Accident Overview
On April 18, 2016, at approximately 1805 Pacific daylight time, a Cessna 182A, registration N9909B, was substantially damaged during a forced landing following a loss of engine power near Selma, California. The airplane was registered to HBC Aero LLC, Rancho Murieta, California, and operated by a student pilot. The student pilot and a Certified Flight Instructor (CFI) sustained minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the instructional cross-country flight.
Flight History
The flight originated from Mc Clellan-Palomar Airport in Carlsbad, California, about 1600, with an intended destination of Madera, California. According to the flight instructor, after an uneventful flight from Rancho Murieta to Hesperia, California, they flew to Apple Valley, California, to refuel, topping off with 56.08 gallons of fuel. They then flew to Carlsbad, a roughly one-hour flight, where they dropped off two people before departing to return to Rancho Murieta.
During the return flight, the FI and student pilot decided to refuel in Madera instead of their original intended stop at Fresno. While descending from 6,500 feet to 4,500 feet mean sea level, the engine lost power. Air traffic control provided vectors to the nearest airport. Despite multiple attempts, the FI could not restart the engine and realized they would not reach Selma Airport. The FI initiated a forced landing to an open field; during the landing roll, the airplane nosed over. The FI reported that carburetor heat was not used during the descent.
Examination and Findings
A Federal Aviation Administration (FAA) inspector examined the wreckage and noted that the right wing and fuselage were structurally damaged. The airplane came to rest in a field containing a mix of sand and dirt. It was recovered to a secure location for further examination.
On June 15, 2016, a detailed examination of the recovered airframe and engine was conducted at Plain Parts in Pleasant Grove, California, under the supervision of the NTSB investigator-in-charge. Representatives from Cessna Aircraft and Continental Motors Inc. participated.
Both wings and the empennage were separated for recovery. Recovery personnel reported less than 2 quarts of fuel in either fuel tank. The left and right fuel caps were attached and secure. The airframe was intact and undamaged, but the nose wheel landing gear was separated. Impact damage to the airframe air filter and air box was observed. When an alternate fuel source was plumbed to the right wing fuel inlet port, fuel leaked from the airframe fuel strainer. The fuel strainer valve was found stuck open with an abundance of sand-like debris. After cleaning the debris, the valve closed normally.
All engine accessories remained attached, the ignition harness was intact, and the right-side engine mounts were fractured. The left-side exhaust was damaged. The crankshaft was rotated by hand, and thumb compression was obtained on all cylinders; spark was observed on all ignition leads. A test club propeller was installed due to propeller damage.
Engine Run and Carburetor Inspection
An external power supply connected to the airplane's electrical system allowed the engine to start. Initially, the engine ran for about 80 seconds before losing power. Multiple attempts to restart were unsuccessful; the engine would only start when primed and would not continue running once the primer fuel was exhausted.
The carburetor was removed and disassembled. A small amount of sand-like debris was cleared from the mixture metering sleeve using light air pressure. No other anomalies were noted. After reassembly and reinstallation, the engine started and ran continuously at various power settings until the mixture was moved to idle cutoff. The source of the debris in the carburetor mixture metering sleeve was undetermined.
Fuel Considerations
Review of the Cessna 182 Pilot's Operating Handbook (POH) indicated fuel burn rates between 9.7 and 14.5 gallons per hour depending on settings. The airplane had two wing fuel tanks, each with a capacity of 32.5 gallons. Usable fuel was 27.5 gallons per tank in all flight conditions, with an additional 3.5 gallons usable in level flight only; each tank had 1.5 gallons of unusable fuel.
The NTSB IIC estimated fuel burn using a rate of 14.5 gallons per hour, resulting in 3 hours of flight time. Since the airplane was topped off, approximately 43.5 gallons would have been consumed.
Weather Conditions
At 1953, weather at Fresno-Yosemite International Airport (about 14 miles north of the accident site) was temperature 81°F and dew point 43°F. According to FAA Special Airworthiness Information Bulletin CE-09-35 (Carburetor Icing Prevention), these conditions were conducive to the formation of carburetor icing at glide or cruise power.