Oklahoma City-Wiley Post

On March 4, 2008, about 1515 central standard time, a Cessna 500, N113SH, registered to Southwest Orthopedic & Sports Medicine Clinic PC of Oklahoma City, Oklahoma, entered a steep descent and crashed about 2 minutes after takeoff from Wiley Post Airport (PWA) in Oklahoma City. None of the entities associated with the flight claimed to be its operator. The pilot, the second pilot, and the three passengers were killed, and the airplane was destroyed by impact forces and post crash fire. The flight was operated under 14 Code of Federal Regulations (CFR) Part 91 with an instrument flight rules flight plan filed. Visual meteorological conditions prevailed. The flight originated from the ramp of Interstate Helicopters (a 14 CFR Part 135 on demand helicopter operator at PWA) and was en route to Mankato Regional Airport, Mankato, Minnesota, carrying company executives who worked for United Engines and United Holdings, LLC.

Approximately 37 minutes after departing on a 928-nautical mile cross-country flight under instrument flight rules, the twin-engine turboprop airplane experienced an in-flight break-up after encountering moderate turbulence while in cruise flight at the assigned altitude of FL230. In the moments preceding the break-up, the airplane had been flying approximately 15 to 20 knots above the placarded maximum airspeed for operations in moderate turbulence. The airplane was found to be approximately 1,038 pounds over the maximum takeoff weight listed in the airplane's type certificate data sheet (TCDS). The last radar returns indicated that the airplane performed a 180-degree left turn while descending at a rate of approximately 13,500 feet per minute. There were no reported eyewitnesses to the accident. The wreckage was located the next day in densely wooded terrain. The wreckage was scattered over an area approximately three miles long by one mile wide. An examination of the airframe revealed that the airplane's design limits had been exceeded, and that the examined fractures were due to overload failure.

The commercial pilot, who managed the airplane and jointly owned it with one of the passengers, departed from a 3,930-foot-long, asphalt runway on a warm day. Weight and balance calculations, which investigators derived from estimated weights for total fuel, passengers, and cargo loads, determined that the airplane was likely within center of gravity limitations and about 208 pounds below its maximum gross weight. One witness stated that the airplane became airborne near the end of the runway before it began a shallow climb and clipped small branches on the tops of trees that were about 30 feet tall. That witness and others observed that the airplane continued past the trees, made a steep bank to the left, rolled inverted, and nose-dived to the ground. The witnesses' descriptions of the airplane's flightpath and the examination of the debris path and wreckage at the accident site are consistent with an impact following an aerodynamic stall. According to calculations performed using the airplane's published performance data chart, for the airplane's configuration and estimated weight and the density altitude conditions at the time of the accident, the airplane would have required about 3,800 feet on a paved, level runway to clear a 50-foot obstacle with the pilot using the short-field takeoff technique. Although the chart does not make any allowances for an upsloping runway or provide data for a 30-foot obstacle, the runway slope is slight (a 27-foot rise over the entire length) and likely did not significantly increase the airplane's takeoff roll, and interpolation of the data revealed no significant distance differences for the shorter obstacle. However, according to the chart, the 3,800-foot distance is contingent upon the pilot holding the airplane's brakes, applying full engine power with the brakes set, and then releasing the brakes to initiate the takeoff roll. In addition, the airplane's ability to achieve its published performance parameters (which are derived from test flights in new airplanes) can be degraded by a number of factors, such as pilot deviations from the published procedures, reduced engine performance, or increased aerodynamic drag associated with minor damage and wear of the airframe. It could not be determined where on the runway the pilot initiated the takeoff roll or at what point full engine power was applied. However, because the runway was only 130 feet longer than the airplane required (according to its published performance data), there was little margin for any deviations from the published takeoff procedure. Although examination of the engines, propellers, and related systems revealed no evidence of precrash anomalies, postaccident damage precluded engine performance testing to determine whether the engines were capable of producing their full-rated power. Therefore, the significance of maintenance issues with the airplane (in particular, a mechanic's assessment that the turbochargers needed to be replaced and that the airplane's required annual inspection was not completed) could not be determined with respect to any possible effect on the airplane's ability to perform as published. A review of Federal Aviation Administration (FAA) and insurance records revealed evidence that the pilot may have been deficient with regard to his ability to safely operate a PA 60-601P. For example, according to FAA records, as a result of an April 2004 incident in which the pilot landed the accident airplane on a wet grassy runway with a tailwind, resulting in the airplane going off the runway and striking a fence, the FAA issued the pilot a letter of reexamination to reexamine his airman competency. However, the pilot initially refused delivery of the letter; he subsequently accepted delivery of a second letter (which gave the pilot 10 days to respond before the FAA would suspend his certificate pending compliance) and contacted the FAA regarding the matter on Monday, August 2, 2004 (the day before the accident), telling an FAA inspector to "talk to his lawyer." In addition, as a result of the same April 2004 incident, the pilot's insurance company placed a limitation on his policy that required him to either attend a certified PA-60-601P flight-training program before he could act as pilot-in-command of the accident airplane or have a current and properly certificated pilot in the airplane with him during all flights until he completed such training. There was no evidence that the pilot adhered to either of the insurance policy requirements. In addition, the FAA had a previous open enforcement action (a proposed 240-day suspension of the pilot's commercial certificate) pending against the pilot for allegedly operating an airplane in an unsafe manner in September 2003; that case was pending a hearing with an NTSB aviation law judge at the time of the accident. Although the FAA's final rule for Part 91, Subpart K, "Fractional Ownership Operations," became effective on November 17, 2003, the regulations apply to fractional ownership programs that include two or more airworthy aircraft. There was no evidence that the pilot had a management agreement involving any other airplane; therefore, the rules of Part 91, Subpart K, which provide a level of safety for fractional ownership programs that are equivalent to certain regulations that apply to on-demand operators, did not apply to the accident flight. In the year before the accident, the FAA had conducted a ramp check of the pilot and the accident airplane and also conducted an investigation that determined there was not sufficient evidence that the pilot was conducting any illegal for-hire operations.

