ALTON, N.H. — Winter on New Hampshire’s Lake Winnipesaukee means ice fishing, hockey tournaments and, if the ice is strong enough, airplanes.

After being grounded by bad ice and worse weather for most of the winter, the Alton Bay Seaplane Base and its ice runway are open.

Dozens of pilots from all over the Northeast took advantage of a rare, sunny, storm-free Saturday to touch down on the frozen lake, the only ice runway in the lower 48 states approved by the Federal Aviation Administration.

“How many times can a non-amphibian plane land on water?” asked pilot Ken Ortmann of Rochester, New Hampshire.

Another pilot, Angela Leedy, flew three hours from Pittstown, New Jersey, to try out the runway.

The 3,000-foot airstrip is popular with pilots, said airport director Paul LaRochelle, who keeps it plowed when the ice is strong enough.

As he directs pilots to park ,he advises them not to use their brakes: “You’ll just skid,” he said.