Three French officials and a technical expert from Airbus arrived in Cairo on Friday morning to assist in the hunt for the missing EgyptAir passenger jet that dropped off radar screens Thursday, airport sources said.

The French investigators are part of the investigations and analysis department of the French civil aviation ministry, the sources told Aswat Masriya website.

Airport officials told AP that three British investigators also arrived on Friday morning to join the investigation. 

French nationals make up the second-largest number of passengers on board the doomed plane, 15 out of a total of 66. Britain had one national on board. Thirty Egyptians was aboard the aircraft, which was flying from Paris to Cairo, including seven crew members and three security staff.

Airbus, the France-based civil aircraft manufacturer, said on Thursday it was "ready to provide full technical assistance" to France and the authorities in charge of the investigations.

A team from the US National Transportation Safety Board is also participating in investigations into the disappearance given that the engines of the aircraft were manufactured in the US.