A French airliner bound for Mauritius that was experiencing technical problems dropped a load of jet fuel over a broad area of Italy and Switzerland on Easter Sunday so that it could return safely to Paris.
Pilots with Corsair International Airlines reportedly learned of the unspecified difficulties while the Boeing 747-400 was above Italy’s Gulf of Genoa, and then decided to turn around.
To lighten the weight of the plane so that it could land properly, the pilots dropped some 70 tonnes of kerosene jet fuel around midnight at elevations sometimes higher than the world’s highest peaks.
They were flying at altitudes between 6,700 and 9,400 metres, along an unspecified path in the broad region that lies between the Italian Alps and the Swiss Jura, Swiss news agencies reported.
The commercial flight landed without further incident, and no one was injured. Technicians are examining the cause of the problem.
Fuel dumping usually occurs at a high altitude through nozzles close to the wingtips and away from engines. Not all planes are equipped to do it. The Swiss cabinet and aviation experts have downplayed risks to the environment, saying discharged jet fuel usually evaporates before it reaches the ground.
When a flight develops a technical problem and must land earlier than expected "it will often need to reduce its weight before doing so by jettisoning or ‘dumping’ fuel", says Skyguide, which manages and monitors Swiss air space.
All fuel-dumping operations occur at a prescribed minimum altitude and are coordinated with air traffic control to keep other aircraft in the clear, according to Skyguide, which employs more than 540 civil and military air traffic controllers and hundreds of others in Switzerland.
The Geneva-based company reports all fuel-dumping cases on behalf of the Federal Office of Civil Aviation (FOCA), which is part of the environment ministry and is responsible for assessing the environmental impacts in such cases.
swissinfo.ch and agencies