time indicated at his last FAA medical examination. This time was reported as 1,025 total flight hours (20 within the previous 6 months), and was recorded on the pilot's third class medical dated June 2, 1988. FAA records showed no later medical certificate for the pilot. It was not determined if the pilot had a current flight review and what date the review may have been conducted. AIRCRAFT INFORMATION FAA records showed that N199JM was registered to the pilot and his wife May 21, 1985. Subsequent to the accident, no insurance carrier for the aircraft could be identified, and the aircraft was presumed to be uninsured. The aircraft's most recent airframe and engine log were recovered from the wreckage. Although heavily fire damaged, the logbooks contained some readable information. The Teledyne Continental Motors (TCM) Gold Medallion Aircraft Engine log showed the TSIO-520R engine as being rebuilt by the manufacturer on March 25, 1988. The logbook was opened on May 4, 1988, at an aircraft tach time of 1,782.5 hours (zero engine time), and was installed on N199JM at that time (refer to ATTACHMENTS EL-I,II, and III). The aircraft's logbooks showed that on January 10, 1995, the engine was again overhauled and zero timed at a tach time of 2,880.1 hours. This major overhaul was carried out by Regal Air, Snohomish County Airport, Everett, Washington, 98204, (refer to ATTACHMENTS EL-IV and AL-I through IV). The last entry of the aircraft's engine logbook was a 100 hour inspection which was signed off on May 13, 1998, at a total tach time of 3,394.8 hours and 514.72 hours since the last major overhaul (refer to ATTACHMENTS EL-V and AL-V). Additionally, this entry showed 0.0 hours since a top overhaul and contained an entry reading "removed all cylinders and installed Cermihil exch. units." The last entry of the aircraft's airframe logbook was an annual inspection which was signed off on May 13, 1998, at a total tach time of 3,394.8 hours (refer to ATTACHMENT AL-V). An envelope containing a two page invoice from Performance Air, PO BOX 1786, Ramona, California, 92065, was found ejected from the aircraft and displaying no fire damage. This invoice, dated May 9, 1998, contained an itemization of parts and labor applied to N199JM at tach time of 3894.8 hours and included six Cermihil cylinders, six piston pins and a reference to a "top overhaul of engine" (refer to ATTACHMENT INV-I). An inspector from the FAA's San Diego Flight Standards District Office (FSDO) examined the records provided by Performance Air related to N199JM. The documents included billing for parts and labor signed off on May 10, 1998, a three page Performance Air discrepancy list, a four page Performance Air 100 hour/annual inspection form, and a two page invoice identical to the invoice ejected from the aircraft at the site (as described above). The last entry on the Discrepancy List was "Cylinder Top O/H, C/W top O/H ECI Inst. & TSIO 520 manual." The airframe & powerplant (A&P) mechanic who performed the top overhaul at Performance Air was interviewed telephonically and recalled that new piston pins did not come with the replacement cylinders. He reported that he intentionally changed the piston pins, rather than leave the old pins in place, based upon his evaluation of the condition of the old pins, which he described as being somewhat discolored with possible corrosion. He also reported that he was fairly certain he did not replace the connecting rod bushings or dimensionally check the inner diameter of the bushings. Additionally, the mechanic related that he had flown the aircraft approximately two hours during/following the top overhaul and inspection, and that the pilot/owner flew the aircraft on a test flight of about one hour following the overhaul. He also reported that the pilot took the aircraft on a round trip flight from Ramona, California, into central/northern California and return for an estimated total flight time of five hours. He also reported that the pilot flew the aircraft from Ramona into the Pacific Northwest and return for an estimated total flight time of ten hours. The remaining flights were those associated with the departure from Ramona through Winnemucca, Nevada, Sun River, Oregon, and into Hillsboro, estimated at another five hours of flight time. Based on these flight time estimates, the total engine time since the January 10, 1995, major overhaul was estimated to be 538 hours. An inspector from the FAA's Seattle FSDO determined that no records were maintained by Regal Air related to the January 10, 1995, engine overhaul for N199JM. The TCM overhaul manual for the model TSIO-520 series engine addresses connecting rod bushings under section 72-20-20 as follows: PISTON PIN BUSHING REPLACEMENT. "TCM recommends connecting rod Piston Pin Bushing to be replaced 100% at overhaul." and "Ream or bore the new bushing to the specified diameter and check alignment" (refer to ATTACHMENT OVH-I). Additionally, the TCM overhaul manual addresses connecting rod bushings under section 72-40-05 as follows: CONNECTING RODS. "Because of the close tolerances required TCM recommends using an air gage with correct size air plug and master setting ring to measure all worn bushings and locally replaced bushings." The manual continues by describing the procedures for this process (refer to ATTACHMENT OVH-II). WRECKAGE AND IMPACT INFORMATION The aircraft came to rest at a location bearing 305 degrees and approximately 2,800 feet from the threshold of runway 30 at the Hillsboro airport, Hillsboro, Oregon (refer to photograph 1 and CHART I. The latitude and longitude of the site was 45 degrees 31.72 minutes north and 122 degrees 56.22 minutes west respectively, and the elevation of the site was approximately 200 feet above mean sea level (MSL). The first evidence of impact was broken tree branches at the tops of trees approximately 150 feet east-southeast of the initial ground impact site (refer to photograph 2). The initial ground impact site was on the crest of the southern edge of a ravine (refer to photograph 3). A double set of light rail tracks oriented along an approximate 053/233 degree magnetic bearing line lay at the bottom of the ravine with power lines paralleling overhead. A second, lighter set of power lines angled off the main power lines from a location nearly overhead of the initial ground impact site and toward the southwest (refer to photograph 