Aviation Accident Summaries

Aviation Accident Summary SEA94FA154

PORT ANGELES, WA, USA

Aircraft #1

N8025B

CESSNA 172

Analysis

THE STUDENT PILOT REPORTED THAT DURING A CROSS COUNTRY FLIGHT, THE ENGINE LOST POWER AND THAT THERE WAS AN INDICATION OF A LOSS OF OIL PRESSURE. DURING THE FORCED LANDING, THE AIRPLANE COLLIDED WITH ROUGH TERRAIN. DURING AN ENGINE INSPECTION, IT WAS FOUND THAT THE NUMBER SIX CONNECTING ROD BROKE DUE TO AN UNDETERMINED OIL EXHAUSTION/STARVATION OCCURRENCE.

Factual Information

HISTORY OF FLIGHT On June 21, 1994, at 1555 Pacific daylight time, a Cessna 172, N8025B, experienced a loss of engine power while in cruise flight. The student pilot initiated a forced landing to an open clear cut area, nine miles west of Port Angeles, Washington. During the landing roll, the airplane collided with the terrain. Visual meteorological conditions prevailed at the time and a visual flight rules flight plan was filed. The airplane was destroyed by fire, and the student pilot was fatally injured. The flight had departed from Port Angeles on June 21, 1994 at 1444, and was en route to Hoquiam, Washington. The Flight Service Station recorded tape indicates that the pilot reported that he was returning to Port Angeles because of deteriorating weather along the coast line. While en route back to Port Angeles, the pilot reported that the engine quit and that there was an indication of a loss of oil pressure. The pilot reported his position and that he was looking for a landing spot. The airplane landed in a clear cut area that was covered with fallen trees, stumps and new growth trees. PERSONNEL INFORMATION It was reported that the student pilot purchased this airplane in October 1993. A flight instructor at the Pierce County Airport, who signed the pilot off for the cross country flight, stated that the pilot was not on any flight instruction program but came into the facility now and then. The flight instructor did not recall the pilot's total flight time or the last time the pilot flew. The Federal Aviation Administration Medical records reported that the pilot indicated that he had accumulated a total flight time of 21 hours on his medical certificate dated January 7, 1993. AIRCRAFT INFORMATION The mechanic who last worked on the airplane stated that an annual inspection was completed on June 1, 1994. At this time, the airplane had accumulated a total time of 3,479 hours. The engine total time is unknown, and it is unknown as to how many hours the airplane flew since the annual inspection. COMMUNICATIONS At 0715, the pilot called Seattle Flight Service Station (FSS) for an abbreviated weather briefing for the coast from Hoquiam, Washington, to Port Angeles, with a departure from the Pierce County Airport. Due to low ceilings and possible Instrument Flight Rules (IFR) conditions, the specialist did not recommend Visual Flight Rules (VFR) flight. The pilot then requested the weather from Pierce County to Bellingham, Washington. The specialist reported IFR conditions along the route of flight for the morning hours, but the fog would be burning off by early afternoon. The pilot then concluded the conversation at 0722. At 0906, the pilot again contacted Seattle FSS for the weather between Pierce County and Hoquiam. The specialist reported IFR conditions and asked the pilot if he had an alternate route. The pilot then requested the weather for Bellingham to Port Angeles, returning to Pierce County. The specialist reported the inland route was VFR. The coastal area west of Port Angeles was still under a fog bank and low ceiling. The pilot concluded the conversation at 0914. At 1023, the pilot contacted Seattle FSS to file a VFR flight plan from Pierce County to Arlington, Washington, with a departure time at 1130 and an arrival time at Arlington at 1220. The pilot reported five and-a-half hours fuel on board at the time. The pilot then filed a flight plan to depart from Arlington at 1240 direct to Bellingham to do a touch and go at around 1310. From Bellingham, the flight was to continue to Port Angeles to arrive at approximately 1400. The conversation concluded at 1028. At 1155, the pilot activated the VFR flight plan to Arlington. At 1229, the pilot contacted Seattle FSS to close the VFR flight plan to Arlington. The specialist reported that the closure of the flight plan was overdue. At 1419, the pilot requested the weather from Port Angeles, to Neah Bay, Washington, to Quillayute, Washington, and Hoquiam. The inland route was reported as VFR. Along the coastal area it was reported at 2,000 feet scattered or broken with 40 miles visibility. The specialist reported good weather conditions at the current time, but the weather would be deteriorating later that afternoon. The pilot then filed a VFR flight plan from Port Angeles departing at 1430, to Neah Bay and Hoquiam. The time en route was reported to be one hour and fifty two minutes. The fuel on board at