Tracy, CA, USA
UNREG
North Wing Mustang II 17.5
No witnesses observed the pilot depart on the flight or the accident sequence. The pilot owned and operated the unregistered airplane. Based upon an examination of the accident site and wreckage, the airplane experienced an in-flight non-mechanical structural failure, which resulted in a loss of wing rigidity. The airplane impacted the ground in an uncontrolled descent. All major structural airframe and engine components were accounted for at the site. The leading edges of the wings were mostly undamaged, indicating they folded prior to impact. A propeller chunk was found imbedded in a strut, indicating crankshaft rotation under torque during the accident sequence as the wings folded. Hardware associated with the pullback shackle (assembly), which provides structural support to the wings for rigidity, was missing. The wings were found folded inward from their normal in-flight rigid position. Specifically, a bolt, horseshoe shackle, and the nylon strap were missing. Because these components were not located, no determination could be made regarding whether the bolt had failed, the nut had become loose, or the parts had been inadequately modified following their manufacture. The airplane did not meet the requirements of FAR Part 103, and night flying was not permissible under FAA regulation. Toxicology revealed evidence of tetrahydrocannabinol and tetrahydrocannabinol carboxylic acid (marihuana) in blood samples.
HISTORY OF FLIGHT On October 25, 2007, at an undetermined time between 2000 and 2400, a North Wing, Mustang II 17.5 (unregistered airplane), experienced an in-flight structural failure. While in an uncontrolled descent, the airplane impacted into a level field (almond orchard) about 9 miles east-southeast of Tracy, California. The private pilot owned and operated the airplane, and he was killed. The flight was performed under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed during the bright nighttime flight. Although the purpose of the flight was not confirmed, an acquaintance of the pilot indicated it was likely personal. The pilot's car was found at the New Jerusalem Airport, about 1 mile north of the accident site. No witnesses reported observing the pilot takeoff or crash. PERSONNEL INFORMATION The pilot, age 54, held a private pilot certificate with an airplane single engine land and instrument airplane rating. He had sport pilot privileges for the weight-shift-control aircraft category, with a land class rating. The pilot's personal flight record logbook was not provided for examination, and the pilot's flying endorsements were not ascertained. According to Federal Aviation Administration (FAA) records, the pilot's most recent aviation medical certificate, third-class, was issued November 1999. The pilot was required to have available glasses for near vision. On the medical certificate application form the pilot reported that his total flight time was 762 hours. An acquaintance of the pilot reported to the National Transportation Safety Board investigator that he believed the pilot's total flying experience was about 2,000 hours. The acquaintance opined that the pilot had flown the accident or similar models of aircraft about 1,300 hours, and he had given about 300 hours of dual instruction in the airplane. During the 90 days preceding the accident, the pilot had flown the airplane an estimated 40 hours. AIRCRAFT INFORMATION The two place trike design is equipped with a pusher propeller, tricycle landing gear, and wing struts. An acquaintance of the pilot reported that he believed the pilot was in the process of completing the required forms to have the FAA certify the airplane as a light sport airplane. The pilot had been operating the airplane as an ultralight vehicle. The FAA's Aircraft Registration Branch searched its records for correspondence with the accident pilot. FAA personnel reported to the Safety Board investigator that as of June 2008, its record search did not reveal evidence of the pilot having submitted the required application or affidavit of ownership to register the ultralight as a light sport aircraft. The airplane has two seats and a fuel tank capacity of at least 8 gallons, according to the acquaintance. The FAA coordinator reported that the pilot's airplane did not meet the ultralight vehicle requirements of 14 Code of Federal Regulations Part 103. The accident flight at night had not been authorized by the FAA. METEOROLOGICAL INFORMATION According to the acquaintance, the weather in the vicinity of the New Jerusalem Airport during the evening of October 25 was adequate for flight under visual flight rules. The sky was clear, the visibility was at least 10 miles, and the wind was light and variable. The moon was full. COMMUNICATIONS The FAA reported no evidence of any radio communications with the accident pilot. WRECKAGE AND IMPACT INFORMATION The FAA coordinator examined the airplane on scene, and he was assisted by an acquaintance of the pilot who had familiarity with the airplane. The airplane was found in an open, vegetation-covered, field. It was on its right side and in a nose down attitude. Terrain and vegetation several yards from the main wreckage, in all directions, did not exhibit impact damage. All structural airframe and engine components were found with the wreckage. There was no evidence of fire. An examination of components revealed evidence of deformation consistent with ground impact. No evidence was noted of preimpact structural airframe or engine failure. The leading edges of the wings were mostly undamaged, and the acquaintance indicated that this was consistent with the wings having folded prior to impact. A propeller chunk was found imbedded in the right strut. According to the acquaintance, this would indicate that the propeller was spinning as the wings folded to the point where the strut was in the radius of a rotating propeller blade. Hardware associated with the pullback shackle (assembly), which provides structural support for the wings, was missing. The wings were found folded inward from their normal in-flight rigid position. Specifically, a bolt, horseshoe shackle and the nylon strap were missing. All other components were found at the site. The acquaintance reported that because these components were not located, no determination could be made regarding whether the bolt had failed, or the nut was loose. A representative of the aircraft's manufacturer stated to the Safety Board investigator that additional possibilities exist for these flight safety critical parts being missing. If the parts had been modified, or if substitute parts for the pull back linkage to the cross bar had been installed, their in-flight malfunction, failure, and/or disconnection may explain why this entire connection assembly was not found at the accident site. When the airplane was located the day following the crash, an estimated 1/2-gallon of fuel was observed in the fuel tank. The rocket powered, emergency use, parachute was found deployed. The canopy was found strung out behind the trike. MEDICAL AND PATHOLOGICAL INFORMATION No FAA medical certificate is required to fly an ultralight vehicle or a light sport airplane. An autopsy was performed on the pilot by the San Joaquin County Sheriff-Coroner, French Camp, California. The autopsy finding indicated that the pilot died from multiple blunt force injuries. Forensic toxicology was performed on specimens from the pilot by the FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The toxicology report stated evidence of tetrahydrocannabinol (marijuana) was detected in blood (0.0078 ug/ml). Also, tetrahydrocannabinol carboxylic acid (marijuana) was detected in blood (0.0167 (ug/ml). Examined specimens exhibited putrefaction. No evidence of ethanol was detected in vitreous, and no other evidence of drugs was found.
Failure or disconnection of a wing support/brace assembly for undetermined reasons during an undetermined phase of flight.
Source: NTSB Aviation Accident Database
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