Pope John Paul II bade farewell to Washington and America last night with a final touch of grace and ebullience on a chilly runway at Andrews Air Force Base.

"God Bless America. God Bless America." Were his last shouted words to the dozens of dignitaries and 15,000 spectators who waited hours to cheer him off.

He seemed truly reluctant to leave as he lingered for about 35 minutes on the windswept airstrip, talking with and touching officials and bystanders alike.

He took time to parade along the airfield fence and hug a small, red-coated girl. Then, after blessing a group of cardinals who led him to the plane, he turned and retraced his steps to shake hands with the Army's band conductor.

Finally, as a full harvest moon clung to the horizon behind the nose of his TWA jet, John Paul climbed the ramp, where he turned and extended his arms in a last, open embrace to the crowd.He disappeared inside the aircraft as hundreds in the crowd waved handkerchiefs below him.

The plane took off about 8:45, and shortly afterward Larry Hastings and his daughter Martha persuaded a security guard to hand them three wilted flowers that had fallen in the pope's path along the fence. "I want to keep them because the pope stepped on them," said Hastings, who drove from his home near Annapolis and waited nearly five hours to see John Paul leave. "It was absolutely worth it to see him. I could have touched his head, he was so close -- only I thought it would be rude."

Thousands of other well-wishers, unable to get beyond the Andrews terminal to the fence, stood shoulder-to-shoulder on the road outside the field to catch a glimpse of the pontiff or his plane as it left the runway.

Vice President Mondale was there to see the pope off, as were House Speaker Thomas (Tip) O'Neill, 12 cardinals and five senators, including Paul Sarbanes and Charles McC. Matthias of Maryland.

There, too, by special arrangement, was Anna Szczepanski, a first-generation immigrant from Poland and a childhood schoolmate of the pope.

"You have built a bridge of friendship to all Americans," Mondale said. "And though you leave tonight, this special bridge remains and so does your special memory."

"Your hospitality has been warm and filled with love," the pope told the crowd. "I believe strongly in the message of hope that I have held up to you, in the justice and love and truth that I have extolled, and in the peace that I have asked the Lord to give to all of you."