US Army test pilot Lt. Frank Tyndall escaped injury after putting this PW-9 into a ground loop at the end of the landing strip at Sand Point, WA. Its landing speed was too high for the Sand Point runway. The aircraft was repaired and resumed test flights weeks later.

The Model 15 (PW-9) was the first successful Boeing-designed fighter and established the company as a major American builder of military aircraft.

Its internal bracing was arc-welded tubing rather than the spruce and wire used in older biplanes. However, it still had wooden spars and ribs. It was designated PW-9 (for “pursuit water-cooled design 9”) by the U.S. Army and designated FB-1 by the Navy.

Between 1923 and 1928, Boeing built 157 PW-9/FBs in different versions, as well as 77 derivatives as NBs (Navy training planes). The NBs were 4 feet (1.21 meters) longer than the PW-9/FBs and powered by either 180- or 200-horsepower engines. Boeing also sold five NBs to Peru.