Oklahoma

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.

The commercial pilot departed on a night instrument flight rules flight in actual instrument meteorological in-flight conditions. Less than 2 minutes after the airplane departed the airport, the controller observed the airplane in a right turn and instructed the pilot to report his altitude. The pilot responded he thought he was at 3,500 feet and he thought he had lost the gyros. The pilot said he was trying to level out, and when the controller informed the pilot he observed the airplane on radar making a 360-degree right turn , the pilot said "roger." Three minutes and 23 seconds after departure the pilot said "yeah, I'm having some trouble right now" and there were no further radio communications from the flight. The on scene investigation disclosed that both wings and the tail section had separated from the airframe. All fractures of the wing and wing skin were typical of ductile overload with no evidence of preexisting failures such as fatigue or stress-corrosion. The deformation of the wings indicated an upward failure due to positive loading. No anomalies were noted with the gyro instruments, engine assembly or accessories

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 2,100-hour instrument-rated private pilot stated that prior to departure for a 507 nautical mile cross-country flight, the fuel gauges indicated approximately 800 pounds of fuel on each side for a total of 1600 pounds; however, he did not visually check the amount of fuel that the tanks contained. During his approach to the destination airport, the right engine started to "sputter" before it finally quit. The pilot then "looked over at the fuel gauges and both tanks were showing empty." The left engine quit just a few moments later. The auto ignition installed in the airplane attempted to restart the engines. The engines restarted momentarily and then shut-off once more. The pilot declared an emergency and executed a forced landing onto a street below. After a hard landing onto the street, the right wing hit a telephone pole, and the left wing then hit several tree limbs before the airplane impacted a hill and came to a stop. The Federal Aviation Administration (FAA) inspector, who responded to the accident site, found the fuel transfer switch in the "right-crossfeed" position. The fuel system was examined and no leaks or anomalies were found. Approximately three-quarters of a gallon of unusable fuel was found in the right engine nacelle. Approximately four gallons (28 pounds) of usable fuel was found in the left engine nacelle.

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.

According to air traffic control communication and radar data, the flight was VFR over the top, approximately 7,900 feet, and requested an IFR clearance to the destination airport. The flight was issued an IFR clearance and, subsequently, was cleared for the localizer runway 03 approach. Radar data indicates that the airplane intercepted the localizer and began tracking inbound. Once the airplane reached the final approach fix, the airplane entered a shallow descent, but did not reach the MDA until after passing the missed approach point (MAP). The airplane flew past the MAP, continued to descend and over flew the runway. The final radar return was captured at 1,200 feet and one mile northeast of the airport, where the airplane was later located. The weather observation facility located at the airport reported that, 11 minutes before the accident, the winds were from 140 degrees at 6 knots, ceiling 200 feet overcast, visibility 1/4 miles in fog, temperature 45 degrees Fahrenheit and dew point 45 degrees Fahrenheit. A person who was at the airport at the time of the accident reported that the "clouds were low and visibility was poor." Toxicological testing performed on the pilot by the FAA's Civil Aeromedical Institute, Oklahoma City, Oklahoma, revealed the following: 0.121 (ug/ml, ug/g) amphetamine detected in blood, 0.419 (ug/ml, ug/g) amphetamine detected in liver, amphetamine detected in kidney, 4.595 (ug/ml, ug/g) methamphetamine detected in blood, 5.34 (ug/ml, ug/g) methamphetamine detected in liver, 3.715 (ug/ml, ug/g) methamphetamine detected in kidney, pseudoephedrine present in blood, and pseudoephedrine present in liver. The airframe and engines were examined and no anomalies were discovered that would have affected operation of the flight.

The pilot reported that light snow was falling, with approximately 2 inches already on the ground, and the runway had been plowed approximately one hour prior to his departure. About 20 minutes had elapsed since the airplane had been towed from the '68 degree F' hangar. During the takeoff, the airplane accelerated 'normally' and became airborne after traveling about 2,160 feet down the 3,240-foot runway. After liftoff, the airplane did not climb above 25 or 30 feet agl. The airplane impacted an embankment at the end of the runway, continued across railroad tracks, and through a fence coming to rest in a brick storage yard about 800-1,000 feet from the departure end of the runway. The pilot stated that someone told him that the airport did not have any deicing equipment, therefore, he did not deice the airplane. The weather facility, located 5 miles from the accident site, reported the wind from 100 degrees at 7 knots, visibility 1/2 mile with snow and freezing fog, temperature 27 degrees F.