ST. JOHN'S, N.L. -- Quebec pilot Gilles Morin, 61, was one of seven people aboard a float plane that crashed into a Labrador lake on Monday, killing at least three people on board.

Four people remain missing today after a full day of searching by military rescuers and RCMP, scanning Mistastin Lake, where the tail of the plane and other debris were spotted early Tuesday.

Jean Tremblay, president of the Quebec airline that owns the plane, confirmed Morin was piloting the de Havilland DHC-2 Beaver that crashed.

He said he does not know who is missing and who has been confirmed dead, but he is not optimistic any survivors will be found.

Tremblay described Morin as a kind man and an experienced, no-nonsense pilot, loved by his friends and colleagues.

Morin has been an employee of Air Saguenay since 2011 and according to Tremblay, he has 20,000 hours of flying experience.

Military helicopters were to remain at the lake until nightfall Tuesday, before handing the search over to the RCMP.

The plane carrying Morin, two guides and four guests left Three Rivers Lodge on Crossroads Lake, east of Schefferville, Que., Monday morning for a fishing camp on Mistastin Lake, but it did not return as planned that evening.

The cause of the crash remains unknown. The Transportation Safety Board of Canada is investigating.