Positioning

After passing the initial approach fix, during an instrument approach to the destination airport, radar and radio contact were lost with the business jet. One witness reported hearing "distressed engine noises overhead," and looked up and saw what appeared to be a small private jet flying overhead. The engine seemed to be "cutting in and out." The witness further reported observing the airplane in a left descending turn until his view was blocked by a ridge. The witness then heard an explosion and saw a big cloud of smoke rising over the ridge. A second witness heard a loud noise and looked up and saw a small white airplane with two engines. The witness stated that the airplane started to turn left with the nose of the airplane slightly pointing toward the ground. The airplane appeared to be trying to land on a road. A third witness heard the roar of the airplane's engines, and looked toward the noise and observed the airplane in a vertical descent (nose dive) impact the ground. The witness "heard the engines all the way to the ground." Examination of the airframe and engines did not disclose any structural or mechanical anomalies that would have prevented normal operation. The National Weather Service had issued a SIGMET for severe turbulence and mountain wave activity. Satellite images depicted bands of altocumulus undulates and/or rotor clouds over the accident site.

The commercial pilot was positioning the airplane from the departure airport to another airport. The flight took place on a dark night with overcast skies, and no discernible horizon. The pilot departed and climbed to a cruise altitude between 1,200 and 1,400 feet msl. About 4 miles south of the departure airport, the airplane collided with an east-west ridge at 1,200 feet msl. The ridgeline is perpendicular to the direct route of flight between the departure and destination airports, and rises from west to east with a summit elevation of 1,714 feet msl. The departure airport was a newly commissioned airport 3 miles east-northeast of the old airport. The accident flight was the pilot's second trip to the new airport, and his first night departure from either the old or new airport. Direct flight from the new airport to the destination airport requires a higher altitude to clear the ridgeline than does a direct flight from the old airport. A direct flight from the old airport crosses the same ridgeline farther to the west, where the elevation of the ridge is less than 500 feet msl.

The aircraft departed Moscow-Domodedovo Airport on a positioning flight Bishkek-Manas Airport where cargo should be loaded. The water ballast tanks were not filled, causing the centre of gravity to be outside the allowed limits. After passing the outer marker on approach to runway 26, a 15-second period of oscillations started with changes in bank angle and heading (between 245° and 255°). The plane passed over the runway threshold at a height of 30 metres and at a speed of 293 km/h. At this point the altitude should have been 15 metres. At a height of 20 metres, at a speed of 297 km/h, the thrust reversers of the n°1 and 4 engines were deployed. This was contrary to regulations, which stipulate that thrust reversers may only be deployed at the leveling-off altitude of 5-8 metres. The nose then rose to a 7° pitch angle. This was caused by the activation of the thrust reversers and the centre of gravity which was too far aft. The pitch-up could not be countered by a 13° nose down elevator application. The plane finally touched down on the maingear wheels 1395 metres down the 4,200 metres long runway. The flight engineer, without telling the pilot in command, shut down the n°2 and 3 engines. With an elevator-down deflection of 10-11° and the stabilizer at -3,3° the crew were still not able to get the nose gear on the ground. After retracting the thrust reversers and with the elevator deflected in a 21° nose-down attitude, the nose pitched down from +7° to -2,5° in 2-3 seconds. The stabilizer was then trimmed from -3,3° to +9° which caused the pitch angle to increase again. The Ilyushin ran off the left side of the runway 3,001 metres past the runway threshold. The plane continued until colliding with a concrete obstruction. The aircraft caught fire and burned out almost completely.

