Troopers say the single-engine Cessna 172N crashed at about 9:45 p.m. Thursday near the Ulster County hamlet of Wallkill, 65 miles north of New York City.
The pilot, 48-year-old Robert Schmidt of Bayshore, and 51-year-old John Brienza of Farmingdale were airlifted to Westchester Medical Center. Thirty-one-year-old Anthony Errera of Baldwin and 42-year-old Robert Kroll of West Sayville were taken to local hospitals.
Kroll was in critical but stable condition. The other's conditions aren't immediately available Friday morning.
Federal aviation officials say the plane crashed while trying to land at Kobelt Airport. The cause is under investigation.