Divers recovered the last body from the sunken wreckage of Air Florida Flight 90 yesterday, completing one part of a ghastly task that began 11 days ago after the jetliner struck the 14th Street bridge and plunged into the Potomac River, killing 78 people.

The body of 2-month-old Jason Tirado, one of three infants aboard the flight, was retrieved from the river at 8:45 a.m. after 45 minutes of diving. Jason's grandfather was notified and the body was taken to the D.C. Medical Examiner's office.

The body of the infant's father, 23-year old Jose Tirado of Spain, was recovered from the river Thursday. His mother, 22-year old Priscilla Tirado, was one of five survivors plucked from the river immediately after the crash. She remains hospitalized at the National Hospital for Orthopaedics and Rehabilitation with a broken leg and various cuts and bruises.

With the bodies of all 74 passengers ans crew members who died aboard the ill-fated flight removed from the water, salvage crews yesterday concentrated on recovering the rest of the wreckage.

Workers at the crash site raised the Boeing 737's right wheels of the landing gear and the right wing tip late Saturday, and hoped to recover the rest of the landing gear and a stabilizer Sunday.

"We have total recovery of the persons and 90 percent of the wreckage," D.C. Police Inspector James P. Shugart said yesterday afternoon.

The D.C. Department of Transportation was expected to open the center commuter spans of the 14th Street bridge last night after salvage crews removed command buses and dismantled the large blue crane that had hoisted much of the wreckage onto flatbed trailers.

Shugart said that "most of the major efforts should be completed by Monday," and that the Army, Navy and Coast Guard units encamped along the river near the crash site would remain until the middle of the week.

Meanwhile the National Transportation Safety Board continued to examine the twisted sheet metal and pieces of the plane in Hangar 12 at National Airport where the wreckage is being laid out. The second engine, recovered Friday, was trucked to the hangar, where investigators were studying the exterior before taking it apart.

Investigators have transferred the information on the flight data recorder, which keeps track of altitude, air speed, headings and stress forces, into a computer at the National Transportation Safety Board headquarters on Independence Avenue NW. They also have been "listening over and over again to the cockpit voice recorder," board spokesman Ira Furman said yesterday, adding that "it will several more days' work before we can begin preparing a transcript of the voice recorder."

However, the investigators have been unable to determine from the cockpit voice recorder whether the landing gear was extended or retracted at the time of the crash. When the landing gear is extended, the plane is slowed down. Part of the investigation is focusing on whether the plane was traveling fast enough to climb appropriately after takeoff.

Investigators hope to find a clue to the status of the landing gear by examining the condition of the filaments in the cockpit indicator bulbs, which are similar to brake and generator lights in automobiles.

Furman said that the board had received the preliminary report from the D.C. Medical Examiner's office ruling out alcohol as a factor in the crash. The medical examiner's office had concluded that the pilot's blood alcohol was "negative," Furman said.

One of the survivors, Bert Hamilton, 40, of Gaithersburg, was released yesterday from the National Hospital for Orthopaedics and Rehabilitation in Arlington.

Two of the five survivors of the crash are still hospitalized.

In all, 74 passengers and crew members on the airplane and four motorists on the 14th Street bridge died in the crash, which was the third and worst air disaster in the history of the nation's capital.