After a normal taxi and takeoff, the airplane's landing gear would not retract after liftoff. After unsuccessfully attempting to raise the landing gear manually, the flight crew elected to return to the airport. During the landing flare, the ground spoilers deployed when the throttles were brought to idle. The airplane descended rapidly and landed hard, and the right main landing gear collapsed. The investigation determined that a mechanic had wedged wooden sticks into the airplane's weight-on-wheels (WOW) switches to force them into the ground mode while the airplane was on jacks during maintenance. The mechanic said that he used the sticks to disable the WOW switches to gain access to the maintenance data acquisition unit, which was necessary to troubleshoot an overspeed alert discrepancy. After the maintenance was performed, the sticks were not removed, and the airplane was returned to service. No notation about the disabled WOW switches was entered in the work logs. Postaccident ground testing of the accident airplane's cockpit crew alerting system and examination of flight data recorder (FDR) data determined that the system was functioning properly and that it produced a blue WOW fault message, an amber WOW fault message, and a red GND SPOILER warning message when the accident flight conditions were recreated. The messages produced were consistent with FDR and cockpit voice recorder (CVR) information. Ground spoilers will deploy when the throttles are brought to idle if the spoilers are armed and the WOW switches are in the ground mode. The G-V Quick Reference Handbook (QRH) cautions flight crews not to move thrust reverser levers and to switch the GND SPOILER armed to off following an amber WOW FAULT message. A red GND SPOILER message calls for the flight crew to disarm the ground spoilers and pull the circuit breakers to make sure the spoilers are not rearmed inadvertently. Based on CVR information, there was no indication that the flight crew followed checklist procedures contained in the G-V's QRH that referenced WOW faults or GND SPOILER faults. Preflight checklist procedures also called for the flight crew to conduct a visual inspection of the WOW switches.

As the airplane was descending to the airport, the pilot-in-command (PIC) calculated that the required distance to land on a dry runway would be 2,720 feet. The second-in-command (SIC) stated to the PIC, "all right if I touch down and there's no brakes I'm going around." The ILS Runway 23 approach was in use, and the braking action was reported "poor" by a Hawker Jet, which had landed prior to the accident flight. All runway surfaces were covered with a thin layer of snow. The airplane touched down with about 2,233 feet of runway remaining, of the 5,101-foot long runway. The airplane departed the end of the runway, and proceeded into an overrun grassy area, where the nose landing gear assembly collapsed. The tower controller advised the flightcrew prior to landing that the wind conditions were from 330 degrees at 18 knots. According to the airplane's Pilot's Operating Manual, the estimated landing distance on a dry runway, for the conditions at the time of the accident, was about 2,750 feet. No charts were available in the FAA approved Airplane Flight Manual, to compute a landing distance incorporating a contaminated runway. Review of 14 CFR Part 25.1, which prescribed airworthiness standards for the issue of type certificates, and changes to those certificates, for transport category airplanes, revealed, "For landplanes and amphibians, the landing distance on land must be determined on a level, smooth, dry, hard-surfaced runway." There were no requirements for the applicant to determine landing distances on a wet or contaminated runway. The latest weather recorded at the airport, included winds from 330 degrees at 12 knots, gusts to 22 knots; visibility 3/4 statute mile, light snow; and overcast clouds at 300 feet.

The airplane was destroyed when it impacted the ground while maneuvering at a low altitude following a loss of control in instrument meteorological conditions. The airplane was on a flight in instrument meteorological conditions when radar and voice contact were lost. Prior to the loss of communication, controllers advised the pilot to check altitude. At this point, the radar data shows that the airplane was about 400 feet below the assigned altitude. Subsequently, the pilot said, "roger sir my auto pilot i just cut off uh correcting immediately." This was the last received transmission from the pilot. The radar data shows that the airplane then began a descending right turn at an average rate of descent of 1,276 feet per minute. This descent was followed by a climbing left turn with an average rate of climb of 5,423 feet per minute. The radar data shows that the radius of the left turn continued to decrease until radar contact was lost about 500 feet above the last assigned altitude. A witness who saw the airplane just prior to impact described the airplane maneuvering beneath the clouds prior to pulling up sharply and then pitching down and impacting the ground. There was a utility wire and associated poles running across the airplane's flight path in the field where the wreckage was located. The airplane exploded and burned upon impact. No anomalies were found with the airplane or associated systems. The autopilot section of the Pilot's Operating Handbook states, "Sustained elevator overpower will result in the autopilot trimming against the overpower force." The result is that if up elevator pressure is applied with the autopilot engaged, the autopilot will trim the airplane nose down.

