Airport (less than 10 km from airport)

Shortly after takeoff from Bogotá-Guaymaral Airport runway 10, while in initial climb, the crew initiated a left turn in accordance with procedures. The copilot contacted ATC and declared an emergency following technical problems. The crew was immediately cleared to land at his discretion when the aircraft entered an uncontrolled descent and crashed in a prairie located 600 metres from the runway 28 threshold. The aircraft was totally destroyed and all eight occupants were killed.

The airline transport pilot was landing a retractable landing gear-equipped turboprop airplane on a 10,900 foot long, by 150 foot wide paved runway. According to the pilot, while on approach to land, he selected 10 degrees of wing flaps, and then selected the landing gear selector switch to the down position, which was followed by "three greens", indicating the landing gear was down, locked, and safe for landing. He said that after touchdown, during the initial landing roll, the landing gear retracted, and the airplane slid on the underside of the fuselage. The airplane veered to the right of the runway centerline, and the right wing collided with numerous runway edge lights. A post crash fire ensued when the right wing's fuel tank was breached. The airplane received structural damage to the underside of the fuselage, and the right wing was destroyed. Propeller strike marks originated in the vicinity of the accident airplane's touchdown point, and extended to the airplane's final resting point, about 2,200 feet from initial contact. A postaccident inspection of the airplane by the IIC and another NTSB air safety investigator, disclosed no evidence of any pre accident mechanical malfunction of the landing gear assembly or its associated operating systems. The airplane was placed on jack stands and hydraulic pressure was supplied to the airplane's hydraulic system using a hydraulic ground power unit. The airplane's landing gear retraction system was cycled numerous times, with no mechanical anomalies noted.

Following an uneventful flight from Lima, the aircraft was descending to Pucallpa-Capitán David Abensur Rengifo Airport runway 02, an intermediate stop on the flight from Lima to Iquitos. As the crew approached the destination, weather conditions deteriorated with heavy rain falls, CB's and turbulences. On final approach, the aircraft was unstable and descended below the glide until it crashed in a swampy and wooded area located 3,5 km short of runway. The aircraft was destroyed by impact forces and a post crash fire. 58 people were injured, some seriously, while 40 other occupants including five crew members were killed, among them 34 Peruvian, three American, one Australian, one Colombian and one Spanish.

During the initial approach, the red GEAR annunciator light above the gear lever illuminated, and the landing gear warning horn sounded after the gear handle was selected down and the flaps were selected to 25 degrees. During the go-around, the captain asked the second officer (SO), "what do you have for the gear lights?" The SO responded, "four here." When all gear are down and locked on the Boeing 747-200, the landing gear indication module located on the SO’s instrument panel has five green lights: one nose gear light above four main landing gear lights. The crew then read through the "Red Gear Light Remains On (After Gear Extension)" emergency/abnormal procedure from the cockpit operations manual to troubleshoot the problem. Although the checklist twice presented in boldface type that five lights must be present for the gear to be considered down and locked, the crew did not verbalize the phrase either time. The captain did not directly request a count, and the SO did not verbally confirm, the number of gear down annunciator lights that were illuminated; instead, the flight crew made only general comments regarding the gear, such as "all gear," "all green," or "got 'em all." Because the crew believed that all of the gear annunciator lights were illuminated, they considered all gear down and locked and decided not to recycle the landing gear or attempt to extend any of the gear via the alternate systems before attempting a second approach. During all communications with air traffic control, the flight crew did not specify the nature of the problem that they were troubleshooting. Although the checklist did not authorize a low flyby, if the flight crewmembers had verbalized that they had a gear warning, the controller most likely would have been able to notify the crew of the nose gear position before the point at which a go-around was no longer safe. Multiple gear cycles were conducted after the accident, and the nose gear extended each time with all nose gear door and downlock indications correctly displayed on the landing gear indication module. Post accident examination of the nose gear door actuator found that one of the two lock keys was installed 180 degrees backward. Although this improper configuration could prevent proper extension of the nose gear, the actuator had been installed on the accident airplane since 2001 after the actuator was overhauled by the operator. No anomalies were found with the landing gear indication module, the nose gear-operated door sequence valve, and the nose/body landing gear selector valve.

During an ILS approach in night instrument meteorological conditions, the airplane impacted terrain and was destroyed by impact forces and post crash fire. Prior to departure, the pilot obtained a weather briefing, which reported light rain, mist, and instrument meteorological conditions at the destination airport. After approaching the terminal area, the pilot received radar vectors to intercept the localizer for the Runway 35R ILS approach. The pilot's keying of the microphone and the timing of his speech exhibited decreased coordination during the approach phase of flight. After crossing the outer marker and at altitude of 7,700 feet, the pilot asked the controller what the current ceilings were at the airport, and the controller stated 500 feet. With the airplane at an altitude of 6,800 feet, the controller informed the pilot of a "low altitude alert" warning, at which the pilot responded, "Yeah, I am a bit low here." Approximately 20 seconds later, the pilot stated, "I'm back on glideslope." No further communications were received from the accident airplane. The controller issued another low altitude warning, and the radar target was lost. The accident site was located on a hilly, grass field at an elevation of 6,120 feet approximately 2.6 nautical miles from the runway threshold
near the extended centerline of the runway. At 2027, the weather conditions at the airport were reported as wind from 360 degrees at 10 knots, visibility 2 statute miles with decreasing rain, scattered clouds at 500 feet, broken clouds at 1,100 feet, and an overcast ceiling at 2,800 feet. An acquaintance of the pilot, who had flown with him on other occasions, provided limited information about the pilot's proficiency, but stated, "a night ILS in IFR conditions would not be [the pilot's] first choice if he had an option." The pilot's logbooks were not located. The pilot did not hold a valid medical certificate at the time of the accident, and postaccident toxicological test revealed the presence of unreported prescription medications. No anomalies were noted with the airframe and engines. Ground inspection and flight testing of the airport's navigational equipment revealed that the equipment functioned satisfactorily.

