A man missing since the small plane he was flying disappeared from radar contact was an experienced pilot and a respected navigation expert.
Professor David Last has not been seen since the aircraft reportedly crashed on Monday. His relatives have said they are "heartbroken".
No trace of the pilot or his plane has been found despite two days of searches off the coast of North Wales.
Coastguard teams were forced to suspend their air and sea operation near Penmon in Anglesey on Tuesday afternoon due to "adverse weather conditions" including strong winds and rain.
The 79-year-old had been flying a Cessna light aircraft which disappeared from radar in the area of Puffin Island close to Anglesey at 12.47pm on Monday.
The plane set off from Caernarfon Airport 25 minutes earlier to fly to the Great Orme in Llandudno and was returning when its altitude plummeted before vanishing.
No passengers were on board the aircraft.
A family statement said: "Professor David Last was a consultant engineer and expert witness specialising in radio navigation and communications systems.
"He was a professor emeritus at the University of Bangor, past president of the Royal Institute of Navigation and a respected figure in the worldwide navigation community.
"He was an experienced, instrument-rated pilot.
"Most importantly to us, he was head of the family: a much-loved father, husband, brother, grandfather, uncle and friend, and we are all heartbroken."
A police spokesman said officers were continuing to support Professor Last's family.