Accident
On February 15, 2011, about 1130 mountain standard time, a Cessna 172H, registration N2561L, executed an off-field forced landing following a loss of engine power near Wikieup, Arizona. The airplane was operated by Sheble Aviation under 14 Code of Federal Regulations Part 91. The certified flight instructor (CFI) and student pilot were not injured. The airplane sustained substantial damage to the firewall.
The cross-country instructional flight originated from Sun Valley, Arizona, at an undetermined time, with a planned destination of Prescott, Arizona. Visual meteorological conditions prevailed, and no flight plan had been filed.
Sequence of Events
The CFI reported that the airplane was in cruise flight at 9,500 feet mean sea level (msl) when the engine power became intermittent, followed by a total loss of power. The CFI took command, established best glide speed, and selected a landing site. Attempts to restart the engine were unsuccessful.
Prior to landing, the CFI turned the mixture control and ignition switches to the OFF position and unlatched the doors. On final approach, flaps were added and the electrical master switch was turned OFF. The airplane was nearly stopped when it contacted a rut, causing the nose gear to shear off.
Investigation
A Federal Aviation Administration (FAA) inspector examined the wreckage on scene. No obvious defects were observed with the engine, and the fuel tanks contained sufficient fuel. The left fuel tank contained fuel up to the bottom of the filler neck; the right fuel tank contained fuel to within 3/4 inch of the filler neck. Maintenance personnel, under the inspector's supervision, drained fuel from the sumps and fuel strainer. The left wing tank measured approximately 15 US gallons, and the right wing tank measured approximately 17 US gallons. No water or contaminants were observed; the fuel was bluish and had an odor consistent with aviation gasoline.
At the accident site, the throttle was at the 3/4 full forward position, the mixture was set to full rich, carburetor heat was on, and the fuel selector was in the OFF position.
Maintenance personnel subsequently disassembled the airplane and relocated it to Sheble’s facility at Fort Mohave, Sun Valley Airport, Arizona.
Inspection and Findings
At the operator’s facility, the FAA inspector supervised an inspection. Before the inspection, the airplane was configured with an external fuel supply, and the engine was ground run. The engine operated at idle power only briefly and would not accelerate as the throttle was advanced. With the engine running, an inspection of the engine compartment revealed fuel dripping from the main fuel supply line in the area between the fuel strainer and the carburetor inlet. Examination of the fuel line revealed that approximately 6 inches of the 18-inch hose assembly had deteriorated and cracked, resulting in the leak. A replacement hose assembly was installed, after which the engine ran normally under all parameters.
The data tag on the hose assembly identified it as a Stratoflex P/N-111417-8D0250, TSO C53A, A, OP2000PSI, A1/92, CD3QT91. The CD3QT91 indicated the hose assembly had been in service since the third quarter of 1991. The engine was installed in the airplane on June 2, 2008, with 1,155.2 hours since major overhaul. At the time of the accident, the engine had 2,120.3 hours since major overhaul. No records or documentation indicated any hose assemblies being replaced or repaired.