En route from Tehran to Khorramabad, while in cruising altitude, the right engine failed. The crew was cleared by ATC to divert to Arak Airport. After landing, the aircraft went out of control, veered off runway and came to rest. All 27 occupants escaped uninjured while the aircraft was damaged beyond repair.

Upon landing at Luena Airport, the four engine aircraft went out of control, veered off runway and came to rest. All occupants escaped uninjured while the aircraft was damaged beyond repair.

The twin-engine airplane sustained substantial damage when it impacted the top of a single story industrial building and then impacted a landscape embankment and trees during an attempted single-engine go-around. The pilot reported that the left engine failed during initial climb. He feathered the left propeller and returned to the airport to execute an emergency landing. The pilot reported that he had "excessive speed" on final approach and "overshot the runway." When the airplane was at mid-field, the pilot elected to do a go-around. He did not raise the landing gear and the flaps remained about 15-degrees down. The airplane lost altitude and impacted the terrain about .5 miles from the airport. A witness reported seeing the airplane attempt to land on the runway twice during the same approach, but ballooned both times before executing the go-around. The Pilot's Operating Handbook (POH) "Rate-of-Climb One Engine Inoperative" chart indicated that about a 450-foot rate-of-climb was possible during the single-engine go-around if the airplane was in a clean configuration. The chart also indicated that a 350-foot penalty would be subtracted from the rate-of-climb if the landing gear were in the DOWN position, and additionally, a 200-foot penalty would be subtracted from the rate-of-climb if the flaps were in the 15-degree DOWN position. Inspection of the left engine revealed that the starter adapter shaft gear had failed. Inspection of the engine maintenance logbooks revealed that the Teledyne Continental Motors Service Bulletin CSB94-4, and subsequent revisions including the Mandatory Service Bulletin MSB94- 4F, issued on July 5, 2005, had not been complied with since the last engine overhaul on July 17, 1998. The service bulletin required a visual inspection of the starter adapter every 400 hours. The engine logbook indicated that the engine had accumulated about 1,270 hours since the last overhaul. The service bulletin contained a WARNING that stated, "Compliance with this bulletin is required to prevent possible failure of the starter adapter shaft gear and/or crankshaft gear which can result in metal contamination and/or engine failure."

After takeoff for a maintenance check flight, both engines on the twin-engine airplane experienced a loss of engine power. The 7,200-hour pilot had recently purchased the airplane, which had not been flown for nearly four years. The pilot, who is also a certificated airframe and powerplant mechanic, completed the inspection of the airplane prior to takeoff. During the engine run-up, the pilot noticed that the RPM and manifold pressure on the left engine did not correspond with those of the right engine. During the takeoff roll, the pilot believed the RPM on both engines began to rise to near acceptable levels, but not entirely. However, he did not abort the takeoff. The airplane became airborne for a short time, and then began to descend into trees before impacting the ground. The reason for the reported loss of engine power could not be determined.

The commercial pilot was executing a precision instrument approach at night in instrument meteorological conditions when the airplane collided with terrain about four miles short of the runway. A review of air traffic control communications and radar data revealed the pilot was vectored onto the final approach course but never got established on the glide slope. Instead, he made a controlled descent below the glide slope as he proceeded toward the airport. When the airplane was five miles from the airport, a tower controller received an aural low altitude alert generated by the Minimum Safe Altitude Warning (MSAW) system. The tower controller immediately notified the pilot of his low altitude, but the airplane collided with terrain within seconds. Examination of the instrument approach system and onboard flight navigation equipment revealed no pre-mishap anomalies. A review of the MSAW adaptation parameters revealed that the tower controller would only have received an aural alarm for aircraft operating within 5 nm of the airport. However, the frequency change from the approach controller to the tower controller occurred when the airplane was about 10.7 miles from the airport, leaving a 5.7 mile segment where both controllers could receive visual alerts, but only the approach controller received an aural alarm. A tower controller does not utilize a radar display as a primary resource for managing air traffic. In 2004, the FAA changed a policy, which eliminated an approach controller's responsibility to inform a tower controller of a low altitude alert if the tower had MSAW capability. The approach controller thought the MSAW alarm parameter was set 10 miles from the airport, and not the 5 miles that existed at the time of the accident. Subsequent investigation revealed, that The FAA had improperly informed controllers to ensure they understood the alarm parameters for control towers in their area of responsibility. This led the approach controller to conclude that the airplane was no longer her responsibility once she handed it over to the tower controller. Plus, the tone of the approach controller's aural MSAW alarm was not sufficient in properly alerting her of the low altitude alert.