David Learmount/LONDON

Kenya Airways, Alaska Airlines and Iran Air suffered accidents at the end of January, resulting in the deaths of more than 250 people.

On 31 January at Tehran Airport, Iran, an empty Iran Air Airbus A300B2 under tow collided with an Iranian air force Lockheed Martin C-130 Hercules, which was about to depart for a test flight. Fire destroyed both aircraft. Six bodies have been found, but more are believed to have died.

Just after take-off from Abidjan, Ivory Coast, on 30 January, a Kenya Airways Airbus A310-300 crashed into the sea about half a kilometre offshore, leaving 10 survivors from the 168 passengers and 11 crew. The 14-year-old General Electric CF6-powered A310 took off at about 21:00 local time in good weather, says the airline.

A controller is quoted as saying that the aircraft hardly climbed following a longer than usual take-off run, and two survivors say that the aircraft felt unstable before it crashed. Since its formation in 1977, the airline has not had a fatal accident.

Alaska Airlines' Boeing MD-83, originally cruising at 31,000ft (9,500m) en route Puerto Vallarta, Mexico, to San Francisco, California, ended by crashing into the sea off Point Mugu, California, at 16:30 local time on 31 January.

The crew notified ATC that they were having pitch control trouble and were cleared to descend for Los Angeles. Initially the aircraft was under control, and the problem identified as a "jammed" horizontal stabiliser trim.

There was no further contact, however, after the crew had indicated that they were going to deploy flap early, presumably to check its effect on pitch stability. The last transponder return showed the aircraft passing through 17,000ft, and eyewitnesses report the aircraft spiralling inverted. All 83 passengers and five crew were killed. The cockpit voice recorder has been recovered.

MD-80 stabilisers serve as a manual pitch trim for the pilots, and as the autopilot pitch control. Stabiliser pitch angle is controlled by an electric motor in both cases. Pilots use the elevators, fitted with geared trailing edge tabs to lighten the control forces, for manual pitch control. This is Alaska's first fatal accident since 1971.

Source: Flight International