A distinguished career came to a close here Feb. 10. After flying senior military leaders and undergoing rigorous testing for more than 31 years, the Speckled Trout tail number 61-2669 officially retired.

"Speckled Trout was the primary transport aircraft for every Air Force chief of staff since General David C. Jones (July 1974 to June 1978)," said Gen. Bruce Carlson, Air Force Materiel Command commander. "Not only has it transported distinguished people ... there are countless examples of technological advantages that our warfighters have reaped as benefits from the work that has been done on this great airplane."

C-135 tail number 61-2669 rolled off the assembly line in 1962, and began its service for the Air Force as a weather reconnaissance aircraft.

In 1975, the aircraft became part of Project Speckled Trout and served primarily as overseas transportation for Air Force chiefs of staff. The Speckled Trout has also been an intricate part of many test programs at the Air Force Flight Test Center.

"It is bittersweet for the men and women of the 412th Flight Test Squadron and Edwards to see this plane leave and go out of service, but the time is now," said Lt. Col. Ed Topps, 412th FLTS commander. "The plane has unique avionics equipment and has difficult-to-maintain, one-of-a-kind systems. And besides, after 31,000 hours flying, I'm sure (she) needs a break."

As the Trout heads into retirement, mission continuity will not be lost. The back-up airplane for the Trout is called KC-01 and is already flying in support of Project Speckled Trout's mission.

"We'll use our back-up airplane for about a year until it retires as well," Colonel Topps said. "Then we'll take delivery of a KC-135R model that's currently in Greenville, Texas, being modified for the same mission."

The new KC-135 will have a slightly different mission that supports greater tests and air refueling requirements here.

The Speckled Trout will rest in the care of the Air Force Flight Test Center Museum here, said Doug Nelson, museum director.

"Our museum's goal is to depict the history of Edwards and of flight testing. The Speckled Trout was definitely a major player in both of these," Mr. Nelson said.