This is a classic Of Wings & Things from the 1980s. GAN continues to run the late Mr. Bowers’ columns for the enjoyment of his readers.
The Travel Air biplane, introduced in 1925, is the most numerous example of the pre-1930 antiques still flying. Although there were well over 40 different designations, as reflected by Approved Type Certificate and lesser Memo Approvals issued, all were basically the same airplane with an almost infinite list of minor variations.
Nearly 20 different engines were used in standard production models before the line shut down in 1930, and others have been added since, including 450 hp Pratt & Whitney Wasp Jrs for some used as dusters and sprayers after World War II (does anyone remember the Floco engine or the Caminez?).
As an airplane, the Travel Air reflected the standards of the time. It had a welded steel tube fuselage and tail assembly and woodframe wings, all fabric covered. It was a three-seater, with a bench-like seat for two in the front cockpit and the pilot alone in the rear. Dual controls could be fitted for training.
At first, the airplane was just The Travel Air and the war surplus 90-hp Curtiss OX-5 water-cooled engine was standard. When a 200 hp Wright J-4 Whirlwind air-cooled radial became optional in 1926, distinction became necessary. The OX-5 model became Model A and the Whirlwind model became Model B (Model C was an entirely different cabin biplane design).
The system soon changed. The OX-5A model became the 2000, versions with the surplus water-cooled 150-180 hp Wright-Hispano, or Hisso, became the 3000 and the former B, with the later 220 hp, Wright J-5 Whirlwind became the 4000. The new monoplane designs were designated the 5000 and 6000, so the biplane continued with the 7000 that used the odd Fairchild Caminez engine while the 9000 used the Ryan-Siemens.
There were getting to be too many different numbers along here, so Travel Air called all the radial-engine models thereafter 4000 and identified the engine with a letter, as A-4000 for the Axelson (formerly Floco), E-4000 for Wright J-6-5, K-4000 for Kinner, W-4000 for Warner, etc. Sometimes the order was reversed and the letter followed the number. In 1929, after Curtiss-Wright took over Travel Air, the numbers were shortened. For example, the D-4000 (or 4000-D) became the 4-D.
However, the engine variations were not the novel feature of the Travel Air biplane. Other manufacturers were doing the same thing with competing models. Travel Air did something entirely different and offered new but interchangeable wings that could fit any standard model.
When the design first appeared in 1925, it had aerodynamically balanced ailerons with the balance area beyond the wingtips. Total span was 34 feet 8 inches and the area was 297 square feet. In 1929, the company cleaned the design up a bit and went to a new style called the Frieze aileron, which had an offset hinge line and was located inboard of a new rounded wingtip. Span was reduced to 33 feet even and the area was 289 square feet. Because of the notable difference, the new wing was called the “standard” wing while the old one, not officially named, was nicknamed the “elephant ear.” Production concentrated on the new style but the old one was still available as a lower-cost option.
For those who wanted a faster airplane, the company offered a still shorter wing with a span of 30 feet 6 inches that was marketed as the “speedwing.” All wings were interchangeable without having to recertificate the airplane, and a single plane could be flown with all three if the owner could afford them all. Many examples of all three are flying with the antiquers and dusters today.
More than 1,200 Travel Air biplanes were built from 1925 into 1930 and FAA figures showed 138 still on the civil register in 1975. Many others not on the books are known to be in storage or various stages of restoration, and again, all three wings are represented.