The 1956 BOAC Argonaut accident occurred on 24 June 1956 when a British Overseas Airways Corporation

British Overseas Airways Corporation

The British Overseas Airways Corporation was the British state airline from 1939 until 1946 and the long-haul British state airline from 1946 to 1974. The company started life with a merger between Imperial Airways Ltd. and British Airways Ltd...

 (BOAC) four-engined Canadair C-4 Argonaut

Canadair North Star

The Canadair North Star was a 1940s Canadian development of the Douglas C-54 / DC-4 aircraft. Instead of radial piston engines found on the Douglas design, Canadair employed Rolls-Royce Merlin engines in order to achieve a 35 mph faster cruising speed. The prototype flew on 15 July 1946 and...

 airliner registered

Aircraft registration

An aircraft registration is a unique alphanumeric string that identifies a civil aircraft, in similar fashion to a licence plate on an automobile...

 G-ALHE crashed into a tree on departure from Kano Airport in Nigeria

Nigeria

Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...

, three crew and 29 passengers were killed.

Accident

At 17:21 the Argonaut departed Runway 25 at Kano Airport on the way to Tripoli in Libya. The flight was from Lagos to London and had made a scheduled stop at Kano. It was raining as the aircraft reached 250 feet when the aircraft began to lose height. The pilot applied full power but the aircraft continued to descend until it hit a tree about 1½ miles from the end of the runway. Three of the seven crew members and 29 of the 38 passengers were killed in the crash, two crew and two passengers were seriously injured.

Investigation

A team from the British Ministry of Transport and Civil Aviation and BOAC flew out from London on the 25 June in a chartered Canadair Argonaut

Canadair North Star

The Canadair North Star was a 1940s Canadian development of the Douglas C-54 / DC-4 aircraft. Instead of radial piston engines found on the Douglas design, Canadair employed Rolls-Royce Merlin engines in order to achieve a 35 mph faster cruising speed. The prototype flew on 15 July 1946 and...

 to help in the investigation. The Nigerian investigation team of four was led by the Director of Civil Aviation.

Inquiry Report

The Board of Inquiry concluded "The accident was the result of a loss of height and airspeed caused by the aircraft encountering, at approximately 250ft after take-off, an unpredictable thunderstorm cell which gave rise to a sudden reversal of wind direction, heavy rain, and possible downdraft conditions. The formation of the cell could not have been predicted by the meteorological forecaster at Kano airport, nor was it visible to the pilot in command before taking off. In the circumstances, no blame can be attached to the pilot in command for taking off."

The report also recommended that the International Civil Aviation Organisation urgently consider investigating the special hazards to aircraft inherent in taking off or landing in close proximity to thunderstorms.

The Kano accident was one of the first to a large airliner to be attributed directly to the weather phenomenon later to be more widely known by the term "microburst

Microburst

A microburst is a very localized column of sinking air, producing damaging divergent and straight-line winds at the surface that are similar to, but distinguishable from, tornadoes, which generally have convergent damage. There are two types of microbursts: wet microbursts and dry microbursts...

", and the subsequent analysis of the tragedy contributed importantly to a better understanding of a grave and hitherto under-appreciated danger to aviation.