The Travel Air Model 11, also known as the Travel Air Model 11000 or the Curtiss-Wright Travel Air CW-11, was an American racing biplane developed from the general-purpose Travel Air 2000, and its derivative the Model 4-D.[1] Two examples competed in different events during the 1929 National Air Races, including the inaugural Women's Air Derby.[1] Pioneering woman aviator Marvel Crosson was killed flying a Model 11 in the latter event.[1]
The two Model 11s built differed considerably,[1] but shared the same general configuration as other Travel Air biplanes of the era. They were single-bay, staggered biplanes of conventional design, with open cockpits and fixed, tailskid undercarriage. They had conventional tails and were powered by nose-mounted radial engines driving tractor propellers.[2] The fuselages were built from welded steel tubes, and the wings from wood.[3]
The first was a re-manufactured Travel Air 2000.[1] This aircraft (construction number 794,[1] registered X-6473[4]) was built in September or October 1928 as a D-2000 subtype, with shorter-span and thinner "speedwings", a narrowed fuselage, and a new tail fin design. It was nicknamed "The Bug" at the factory,[5] and its aerodynamic improvements while retaining its standard Curtiss OX-5 engine made it competitive in the 90hp racing class.[5] Ira McConaughey flew it to a race victory at Newton, Kansas in early October.[5] Art Goebel raced it in Jackson, Mississippi in November, naming it The Chaparral.[5] A plan existed to re-engine it with a Warner Scarab, but it is now uncertain whether this was carried out before it was rebuilt into a Model 11.[5] The rebuild gave the aircraft new, thicker wings, different strut and aileron arrangements, new undercarriage, and a 240hp Wright J-6-7 engine enclosed by a NACA cowling.[1]
The second was a new-build aircraft, based on the Model 4-D fuselage design, albeit shortened and narrowed.[1] It was the result of a proposal by Travel Air engineers Herb Rawdon and Walter Burnham to develop a dedicated competition aircraft for the 1929 National Air Races.[6] In June 1929, company president Walter Beech approved the construction of three aircraft for the competition, two were to be a new monoplane design, the Type R, and one was to be based on an existing Travel Air biplane design, modified for speed, which became the second Model 11.[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.[1] This second Model 11 was awarded airworthiness approval 2-399 on February 3, 1932.[8]
Union Oil sponsored Marvel Crosson's entry in the 1929 Women's Air Derby,[9] and as the first competitor to file her race paperwork, she was assigned race number "1" for the event.[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.[12] Unwilling to wait for the new engine to arrive from Los Angeles, Crosson decided to start the event with her original engine and meet its replacement in Phoenix, Arizona.[12]
August 19, the second day of flying, was to bring the competitors from San Bernadino, California to Phoenix via stops in Calexico, California and Yuma, Arizona.[11] Crosson departed Yuma at 11:54 a.m., and never arrived in Phoenix.[11] She had not reported any problems with the aircraft.[11] As event officials traced her probable route, a six-year-old girl reported seeing a plane go down near Wellton, Arizona.[9] The following day, a search party covered 100sqmi on horseback on the banks of the Gila River.[13] Searchers found the wreckage of the Model 11 in a ravine,[9] and Crosson's body 100yd away.[13] She was wrapped in her partially-opened parachute, suggesting that she had stayed with the aircraft too long before bailing out.[11] The cause of the accident was never determined.[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.[12] [14]
The second Model 11 had started tests the day before Crosson's accident, but suffered a mishap of its own. While mechanics tested the throttle, the engine backfired and set fire to the nitrate-doped wings.[16] Fortunately, another set of wings was under construction, but the incident delayed NR612Ks departure for the races.[16] William H. Emery flew it to fourth place in its class in the Portland-to-Cleveland race.[1] [16] Ira McConaughey then flew it to fourth place in the "Australian pursuit" event at Cleveland.[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.[1] Still later, the wingspan was further reduced.[1] The aircraft remained on the FAA register until February 1956.[17]