I can see where the cover illustration for this issue became mis-identified as being Buck Rogers. In the early Buck Rogers comic strip, Buck used a 'jumping belt' or pack made of an antigravity substance called "inertron" -- propulsive power was supplied by the wearer's own legs. A further development (mentioned in the story "Armageddon 2419 AD") led to small rocket motors encased in inertron blocks. Much later in the BUCK ROGERS comic strip the anti-grav 'inertron belt' gave way to the more familiar-looking personal rocket pack, and "inertron" was seldom mentioned any more. As for Philip Francis Nowlan, after writing 4 more science fiction prose stories for the pulp magazines, he died in February 1940 at the relatively young age of 51. Apparently his only other prose story featuring Buck Rogers after "The Airlords of Han" was the 1934 Whitman "Big Big Book" THE ADVENTURES OF BUCK ROGERS (so titled on the cover -- on the interior title page the title is given as "The Story of Buck Rogers on the Planetoid Eros"). Similar in format but larger in size than the more familiar Big Little Books, the 356-page hardcover (picture boards, no dust jacket) book contained "over 150 pictures to color" (credited to Dick Calkins) in addition to Nowlan's text.
For the record, the original contents page of Amazing Stories (August, 1928) Vol. 3, No. 5 describes the cover illustration thusly:
"Our cover this month depicts a scene from the first installment in this issue of the story entitled THE SKYLARK OF SPACE, by Edward Elmer Smith and Lee Hawkins Garby, in which the scientist, who has discovered a chemical substance for the liberation of intra-atomic energy, is making his initial tests, preparatory to his interstellar flight by means of this liberated energy, which makes possible his interstellar space-flyer." The scientist mentioned and depicted by Frank R. Paul here is Richard Seaton, hero of the novel.
Link to the book:
Amazing Stories - First 2 Buck Rogers Stories