Four persons, including two veteran Prince George's County firefighters, died early yesterday morning when their single-engine Piper Comanche aircraft crashed into a grassy knoll on a turf farm outside of Bowie, minutes after takeoff. The four had been headed for a week-long vacation in the Bahamas.

Capt. Alexander W. Hamilton, 45, commander of the fire department's seventh battalion in southeastern Prince George's was cleared for takeoff from the Bowie Freeway airstrip off Church Rd. at about 5:55 a.m. by officials at the Washington towere at National Airport.

Hamilton, who owned the green-and-white, four-seater aircraft, told the Washington tower he would leave the 2,200-foot strip in fog and light rain before 6 a.m., using only his instruments for guidance. He also said he would contact air controllers in Burke, Va., after he became airborne.

The radio call never came. Instead, the Comanche, a relatively small craft equipped to handle only about 550 pounds of weight other than fuel, apparently took off to the north, swerved east, then struck the ground with its right wing about one-half mile north-northeast of the takeoff point, officials said. The plane skidded more than 30 yards, then apparently ground to a halt, wrenching its nose and cockpit almost over one wing.

Found dead among the plane's wreckage were Hamilton, his fiancee, Beverley M. Come, 44, of 8150 Lake-hurst Dr., Greenbelt; Sgt. Joseph L. Tippett Jr., 32, of Owings, Md., and his wife Marlene, 25. Around them, the wreckage of a vacation was strewn across almost 50 yards: torn maps, sun lotion, track shoes, cigarette cartons and a paperback novel: "Dust in the Sea."

Juanita Forbes, who has been leasing 100 acres from the Fairwood Turf farm adjacent to the airport, found the plane's wreckage only 50 yards from her home early yesterday morning when she arose to feed her dogs.

It was barely dawn. "I looked out and thought I saw a car wreck or something, so I called the manager of the farm," Forbes said. "Then I walked out halfway and saw that it was a plane - and I saw one of the bodies. I ran back and called again."

Minutes later, the farm manager, Walter Livingston, arrived at the scene, and after the two had circled the site and seen that the four bodies showed no signs of life, Livingston called state police.

When Come's youngest son, David, 18, heard the first, sketchy reports of the crash over the radio hours later, he jumped into his mother's brown Corvette and drove straight to the Bowie airfield. "It was intuition," he said. "I knew it had to be her."

Come said that the group had planned to begin the 4 1/2 hour flight to Jacksonville, Fla. - a common stop-over point for commuters to Nassau - at around midnight from the College Park airstrip, where Hamilton, who lived at 5903 Roanoke Ave. in River-dale, usually kept his plane. Hamilton had been a pilot for more than 15 years.

"They couldn't take off from College Park because of the weather, so they planned to come to Bowie and leave around 5 or 6," Come said.

Workers at the Bowie airstrip said yesterday that the owner of the terminal leaves the runway lights on at nights, but no attendants are present and pilots are free to land or takeoff at the strip after receiving clearance from the Washington National tower. Airport officials refused to speak to reporters.

Hamilton, who first began as a volunteer firefighter in 1954 and began working as a professional in 1960, had been chief of the seventh battalion since August 1977. As the commander of five companies, he ranked as "a middle-level manager" in the department, Fire Capt Duncan Munro said.

Hamilton and Come, both divorced, met several years ago when Come was working for the county payroll department, friends said yesterday. Come, who had four children, also worked as a substitute teacher and was employed as a bookkeeper at Century 21-H.T. Brown Real Estate in Laurel.

Tippett joined the fire department in 1968, was promoted to sergeant in 1963, and was working as a fill-in for vacationing officers around the county. He had two children by a previous wife before marrying Marlene Tippett.

FAA and National Transportation Safety Board Officials were investigating the cause of the accident, but had reached no conclusions by late yesterday, officials said.