US Republican Representative Don Young, who had served in Congress since 1973, has died, his office said in a statement on Friday local time.
Young's office said the 88-year-old congressman had passed away on Friday while traveling home to Alaska.
"Don Young's legacy as a fighter for the state will live on, as will his fundamental goodness and honour. We will miss him dearly," the statement said.
His office did not state the cause of death. The Anchorage Daily News reported that Young had lost consciousness on a flight from Los Angeles to Seattle and could not be resuscitated. The newspaper report cited Jack Ferguson, who had served as Young's chief of staff.
Young was Alaska's only House representative. He was the longest serving member of the current US Congress, according to his website.
"His fiercely independent voice for Alaska and one of a kind wit and character will be missed," US Representative Dean Phillips, a Democrat from Minnesota, said on Twitter.
- Reuters