LONDON — Emiliano Sala, a soccer player who recently moved to the English Premier League, was aboard a small airplane that disappeared Monday night while crossing the English Channel, and he and the pilot are feared dead, the authorities said on Tuesday.

John Fitzgerald, chief officer for Channel Islands Air Search, said that an air and sea operation would continue, but he did not expect to find either survivors or parts of the aircraft.

“I think we’re sort of getting to that stage now that it would be difficult to find anyone alive,” Mr. Fitzgerald, 58, said in a telephone interview on Tuesday. “The cold would have taken effect. The tide flows so fast, there’s the wind and a lot of white water — it’s more and more unlikely for the chance of survival.”

France’s Civil Aviation Authority confirmed that Mr. Sala, 28, who was about to begin playing for the club Cardiff City, was on the plane along with the pilot. Edwige Leroy, a spokeswoman for the agency, said it was not yet sure whether anyone else was aboard.