David Herbert Hoffman, 52, a former Saigon bureau chief for The Washington Post who filed one of the most famous expense accounts in this newspaper's history, died of cardiorespiratory arrest Feb. 15 at his home in Alexandria.

A former Air Force pilot who had flown commercially for Trans World Airlines, Mr. Hoffman came to the Post in 1967 from the old New York Herald Tribune, where he had been aviation editor. He left the Post in 1971, and since then had been a free-lance writer.

His work appeared in The Washington Post Magazine and the Post's Outlook section, and in many other newspapers and magazines.

The expense account for which Mr. Hoffman long will be remembered at the Post was filed in late 1969. It was for several thousand South Vietnamese piastres (less than $100), which Mr. Hoffman had paid to hire a platoon of South Vietnamese militia to escort him into a South Vietnamese hamlet named My Lai 4, site of a massacre of Vietnamese civilians by American troops. Lt. William Calley later was court-martialed for his part in the incident.

The My Lai story had been broken by Seymour Hersh, then writing for a small news agency. The Post had been scooped, but sent Mr. Hoffman from Saigon to the site of the incident to see if he could find any trace of it.

It was the kind of assignment he loved -- improbable, a little dangerous, but likely to provide interesting copy. Upon his arrival in the northern part of South Vietnam, near My Lai, Mr. Hoffman found that the hamlet, part of the village of Son My, was in a contested area where security was uncertain. He decided to try to hire armed escorts, and the local platoon of militia agreed to take the assignment.

Reporting on the scene in My Lai 4 to his readers in Washington, Mr. Hoffman wrote: "A fence of towering bamboo surrounds the cemetery. Peasants say that many more graves lie beyond the bamboo. But the graves cannot be counted. There are mines amid the graves and visitors are advised to take as few steps as possible and to leave hurriedly."

The Post initially disallowed Mr. Hoffman's expense account item for hiring the platoon on the grounds that it was not an authorized expenditure. Later, his dispute with the home office was settled amicably.

Mr. Hoffman was born in Coral Cables, Fla., and graduated from the University of Florida. He took a master's degree in political science from Boston University, and later was a Nieman Fellow at Harvard University.

Mr. Hoffman learned to fly in the Air Force and later was a pilot for TWA.

An itch to write took him out of the airline business and he went to work for a small weekly in upstate New York. He worked for Aviation Week and Space Technology and then the Herald Tribune, first to write about aviation and later to report from Washington.

Mr. Hoffman's interest in flying led him into one of the great stories of his career, an exclusive report on a scavenging operation by the Israeli government to build four flyable C-97 freighters, an old Boeing aircraft long out of service when this occurred in 1967.

Mr. Hoffman befriended the Israeli mechanics who stitched the planes together from scrap pieces in an airplane graveyard near Tucson, then flew himself in one of the planes from Tucson to Tel Aviv. The adventure produced two long and memorable articles that ran in the Post in late October 1967.

Mr. Hoffman believed that no story was more important than the individuals who were part of it. His description of the chief Israeli mechanic in this operation was typical of his concern for personal detail:

"Moishe the Israeli mechanic , nearing 40, is from southern Russia. His English, impeccable until he speaks it, carries an overlay of Russian and Hebrew inflection that makes the listener squint . . . . "

After he left the Post, Mr. Hoffman worked briefly for The Miami Herald, then returned to Washington to free-lance. Many of his pieces were on outdoor subjects, particularly the Chesapeake Bay and its environs. He was an avid sailor.

His marriage to Joan Hoffman ended in divorce.

Survivors include his wife Kay, of Alexandria; a son by his first marriage, Dayle M. Hoffman of Columbus, Ohio, and his father, David Hoffman of Las Vegas.