The first thing you notice when you look at the Northrop Gamma 2B “Polar Star” is that it doesn’t have wheels–it has skis. This airplane was not designed to land on runways–the Polar Star was specially built as an Antarctic explorer.
In 1930, the Northrop company began producing one of its first all-metal monoplanes, the Northrop Alpha. It was used by the fledgeling TWA company to carry airmail and passengers.
Just a year later, Northrop began work on the Alpha’s successor, the Gamma. This was also an all-metal monowing, which differed from the Alpha in having an enclosed cockpit. It was intended as a mail carrier and passenger plane.
The first prototype to be produced was finished in December 1932, designated the Model 2A, and went to air racer Frank Hawks, who was part of the Texaco racing team. With its 14-cylinder Wright Whirlwind GR-1510 engine, the Texaco Number 11 “Sky Chief” promptly set a new transcontinental speed record in June 1933, flying nonstop from Los Angeles to New York in 13 hours and 27 minutes.
The Model 2B prototype was being built at the same time, as a special project for Arctic explorer Lincoln Ellsworth. Ellsworth was from a prominent Chicago family that had made a fortune in coal mining. As a young man he had enlisted in the Army and served as a pilot in the First World War. After the war, he took an interest in Arctic exploration, and in 1925 went on his first expedition, accompanying famed Norwegian explorer Roald Amundsen (who had been the first to reach the South Pole) on a mapping mission. In May 1929, Ellsworth once again accompanied Amundsen on another trip–this time by air. The dirigible “Norge” took off from Norway, crossed the ice over the North Pole, and landed in Alaska.
As a pilot, Ellsworth recognized that the best and safest way to map the polar regions was by air. In 1932, he ordered a modified version of the Northrop Gamma, purpose-built for flying across the open ice fields in Antarctica. The “Polar Star”, as Ellsworth called her, differed from Texaco’s “Sky Chief” in a number of ways. The engine was intended for fuel economy and reliability instead of raw speed, and so was much smaller in the 2B, being a 9-cylinder Pratt and Whitney Wasp. The Polar Star was also to be a dual-seat aircraft. The engine was shifted forward 16 inches, allowing a second cockpit to be added with full controls for the co-pilot. She also had her main landing gear replaced with skis, for landings on ice. The finished Gamma 2B was delivered in 1933.
Ellsworth loaded the Polar Star on a ship and headed to Antarctica with co-pilot Bernt Balchen. Arriving at the Bay of Whales in January 1934, they planned to fly across the ice to the Weddell Sea and back, mapping mountains and inlets along the way. However, as they prepared the plane for launch, the sea ice cracked underneath them, one of the Polar Star’s skis slipped through, and it was sheer luck that the plane didn’t fall through the ice and sink to the bottom of the ocean. Ellsworth and Balchen managed to extract the plane and get her back aboard ship, where she was taken to the US for repairs.
They were ready to try again in September, this time planning to take off from Deception Island. But once again they had bad luck–the Polar Star broke a connecting rod in her engine and had to be shipped to Chile for repair. In January 1935 they successfully took off from Snow Hill Island, but bad weather forced them back after just a few hours of flight.
In November 1935, Ellsworth was back, this time with new Canadian co-pilot Herbert Hollick-Kenyon. They planned to take off from Dundee Island in the Weddell Sea and fly all the way across Antarctica to the US scientific camp at Little America, 2400 miles away. The Polar Star took off on November 23. Four times, they made scheduled landings on the ice to camp for a few days and take scientific measurements. On one occasion a sudden storm blew in and filled the Polar Star’s cockpits with snow; it took an entire day to dig out all the powder with a teacup.
On December 3, after two weeks and only 25 miles away from Little America, bad luck struck again. The Polar Star ran out of fuel, and Ellsworth and Hollick-Kenyon had to set her down on the ice, unpack all their supplies, and make the rest of the trip on foot. They were finally picked up by a British research ship on January 15, 1936. After a hero’s welcome in the US, Hollick-Kenyon went back to Little America and recovered the Polar Star. She was donated to the Smithsonian, where she is now on display.
Northrop, meanwhile, was trying to make a commercial success of the Gamma. The Federal government had mandated that all passenger planes flying at night had to be multi-engine, which killed off the Gamma’s intended market. Three airplanes were bought by TWA, which used them for high-altitude experiments and weather research. A two-seat version with retractable landing gear was intended as an Army Air Corps trainer, but Northrop didn’t get the contract. Another version was equipped with guns and fitted out as the A-17 Nomad light attack bomber: about 400 of these were produced. A few of them went to the Republic of Spain and served in the Spanish Civil War and about 25 went to China where they were used against the Japanese in World War Two. The rest flew with the US Army but were phased out by 1939, with only a few serving during the war as coastal patrols.