Cessna 414 Chancellor

The instrument-rated commercial pilot departed from an airport adjacent to the Gulf of Mexico with an instrument flight rules clearance for a cross-country flight in dark night, visual
meteorological conditions. The flight continued in a south-southwesterly direction, climbing to about 900 ft over the gulf, where it entered a steep right turn. The airplane then descended at a steep rate and impacted the water in a nose-low attitude. Post accident examination of the recovered wreckage, including flight controls, engines, and propellers revealed no evidence of preimpact failure or malfunction. While the outlet fuel line from the left auxiliary fuel pump was found separated and there was evidence that the B-nut was loose and had been only secured by the first 2 threads, recorded data from the engine monitor for the flight revealed no loss of power from either engine. Therefore, the final separation likely occurred during the impact sequence. Although the accident pilot was instrument rated and had recently completed instrument currency training, the dark night conditions present at the time of the accident combined with a further lack of visual references due to the airplane's location over a large body of water, presented a situation conducive to the development of spatial disorientation. The pilot had been instructed by air traffic control to turn southwest after takeoff; however, the continuation of the turn past the intended course and the airplane's steep bank angle and excessive rate of descent are consistent with a loss of control due to spatial disorientation.

The twin-engine airplane, flown by an airline transport pilot, was approaching the destination airport after a cross-country flight in night instrument meteorological conditions. The destination airport weather conditions about 1 minute before the accident included an overcast ceiling at 200 ft and 1/2-mile visibility with light rain and fog. According to air traffic control (ATC) data, the flight received radar vectors to the final approach course for an instrument landing system (ILS) approach to runway 20. As shown by a post accident simulation study based on radar data and data recovered from the airplane's electronic horizontal situation indicator (EHSI), the airplane's flight path did not properly intercept and track either the localizer or the glideslope during the instrument approach. The airplane crossed the final approach fix about 360 ft below the glideslope and then maintained a descent profile below the glideslope until it leveled briefly near the minimum descent altitude, likely for a localizer-only instrument approach. However, the lateral flight path from the final approach fix inbound was one or more dots to the right of the localizer centerline until the airplane was about 1 nautical mile from the runway 20 threshold when it turned 90° left to an east course. The turn was initiated before the airplane had reached the missed approach point; additionally, the left turn was not in accordance with the published missed approach instructions, which specified a climb on runway heading before making a right turn to a 270° magnetic heading. The airplane made a series of pitch excursions as it flew away from the localizer. The simulation study determined that dual engine power was required to match the recorded flight trajectory and ground speeds, which indicated that both engines were operating throughout the approach. The simulation results also indicated that, based on calculated angle of attack and lift coefficient data, the airplane likely encountered an aerodynamic stall during its course deviation to the east. The airplane impacted the ground about 2.2 miles east-northeast of the runway 20 threshold and about 1.75 miles east of the localizer centerline. According to FAA documentation, at the time of the accident, all components of the airport's ILS were functional, with no recorded errors, and the localizer was radiating a front-course to the correct runway. Additionally, a post accident flight check found no anomalies with the instrument approach.An onsite examination established that the airplane impacted the ground upright and in a nose-low attitude, and the lack of an appreciable debris path was consistent with an aerodynamic stall/spin. Wreckage examinations did not reveal any anomalies with the airplane's flight control systems, engines, or propellers. The glideslope antenna was found disconnected from its associated cable circuit. Laboratory examination and testing determined that the glideslope antenna cable was likely inadequately connected/secured during the flight, which resulted in an unusable glideslope signal to the cockpit avionics. There was no history of recent maintenance on the glideslope antenna, and the reason for the inadequate connection could not be determined. Data downloaded from the airplane's EHSI established that the device was in the ILS mode during the instrument approach phase and that it had achieved a valid localizer state on both navigation channels; however, the device never achieved a valid glideslope state on either channel during the flight. Further, a replay of the recorded EHSI data confirmed that, during the approach, the device displayed a large "X" through the glideslope scale and did not display a deviation pointer, both of which were indications of an invalid glideslope state. There was no evidence of cumulative sleep loss, acute sleep loss, or medical conditions that indicated poor sleep quality for the pilot. However, the accident occurred more than 2 hours after the pilot routinely went to sleep, which suggests that the pilot's circadian system would not have been promoting alertness during the flight. Further, at the time of the accident, the pilot likely had been awake for 18 hours. Thus, the time at which the accident occurred and the extended hours of continuous wakefulness likely led to the development of fatigue. The presence of low cloud ceilings and the lack of glideslope guidance would have been stresses to the pilot during a critical phase of flight. This would have increased the pilot's workload and situational stress as he flew the localizer approach, a procedure that he likely did not anticipate or plan to conduct. In addition, weight and balance calculations indicated that the airplane's center of gravity (CG) was aft of the allowable limit, and the series of pitch excursions that began shortly after the airplane turned left and flew away from the localizer suggests that the pilot had difficulty controlling airplane pitch. This difficulty was likely due to the adverse handling characteristics associated with the aft CG. These adverse handling characteristics would have further increased the pilot's workload and provided another distraction from maintaining control of the airplane. Therefore, it is likely that the higher workload caused by the pilot's attempt to fly an unanticipated localizer approach at night in low ceilings and his difficulty maintaining pitch control of the airplane with an aft CG contributed to his degraded task performance in the minutes preceding the accident.

The twin engine aircraft, owned by Lawrence R. Liptack, crashed in flames in an open field located northeast of Bowie, Texas. The pilot and owner, aged 51, was killed with his son aged 10. The multi-engine airplane was about 500 ft above ground level (agl) and on a left base landing approach when a witness saw the airplane suddenly point straight down, begin spinning, and make three complete rotations before impacting terrain in a partially nose-down attitude. The airplane came to rest upright, and was mostly consumed by an immediate post impact fire. A post accident examination of the wreckage revealed no evidence of preimpact mechanical malfunctions or failures that would have precluded normal operation. A pilot operating another pipeline patrol airplane in the vicinity reported frequent severe-to-extreme turbulence about 1,000-2,000 ft above ground level. Data from an on-board GPS unit indicated that, while on the base leg of the airport traffic pattern for landing, the accident airplane's airspeed decayed 10 knots below the manufacturer's recommended approach speed for turbulent conditions. An autopsy performed on the pilot found significant existing atherosclerotic disease (60 to 80 percent) and described evidence of an acute, premortem, nonocclusive thrombosis of the left anterior descending coronary artery. The medical examiner's conclusion stated it "appears the decedent likely suffered an acute cardiac event while piloting his aircraft" and "died primarily due to hypertensive and atherosclerotic cardiovascular disease and that his multiple blunt force injuries likely contributed to his death." It is likely that the pilot was incapacitated due to the acute cardiac event and lost control of the airplane during the approach to land.

The pilot reported that, shortly after takeoff, the twin-engine airplane's left front baggage door opened. He attempted to return to the airport, but the left engine lost engine power while the airplane was on the downwind leg of the traffic pattern. The airplane subsequently impacted power lines and terrain. An explosion occurred during the impact sequence, and a fire ensued that almost completely consumed the airframe. Tear down examination of the right engine revealed no anomalies. A test run of the left engine revealed no anomalies; however, due to impact and fire damage, it was not possible to fully test or examine the left engine's fuel system. The reason for the left engine’s loss of power could not
be determined.