Muskogee

The pilot was conducting an instrument flight rules cross-country flight and climbing to a planned altitude of 23,000 ft mean sea level (msl). According to air traffic control data, as the airplane climbed through 18,600 ft msl, its groundspeed was 171 knots, and a gradual reduction in groundspeed began. After reaching an altitude of about 20,200 ft msl, the airplane began a descent on a southeast heading. Just before the descent began, the airplane’s groundspeed had decreased to 145 knots. About 2 minutes after the descent began, the airplane turned right to a northeast heading on which it continued for about 30 seconds. The flightpath then became erratic before the data ended. The pilot made no distress calls and did not respond to repeated calls from the controller. The main wreckage of the airplane was located in densely forested terrain at an elevation of about 930 ft about 1,000 ft south of the last radar return. The outboard portion of the right wing, right aileron, right horizontal stabilizer, and right elevator were not located with the main wreckage and, despite ground and aerial searches with a small unmanned aircraft system, were not found. Examination of the wreckage indicated that the missing wing and tail sections separated in flight due to overload. Examination of the recovered airframe and engine did not reveal evidence of any pre-existing mechanical malfunctions or anomalies that would have precluded normal operation. Weather forecasts indicated that the accident site was in an area where moderate icing conditions up to 25,000 ft msl, embedded thunderstorms, and 2-inch hail were forecasted. Review of preflight weather information received by the pilot indicated that he was aware of the conditions forecast on the route of flight before initiating the flight. Meteorological data revealed that the airplane likely entered icing conditions that ranged from light to heavy as it climbed through 14,000 ft msl about 23 minutes after takeoff and remained in icing conditions for the remaining 16-minute duration of the flight. Freezing drizzle conditions were likely present along the flightpath. Although the airplane was equipped for flight in icing conditions, the pilot’s operating handbook contained a warning about flight into severe icing conditions, which stated that flight in freezing drizzle could result in ice build-up on protected surfaces exceeding the capability of the ice protection system. The airplane’s gradual loss of groundspeed as it climbed was consistent with ice accumulating on the airplane. It is likely that during the 16 minutes the airplane was operating in icing conditions, the capability of the ice protection system was exceeded, which resulted in a degradation of aircraft performance and subsequent aerodynamic stall. During the ensuing uncontrolled descent, the structural capability of the airplane was exceeded, which resulted in an inflight break up. A review of the pilot’s records revealed multiple certificate application failures for reasons that included inadequate knowledge of cross-country flight planning, aircraft performance, and stalls. Review of the pilot’s airman knowledge written tests found areas answered incorrectly over multiple exams included meteorology, aircraft performance, aeronautical decision-making, and stalls. The ethanol identified in the pilot’s cavity blood was most likely the result of postmortem production. Therefore, effects from ethanol did not play any role in this accident. The cargo was documented as it was removed from the airplane and remained secure until after it was weighed. Based upon the weight of the cargo, passengers, airplane, and fuel from the filed flight plan, at the time of departure, the airplane would have been about 361 lbs over maximum gross weight. According to the FAA Pilot’s Handbook of Aeronautical Knowledge, an overloaded airplane “may exhibit unexpected and unusually poor flight characteristics,” which include reduced maneuverability and an increased stall speed.

A pilot (whose instrument currency could not be determined) took off at night in IMC. Shortly after takeoff, the aircraft crashed about 1.5 mile from the departure end of the runway. There was evidence that it impacted in an 85° right bank, nose down attitude at high speed. No preimpact part failure was found during the investigation; however, during a pre-purchase inspection on 10/16/90, several discrepancies were noted. These included an inop flight director, an autopilot malfunction and a misrigged flight control system that allowed the control wheel to indicate a left turn when the aircraft was in level flight. There was no record of these being repaired. Records showed the pitot-static system was last tested on 3/24/88. The pilot was taking sine-aid and tylenol for a chronic sinus infection. Although tox checks indicated the presence of 50.7 ug/ml of pseudoephedrine and 36.4 ug/ml of acetaminophen in the pilot's urine, none was found in his blood. The sinus cond could have affected the pilot's balance and equilibrium. All six occupants were killed.

On final approach, the twin engine airplane was too low and struck power cables. It stalled and crashed in flames few dozen yards short of runway, killing all three occupants.

While approaching Victoria Regional Airport, Texas, the pilot encountered poor weather conditions with low clouds and fog. On final, he descended below MDA when the twin engine airplane struck trees and crashed. All five occupants were injured, two of them seriously, and the aircraft was destroyed.

En route to Muskogee, while cruising by night, the pilot reported engine trouble but did not report any emergency. Twenty minutes later, the airplane went out of control and crashed in a huge explosion near Altus. The pilot, sole on board, was killed.