History of Flight
On September 16, 2009, at about 1450 Pacific daylight time, a Cessna 140, registration N326DW, experienced a loss of engine power and nosed over during a forced landing near Santa Paula Airport in Santa Paula, California. The commercial pilot, who owned the aircraft, was operating under 14 Code of Federal Regulations Part 91 for a local personal flight that departed Santa Paula about 1430. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot sustained minor injuries. The airplane sustained substantial damage to the fuselage and tail.
The pilot reported conducting a preflight inspection that included a visual check of fuel in each tank using a calibrated fuel tube, confirming about 6 gallons in both left and right wing tanks. She then performed an uneventful engine run-up with magneto and carburetor heat checks. Departing for practice landings, she completed two touch-and-go landings followed by a full-stop takeoff and landing. While turning left crosswind after the fourth takeoff, she felt engine power reduce gradually but completely. She verified throttle and mixture controls full forward, primer in and locked, and checked fuel tank gauges. Both tanks appeared to contain the same amount of fuel, and the fuel selector was set to the left tank. She turned to downwind and engaged carburetor heat. Unable to reach the runway, she elected to land in a dry riverbed adjacent to the airport. Just before landing, she pulled throttle and mixture to full out, turned the fuel selector off, and landed; during the landing sequence, the airplane nosed over, causing substantial damage to the firewall, aft fuselage, and empennage. After landing, she secured the airplane by turning the magneto and master switch off.
The engine tachometer advanced 0.2 hours from start to accident.
A Federal Aviation Administration (FAA) inspector arrived at the accident site about 1 hour 40 minutes after the accident. Initial examination revealed carburetor impact damage and separation from the inlet manifold, and the gascolator bowl dislodged. Fuel was leaking from the right wing fuel cap.
Recovery personnel repositioned the airplane onto its main landing gear about 4 hours after the accident. The inspector noted about 5 gallons of fuel in the right tank and residual fuel in the left tank. The left fuel tank filler cap vent line had separated from the cap. Removal of the carburetor showed fuel present at the inlet line.
The airplane was moved to a storage facility at Santa Paula. The inspector tested the fuel selector valve by adding fuel and observing flow to the carburetor inlet line at each tank position. Disassembly of the carburetor revealed residual fuel in the bowl and accelerator pump chamber.
Aircraft Information
The high-wing, tailwheel airplane was manufactured in 1946 and equipped with a Teledyne Continental Motors O-200-A engine. According to the airplane’s logbooks, at the last annual inspection on August 9, 2009, 4 flight hours before the accident, the airframe had accumulated 3,314.7 total hours. The pilot stated the engine had 814 flight hours since overhaul.
Tests and Research
The NTSB investigator-in-charge and a TCM representative further examined the aircraft.
Engine: Engine controls were continuous from cabin to firewall. The carburetor heat line was cut by recovery personnel but intact at its control arm. The carburetor heat box sustained crush damage, preventing confirmation of operation. The air filter was free of debris.
The carburetor, a Precision Airmotive Corporation MA-3SPA, had an inlet screen free of debris. The brass float showed scoring on the inner surface of the float bowl adjacent to the float pivot cotter pin. Immersion in fuel revealed no leaks.
Mechanical rotational continuity was established through the engine and valve train when the crankshaft was turned by hand. Thumb compression was obtained on all four cylinders in proper firing order. Internal borescope examination showed light grey deposits on piston heads, chambers, and valves, with no evidence of catastrophic internal failure. Number 2 and 4 exhaust valve heads exhibited asymmetrical thermal discoloration, and external fins around the number 2 exhaust valve had pink discoloration.
Upper spark plug removal showed wear consistent with short service life per the Champion AV-27 chart. Plugs 1 and 3 had light grey deposits; plugs 2 and 4 were oil-soaked.
Ignition switch and cables tested for continuity and short circuits showed no anomalies.
The right magneto was firmly attached. The left magneto separated at its mounting flange, which was fractured and grainy in appearance; an indentation on the firewall corresponded to the magneto’s position. Both magneto drive shafts produced sparks at spark plug leads when rotated by hand. The damaged left magneto produced an intermittent spark at two plug output leads simultaneously.
Additional Information
The pilot reported using a Cessna 152 dipstick recalibrated for the Cessna 140. Examination showed a clear plastic tube fuel gauge calibrated for a Cessna 152 with 12-gallon tanks, with a white mark at the 4.5-gallon point. The pilot stated this mark was calibrated by comparison with the half-full indication on the wing-mounted fuel quantity gauge. When inserted into the Cessna 140 fuel tank, the 12-gallon mark aligned with the top of the tank.
The pilot stated the airplane typically consumes 5.32 to 6.5 gallons of fuel per hour. Data was not available to confirm fuel consumption during takeoff and climb.
The airplane has two wing-mounted fuel tanks, each with an individual capacity of 12.5 gallons.