United States of America

A Cessna 414 collided with a tree in a mountainous residential area about 1 mile from the airport. Instrument meteorological conditions with 1/8 mile visibility prevailed and an instrument flight rules (IFR) flight plan was filed, but was not opened. The airplane departed under visual flight rules. The elevation of the collision was about 100 feet higher than the airport. The standard instrument departure procedures for the airport prescribe takeoff minimums of 3,500 foot ceiling and 3 miles visibility. The procedure requires a minimum climb rate of 425 feet per nautical mile, a right turn after takeoff to intercept a 002° radial off a VOR, and a climb to a specified altitude. The airman's information manual recommends that pilots climb to 400 feet agl before turning when executing standard instrument departure under IFR. The airplane was also determined to be about 400 pounds over maximum gross weight at the time of the takeoff. The wreckage examination disclosed no evidence of any pre existing aircraft or engine malfunctions or failures. All four occupants were killed.

The aircraft was designed and used as the company's engineering test bed. An evaluation of the fly-by-wire rudder actuator and ground minimum control speed (vmcg) was being conducted. During the final hi-speed ground test run, the aircraft abruptly veered left and became airborne. It entered a left turn, climbed to about 250 feet, departed controlled flight and impacted the ground. Investigation revealed a design feature in the rudder actuator that removes hydraulic pressure within the actuator if the rudder position commanded by the pilot exceeded the actual rudder actuator position for a specified time, and the rudder aerodynamically trails. The actuator previously disengaged in flight. The company did not conduct a system safety review of the rudder bypass feature and its consequences to all flight regimes, nor of the vmcg test. The flight test plan specified that engine power be retarded if the rudder became ineffective. Neither pilot had received training as an experimental test pilot. The company allowed experimental flight tests at a confined, metropolitan airport. All seven occupants were killed.

During a dark night cross country in instrument meteorological conditions, the airplane was cleared for a VOR approach to runway 30. Due to unfavorable winds, the pilot elected to circle to land on runway 12. While on a right downwind, visual contact with the runway was lost and not reestablished. The pilot continued the descent on the base leg and impacted the terrain in a slight right turn.

A Cessna 414 collided with a level ground while attempting to land during a snow shower. The pilot reported an emergency one minute after departing ifr and requested to return to the airport under visual rules. The pilot indicated to air traffic control that 'I can't get any speed.' The visibility was variable around the airport with the lowest report of 1/2 mile. Witnesses observed the airplane traveling fast at low altitude and indicated both engines were running. Investigation revealed during servicing before the flight, the pitot tube covers were not used. About 1.5 inches of snow had accumulated on the airplane during the refueling and was brushed off. The airplane was seen flying into a snow shower and reversing course. Witnesses reported the airplane's angle of bank to be 80 to 90° with a 20° pitch down attitude. The airplane descended into a snow covered pasture. Witnesses reported the airplane leveled its wing just before impact. Manufacturer's safety and warning supplements indicate inflight ice protection is not designed to remove snow on parked aircraft. The manufacturer recommends use of heated hangars or approved deicing solutions to insure the are no internal accumulations in pitot static system ports. Both occupants were killed.

After making a refueling stop, the pilot took off at night and was cruising at FL200. After about 30 minutes of flight, the right engine fuel filter bypass warning light illuminated. About 2 minutes later, the same warning light for the left engine illuminated. Soon thereafter the right engine, then the left engine, lost power. The pilot made a forced landing on a moving ice pack in the Bering sea, which resulted in substantial damage. Ice was found in the engine and main fuel screens. Significant amounts of water and/or ice were found in 3 tanks, which had been refueled before takeoff. A higher than normal amount of water was also found in the fuel sample taken from the nozzle of the refueling tanker. The flight manual required that an approved ice inhibitor be added to the fuel, if not premixed. Fuel at the refueling stop was not premixed and the pilot had no icing inhibitor (prist) with him on this flight. He did not drain fuel from the tanks during preflight, since the temperature was so cold he feared the drain might freeze open.

During the approach, the 1st officer (FO) asked the captain if he wanted to '...pop the boots?' to remove ice off the wings. The capt responded '...it's going to the hangar. I'll run'em on the ground...' The FO retarded power over the threshold and the sink rate increased; the capt observed 900 fpm. The FO applied additional back pressure on the yoke, but it was inadequate to arrest the high sink rate. Additional back pressure was applied, and the stall horn sounded followed shortly thereafter by the captain stating 'I got it.' During the hard landing the right main landing gear broke, the fuel tank ruptured, and the right wing rear spar bent upward. Aprx 18 hrs after the accident, 3/16 inch of rime mixed with clear ice was observed on the leading edges of the wing, horizontal stab, and vertical stab. The ice had finger-like protrusions positioned vertically to the wing surfaces. The company's line ops manual does not discuss flight characteristics or landing techniques specific to wing ice. Neither pilot had received company's current crm training.

The pilot and flight nurse were en route to pick up a medical patient. The airplane experienced an in-flight breakup while flying by the leeward side of the sierra nevada mountains in the general area where standing lenticular clouds had been observed. No evidence was found that the pilot obtained a weather briefing from flight service or the duat vendors prior to departure. Pilots flying in the general area had reported airspeed variances from plus 60 to minus 40 knots. An in-flight weather advisory for occasional moderate turbulence was in effect. About one hour after the accident the weather service issued a sigmet for severe turbulence. Cause: an inadvertent encounter with severe turbulence which exceeded the design strength of the airplane's structure. Both occupants were killed.

After departure, the airplane intercepted airway V-2, and appeared to climb normally until reaching 8,300 feet (9,000 assigned) while tracking approximately 110° magnetic. Radar analysis showed the airplane at 128 kias when it abruptly turned left 30° and then appeared to recover. Voice communication during this event was normal with no change in the pilot's level of anxiety. Immediately thereafter, the heading changed over 90° to the left (northbound), and a maximum 6,750 fpm rate of descent developed before the heading stabilized and the descent slowed. The airplane's ground impact site was approximately 1 nm southwest of the last radar target. Wreckage distribution was roughly parallel to V-2. The airplane impacted the mountainside in a steep nose low, left wing down attitude. The engines, propellers/governors were disassembled and inspected with no evidence of mechanical malfunction. Exam of the left propeller indicated low power on impact. There was no evidence of significant icing/turbulence. The pilot, sole on board, was killed.

While in a descent for arrival at the destination airport, the aircraft sustained structural failure with the right outer wing, horizontal stabilizer, and vertical stabilizer separating from the aircraft. The aircraft impacted approximately 10 miles from the planned destination. According to radar data and other research, the descent was conducted at vne and known severe turbulence was present in the area at the time of the accident.

Pilot reported level at 6,000 feet; no further transmissions were received. Radar data shows that after 5 minutes at cruise flight ground speed began to slow, and as speed reached 85 knots (VMC is 83 knots) aircraft made a rapid turn to the left and the speed dropped to 74 knots. Radar contact was then lost. Witnesses reported hearing and seeing aircraft with an engine sputtering and quitting, at which time no engine noise was audible. Engine would then restart, and at one point aircraft was observed initiating a climb after engine start. Engine restarted and obtained near full power, and a short time later sound of impact was heard. The left engine fuel servo was found contaminated with corrosion and dirt, and would not allow fuel flow to the engine. The fuel strainer for this engine was installed backwards allowing unfiltered fuel to enter the engine. The left propeller was not feathered and had no signs of rotation under power. Right engine fuel servo also contained corrosion and contamination. The aircraft did not have a current annual inspection. All five occupants were killed.