3). The aircraft was observed lying on the ground at its final resting place at the bottom of the -20 degree sloped ravine alongside the light rail tracks (refer to photographs 4 through 7). The aircraft was heavily fire damaged. All major portions of the aircraft were located at the final resting place. The landing gear were observed in the retracted position within the underside of the fuselage (refer to photograph 8). The right wing, which remained attached to the fuselage, was continuous from the absent tip cap inboard to the fuselage. The flap was observed to be retracted (refer to photograph 9). The right plastic tip cap was observed lying on the ground adjacent to the left cabin door near the initial ground impact site. The left wing was almost completely consumed in the post-crash fire. The left plastic tip cap was observed lying on the gravel buildup under the light rail tracks and slightly northeast of the aircraft's final resting place. The fuselage/cabin area was consumed by the post-crash fire as far aft as the leading edges of the horizontal stabilizers. The empennage remained intact but fire damaged. All control surfaces remained attached (refer to photographs 10/11) and there was no evidence of any control cable discontinuity from the cabin area outboard to the respective control surfaces. A distinct, narrow impact impression was observed diagonally across the leading edge of the vertical stabilizer approximately mid way between the top of the empennage and the top of the vertical stabilizer (refer to photograph 12). The angle measured between the axis of the impression and the aircraft's vertical axis was approximately 55 degrees (left wing down assuming the impression is in a horizontal attitude at the time it was made). The flap jackscrew was examined and found to be fully extended consistent with a "flaps fully retracted" position (refer to photograph 13). The three-bladed propeller was observed to be still attached to the engine. The two lower blades displayed extensive aftward bending deformation and were folded under the engine, while the top blade show no significant bending or chordwise scratching (refer to photograph 14). The engine, which was heavily fire damaged, was observed to have a hole in its case above the number one cylinder. A portion of the crankshaft, which was visible through the hole, was observed to be skewed approximately 45 degrees from the longitudinal axis of the engine (refer to photograph 15). MEDICAL AND PATHOLOGICAL INFORMATION Post mortem examination was conducted by Nikolas J. Hartshorne, M.D., at the facilities of the Oregon Medical Examiner's Office, 301 NE Knott Street, Portland, Oregon, 97212, on June 10, 1998. Toxicological evaluation of samples from the pilot was conducted by the FAA's Toxicology and Accident Research Laboratory, Oklahoma City, Oklahoma. The results were negative except for a finding of triamterene detected in blood and urine (refer to attached report). TESTS AND RESEARCH The engine was disassembled at the facilities of Teledyne Continental on November 13, 1998. During the engine's disassembly the following observations were noted: The crankshaft was broken at the #2 cheek in the forward fillet area of the #1 connecting rod. Circumferential grooving and wear, characteristic of rod rub, was evident in the area of the cheek wall above the forward journal fillet of the #1 connecting rod journal. The crankshaft was observed to be separated through the #2 cheek, and an approximate six inch section of the crankshaft (aft-most portion) was observed to be separated from the forward crankshaft section. Closer examination of the separation surfaces along the #2 cheek fracture surface revealed a smooth, compound, curved surface displaying fatigue striations. Several additional cheek areas just outside of the crankshaft bearing surface fillets were noted to display wear patterns consistent with the previously described circumferential grooving and wear, characteristic of rod rub. This grooving was characteristic of the crankshaft ends of the piston arms riding against the fillet areas and creating rotational scoring on some of the cheek surfaces just outboard of the fillets. Most of this scoring was observed to be on the aft cheek surfaces and one area of scoring was observed on a forward cheek surface. Additionally, crankcase parting surfaces displayed some light fretting as did the pads for the third through the sixth cylinders. The inside diameter of connecting rod bushings one and three through six were dimensionally examined and found to be less than the manufacturer's specified inside diameter. The cotter keys securing the rod bolt nuts were found to be easily bent by hand and were thinner than those specified by the manufacturer (refer to attached Teledyne Continental Motors (TCM) report). Both crankshaft sections, along with connecting rods one, three and four, one half of the aft journal bearing (the other half being destroyed), and a number of connecting rod end bolt cotter pins, were shipped by the manufacturer at the request of the Investigator-in-charge to the Safety Board's Office of Research and Engineering, Materials laboratory in Washington, DC, for further examination. Metallurgical examination of the crankshaft revealed that although the mating fractures of the crankshaft for the most part exhibited severe mechanical damage that obliterated most of the fracture features, a small area on this fracture surface contained crack arrest marks typical of fatigue cracking that emanated from a circumferential gouge mark on the aft face of the #2 cheek. The fracture surface in the vicinity of the fatigue origin area contained heavy mechanical damage, but outlines of what appeared to be ratchet marks emanated from the circumferential gouge mark. No indication of a shear lip was noted at the fatigue origin. The circumferential gouge mark was situated slightly outboard of the forward radius of the #1 rod journal and extended all around the #1 rod journal. The gouge mark measured approximately 0.1 inch deep. The crankshaft contained a bending deformation a
Improper installation (bushing), mechanical binding (bushing), mechanical binding (connecting rod), and fatigue within the crankshaft. Contributing factors were inadequate major (engine) overhaul and trees.
Source: NTSB Aviation Accident Database
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