Aviation Accident Summaries

Aviation Accident Summary LAX00LA202

BOULDER CITY, NV, USA

Aircraft #1

N9591Y

Beech 35-B33

Analysis

The airplane collided with a berm during a forced landing following a catastrophic engine failure as the airplane descended toward the destination airport. The pilot reported that the flight was uneventful until they were preparing to start a descent over Lake Mead. Suddenly a loud 'pop or clunk' noise came from the engine compartment and the engine began to vibrate and run roughly, then quit altogether. This was accompanied by a large amount of smoke. The pilot setup for a landing on a paved model airplane field and landed successfully; however, he could not stop the airplane prior to colliding with a berm and collapsing the landing gear. Following recovery of the aircraft, the engine was examined by an FAA airworthiness inspector. A large hole was observed in the upper left rear engine case in the area of the Nos. 1 and 2 connecting rods. The No. 2 connecting rod had separated from the crankshaft with the journal end severely peened and damaged. The rod end was protruding from the hole in the case. The No. 2 bearing insert was destroyed, with heat discoloration noted on the journal saddle. The corresponding portion of the crankshaft was also heat discolored and scored. The inspector observed that the oil pressure line from the engine to the Hobbs meter pressure switch was broken at the switch's fitting. Oil was noted covering the engine compartment area around the broken fitting.

Factual Information

On May 20, 2000, at 1849 hours Pacific daylight time, a Beech 35-B33, N9591Y, collided with a berm during a forced landing near Boulder City, Nevada. The forced landing was precipitated by a catastrophic engine failure during cruise. The aircraft was operated by Glendale Aviation of Glendale, Arizona, and rented by the pilot for a personal cross-country flight. The airplane sustained substantial damage. The private pilot and the two passengers on board were not injured. Visual meteorological conditions prevailed and a VFR flight plan was filed. The flight originated from the Glendale airport at 1650 as a nonstop cross-country flight to Las Vegas, Nevada. In written statements and a telephone interview, the pilot and the right seat passenger, who also holds a private pilot certificate, reported that the flight was uneventful until they were preparing to start a descent over Lake Mead. Suddenly a loud "pop or clunk" noise came from the engine compartment and the engine began to vibrate and run roughly. This was accompanied by a large amount of smoke. Las Vegas TRACON had been providing radar vectors for sequencing into the Las Vegas McCarran airport and gave the pilot a vector toward the lowest and flattest terrain. During this time the engine quit altogether. The pilot set up for a landing on a paved model airplane field on the shore of Lake Mead and landed successfully; however, could not stop prior to colliding with a berm and collapsing the landing gear. Following recovery of the aircraft, the engine was examined by a Federal Aviation Administration airworthiness inspector. A large hole was observed in the upper left rear engine case in the area of the Nos. 1 and 2 connecting rods. The No. 2 connecting rod had separated from the crankshaft with the journal end severely peened and damaged. The rod end was protruding from the hole in the case. The No. 2 bearing insert was destroyed, with heat discoloration noted on the journal saddle. The corresponding portion of the crankshaft was also heat discolored and scored. During the initial assessment of the engine prior to removal from the airframe for disassembly, the inspector observed that the oil pressure line from the engine to the Hobbs meter pressure switch was broken at the switch's fitting. Oil was noted covering the engine compartment area around the broken fitting. The oil line was supported by Adel clamps. According to the inspector, the fracture surfaces were shiny and granular. According to the maintenance records, the engine had accumulated 481 hours since major overhaul. The fractured line was estimated to have about 1,500 hours of operation.

Probable Cause and Findings

The fracture and separation of the oil pressure line fitting, which resulted in a loss of oil and an oil starvation failure of the engine.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports