MELBA, Idaho (AP) _ Only a large poster tacked to the main high school bulletin board marked the occasion. It said simply: ''Welcome back, Chris.''

Very quietly, the small farming community of Melba in southwestern Idaho ushered out one of the darkest periods in its history this past week when Christopher Davis returned to classes after recovering from plane crash injuries.

''We try not to do anything special - it makes it harder,'' said Melba High School Principal Jim Potter.

Davis, 17, was the last of seven Melba survivors to return to school after recovering from last November's crash of Continental Airlines Flight 1713, which was carrying the school's 10-member delegation returning from a Future Farmers of America convention in Kansas City.

The plane flipped over onto its back while taking off from Denver's Stapleton International Airport and 28 people died, including two of Davis' classmates and the wife of an adviser.

The National Transportation Safety Board has scheduled four days of public hearings into the crash, beginning March 8. Investigators are considering ice contamination as a possible cause, although documents made public Thursday by the NTSB indicated that the aircraft seemed to have been thoroughly de-iced 23 minutes before takeoff.

While routines have returned to normal and students have ceased showing outward grief, Potter said, ''I don't think the hurt and the feeling of loss has diminished at all.''

''In Melba, we bury our dead with dignity and respect, and then we get on with the process of living,'' said school counselor Corky Hill.

Agriculture is the mainstay of this town on the Snake River Plain about 40 miles southwest of Boise. A billboard on the outskirts of town hails Melba as ''Seed Heart of America,'' recalling a time four decades ago when 80 percent of the nation's sweetcorn seed was produced here.

FFA remains a major activity for Melba's young people and everyone in the town of 300 knew the victims.

''Most of these kids will never get over it,'' Potter said. ''Every time they go to a high school reunion or a football game'' they will be reminded.

Counselors quickly moved into the community the week before Thanksgiving to help residents cope with the deaths of students Janine Ledgerwood, 17, and Sherry Nelson, 18, and Tami Daniel, the wife of the FFA chapter adviser.

Calls and letters offering condolence poured in from FFA chapters throughout the country. The school and the Melba FFA chapter received $10,000 in contributions and a variety of trees as memorials to those killed. A campus picnic area will be lined with the trees and a scholarship fund will be established.

The school's yearbook will be dedicated to the flight's victims and survivors.

Davis, described by school officials as an outstanding student, said returning to school for half days felt good and he'll try full days this coming week. ''It seems like the teachers are going to help out as much as they can,'' he said.

He suffered a head injury, multiple broken bones, collapsed lungs and a bruised heart in the crash.

For FFA adviser David Daniel, getting back to teaching agriculture several weeks after the crash and his wife's death was therapeutic.

''It's nice to have something to occupy your time,'' he said. ''I can't imagine sitting home and staring at the walls. Some days are better than others. It depends on the day and hour.''

He met his wife when she was one of his students in the 1970s. They began dating after she graduated.

''They say time heals,'' he said. ''I guess you just have to go on.''

Daniel, who was not seriously injured in the crash, said he was touched by the cards and letters.

''We always talk about the FFA as being a close-knit group,'' Daniel said. ''I never could have guessed how caring people could be.''