San Carlos

Shortly after takeoff for a repositioning flight for the airplane’s upcoming annual inspection, numerous witnesses, including the two air traffic controllers, reported observing the airplane climbing out normally until it was about 1/2 mile beyond the runway. The witnesses stated that the airplane then underwent a short series of attitude excursions, rolled right, and descended steeply into a lagoon. All radio communications between the airplane and the air traffic controllers were normal. Ground-based radar tracking data indicated that the airplane's climb to about 500 feet was normal and that it was airborne for about 40 seconds. Postaccident examination of the airframe, systems, and engines did not reveal any mechanical failures that would have precluded continued normal operation. Damage to both engines’ propeller blades suggested low or moderate power at the time of impact; however, the right propeller blades exhibited less damage than the left. The propeller damage, witness-observed airplane dynamics, and the airplane’s trajectory were consistent with a loss of power in the right engine and a subsequent loss of control due to airspeed decay below the minimum control speed (referred to as VMC). Although required by the Federal Aviation Administration (FAA)-approved Airplane Flight Manual, no evidence of a cockpit placard to designate the single engine operating speeds, including VMC, was found in the wreckage. The underlying reason for the loss of power in the right engine could not be determined. The airplane's certification basis (Civil Air Regulation [CAR] 3) did not require either a red radial line denoting VMC or a blue radial line denoting the single engine climb speed (VYSE) on the airspeed indicators; no such markings were observed on the airspeed indicators in the wreckage. Those markings were only mandated for airplanes certificated under Federal Aviation Regulation Part 23, which became effective about 3 years after the accident airplane was manufactured. Neither the Federal Aviation Administration (FAA) nor the airplane manufacturer mandated or recommended such VMC or VYSE markings on the airspeed indicators of the accident airplane make and model. In addition, a cursory search did not reveal any such retroactive guidance for any twin-engine airplane models certificated under CAR 3. Follow-up communication from the FAA Small Airplane Directorate stated that the FAA has "not discussed this as a possible retroactive action... Our take from the accident studies is that because of the accident record with light/reciprocating engine twins, the insurance industry has restricted them to a select group of pilot/owners…" Toxicology testing revealed evidence consistent with previous use of marijuana by the pilot; however, it was not possible to determine when that usage occurred or whether the pilot might have been impaired by its use during the accident flight.

During the flight, the instrument-rated private pilot was monitoring the weather at his intended destination. He noted the weather and runway conditions and decided to conduct a global-positioning-system instrument approach to a known closed runway with the intention of circling to a different runway. As the airplane neared the missed approach point, the pilot established visual contact with the airport's runway environment and canceled his instrument flight rules clearance. As he entered the left downwind leg of the traffic pattern for his intended runway, the pilot noticed that the first part of the runway was covered in fog and that the visibility was 0.75 of a mile with light snow. With at least 5,000 feet of clear runway, he opted to land just beyond the fog. Prior to touchdown, the pilot concluded that there was not enough runway length left to make a landing and performed a go-around by applying power, pitching up, and retracting the landing gear. During the go-around, the pilot focused outside the airplane cockpit but had no horizon reference in the dark night conditions. He heard the stall warning and realized that the aircraft was not climbing. The pilot pitched the nose down and observed only snow and trees ahead. Not being able to climb over the trees, the airplane subsequently impacted trees and terrain, coming to rest upright in a wooded, snow-covered field. The pilot stated that there were no anomalies with the engine or airframe that would have precluded normal operation of the airplane.

The airplane just had undergone a routine maintenance and this was planned to be the first flight after the inspection. During the initial climb, the pilot observed that the airplane was drifting to the left. The pilot attempted to counteract the drift by application of right aileron and right rudder, but the airplane continued to the left. The pilot reported that, despite having both hands on the control yoke, he could not maintain directional control and the airplane collided into a building. The airplane subsequently came to rest on railroad tracks adjacent to the airport perimeter. A post accident examination revealed that the elevator trim wheel was located in the 9-degree NOSE UP position; normal takeoff range setting is between 2 and 3 degrees NOSE UP. The rudder trim control knob was found in the full left position and the right propeller lever was found about one-half inch forward of the FEATHER position; these control inputs both resulted in the airplane yawing to the left. The pilot did not adequately follow the airplane manufacturer's checklist during the preflight, taxi, and before takeoff, which resulted in the airplane not being configured correctly for takeoff. This incorrect configuration led to the loss of directional control immediately after rotation. A post accident examination of the airframe, engines, and propellers revealed no anomalies that would have precluded normal operation.

The four engine aircraft departed Swan Island Airport (Islas del Cisne) off Honduras on a supply mission to the Contras rebels in Nicaragua. It was carrying a load of weapons, ammunition, clothing and food as well as 10 people. After 11 pallets were dropped, the aircraft was hit by a surface-to-air missile that struck one of the right engine. The aircraft continued for about 30 km when it was shot down by a second surface-to-air missile and crashed four minutes later. One occupant was injured while nine others were killed.

The aircraft departed San Salvador-Ilopango Airport and was dispatched over Nicaragua to deliver military supply to the Contras on behalf of a US program. On board were 70 AK-47 rifles, about 100,000 ammunition, rockets and grenades. Approaching San Carlos after flying along the coast, the crew descended to an altitude of 2,500 feet and was preparing to jettison the cargo when the aircraft was shot downy by a surface-to-air SAM-7 missile from the Sandinista forces. The aircraft lost height and crashed. Three crew members were killed while the fourth was able to parachute to safety. He was later captured by the Sandinista National Liberation Front.

The aircraft was on a flight from Managua to Bluefields and San Carlos and then returning to Managua. It departed San Carlos for Managua at 1049LT carrying a crew of 3 and 13 passengers. This information was given directly by the captain over the aircraft's transmitters, as the radio station for point-to- point communication is in the town, some distance from the landing field. The aircraft made no further contact. It crashed into the side of Concepción Volcano at 1118LT at a height of 2,650 feet killing all occupants. The aircraft crashed while performing a sharp ascending left curve at an altitude of 2,650 feet (according to the reading of the operating altimeter found at the accident site) and on a magnetic heading of 1700, i. e. 127° off its original course of 297°, and 350 feet below its cruising level, reported by the pilot as 3 000 feet. Witnesses stated that the weather was clear and fog covered only the top of the volcano, from 3 200 feet to its summit. A number of persons saw the aircraft flying on its normal heading to Managua shortly before the accident. Had the weather been unfavorable the pilot could very well have taken the usual action of flying at an altitude above all obstructions on the route and would have reported such action.