Navy Secretary John F. Lehman Jr. charged yesterday that the jet engines used in the $20 million F14 Tomcat fighters since 1971 are so "terrible" that they have caused 24 accidents, including one last weekend in the Arabian Sea.

Capt. Lee Tillotson, the Navy's F14 program coordinator and a former wing commander on the USS Enterprise, also said, "I don't think there's any question" that the problem engine creates a greater risk for pilots in combat because of "a very high probability of engine stalling."

"From the very start you essentially teach the pilots to fly the engine as a priority over flying the airplane," Tillotson said in an interview. "The pilot has to be very aware of what he does with the throttle at all times."

Although problems with the $2.5 million TF30 engine, built by the Pratt & Whitney division of United Technologies Corp., have been recognized almost since the first F14s were built, Lehman, a pilot, raised the issue again with an unusually strident statement before a closed congressional hearing.

The TF30 engine "in the F14 is probably the worst engine-airplane mismatch we have had in many years. The TF30 engine is just a terrible engine and has accounted for 28.2 percent of all F14 crashes," Lehman told a House Appropriations subcommittee last spring in testimony that was just released.

"The sooner we are out of it, the happier I will be," Lehman added. "I guess the good news is that all the Iranian F14s have the TF30, too."

The Navy has bought 1,418 TF30 engines for its 410 twin-engine F14s, which usually are flown from aircraft carriers. Lehman told the House subcommittee that the Navy was so distressed at the engines' performance that it was considering replacing the existing engines with a new model made by General Electric Co.

In an interview yesterday, however, the secretary said TF30s will be replaced only as they wear out, adding that "one of the problems with the TF30 is that it wears out so fast." The Navy is still buying the TF30 because the GE engine won't be available until 1987, Lehman said.

Phillip Giaramita, a Pratt & Whitney spokesman in Hartford, Conn., defended the engine yesterday, saying, "We are expecting that Pratt & Whitney engines will power some F14s right up to the year 2000."

The TF30 initially was intended as an "interim" engine for only the first 25 F14s, but because of budget cuts in the 1970s the Navy was forced to scrap plans for a new engine specifically tailored for the F14, Lehman said.

Pratt & Whitney has been trying to fix some of the engine's more egregious problems, Giaramita said, and "our records show that since '81 there have been 17 F14s lost but only one was engine-caused."

Lehman responded, "We're a little disappointed that they didn't do that 10 years ago, but better late than never . . . . The problem should not be laid solely at the contractor's doorstep. The engine was designed for a different airplane."

The Navy plans to buy 300 additional F14s later in the decade, but those will be powered by GE's F110 engine. The decision to use the GE model, which is based on the company's B1 bomber engine, was announced by the Navy in February at the end of what was dubbed the Great Engine War between GE and Pratt & Whitney.

The F14 is intended to provide air cover for carriers and their escorts.

"I think people have rationalized [the engine limitations] a little bit by saying that we're going to stand off and use our long-range missiles rather than get mixed up in a classic dogfight," Tillotson said. "There will be many cases in a combat situation where you're going to close eyeball to eyeball . . . . It's a major limitation."