Far out on the Manhattan Beach Pier, Frank Jacobs squinted into the bright afternoon light, his hands framing an imaginary spot in the dark blue water off LAX as he willed his mind to replay images that he saw more than 60 years ago.

"What I observed probably was right out there," Jacobs announced after scrutinizing the ocean for a short while, pointing to an area perhaps half a mile offshore. "I can picture it in my mind."

A few feet away from Jacobs, Pat Macha held a compass and got a rough heading on the area.

Macha, an aviation archaeology expert and retired Hawthorne High School history teacher, has hunted since 1996 for a P-51D Mustang fighter plane that he believes crashed and sank off LAX on Oct. 26, 1944, sucking its pilot, Gertrude Tompkins, to a watery grave. Jacobs thinks he witnessed the crash while fishing off the Manhattan Beach Pier for halibut when he was 12 years old.

Macha believes Jacobs' recollections confirm that he is searching in the right place for the plane.

"That's within the area where we're looking," Macha said after taking the compass reading.

Tompkins was a member of an elite group of about 1,100 Women's Air Force Service Pilots (WASPs) who served during World War II, primarily ferrying planes for shipment overseas. The day she disappeared, she was among a trio of WASPs who were to fly brand-new P-51Ds from their manufacturing site to Palm Springs, where they would spend the night before continuing on a three-day journey to Newark, N.J.

Her takeoff was delayed by a canopy that wouldn't close properly; witnesses later reported seeing two P-51Ds buzzing east above Imperial Highway but never a third. She wasn't reported missing until the other pilots got to Newark because they had assumed that she had been unable to take off because of the mechanical problem.

Early next month, divers from a 40-foot San Pedro-based boat called the Ranger are scheduled to make the latest -- and quite possibly last -- in a series of searches for Tompkins' plane. Descending to the ocean bottom just off LAX, they'll examine and photograph two masses of metal that crews found during the last hunt for the wreckage in 2002.

Jacobs, a retired aerospace engineer from Redondo Beach, came forward after reading an account of the search two weeks ago in the Daily Breeze.

He said he had just arrived at the pier on a cloudy day in October 1944 when a loud engine noise prompted him to look north. He watched a fighter plane climb after taking off over the ocean from what is now Los Angeles International Airport's southern runway complex. Suddenly, there was a sharp drop in the noise level and the plane's engine began sputtering. Then the plane angled over into a shallow, controlled dive that became steeper before it disappeared into the cloud bank that hung low just offshore.

Jacobs said he remembers that one of two adults nearby said something about a P-51 Mustang.

"This event left a very strong, vivid impression on me as a 12-year-old boy," Jacobs said. "I sensed that someone must have died."

Jacobs said he heard no sirens after the crash and was surprised to see nothing about it in the next day's newspaper.

Macha is certain that Jacobs witnessed Tompkins' plane go down, the only P-51 to crash into Santa Monica Bay.

Jacobs' description of the plane's sounds and movements mirror what a half-dozen P-51D pilots have told him could happen if the aircraft went into a low-speed stall, Macha said. The area where Jacobs believes the plane hit the water is within the area where Macha is searching. Nobody realized Tompkins was missing for four days, which explains the lack of next-day newspaper coverage of the crash. And his memory of the weather matches the actual conditions on the afternoon of Oct. 26, 1944.

"It's certainly something we've been hoping for, to have another source that would indicate or say they saw the plane go in the bay at that time frame," Macha said. "What he described is completely consistent with what every P-51 pilot I talked to said."

Jacobs hopes his memories help.

"I hope that's what I saw," Jacobs said. "It was definitely that year. Definitely that month."