I'd like to offer corrections to the article " 'Red Baron's' Fatal Fixation" [Science Notebook, Sept. 20], which is based on a flawed study. During research on five books on the World War I flying ace Baron Manfred von Richthofen (the "Red Baron") over more than 35 years, I gained access to original German research sources that offer more insight into his life and career than the analysis by the researchers quoting secondary sources in your article.

An example of their historical errors appears on Page 16 of the study, where they write that, during his last (and fatal) flight, von Richthofen could "see bits of his airplane being chipped away." As he died at the end of that flight, to whom would he have revealed that information? The statement is pure fantasy.

The researchers contend on Page 23 that, during the last fight, "the sight of [a] disabled British plane must have triggered something rather primitive in Richthofen's brain." That is speculation. No one knows what he was thinking.

About your article, my colleague Dr. Dieter H.M. Groschel, a professor at the University of Virginia School of Medicine, wrote to me:

"The most obvious mistake is their statement . . . that 'a British machine-gun bullet splintered a portion of the top frontal area of his skull.' That is not true. It was a tangential hit on the left border between the occipital and parietal bones and did not penetrate or fracture the bone. An X-ray proved that. Thus, there was no direct injury to the frontal brain, as the authors claim, and, therefore, their theory of frontal lobe damage is wrong. They may claim that the frontal lobes were involved in the concussion but I know from patients I have seen myself that it takes a major injury (or tumor) before the symptom of perseverance occurs."

From Australia, Dr. Geoffrey Miller wrote: "When he suffered his head injury he had shot down 57 airplanes and after he returned to duty he shot down 23 more! This would be most remarkable if he had frontal lobe disease!"

I fail to understand how the contemporary researchers quoted by your paper can analyze a pilot who last flew 86 years ago and with whom the researchers had no personal -- and only secondary, anecdotal -- contact.

-- Peter Kilduff

New Britain, Conn.

The writer is president emeritus of the League of World War I Aviation Historians.