The opening ceremony is at 9 a.m., with the Chambersburg Skydiving Center dropping down with the American flag. A pig roast will begin at noon.
Ultralight and experimental aircraft will be on display, along with aircraft from the Commemorative Air Force, once known as the Confederate Air Force, Ridgway said. At least two World War II-era aircraft from the group, a Stinson L-5 light reconnaissance plane and a Vultee BT-13 trainer, are expected for the fly-in, she said.
There are no landing, parking or admission fees. Activities include live entertainment, a silent auction and a chance to win a tandem sky dive or bid for a biplane ride. Candy and teddy bear drops are among the events scheduled for children, Ridgway said.
"Angel Flight is, specifically, a volunteer pilot organization," said Gene Smelser, program coordinator for Mercy Medical Airlift in Virginia Beach, Va. Those volunteers fly patients at no cost, he said.
Mercy Medical, Smelser said, is an umbrella organization that helps bring pilots and patients together.
"Due to distance, or a patient's inability to get in and out of a small plane, there are commercial airline resources to fly those patients" that Mercy Medical also can help arrange, he said.
"We'll have a representative at the event," Smelser said. "The benefit they do every year ... helps us so we can help others."
In 2002, 168 patient missions were flown to and from the Chambersburg area with 371 patients and patient escorts flown by 27 volunteer pilots, according to Mercy Medical figures supplied to the borough last year.
Because the pilots donate their time and use their own planes, Ridgway said every dollar raised for fuel or other expenses pays for the equivalent of $5 in flight services.
Members of the Millennium Flyers enjoy flying at its most basic seat-of-the-pants, stick-and-rudder level. Although made of stronger, lighter materials and powered by more efficient engines, ultralights are as close as one can get to experiencing flight as Orville and Wilbur Wright or Glenn Curtiss did a century ago.
An ultralight, according to Federal Aviation Administration regulations, is an aircraft that weighs no more than 254 pounds empty, has a top speed in level flight of no more than 55 knots and a fuel capacity of five gallons.
The rain date for the fly-in is Sunday, July 25.