departure time was three and-a-half hours. The conversation continued to resolve a problem the pilot had in closing his flight plan at Arlington, that resulted in an overdue report. It was also noted that the pilot had used an incorrect frequency to activate the flight plan from Arlington to Port Angeles. That flight plan was never activated. The pilot then confirmed the radio frequencies to Hoquiam. The conversation concluded at 1425. At 1444, the pilot activated his VFR flight plan to Hoquiam. At 1523, the pilot contacted Seattle FSS in flight. After several tries due to unreadable transmissions from the pilot, the specialist eventually determined that the pilot was reporting IFR conditions on the coast at Neah Bay and that he was returning to Port Angeles. The flight plan to Hoquiam was cancelled at 1532 to reflect the diversion. At 1548, the pilot contacted Seattle FSS and reported that his engine quit near Crescent Lake. The pilot reported seeing a highway and a dirt road that he was going to use for an emergency landing. At 1550, the pilot reported that he believed that he "lost oil pressure." There were no further transmissions from the pilot. WRECKAGE AND IMPACT INFORMATION The wreckage was located in an open clear-cut area on level terrain. The ground consisted of low brush and large sized tree stumps and logs that were hidden by the overgrown brush. A dirt road paralleled the wreckage distribution path approximately 200 feet to the north. The brush and logs immediately surrounding the wreckage was burned as well as the wreckage itself. The initial ground impact was located at the base of a large tree stump. The nose landing gear had separated at this stump and impact damage to the stump itself was noted. The wreckage distribution path was magnetically measured at 110 degrees from this point to the main wreckage. Approximately 75 feet from the stump, a ground disturbance and damage to another stump was noted. Approximately 25 feet further into the path, the main wreckage was located. The fuselage, engine and both wings were found among several logs. The entire fuselage and inboard sections of the wings had been completely consumed by fire. The outboard sections of the wings remained intact. A small portion of the rudder and one elevator remained of the empennage. Sections of control cables were located, however, debris melted around the cable made it impossible to establish complete control cable continuity. The engine was found separated from the main fuselage and was laying inverted near the logs. The outboard section of one propeller blade had separated at mid span and was found near the engine. The other blade was intact. Both blades remained relatively straight. The oil pan was burned out and exposed the crankshaft and connecting rods. The accessory section was completely destroyed by the fire. The engine was turned over and revealed a hole in the top of the crankcase above the number six connecting rod. Further inspection revealed that the number six connecting rod was broken. A section of the connecting rod cap was found loose inside the case. MEDICAL AND PATHOLOGICAL INFORMATION There were no samples available for toxicological analysis. TESTS AND RESEARCH The engine was completely torn down and inspected on October 19, 1994, at Teledyne Continental Motors, Mobile, Alabama. During the inspection, it was noted that the crankcase was broken above the number five and six cylinders. The number six connecting rod was detached from the crankshaft. The remainder of the connecting rod remained attached to the piston inside the cylinder. The number six connecting rod crankshaft journal was partially melted. The rod bolt was broken. The fractured section exhibited necking down where it was broken. There was no evidence of oil throughout the interior of the engine. All main engine bearings were dry from the fire and the babbitt overlays were melted. The connecting rod bearing babbitt overlays were also melted. Number four and five connecting rod bearings indicated some wiping signatures. All crankshaft journals were discolored from the post impact heat. The number six connecting rod journal was partially melted. All oil galleries that feed the number six connecting rod were checked for blockage. All were clear and unobstructed. The remainder of the interior components were inspected and exhibited normal operating signatures. ADDITIONAL INFORMATION The wreckage was retrieved by Air Metal Fabricators, Arlington, Washington, on June 23, 1994. At the completion of the engine teardown on October 19, 1994, the engine was released to be returned to Air Metal Fabrications. The wreckage was released to the owner's representative on October 21, 1994.

Probable Cause and Findings

LACK OF OIL AND CONNECTING ROD FAILURE. A FACTOR TO THE ACCIDENT WAS ROUGH/UNEVEN TERRAIN.

 

Source: NTSB Aviation Accident Database

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