When Tom Addison thinks he's having a bad day, the 44-year-old building inspector pulls out the photograph he keeps in his glove compartment. It's a picture of his daughter, Christina--at 1 pound, 6 ounces--clinging to life.

She's lying under a heating lamp in what looks like a dish covered with plastic wrap. A ventilator is pumping air into lungs no bigger than lima beans. Her veins are as thin as human hair, and her daddy's wedding ring slips easily on her arm like a bracelet, all the way up to her shoulder.

"No, this," he reminds himself, "is a bad day."

Addison needs no reminder, however, of the role the nurses and doctors at Inova Alexandria Hospital played in helping Chrissy blossom into the healthy 11-year-old she is today. Despite virtually no chance of her survival, the medical staff never gave up on her, tending to their tiny patient around the clock for 96 days.

So Addison, just as he has done each of the last 11 Thanksgivings of Chrissy's life, will bake two pumpkin pies in the kitchen of his Fairfax County home. There'll be an "a.m. pie" and a "p.m. pie" for the day and night shifts at the hospital.

Then today, the Addison family--Tom, his wife, Dee, 38, Chrissy, and her sister, Lyndsey, 8--will pack up their pies and make their annual pilgrimage to the hospital's Neonatal Intensive Care Unit.

"We get goose bumps every time we go," Tom Addison said. "It's just a little something we can give back."

The Addisons and their pies have become a Thanksgiving tradition at the neonatal unit, and inevitably this morning, the questions will start bouncing off the incubators: Have the Addisons stopped by yet? Are the pies here? Seen Chrissy?

Lisa A. Goldberg, the medical director of the 16-bed unit, says parents often bring their children in for a visit on their birthdays to show everyone their progress and to thank her staff. But the Addisons have forged a special relationship.

"Not everyone brings a pie with them," Goldberg said. "I think it's wonderful. It kind of helps the staff get through the holidays. It helps them remember what a good thing they're doing."

Sharyl Williams, a nurse in the intensive care nursery, looks forward to the Addisons' visit every Thanksgiving. She witnessed Chrissy's arrival at 4:16 a.m. on Aug. 11, 1988--3 1/2 months ahead of schedule.

At that time, technology was not nearly as advanced as it is now, and the prognosis was grim, said Williams, expertly cradling a baby in the crook of her left arm.

"Christina was not expected to survive," she said. "She was a very sick baby. But she came out a lot more vigorous than expected. This was a family that was very, very involved in the child's care."

The Addisons came to the hospital every day, not sure if it would be their last visit with their daughter.

They measured progress in ounces, starting when Chrissy weighed only about as much as a can of biscuits. Then she started losing weight, dipping to a harrowing 15 ounces.

"We were scared," said her father. "But I was attached--hook, line and sinker."

Everyone always thinks he's a dead ringer for Chuck Norris, so Addison put a plastic action figure made in the actor's image in his daughter's incubator so "daddy" could watch over her.

As days grew into weeks, and weeks into months, the nurses suggested that Tom Addison buy his daughter some clothes. He found some pretty dresses just her size, in the doll aisle at Toys R Us.

The Addisons photographed every milestone along the way. Chrissy wearing the Redskins cap her aunt knitted for her. Chrissy clinging to her daddy's finger. Chrissy all dressed up in the angel costume her mommy sewed for Halloween. And, at long last, Chrissy cuddled in her parents' arms.

"We didn't know if those were the only memories we would have," said her mother, a computer technician. "She was doing good, then she'd have a relapse."

Finally, Dee Addison, who had already lost one child, heard the words she was aching to hear: Chrissy is going home.

Chrissy, a sixth-grader at Westlawn Elementary School, has had to wear eyeglasses since about age 1, but, other than that, she has had remarkably few problems. She's a quiet, petite girl, her parents say, but she has seized life with zeal, becoming a Junior Girl Scout, playing the flute and joining the bell choir at church.

Now Chrissy dresses her dolls in the clothes she wore as a baby. "I was a teeny little baby," she said, curling up in her father's lap and studying her family's photo albums.

She doesn't remember any of it, of course, but her parents will never forget.

Said Tom Addison: "Unless you're in that unit, you cannot believe what those nurses and doctors do."

There's nothing fancy about Tom Addison's pumpkin pies. He buys frozen pie shells and, except for his mother's secret ingredient (two teaspoons of vanilla), he follows the recipe on the pumpkin filling can.

He says he started baking pies for the hospital staff because "that's something I can do myself." He always takes along a tub of Cool Whip and plenty of paper plates and plastic forks.

The first few years the family took their pies to the hospital, the nurses just did what came naturally, he said. They scooped Chrissy into their arms, peeled off her clothes and gave her a physical on the spot, just to make sure she was doing okay.

Now during their visits, the family tries to help other apprehensive parents they see anxiously peering into incubators. Dee Addison tells them their babies are in good hands, as she has told the doctors and nurses in a poem of thanks.

Very special people with very big hearts,

Take care of special babies right from the start,

Some in glass houses, some in open cribs, some under warmers, some in bibs,

All have special needs, all need special care,

Many special babies have come home from there,

Many of the parents, trying hard to cope,

Everyday leave with a little more hope . . .

CAPTION: Christina Addison, 11, who was born 3 1/2 months premature, sits with her father, Tom.

CAPTION: Chrissy weighed 1 pound, 6 ounces when she was born at Inova Alexandria Hospital.