The pilot said that the copilot was flying a visual approach to runway 15 at the Lawrence Municipal Airport, Lawrence, Kansas. The pilot said, "With gear down and full flaps at approximately 15 to 20 feet above the runway and 115 KTS, the nose abruptly dropped and there was no elevator effectiveness with the yoke pulled back to the mechanical stop." The pilot said, "After landing, I noticed that the stabilizer trim indicated full nose down in the cockpit and, upon exterior inspection, the stab was in that position." The copilot said, "I made my turn to base and proceeded to make my turn to final. No problems with the controllability were noted at this time. The turn to final was made and the airplane was lined up with the runway on final approach with normal glide path. My altitude was dropping normally and my airspeed was approximately 140 knots." The copilot said, "When it got time to pull the power back to idle for landing our airspeed was approximately 110 knots and power was reduced. At that point in time the nose of the aircraft seemed to pitch over towards the runway and increase speed. I pulled back on the yoke to raise the nose and at that same instance the pilot recognized the pitch over and pulled back on the yoke at the same time. The yoke did not seem to pull all of the way to its full extent of travel and felt to mechanically stop at about 3/4 the way travel. Even with both pilot's pulling on the yoke it seemed unresponsive and failed to raise the nose back to a proper landing attitude. The aircraft hit the runway very hard and came to a stop on the runway." A preliminary inspection of the airplane showed the stabilizer positioned at 4 degrees nose down. An examination of the airplane's systems revealed no anomalies.

While on a positioning flight from Cozumel to Playa del Carmen, both engines failed. The aircraft lost height and was ditched off Playa del Carmen. All four crew members were injured and rescued by the crew of the Mexican coast-guards while the aircraft sank and was lost.

A commercial pilot, who observed the airplane during the takeoff attempt, stated that it used "lots" of runway, and that the nose lifted "too early and way too slow." The airplane "struggled" to get in the air, and it appeared tail heavy, with "extreme" pitch, about 45 degrees nose-up. It also appeared that the only thing keeping the nose up was ground effect. The airplane became airborne for "a very short time," then sank to the ground, and veered off the left side of the runway. The nose was "up" the whole time, the airplane never "rolled off on a wing," and the wings never wobbled. The engines were "really loud," like a "shriek," and engine noise was "continuous until impact." Another witness at a different location confirmed the extreme nose high takeoff attitude and the brief time the airplane was airborne. It seemed odd to him that an airplane with that much power used so much runway. A runway inspection revealed no evidence of foreign objects or aircraft debris. Tire tracks from the airplane's main landing gear veered off the left side of the paved surface, at a 20-degree angle, about 3,645 feet from the runway's approach end. They continued for about 775 feet, then turned back to parallel the runway for another 650 feet, before ending about 50 feet prior to a chain link fence. There was no evidence that the nose wheel was on the ground prior to the fence. The fence, which was about 1,300 feet along the airplane's off-runway ground track and 200 feet to the left of the runway edge stripe, was bent over in the direction of travel. Ground scars began about 150 feet beyond the fence, and the main wreckage came to rest 300 feet beyond the beginning of the ground scars. The first officer advised a witness that he'd be making the takeoff; however, the pilot at the controls during the accident sequence could not be confirmed. When asked prior to the flight if he'd be making a high-performance takeoff, the captain replied that he didn't know. There was no evidence of mechanical malfunction.

The airplane collided with an airport boundary fence during an aborted landing. The pilot made a normal approach following the visual approach slope indicator (VASI) with gear down and full flaps and touched down just past the numbers and began to decelerate. The pilot selected reverse thrust with both engines. As he added power to decelerate, the airplane suddenly veered to the left and off the runway when the right engine did not go into reverse thrust. He deselected reverse thrust and aligned the airplane with the runway. He was approaching the end of the runway at high speed and elected to attempt a takeoff. The airplane went off the end of the runway onto smooth grass. The pilot rotated the airplane, but the airplane collided with an airport boundary fence and came to rest in a field. In a post accident examination, when the power levers were placed in the full reverse position, the left fuel control measured 4°, while the right measured 0°. The left pitch control measured 10°, while the right measured 0°; the controls should have read 0°. A controls engineer determined that during landing, there would be a 10° propeller pitch control (PPC) angle mismatch, which would be about 2.5° of BETA angle. With matched levers, there would be asymmetric reverse thrust with the left engine lower in torque. This would result in the airplane turning towards the left if both propellers had gone into reverse pitch.