# NTSB SEA95LA186: Beech P-35, N9531Y, Bend, OR, August 18, 1995 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 18, 1995, 15:35 local (22:35 UTC) - Place: Bend, OR - Location: 44.0582° N, 121.3153° W: Placed by OpenAirDocs: center of Bend, OR, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=44.0582&lon=-121.3153&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 18, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 42225 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA95LA186 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42225/pdf - Page: https://openairdocs.org/ntsb/SEA95LA186 ## Probable cause seizure of the #4 connecting rod bearing due to overtemperature resulting in the separation of the connecting rod and total loss of engine power. A factor contributing to the accident was the lack of suitable terrain for a forced landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, cruise - normal - engine assembly,bearing - overtemperature (cause) - engine assembly,bearing - seized (cause) - engine assembly,connecting rod - separation (cause) - Ditching, emergency landing - terrain condition - none suitable (contributing factor) - terrain condition - water ## Analysis While in cruise flight, the pilot noticed a loss of oil pressure which was followed by a total loss of engine power. He elected to ditch the airplane in a lake as no other suitable forced landing site was available. An examination of the engine revealed the that the #4 connecting rod had separated from the crankshaft at the end cap. The rod end cap bolts had separated from the cap, and exhibited evidence of necking and heat distress. The #4 rod journal also exhibited evidence of heat distress. The bearings associated with the #4 rod journal were destroyed. All other rod journals and all of the main bearing journals did not exhibit evidence of heat distress or lack of lubrication. ## Factual narrative On August 18, 1995, at 1535 Pacific daylight time, N9531Y, a Beech P-35, operated by the owner/pilot, ditched in Lava Lake near Bend, Oregon, and was substantially damaged. The ditching was precipitated by a total loss of engine power during cruise flight. The commercial pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed and no flight plan had been filed. The business flight departed from North Bend, Oregon, and was destined for Alfalfa, Oregon. The flight was conducted under 14 CFR 91. The pilot stated that he was in cruise flight at 7,500 feet above mean sea level for about 45 minutes when he noticed a loss of oil pressure and an increase in oil temperature. Shortly thereafter, he noticed oil on the engine cowling and a "funny" noise. The engine immediately lost all power and the pilot initiated a forced landing. The pilot stated that there was no suitable terrain for a safe landing beneath him, so he elected to ditch the airplane in a lake. According to an FAA aviation safety inspector from Reno, Nevada, who was also a witness to the accident, the airplane circled the lake during the emergency descent. The flaps were fully extended and the landing gear was retracted as the airplane approached the lake. The airplane was observed to land tail first and come to a stop in the water with its nose down. The pilot exited the airplane. About two minutes later, the airplane sank in about 30 feet of water. After the airplane was recovered, the FAA inspector performed a cursory external examination. He reported that the engine had a hole in the crankcase above the number 4 cylinder. He also reported that the airplane was substantially damaged due to the impact with the water. Structure in the vicinity of the leading edge of the left wing root was deformed. The engine, a Continental IO-470-LCN, was removed from the airframe for investigative purposes. The engine was subsequently disassembled and inspected by the Safety Board on January 18, 1996, in Mobile, Alabama. The no. 4 connecting rod was found separated from the crankshaft at the end cap. The rod end cap bolts had separated from the cap and exhibited evidence of necking and heat distress. The crankshaft was intact. The no. 4 rod journal exhibited evidence of heat distress; the no. 3 rod journal did not. These two journals share the same oil gallery. All other crankshaft oil passages were also verified open and unrestricted. The bearings associated with the no. 4 rod journal were destroyed. All other rod journals and all of the main bearing journals did not exhibit evidence of heat distress or lack of lubrication. About 1.5 quarts of oil were found in the oil sump, along with shavings of bearing material. The oil screen and oil pump did not exhibit evidence of malfunction or blockage. All six piston faces did not exhibit evidence of preigintion or detonation. An examination of excerpts from the engine log books revealed that the engine had undergone an 100-hour inspection 16 months prior to the accident. The engine accumulated 20 operating hours since the inspection. Entries in the log books also indicated a total engine time of 2,328 operating hours, and 925 hours since its last major overhaul. No unresolved discrepancies were noted in the most recent entries in the log books. The pilot reported that he had never noticed any engine abnormalities prior to the accident. ## Aircraft - Registration: [N9531Y](https://openairdocs.org/aircraft/N9531Y), registered now, S/N D-7020 (OpenAirDocs) - Reported make and model: BEECH P-35 - Registry model: [Beech P35](https://openairdocs.org/model/beech-p35) (registry code 1151530) (OpenAirDocs) - Registry engine: [Continental I0-470 series](https://openairdocs.org/engine/continental-i0-470-series) (registry code 17027, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: D7020 - Airframe hours: 4610 - Engines: CONTINENTAL IO-470-LCN 260 horsepower reciprocating - Damage: Substantial damage - Flight: Business, Part 91 - Registered owner: Young, D. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 4, 1994, 20 hours before - Departed: OTH, NORTH BEND, OR - Destination: 50OR, ALFALFA, OR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 72; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 4,800 total, 1,500 in this make and model, 6 in the last 90 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 300° at 5 knots - Visibility: 50 statute miles - Lowest ceiling: none - Temperature: 75 °F ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19950818047779A](https://openairdocs.org/incident/19950818047779A), Aug 18, 1995: Beech P35BEECH, Bend, OR, Substantial damage. Lost power at cruise. Ditched in a lake. Thru a rod into engine case. Rod cap bolts broke. Only 20HRS since 100HR. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.