Accident Overview
On June 18, 2016, about 0815 mountain standard time, a Beech C23 airplane, registration N9246S, was substantially damaged during a forced landing following a total loss of engine power near Prescott, Arizona. The private pilot/owner was not injured, and the pilot-rated passenger received minor injuries. The airplane was operated under 14 CFR Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. The cross-country flight departed Grants-Milan Municipal Airport (GNT), Grants, New Mexico, about 0715 mountain daylight time, destined for Ernest A. Love Field Airport (PRC), Prescott, Arizona.
Flight History
The pilots were participating in a point-to-point air race event. The previous day, they departed Philip Billard Municipal Airport (TOP), Topeka, Kansas, at 0815 central time with about 52 gallons of fuel. They flew to Dalhart Municipal Airport (DHT), Dalhart, Texas, where they topped off with 35.5 gallons. They then departed for Tucumcari, New Mexico (TCC). During that flight, after reaching 8,500 ft, they leaned the mixture and the engine lost power. The pilot enrichened the mixture and engaged the fuel boost pump, restoring power. Later, an Air Route Traffic Control Center controller informed them of a temporary flight restriction (TFR), so they landed at an airport in Sandia, New Mexico, to adjust their route. They subsequently flew to Socorro Municipal Airport (ONM), Socorro, New Mexico, where they refueled: the left tank was filled to 26 gallons usable fuel, and the right tank was filled to the tabs, providing 15 gallons usable fuel per the aircraft's flight manual. During the next flight to PRC, the engine lost power again when they leaned the mixture at 8,500 ft; they restored power by enrichening and using the boost pump. They then decided to land at GNT for the night.
Fuel Management and Accident Sequence
The following morning, the pilot/owner contacted a mechanic, who attributed the power losses to vapor lock due to density altitude and high temperatures, and recommended a higher run-up power setting and leaning for best power on the ground. The pilots followed these instructions and departed with the fuel selector on the left tank. About 1 hour and 10 minutes into the flight at 10,500 ft, the pilot switched to the right tank, believing it had more fuel. Near the destination, they prepared for descent: they activated the fuel boost pump, selected the right tank, lowered the landing gear, set the mixture to full rich, and reduced throttle to about 1,800 rpm. The engine then experienced a total loss of power. They advanced the throttle and cycled the mixture, but only a brief burst of power occurred. The pilot attempted to restart the engine unsuccessfully. They notified the PRC tower, which cleared them to land on runway 21L, but they could not reach the runway and landed straight ahead. The airplane impacted the ground hard at about 80 mph, bounced, and then returned to the ground. The main landing gear separated, and the airplane skidded up a small berm, coming to rest about 1/2 mile north of PRC.
Post-Accident Inspection
Photographs showed substantial damage to the right aileron and left wing. A fuel performance computation indicated that at the time of power loss, the left tank should have contained about 9.7 gallons and the right tank about 7.6 gallons of usable fuel. However, after the accident, 10 gallons of fuel were drained from the left tank, and the right tank was void of fuel. An airport representative did not detect fuel odor or leaks at the scene. A fuel system inspection and engine test run were conducted by the manufacturer under NTSB supervision. No breaches of the fuel tanks were found. The fuel strainer's quick drain had been sheared off during the accident. The engine was test-run with external fuel from both sides; it operated normally except for one backfire when the throttle was rapidly reduced from 2,200 rpm to 700 rpm. The fuel gauges indicated full when manually moved to full and 1/4 when moved to empty. According to the pilot's operating handbook, the yellow band on the fuel gauges represents between empty and 3/8 full (about 9 gallons).