Cessna 550 Citation II

While approaching class B airspace, the airline transport pilot was in communication with a controller who later stated that the pilot's speech was slurred, and the controller repeatedly asked if the oxygen system on the airplane was working properly. As the airplane approached a nearby airport, about 85 miles from his destination airport, the pilot stated he had the airport in sight and repeatedly requested a visual approach. The controller instructed the pilot to continue his flight to his destination, in a southwest direction. As the controller attempted to maintain communications, the pilot dropped off radar shortly after passing the nearby airport and subsequently landed at the nearby airport, which was not his destination airport. According to a surveillance video and impact marks on the runway, the airplane landed hard about halfway down the runway and slid to a stop on the left side of the runway. The airplane fuselage and wings were mostly consumed by postimpact fire. After authorities arrived onsite, the pilot was arrested for operating an aircraft under the influence of alcohol. The pilot was found to have a blood alcohol level of .288, which likely contributed to the pilot landing at the incorrect airport and his subsequent loss of airplane control during landing.

The pilot was conducting a personal cross-country flight in a turbofan-powered airplane. Shortly after departure, the airplane entered a witness-estimated 90° left bank with the nose parallel to the horizon; as the airplane began to roll out of the turn, the nose remained at or below the horizon before it dropped and the airplane impacted the ground. Flight track data revealed that, shortly after departure, the airplane's ground speed immediately began decreasing from its maximum of 141 knots during takeoff and continued decreasing until the last recorded data point, which showed that the airplane had a ground speed of 100 knots. The surface wind reported about 10 minutes before the accident was from 170° at 9 knots, gusting to 14 knots, which resulted in a 1- to 2-knot tailwind component. Given this information and the airplane's configuration at the time of the accident, the airplane's indicated airspeed (IAS) would have been between about 86 and 93 knots. The airplane's stall speed was calculated to be 100 knots IAS (KIAS) with a bank angle of 45° and 118 KIAS with a bank angle of 60°. Thus, the pilot failed to maintain airspeed or accelerate after departure, which resulted in an aerodynamic stall A pilot who had flown with the accident pilot twice before the accident reported that, during these flights, the pilot had flown at reduced power settings and slower-than-normal airspeeds. During the flight 1 year before the accident, he reached over and pushed the power levers forward himself. He also stated that every time he had flown with the pilot, he was "very behind the airplane." Postaccident examination of the engines revealed no signs of preimpact mechanical failures or malfunctions that would have precluded normal operation, and both engines exhibited circumferential rub marks on all rotating stages, blade tip bending opposite the direction of rotation, and debris ingestion through the gas path, indicating that the engine had power at impact. Further, the right engine full authority digital electronic control (FADEC) nonvolatile memory recorded no faults. (The left engine FADEC could not be downloaded due to damage.) The Airplane Flight Manual stated that the pilot must, in part, advance the throttle lever to the maximum takeoff detent for the FADEC's nonvolatile memory to record a logic trend snapshot 2 seconds after takeoff. The lack of a FADEC logic trend snapshot is consistent with the pilot not fully advancing the throttles during the takeoff and initial climb and is likely why he did not attain or maintain sufficient airspeed. The flight track data, pilot witness account, and airplane damage are consistent with the pilot failing to fully advance the power levers while maneuvering shortly after takeoff, which led to his failure to maintain sufficient airspeed and resulted in the exceedance of the airplane's critical angle of attack and a subsequent aerodynamic stall.

The commercial pilot was conducting a cross-country, business flight with 10 passengers onboard the 8-passenger airplane. He reported that air traffic control cleared the flight for an instrument landing system (ILS) approach to the runway. While descending, the airplane entered instrument meteorological conditions (IMC) at 3,100 ft mean sea level (msl), and ice started to accumulate on the wing's leading edges, empennage, and windshield. The pilot activated the pneumatic deice boots multiple times during the approach and slowed the airplane to 120 knots. The airplane then exited the clouds about 400 ft above ground level (agl), and the pilot maintained 120 knots as the airplane flew over the airport fence; all indications for landing were normal. About 100 ft agl, the airplane started to pull right. He applied left correction inputs, but the airplane continued to pull right. He applied engine power to conduct a goaround, but the airplane landed in grass right of the runway, sustaining damage to the wings and landing gear. Witnesses and passengers reported that the airplane stalled. During examination of the airplane immediately after the accident, about 1/2 to 1 inch of mixed ice was found on the right wing's leading edge, the vertical and horizontal stabilizers, and the angle of attack probe. Ice was also observed on the windshield. The flaps were found in the "up" position. Flight control continuity was established. Although the airplane was originally certificated for two-pilot operation, the pilot was flying the airplane under a single-pilot exemption. The pilot received a logbook endorsement indicating that he had received single-pilot training and was properly qualified under the single-pilot exemption. However, he
had not met the turbine flight time qualifications (1,000 hours) to be properly authorized to conduct the flight under the single-pilot exemption because he only had 500 hours. A review of cockpit voice recorder information indicated that, although the pilot verbalized that the landing gear was "all green," followed by stating "check, check, check," he did not verbalize all the approach or landing checklist items nor did he make any audible comments about activating the pneumatic deice boots or windshield anti-ice. A review of radar data for the flight indicated that, during the last 2 minutes of flight, while the airplane was on final approach to the runway, the indicated airspeed got as low as 99 knots. The last recorded radar return indicated that the airplane had an airspeed of 104 knots at 900 ft msl. The pilot's lack of minimum flight experience required to fly the airplane without a copilot likely led to task saturation as he flew the airplane entered IMC and icing conditions while on an ILS approach. He subsequently failed to lower the flaps during the approach, which resulted in a no-flap approach instead of a full-flap landing. The ice on the leading edges of the wings, the no-flap approach, and the low airspeed likely led to the exceedance of the airplane's critical angle of attack, which resulted in an aerodynamic stall.