A New York man was "grabbing at everything" as he allegedly grappled with the crew of a small passenger plane enroute from National Airport to Montreal Tuesday and shut off one of its two engines, sending the plane into a dive, an airline spokesman said yesterday.

The plane, an Empire Airlines flight carrying 17 people, landed safely in Syracuse, N.Y., after the man was subdued. Police identified him as Christopher Bradshaw, 27, of Baldwinsville, N.Y., and charged him with four counts of attempted murder. He was scheduled to undergo a psychiatric examination yesterday.

According to Empire spokesman Frederick Hager, Tuesday's incident began at about 4:50 p.m. as the plane, operating as Flight 841 between Washington, Ithaca, N.Y., Syracuse and Montreal, was on its final approach to Hancock International Airport in Syracuse.

It was carrying a two-man crew and 15 passengers, none of them residents of the Washington area. As it reached a point about 1,000 feet high and one mile from the runway, a man stepped into the cockpit and without a word began grappling with copilot Marshall Banks and pilot J.B. Whitehead, Hager said.

"He was grabbing at everything," Hager said. During the scuffle, the man's hand touched a fuel control switch for the left engine and shut it off. The engine stopped. The plane banked to the left and began descending rapidly as pilot Whitehead fought to regain control, the spokesman said.

With the help of another passenger, Banks propelled the man from the cockpit and held him down in the aisle. Whitehead regained control of the plane as it reached about 250 feet and guided it to a safe landing with one engine out, Hager said. The entire incident lasted only about 30 seconds, according to the spokesman.

Bradshaw was arrested by Syracuse police. After the plane was inspected and statements taken from crew and passengers, it continued on to Montreal.

Hager said the crew believed the man was unfamiliar with cockpit instruments but may have spotted the fuel shut-off switch during the scuffle.

Syracuse police investigator Rod Carr said Bradshaw described himself as an unemployed former computer programmer. He boarded the flight in Washington, where he had visitied friends and relatives. "We feel we have some idea of why he did it, but we're not releasing it," Carr said.

Federal Aviation Administration officials said yesterday there was no indication the incident would create pressure for tighter security aboard small passenger aircraft, which have rarely been subjected to hijackings or other interference in the cockpit.

Since 1964, the FAA has required large airliners to fly with their cockpit doors locked, a precaution intended to make hijacking more difficult and reduce distractions for pilots.

There are no such rules for small commuter planes. In fact, the plane in Tuesday's incident, a Swearingen Metro II with seats for 19 passengers, and many other commuter aircraft have only a curtain between the cockpit and cabin.

In February, a Rio Airways flight out of Killeen, Tex., was hijacked to Mexico, the first commuter plane commandeered in 12 years, officials said. "Your average hijacker wants a big plane that he thinks can take him where he wants to go," said FAA spokesman Fred Farrar.