N7532VCessna 177RG · 1976

On July 7, 2017, about 0830 Pacific daylight time, a Cessna 177RG airplane, N7532V, was substantially damaged during a forced landing shortly after takeoff from the Nut Tree Airport (VCB), Vacaville, California. The private pilot was not injured. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The flight was originating at the time and was destined for Rio Vista Municipal Airport (O88), Rio Vista, California.

In a statement provided to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot reported that prior to departing all indications on the engine runup checks were good. After taking off and at about 200 ft above ground level during the initial climb, the engine "wheezed" and then provided minimum power. The pilot added that after [about] 30 seconds the engine stopped providing power/thrust, which resulted in a forced landing straight ahead to an open field; during the landing the left wing and fuselage were substantially damaged. The pilot reported that the airplane had 30 gallons of fuel on board at the time of takeoff. During the recovery of the airplane, recovery personnel reported that between 18 gallons to 20 gallons of fuel was drained, with about an equal amount from the left and right fuel tanks.

The airplane was equipped with a Lycoming IO-360-A1B6D, fuel injected, reciprocating engine. A postaccident examination of the engine and airframe by representatives from the National Transportation Safety Board (NTSB) and the Federal Aviation Administration (FAA), revealed the following: all accessories, including the fuel/oil lines, remained secured and attached to the engine. Mixture and propeller control continuity was established from the cockpit to the engine controls, however, the throttle control handle was observed bent downward about 70 ° during impact. Despite attempts to bend the throttle back to its near original position, full travel could not be attained; estimated movement was about 2 inches. The upper spark plugs were removed and exhibited normal wear signatures. Thumb compression was obtained on all 4 cylinders when the crankshaft was rotated by hand. Additionally, spark was obtained on all ignition leads when the crankshaft was rotated. When air pressure was applied to both the left and right wing fuel vent lines, air passed through the lines unobstructed.

Prior to an attempt to facilitate the engine run, an external fuel source was attached to the left wing fuel inlet port. Additionally, due to propeller damage, the propeller was replaced with a serviceable propeller.The airframe fuel pump was actuated to prime the engine. Subsequent to the engine starting, it was run at various power settings for about 5 minutes before securing the engine with the mixture control. During the engine run, when the magneto switch was placed to the right magneto position, the engine lost power. The reason for this anomaly was not determined during the examination. The magneto and ignition switch were retained for further examination.

In a subsequent examination of the ignition switch by an NTSB investigator, an OHM meter was used to establish continuity at the various switch settings. No evidence of a malfunction was noted.

On July 28, 2017, at a FAA certified repair station, and under the supervision of an FAA airworthiness inspector, a certified magneto technician inspected and tested the airplane's Dual Magneto D4LA-2000, part number 10-382555-11, serial number 8016457. As a result, the technician reported that the magneto achieved a coming in speed of 70 rpm at 5mm gap, with 150 rpm maximum allowable. The technician further reported that when the speed was increased to 3,000 rpm and spark gap was opened to 10mm, no missing was observed in either the right or left position. The technician concluded that the magneto was clean and functioned normally.