San Manuel, AZ, USA
N112MW
WOOD MUSTANG II FB
The pilot was flying on the first flight in the airplane since certification. Shortly after takeoff, he reported over a common airport frequency that the airplane had low engine oil pressure and that he was returning to the airport to land. Witnesses observed the airplane maneuver from the downwind leg to final approach for the intended runway by executing a 180-degree left turn. One witness observed the airplane's bank increase to about 90 degrees and descend out of sight. Another witness observed that the airplane was low and slow and appeared to stall. The witness stated that the left wing dropped and that the airplane went straight down. Postaccident examination of the airframe, flight control components, and the engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. It is likely that, because this was the pilot's first flight in the airplane and he was distracted by the low oil pressure, he failed to maintain adequate airspeed while maneuvering, and the airplane subsequently stalled. The toxicology report indicated that the pilot was taking medication for several medical conditions; however, insufficient information was available to determine if the pilot's medical conditions contributed to the accident.
HISTORY OF FLIGHT On October 4, 2012, about 0930 mountain standard time, an experimental amateur built Wood, Mustang II FB, N112MW, sustained substantial damage when it impacted terrain near the San Manuel Airport (E77) San Manuel, Arizona. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. The private pilot, sole occupant of the airplane, was fatally injured. Visual meteorological conditions prevailed and no flight plan was filed for the local personal flight which originated from San Manuel Airport, San Manuel Arizona at an undetermined time. According to witnesses, located at the airport, the pilot was on his first flight in the airplane since certification. One witness located on the taxiway approximately 2300 feet from the approach end of runway 11, reported that he was in communication with the accident pilot through a hand held radio. He heard the pilot report low engine oil pressure on the engine and that he was coming back to land. He asked the pilot how low the oil pressure was, and he responded 40 psi and that he needed 80 psi. The witness observed the airplane on downwind for runway 11. As the airplane was about one half mile from the end of the runway, the witness observed the airplane's nose drop suddenly, followed by the airplane leveling off. The pilot started a left 180 degree turn to final with about 15 degrees of bank. As the airplane descended through about 500 feet above ground level (agl), the witness saw the landing gear extend. Shortly thereafter, the witness observed the airplane at an approximate bank angle of 90 degrees and then it descended out of sight, behind a hill. Another witness, a flight instructor, was flying the airport traffic pattern with a student pilot when the accident airplane took off. He reported seeing the airplane flying a large arc southeast of the airport. He heard the accident pilot report low oil pressure of 40 psi. The witness asked the pilot if he had cycled the propeller and the pilot responded that he had, however, the oil pressure dropped to 30 psi, so he was coming in to land. The witness decided to land immediately in order to keep the runway clear for the low oil pressure airplane. The witness taxied to the ramp and observed the accident airplane in a tight final turn for runway 11, at about 300 to 400 feet agl. The witness stated it looked low, slow, and appeared to stall. He witnessed the left wing drop and the airplane go straight down. The airplane struck a ridge line approximately 0.8 miles northwest of E77. Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed that the forward portion of the airframe and wings were consumed by fire. The wreckage was transported to a secure location for further examination. PERSONNEL INFORMATION The pilot, age 77, held a private pilot certificate with an airplane single-engine land rating. A third-class airman medical certificate was issued on December 17, 2010, with a limitation of must have glasses for near vision. The pilot reported on his most recent medical certificate application; that he had accumulated 1,189 total flight hours. AIRCRAFT INFORMATION The experimental amateur built two seat, low-wing, retractable-gear airplane, serial number (S/N) 963, was built in 2009 by the pilot. It was powered by a Lycoming O-360-A1A engine, serial number L-2641-51A, rated at 180 horse power. The airplane was also equipped with a Hartzell model HC-E2YR-1BF, serial number CH8191 constant speed metal propeller. METEOROLOGICAL INFORMATION A review of the automated weather observing system (AWOS) located at E77 reported at 0930; wind from 100 degrees at 5 knots, visibility 10 statute miles, clear sky, temperature 27 degrees Celsius, dew point 0 degrees Celsius, and an altimeter setting of 30.24 inches of mercury. Using the reported weather conditions and field elevation, the calculated density altitude was about 5,107 feet. AIRPORT INFORMATION The San Manuel Airport (E77) is a non-towered, privately owned airport with a field elevation of 3,272 feet msl. The airport was equipped with one asphalt runway, runway 11/29 (4,207 feet long and 75 feet wide). The standard traffic pattern for runway 11 is left turns. WRECKAGE AND IMPACT INFORMATION Examination of the accident site by a FAA inspector revealed the airplane impacted terrain approximately eight tenths of a mile from the approach end of runway 11. The entire debris path was contained to an approximate 80 foot wide radius from the main wreckage. The wreckage came to rest at a heading of about 210 degrees magnetic and the measured coordinates were N32.38.922 W110 39.698. A post impact fire consumed the left wing, engine and cockpit area. TEST AND RESEARCH Examination of the recovered airframe and flight control components revealed no evidence of preimpact mechanical malfunction. Examination of the engine revealed that it remained partially attached to the mounting assembly and sustained thermal damage. The propeller was not attached to the engine. The spinner was crushed onto the propeller hub and both propeller blades displayed chordwide scratches and twisting. One propeller blade was twisted from mid-span root to tip, and the other propeller blade was bent and twisted from approximately one third from the outer tip. There was no evidence of oil lubrication depravation or contamination found. Examination of the recovered engine and system components revealed no evidence of preimpact mechanical malfunction. The turbocharger assembly had been designed, fabricated and installed by the pilot. Disassembly of the turbo charger assembly revealed no contamination and the components were unremarkable. There was no oil residue observed in the exhaust system components. MEDICAL AND PATHOLOGICAL INFORMATION The Pinal County Medical Examiner conducted an autopsy on the pilot on October 9, 2012. The medical examiner determined that the cause of death was "...blunt force injuries." The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, performed toxicology tests on the pilot. According to CAMI's report, toxicology was positive for three over-the-counter medications and one prescription medication. Acetaminophen (Tylenol) was detected and is an over the counter medication used to treat aches, pains and fever. Ranitidine (Zantac) was detected, an over-the-counter histamine used to decrease gastric acid production and treat ulcers. Salicylate was detected and is a metabolite of aspirin, an over-the-counter anti-inflammatory medication used to treat aches and pains and reduce fever. Aspirin also is used to reduce the risk of heart attacks. Amlodipine was detected and is a prescription calcium blocker medication used to treat high blood pressure and angina. The National Transportation Safety Board's Chief Medical Officer reviewed the pilot's certified medical records on file with the FAA, and an email from the pilot's family regarding his health. The medical officer prepared a factual report, which is part of the public docket for this accident.
The pilot's failure to maintain adequate airspeed while maneuvering to final approach due to his distraction by the low engine oil pressure, which resulted in an aerodynamic stall.
Source: NTSB Aviation Accident Database
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