Introduction
On May 20, 2023, at approximately 0900 Pacific daylight time, a Cessna 210, registration N9433T, was substantially damaged in an accident near Redding, California. The pilot, the sole occupant, sustained minor injuries. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Flight Details
The planned route was from Salem, Oregon (SLE), to Willows, California (WLW). While overflying Redding Regional Airport (RDD) at an altitude of 7,500 feet mean sea level (msl), the engine lost power. The pilot executed emergency restart procedures and observed that fuel pressure was zero. Although the engine would not restart and the propeller was still spinning, he obtained a surge of power by cycling the auxiliary fuel pump. He was in communication with Oakland Center air traffic controllers and decided to turn back toward RDD.
The pilot did not declare an emergency initially, as he believed sufficient altitude remained. When the airplane was on a 5-mile final approach for runway 34 at about 4,500 feet msl (approximately 4,000 feet above ground level), it became apparent that the airport would not be reached. He then declared an emergency with RDD tower controllers. A final cycle of the fuel pump produced no engine response, and the propeller stopped. The pilot elected to keep the landing gear retracted and landed in a field approximately three-quarters of a mile short of the runway threshold.
Examination Findings
The aircraft sustained substantial damage, including separation of the tailcone aft of the rear cabin bulkhead. Both wings remained attached, with the right wing bent upward at the wing strut attach point. Each wing tank contained more than 20 gallons of fuel, and no fuel leak was evident.
Examination of the fuel supply system within the airframe revealed no anomalies that would have precluded normal operation. The engine remained partially attached to the firewall and was essentially undamaged. No evidence of catastrophic internal engine failure or oil leak was found. The ignition system was functional, and all spark plugs exhibited normal wear and deposits. Internal cylinder combustion surfaces showed consistent deposits indicative of normal operation.
The crankshaft could be turned by hand using the propeller, and compression was confirmed on all cylinders. Mechanical continuity was established throughout the rotating group, valvetrain, and accessory section.
All fuel and oil supply hoses remained attached at their fittings, but most were hard and inflexible. The metered-side fuel pressure sender hose had broken away from the fuel controller. This rubber hose had limited flexibility, lacked a fire sleeve, and exhibited white oxidization-like deposits at the break. The rubber remnants were brittle and could be easily broken off with a fingernail.
The entire engine fuel control system was disassembled and examined. Although all components appeared functional, they showed evidence of water ingestion and corrosion.
Maintenance History
Airworthiness records showed that the airplane's previous owner replaced the fuel caps and fuel tank inlets in June 2017. The current owner reported that early in his ownership, he routinely drained water from the fuel system during preflight inspections, and he understood that the airplane had sat unused for extended periods before his purchase.
The only maintenance records available covered from the accident period back to 2017, and the fuel pressure sender hose was not replaced during that time. Evidence suggested that the engine and its fuel control components were last overhauled about 28 years before the accident, in 1995. Teledyne Continental Motors Service Information Letter SIL98-9C stated that the time between overhaul for IO-470 series engines is 1,500 hours or every 12 years, whichever occurs first. Although advisable, adherence to manufacturer overhaul periods is not required for Part 91 operations.