Exclusive: Air France faces new safety probe after freighter takeoff scare

An Air France aircraft takes-off at the Charles-de-Gaulle airport, near Paris April 8, 2015. REUTERS/Gonzalo Fuentes

PARIS (Reuters) - Air France faces its second safety investigation in as many weeks after pilots were forced to recover in mid-takeoff after entering the wrong data into the computer of a cargo jet, airline and safety officials said.

The mistake over the plane's weight was discovered when the Boeing 777 freighter accelerated too slowly while starting off down the runway at Paris Charles de Gaulle airport on May 22.

Underestimating the weight can cause the plane to settle for less thrust than needed and try to leave the ground too early, increasing the risk of damage from a 'tail strike'.

A person familiar with the matter said the weight entered into the system of the Mexico-bound jet was drastically lower than the correct value, lagging by as much as 100 tonnes, which is over a quarter of its maximum take-off weight.

To compensate, pilots had to override the automated settings and order up maximum power from the aircraft's two engines.

Air France confirmed the incident in response to a query from Reuters and said the crew had been taken off flying duties once they had reached their initial destination.

A spokeswoman for France’s BEA air crash investigation agency said it had launched an investigation in addition to the airline’s own internal probe.

"I confirm that an investigation has been opened in response to information provided by Air France," she said.

It is the second time this month that Air France has grounded one of its crews and issue a safety alert to all pilots after a Boeing 777 jetliner narrowly avoided hitting Mount Cameroun, the highest peak in Central Africa.

In both cases, the airline said crew had identified the problems in time and responded correctly.

(Reporting by Tim Hepher; editing by Geert De Clercq)