Northrop Gamma by Williams Brothers

1/72 scale
Kit No. 72-214
Cost: $12.00
Decals: (Microscale) Two versions – Frank Hawks’ record breaking “Sky Chief” or Dr. Lincoln Ellsworth’s Antarctic explorer “Polar Star”
Comments: Old kit (1970’s); fine raised panel lines; historic record-breaking aircraft from the Golden Age; dual options for engine, cowling, nose section, propellers, canopy, and tail wheel


The Northrop Gamma was a single-engine, all-metal monoplane used briefly by TWA as a mail carrier and employed to break or set a number of aviation records in the mid-1930’s. Designed in 1932 and delivered in 1933, it was a development of the earlier successful Northrop Alpha, a fast mail and passenger transport plane also built by Northrop. Like the Alpha, the Northrop Gamma employed revolutionary aerodynamic advancements: all-metal construction, wing fillets, full span flaps, and a multicellular stressed-skin wing of Northrop’s own design. Jack Northrop’s innovations had far reaching effects on the aviation industry. Douglas aircraft such as the DC-2, DC-3, and the SBD Dauntless were direct descendants of the Gamma, all of them employing structural techniques developed specifically for that aircraft. Like aircraft built late in the Alpha series, the Gamma’s fixed landing gear was covered in distinctive aerodynamic spats, and the Gamma introduced a fully enclosed cockpit.

The original Gamma, built for pilot Frank Hawks, was equipped with a Wright 14-cylinder engine of 785 horsepower. Its top speed was 248 miles per hour and thanks to an efficient wing design and generous flaps, it could land at speeds ranging from only 40 to a high of 55 miles per hour. Range at cruising speed was 25,000 miles, allowing non-stop coast-to-coast flying capability. On June 2, 1933 Frank Hawks flew his Gamma 2A “Sky Chief” from Los Angeles to New York in a record 13 hours, 26 minutes, and 15 seconds. In 1935, Howard Hughes improved on this time in his modified Gamma 2G making the west-east transcontinental run in 9 hours, 26 minutes, and 10 seconds.

While used as a mail plane for a time, the Gamma’s greatest fame came from its use as the aircraft of choice for pushing the envelope of aviation achievements in the early and mid-1930’s, including setting transcontinental speed records flying across the United States, being the first aircraft to fly across Antarctica, and being employed as a test-bed for the Sperry auto-pilot, used by combat aircraft during World War II. The U.S. Army Air Corps was sufficiently intrigued by the design to encourage Northrop to develop it into what became the A-17 light bomber. Military versions of the aircraft were flown by the Chinese and Spanish Republican Air Forces.

The Kit

Williams Brothers’ Northrop Gamma is molded in grey and consists of 48 parts on three sprues, inluding 6 clear plastic parts for the canopy and passenger windows. There is an option to build the kit as one of two historic aircraft. The first is the single seat Gamma 2A, better known as the Texaco “Sky Chief.” This was the first Gamma, built expressly for Frank Hawks, who, sponsored by the Texaco Oil Company, set a speed record when flying it from Los Angeles to New York on June 2, 1933 in just 13 hours, 26 minutes, 15 seconds. This record was broken in 1935 by Howard Hughes, founder of Hughes Aircraft Company and later creator of the “Spruce Goose,” when he flew a modified Gamma 2G along the same transcontinental route in 9 hours, 26 minutes, 10 seconds.

The second aircraft is the “Polar Star,” a two-seater version flown by Dr. Lincoln Ellsworth on a 1934 expedition to Antarctica. That expedition ended in failure when the Polar Star broke through the pack ice supporting it and had to be returned to the United States for repairs. A second attempt in September 1934 also ended with the Polar Star suffering damage and needing repair in the U.S. Ellsworth returned a third time in 1935 and made the first successful flight across Antarctica.

Each version requires different parts for the propeller, cowling, engine, canopy, tail wheel, and cockpit interior, so it is essential to decide at the outset which version you will build. The Texaco Sky Chief has a three-bladed propeller; streamlined cowling; double-row radial engine (seven cylinders each); smaller canopy with a single seat cockpit; extended turtleback spine on the fuselage; and a tail wheel protected by an aerodynamic spat. The Polar Star has a two-bladed propeller; more bulbous cowling; a single-row, nine-cylinder radial engine; an enlarged canopy to accomodate the second, tandem seat in the cockpit; a shorter turtleback spine, and an exposed tail wheel. An extra wrinkle is the fact that both aircraft were modified during their lifetimes, with visible differences between the earlier and later versions. There are additional differences, such as the pitot tubes, but these parts are not provided and will have to be scratch-built. Both aircraft had two different tails, smaller initially but enlarged with subsequent modifications. The kit comes with the larger tail, which will need to be shortened and reshaped by sanding to depict the initial version of either the Sky Chief or the Polar Star. Profile illustrations of both aircraft in both configurations, and a slightly larger illustration of larger and smaller versions of the tail, will help with this minor conversion. Finally, the earlier version of the Polar Star had no fairing between the bottom of the rudder and the tail cone of the fuselage, so this section will need to be removed to build the Polar Star in its Phase I configuration.

The cockpit is simply laid out with a floorboard, either one or two seats, a control stick, and an instrument panel for which a decal is provided. Unlike many aircraft models, the engine is not actually attached to the fuselage, but fits snugly inside the two halves of the cowling. The cowling is then cemented to the fuselage. If you decide to build the Gamma with windows, bear in mind that the early version of the Sky Chief had no windows at all, whereas both versions of the Polar Star had them. Also, the windows are located at a lower position on the fuselage of the Sky Chief than they are on the Polar Star. Installing the windows will require that openings be made in the fuselage — before glueing its two halves together.

As always with Wiliams’ Brothers kits, the instruction sheet does not follow a traditional sequence, beginning instead with the cockpit canopy and turtleback modification, then the engine assembly, then the cockpit, then the landing gear and wings, For those unfamiliar with Williams Brothers kits this can seem a bit confusing, but it is your choice what to focus on first. Everything you need in the way of instruction is all there, augmented with both photographs of the kit in progress as well as scale illustrations. These kits are unique in that there is a great deal of written instruction which, if you take the time to read it, can make for a more informed, more enjoyable modeling experience. In the process, you may learn more about the subject!


This is a fine kit of an historic Golden Age aircraft whose pioneering innovations helped drive aircraft development for over a decade. Highly recommended.




Northrop Gamma Polar Star

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