Accident Overview
On October 2, 2022, about 2000 Pacific standard time, a Cessna 182C airplane, registration N511W, was substantially damaged after ditching in Lake Mead near Boulder City, Nevada. The pilot and pilot-rated passenger were not injured. The flight was operated as a personal flight under Title 14 Code of Federal Regulations Part 91.
Flight History
The cross-country flight originated in Amarillo, Texas, with refueling stops in Santa Fe, New Mexico, and Grand Canyon National Park Airport (GCN), Grand Canyon, Arizona. After verifying oil and fuel quantity at GCN, the pilot departed for Las Vegas, Nevada, climbing to 11,000 ft mean sea level (msl) and intercepting an instrument flight rules clearance. About 30 minutes into the flight, the pilot declared an emergency with air traffic control (ATC) after observing a decline in engine oil pressure.
During descent to 7,000 ft msl, oil pressure dropped to 0 psi. The pilot diverted toward Boulder City, about 10 minutes away at their 11 o'clock position. Shortly after, engine speed became erratic, described as a pop and bang, followed by cabin smoke and a total loss of engine power, with the propeller stopping. The pilot queried ATC about nearby roads for an emergency landing and was advised they were above Lake Mead. They circled the lake under moonlight while reviewing the emergency checklist for a lake ditching.
Ditching and Rescue
The airplane touched down on the water, nosed over, came to rest inverted, and sank. The pilot and passenger exited the airplane and swam about 200 yards to shore. Law enforcement personnel located and rescued them a few hours later.
Engine Examination
Post-accident examination of the engine revealed a large hole (about 3-4 inches wide) in the upper side of the crankcase halves between cylinders No. 3 and 4. The number 4 connecting rod was not recovered. Discoloration of cylinder and bearing surfaces was consistent with high heat due to oil starvation. The engine was void of oil. No preimpact mechanical anomalies were found.
The oil filter adapter fiber gasket was torn, deformed, stretched, and protruded beyond the adapter flange edge. The safety wire securing the spool and sleeve remained attached. The oil pump could be moved by hand; no contaminant blockages were found in oil scavenge screens or filters.
Maintenance History
According to maintenance records, the engine was overhauled as a rebuild on October 30, 2010. No historical anomalies were noted after overhaul. No record was found of the fiber gasket being replaced on the oil filter adapter or inspected in compliance with Stratus Tool Technologies Mandatory Service Bulletin SB-001.
Related Actions
The National Transportation Safety Board (NTSB) investigated other oil filter adapter gasket failures. On December 3, 2020, the NTSB recommended the Federal Aviation Administration (FAA) issue an Airworthiness Directive (AD) addressing unsafe conditions with F&M Enterprises Inc. or Stratus Tool Technologies oil filter adapters. On February 22, 2022, the FAA published AD 2022-04-04, requiring replacement of the fiber gasket with a copper gasket, prohibiting future use of the fiber gasket, and mandating compliance with Stratus Mandatory SB-001 Rev B.