[1] This aircraft (construction number 794,[1] registered X-6473[4]) was built in September or October[4] 1928 as a D-2000 subtype, with shorter-span and thinner "speedwings", a narrowed fuselage, and a new tail fin design.
[4] It was nicknamed "The Bug" at the factory,[4][5] and its aerodynamic improvements while retaining its standard Curtiss OX-5 engine made it competitive in the 90-horsepower (67 kW) racing class.
[5] The rebuild gave the aircraft new, thicker wings, different strut and aileron arrangements, new undercarriage, and a 240-horsepower (180 kW) Wright J-6-7 engine enclosed by a NACA cowling.
[7] Designated B-11-D (construction number 1267, registration NR612K), the aircraft adopted the shorter wings, redesigned fin, and NACA-cowled Wright J-6-7 as used on X-6473.
[10] While ferrying her Model 11 from Wichita, Kansas to the Derby start line at Santa Monica, California,[11] Marvel had reported engine problems and had ordered a replacement.
[14] Theories put forward included sabotage by someone unhappy to see women flying,[9][15] and carbon-monoxide poisoning, as Louise Thaden had been almost overcome by exhaust fumes in her similar Travel Air on her way to the Derby.
[1] Following the 1929 National Air Races, NR612K underwent further modifications, including a new forward fuselage, revised undercarriage, and a turtledeck that faired in the rear cockpit.