1928 Stearman C3MB

Specifications

Length

24 feet

Wingspan

35 feet

Height

9 feet

Engine

Lycoming R680

Max Speed

110 MPH

Propeller

Hamilton Standard 2B20

Letters, Landings, and Legacy: 1928 Stearman C3 MB

Aside from the necessity of inventing new warplanes for World War I, the desire to speed communication by carrying letters by air led to more innovation and economic activity in the aviation industry than anything else during the 1920s and into the 1930s. The Postal Department was very active in finding ways to deliver the mail, which led to the creation of standardized routes, a tremendous amount of airplane design progress, and the creation of hundreds or perhaps thousands of “flying fields” which in time, became airports. Ultimately, it formed the foundation of the airlines as we know them today.

Carrying the mail by air was, at a stroke, the creation of an entirely new industry. The first airmail flight took place in May of 1918, and less than a decade later, the country had a commercial airline system. This dramatically fast-growing industry spawned tremendous entrepreneurial activity as businesspeople developed new aircraft, created airlines, and sometimes built private airfields.

The government, through the Postal Department and the Commerce Department’s Aeronautical Branch, was not just the regulator of these activities but the funders as well. One of the Collection’s aircraft, the 1929 Travel Air B4000 was operated by the Aeronautical Branch at the beginning of the 1930s to fly potential air mail routes. The Collection’s Stearman C3 MB (the MB denoting its design as a mail plane) was built in 1928 by the newly formed Stearman Aircraft Company.

Stearman Aircraft was formed by Lloyd Stearman, late of Swallow Aircraft Company and Travel Air Manufacturing Company. Formed in 1926, Stearman built two early biplanes in California before moving manufacturing back to Wichita, Kansas, and renaming their second design – the C2 - the C3 model. The C3 was intended, like Travel Air, primarily for commercial use and was a rugged, simple, open-cockpit design. A specialized version of the plane was built for use by airline mail carriers and had a large front cockpit equipped with bins for holding mail. Of the 179 C3 models constructed, fewer than 15 were sold as mail planes.

Stearman designed and built another open-cockpit biplane for mail-carrying airlines, the 4E “Mailwing,” which is an enormous airplane for the era, standing nearly 10 feet tall.

Not many Stearman aircraft survive today (except for the eponymous “Stearman” trainers, which were manufactured by Boeing), and few aircraft from the 1920s designed primarily for mail carrying exist either. There are 17 C3s on the FAA registry with an estimated half dozen still flying. Of these, the Collection’s C3 MB is the only known mail plane still flying.

The Story of C6487:
From Mountains to Mail Carrier

C6487 was constructed in 1928 and sold to National Parks Airways Inc., a small airline and airmail carrier based in the rugged, mountainous states of Idaho, Utah, and Montana. The airline was established in 1927 with the primary purpose of carrying the mail and was awarded the CAM 26 airmail route contract, which required deliveries from Salt Lake City, Ogden, Pocatello, Butte, Helena, and Great Falls. Their second aircraft was the Collection’s Stearman C3MB.

Eventually, in September 1931, when it was referred to as a “C3B” model, C6487 was converted from its strict mail-carrying duties to passenger travel, and two passenger seats were installed in the front cockpit. This change created quite a bit of back-and-forth struggle between the airline and the government, who insisted that the landing lights and flares be removed from the airplane to prevent it from flying passengers at night. In 1932, the plane’s license was changed again to allow only one passenger, and it was referred to as a model “C3MB”. In 1933, the aircraft was assigned the designation “C3B Special” by the Department of Commerce Aeronautics Branch, which is how it is designated today.

By 1934, National Parks Airways had become a feeder airline for United Airways. Continued growth in passenger travel and natural airline consolidation led to Western Airlines acquiring National Parks, and C6487 disappeared from history. Western Airlines soldiered on as a regional carrier until being acquired by Delta Airlines in 1987.

National Parks Airways sold C6487 to Johnson Flying Service of Missoula, Montana, in July 1934, where it became a training and personal pleasure aircraft for a time. In 1945, it was converted to crop dusting operations. That is the last entry in the government’s records for the airplane until it received a Standard Airworthiness Certificate after restoration in 2019.

C6487 is a rugged design, ideally suited to the tasks it was given by National Parks Airways. Originally powered by a Wright Whirlwind J5 engine and carrying five hours’ worth of fuel, it could make its route round-trip in a single day without refueling. Now powered with a Lycoming R680 9-cylinder radial of close to the same horsepower, it still flies at a top speed under 110 mph. Its rugged landing gear design, coupled with large diameter 30-inch by 5-inch wheels, allowed it to land practically anywhere. A large useful load made the big biplane capable of carrying 400 pounds of airmail or two passengers and baggage with ease.

C6487 was restored by the well-known restorer Tim Talen. Talen admits that it was never the first priority of his workshop, as he restored it for himself when he had a break from working on customers’ projects. Tim is a meticulous restorer, and over the decades of working on the plane, he sought to make it as historically accurate as he could. At the same time, he did want the plane to be practical to fly, which was why he elected to install the Lycoming engine rather than a hard-to-source, and harder to maintain Wright. He tried flying with the original tail skid, but a modern Scott tail wheel now makes safe ground operations much easier. An alternator and battery power the E80 starter so that a pilot may fly easily without a ground crew. Despite these changes, there are no radio or transponder, and the instrument board, populated with period-correct instruments, is as it was originally.

Having searched all over the country, looking for a mail plane to go with our mail route, discovering Travel Air, and our 1931 mail truck, I knew immediately that I’d found the perfect plane for the Collection when Tim dropped by for a visit during AirVenture 2025. It brings to us the practical history of an early airline and a perfectly restored, rare airplane.