In his Aug. 12 op-ed column, George F. Will repeated the myth, promulgated by author Anthony Cave Brown but long since refuted, that in November 1940 the British knew that German bombers would attack the city of Coventry but did nothing in order to protect the security of Ultra, their code-breaking system. This is not so.

The British were aware, from a variety of sources, that the Germans were going to launch a major raid on southeastern England. But these sources -- especially Ultra -- did not identify Coventry as the target. The British did launch a preemptive attack on German bases that was unfortunately ineffect- ive, and they took measures to increase antiaircraft and fighter defenses.

But not until four hours before Coventry was attacked -- not 48 hours, as Mr. Cave Brown stated -- did it become clear that Coventry was the German target; the British detected the Germans' navigational beams intersecting over the city. By then it was too late to evacuate the city's 100,000 inhabitants, and the British defenses were overwhelmed by the huge German attack force. In the clear, moonlit night, the German bombers had no difficulty locating their target and devastating the city.

STANLEY L. FALK

Alexandria

The writer, now retired, was chief historian of the U.S. Air Force from 1974 to 1980.