***This report was modified on November 7, 2012. Please see the docket for this accident to view the original report.*** Use your browsers 'back' function to return to synopsisReturn to Query Page
HISTORY OF FLIGHT
On June 30, 2011, approximately 1350 central daylight time, N358MA, a kit-built Lancair 320 airplane, collided with terrain at the Sundance Airpark (HSD), Yukon, Oklahoma. The commercial pilot was fatally injured. The airplane sustained substantial damage to the wings, fuselage, empennage, vertical fin, and rudder. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a positioning flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The flight originated from the Wiley Post Airport (PWA), Oklahoma City, Oklahoma, about 1345.
According to eyewitnesses, prior to the airplane departing PWA, the engine was making rough running engine sounds. The airplane was observed to depart PWA and the engine continued to produce rough running sounds. Eyewitnesses at HSD reported hearing a rough running engine as the airplane approached the airfield. The airplane entered a left base turn for runway 17. As the airplane turned to align with the extended runway centerline, the airplane’s bank angle increased to near 90 degrees. The nose of the airplane dropped, the airplane rapidly descended and impacted terrain.
The pilot, age 57, held a commercial pilot certificate with airplane single engine, airplane multi-engine, and instrument airplane ratings. On November 24, 2010, a third class medical certificate was issued to the pilot; at that time the pilot reported to have over 9,500 hours total time, with zero hours logged in the preceeding 6 months.
A pilot’s logbook could not be located during the course of the investigation; it is unknown when the pilot last accomplished a flight review and the pilot recent flight history is not known. Prior to the accident flight, the pilot told a line service technician at PWA, "I've never flown this plane before. I've ridden in it, but I get to take her up myself."
The kit-built, two-seat, retractable gear airplane, serial number 007, was manufactured in 1991. A 150 horsepower Lycoming IO-320-B drove a two-bladed, constant speed, Hartzell metal propeller. A review of maintenance records showed an annual condition inspection was completed on November 5, 2010, at a total airframe and engine time of 961.5 hours.
An automated weather reporting facility located at PWA, approximately 5 nautical miles southeast of the accident site reported winds 210 degrees at 14 knots gusting to 20 knots, visibility 10 miles, clear skies, temperature 99 degrees Fahrenheit (F), dew point 63 degrees F, and a barometric pressure of 29.96 inches of Mercury.
WRECKAGE AND IMPACT INFORMATION
On-scene ground scars were consistent with the airplane’s impact at the parallel taxiway in a left bank, steep nose low attitude. The wingtip struck the taxiway followed shortly by the nose of the airplane. The wreckage path was aligned along a 220 degree heading. The airplane’s propeller fractured from the hub and was found in a divot near the taxiway edge. The airplane came to rest about 60 feet from the ground scars with the nose of the airplane facing 095 degrees. Flight control continuity was established from the cockpit flight controls to the control surfaces. The rudder hinges were fractured in overload. The airplane’s gear was found in the retracted position, which corresponded with its cockpit switch. Only one of the airplane’s propeller blades showed signs of leading edge polishing and chordwise scratches. Neither blade displayed any signs of twisting or curling. An examination of the engine established continuity and compression. All fuel screens were examined and found clear of contaminates. The magnetos and fuel servo were removed for examination.
MEDICAL AND PATHOLOGICAL INFORMATION
An autopsy was performed on the pilot on July 1, 2011, by the Office of the Chief Medical Examiner, Oklahoma. The manner of death was ruled an accident.
FAA Civil Aerospace Medical Institute (CAMI), Oklahoma City, Oklahoma, performed forensic toxicology on specimens from the pilot. Testing was negative for carbon monoxide, cyanide, and ethanol. The report noted the following findings:
0.29 (ug/ml, ug/g) Diphenhydramine detected in Blood (Cavity)
Diphenhydramine detected in Urine
Ibuprofen detected in Urine
CAMI’s web-based collection of toxicology drug information noted that Diphenhydramine is a common over the counter antihistamine used in the treatment of the common cold and hay fever. A warning states that this medication "may impair mental and/or physical ability required for the performance of potentially hazardous tasks (e.g., driving, operating heavy machinery)." Ibuprofen is listed as a nonnarcotic analgesic and anti-inflammatory agent.
TEST AND RESEARCH
The airplane’s magnetos were tested at a magneto repair shop in Oklahoma City, Oklahoma, under the auspices of the FAA. The magnetos were found to operate normally.
The fuel servo was tested at a repair station in Oklahoma City, Oklahoma, under the auspices of the FAA. The fuel servo had not been updated per the manufacturer’s recommendation, but since the engine operated on an experimental airplane, it was not required to be completed. Flow testing of the fuel servo found that the servo allowed a rich mixture at idle; approximately 8 pounds per hour. Across all test points, the servo exceeded all of the manufacturer’s recommended maximum flowmeter limits.
Lancair Stall Speeds
A review of a Lancair 320 stall speeds chart found in the accident airplane showed that, on average, the airplane’s stall speed increased about 7 knots for 30 degrees of bank and 17 knots for 60 degrees of bank. The chart’s maximum bank angle provided is 60 degrees of bank.
An excerpt from the FAA’s “Airplane Flying Handbook,” 2004 (FAA-H-8083-3A):
Normally, it is recommended that the angle of bank not exceed a medium bank because the steeper the angle of bank, the higher the airspeed at which the airplane stalls. Since the base-to final turn is made at a relatively low altitude, it is important that a stall not occur at this point. If an extremely steep bank is needed to prevent overshooting the proper final approach path, it is advisable to discontinue the approach, go around, and plan to start the turn earlier on the next approach rather than risk a hazardous situation.
An excerpt from the FAA’s “Airplane Flying Handbook,” 2004:
The airplane will, however, stall at a higher indicated airspeed when excessive maneuvering loads are imposed by steep turns, pull-ups, or other abrupt changes in its flightpath. Stalls entered from such flight situations are called “accelerated maneuver stalls,” a term, which has no reference to the airspeeds involved.
Stalls which result from abrupt maneuvers tend to be more rapid, or severe, than the unaccelerated stalls, and because they occur at higher-than-normal airspeeds, and/or may occur at lower than anticipated pitch attitudes, they may be unexpected by an inexperienced pilot.
Experimental Amateur-Built Aircraft Training
In a 2012 safety study on "The Safety of Experimental Amateur-Built Aircraft," the NTSB concluded that "purchasers of used [experimental amateur-built] (E-AB) aircraft face particular challenges in transitioning to the unfamiliar E-AB aircraft. Like builders of new E-AB aircraft, they must learn to manage the unique handling characteristics of their aircraft and learn the systems, structure, and equipment, but without the firsthand knowledge afforded to the builder." Thus, the NTSB recommended that the Federal Aviation Administration and the Experimental Aircraft Association "complete planned action to create a coalition of kit manufacturers, type clubs, and pilot and owner groups and (1) develop transition training resources and (2) identify and apply incentives to encourage both builders of experimental amateur-built aircraft and purchasers of used experimental amateur-built aircraft to complete the training that is developed."