A couple from East Yorkshire have gone missing during a microlight flying trip between Spain and France.
The man and woman from Bridlington have not been heard from since they sent a radio message to a friend on Friday morning.
The plane left the Spanish area of Le Startit on Friday heading towards France but did not reach its destination at the appointed time.
French and Spanish authorities are investigating the disappearance.
The alarm was raised after a friend of the couple contacted Humberside police saying they were missing.
The last radio message was received from the plane at 1030 local time on Friday from the Spanish town of Rosace, 50km away from the border with France.
Although Humberside Police are not involved in the investigations, they are helping the European authorities.
Inspector Steve Page said: "We have been asked to contact various family members, however, this is proving difficult and a daughter has not yet been traced.
"This matter is being dealt with in its entirety by the French and Spanish authorities who have been conducting search operations in the relevant areas."