The twin-tubofan airplane overran the runway during an aborted takeoff, impacting two fences before coming to rest. The pilot reported experiencing no anomalies with the airplane during the preflight inspection and taxi portion of the flight. During takeoff roll, at V1 (103 knots), the pilot began to pull aft on the control yoke. The pilot noticed the nose landing gear was not coming off of the runway and at 120 knots, with full aft control input, elected to abort the takeoff. He pulled the power to idle and applied maximum braking. Upon seeing the localizer antennas approaching the airplane at the departure end of the runway, the pilot veered the airplane to the right of centerline. The airplane departed the runway surface and impacted the fences. Post-accident examination of the runway revealed tire skid marks on the runway that led to the airplane's final resting place. The tire skid marks measured 1,765 feet in length. Examination of the wreckage revealed no pre-existing brake system anomalies that would have hindered the airplane's braking capability. Examination of the elevator trim system revealed it was 12 degrees out of trim in the nose down direction. The airplane underwent a Phase B and Phase 1 through 5 inspections approximately 5 months prior to the accident. The manufacturer's inspection manual indicates the elevator system should be examined every Phase 5 inspection. The aircraft's flight manual informs the pilot that the right elevator and trim tab should be inspected during the exterior inspection to ensure the elevator trim tab position matches its indicator.

During takeoff, the twin-engine airplane was observed to roll left, pitch nose down, and impact terrain shortly after the pilot reported to ATC that he had a problem. Witnesses reported that the left engine was producing black smoke during the takeoff roll. One witness stated that the airplane had slowed to approximately 60-70 mph prior to rolling to the left. A mechanic, who worked on the airplane prior to the accident, stated that the pilot reported being unable to maintain manifold pressure (MP) with the left engine. The mechanic found that the left engine's rubber interconnect boot, which routes induction air between the turbocharger controller elbow and the fuel servo, was 'gaping open.' The mechanic reseated the boot and tightened the clamp. The pilot flew the airplane and reported no problems. During a second flight, the pilot reported that the left engine was again unable to maintain MP. Prior to the accident flight, the pilot informed the mechanic that the 'hose had slid off again' and that it had been reinstalled and he 'felt sure it was o.k.' A witness stated that he saw the pilot working on the left engine the morning of the accident. At the accident site, the left engine's interconnect boot was found disconnected. The clamp securing the boot was not located. No other preimpact anomalies were found with the engines, propellers, turbochargers, or fuel servos.

Just after liftoff, while in initial climb, the single engine airplane lost speed and height and crashed in flames. The aircraft was destroyed and all five occupants who were taking part to a demonstration flight were killed.

The crew left Oklahoma City-Wiley Post Airport on a local test flight. While in cruising altitude, the airplane disappeared from radar screens, dove into the ground and crashed in an open field. Debris scattered on a wide area and both occupants were killed.

The crew was engaged in a local test flight and departed Oklahoma-Wiley Post Airport in the early afternoon to test the aircraft that has a new tail design. While cruising at a speed of 243 knots in the vicinity of the airport, the rudder detached. The airplane entered a dive and crashed in a field located in Bethany, by the airport. All three crew members were seriously injured and the aircraft was destroyed.