Boeing Y1B-17 (YB-17)

One of America's new warships of the air, a mighty YB-17 bomber, is pulled up at a bombardment squadron hangar, Langley Field, Virginia. It is all set to taxi out to a runway and take off; May 1942.

Though still enthusiastic about the Boeing design, despite it being disqualified from the fly-off contest following the crash of the Model 299 prototype, the Army Air Corps cut its order from 65 service test YB-17s to just 13. On November 20, 1936, the bomber's normal acquisition funding was changed to "F-1", and the heavy YB-17 bomber was redesignated "Y1B-17", as a result.

Unlike its predecessor, which had used Pratt & Whitney R-1690 Hornet radial engines, the Y1B-17 used the more powerful Wright R-1820 Cyclone that would become the standard power plant on all B-17s produced. Several changes were also made in the armament, and the crew was reduced from seven to six. Most changes were minor: the most notable was switching from double-wishbone to single-arm landing gear for ease of regular maintenance.

On 7 December 1936, five days after the first flight of the Y1B-17, the brakes on the bomber fused during landing, and it nosed over. Though damage was minimal, the cumulative impact of this event, combined with the crash of the Model 299, triggered a Congressional investigation. Following the crash, the Army Air Corps was put on notice: another such crash would mean the end of the bomber's "F-1" procurement program.

Though the heavy bombers were meant for testing, the commander of Army General Headquarters (Air Force), Major General Frank Andrews, decided to assign twelve Y1B-17s to the 2nd Bomb Group located at Langley Field, Virginia. Andrews reasoned that it was best to develop heavy bombing techniques as quickly as possible. Of the thirteen Boeing aircraft built, one was assigned for stress testing.

In 1937, the twelve Y1B-17s at Langley Field represented the entire fleet of American heavy bombers. Most of the time spent with the bombers entailed eliminating problems with the aircraft. The most important development was the use of a detailed checklist, to be reviewed by the pilot and copilot just prior to each takeoff. It was hoped that this procedure would prevent accidents similar to that which led to the loss of Boeing's Model 299 prototype.

In May 1938, the Y1B-17s (now redesignated just B-17) of the 2nd Bombardment Group, led by the lead bombers' navigator Curtis LeMay, took part in a demonstration in which they intercepted the Italian liner Rex. Coming into contact with the liner while it was still 610 mi (982 km) out at sea, the demonstration was meant to prove the range and navigational superiority of the B-17. It also showed that the bomber would be an effective tool for attacking a naval invasion force before it could reach the United States. The Navy was furious about the Army's intrusion into their mission, and forced the War Department to issue an order restricting the Army Air Corps from operating more than a hundred miles from America's coastline.

After three years of flight, no serious incidents occurred with the B-17s. In October 1940, they were transferred to the 19th Bombardment Group at March Field.

Boeing Y1B-17 in flight.

Boeing Y1B-17 flying near Mt Ranier, 28 February 1938.

Boeing Y1B-17 at Hamilton Field, California, circa 1937.

Boeing Y1B-17 (36-149, the first YB-17). Thirteen Y1B-17 Flying Fortresses were delivered to the Army Air Corps on 5 August 1937.

Boeing Y1B-17 (36-149, the first YB-17) at Hamilton Field, California; late 1930s.

Boeing Y1B-17 (36-149, the first YB-17).

Boeing Y1B-17 at Hamilton Field, California.

Y1B-17 of the 2nd Bomb Group, which was charged with the operational evaluation of the type.

Boeing Y1B-17 (BB/52) of the 2nd Bomb Group, Langley Field, Virginia.

Boeing Y1B-17 with camouflaged paint scheme, assigned to the 20th Bomb Squadron, 2nd Bomb Group, based at Langley Field, Virginia.

The waist gun blisters of the Y1B-17 were innovative but not very practical. They were an attempt to provide the greater field of fire of a turret while minimizing aerodynamic drag. In service it was found that while they gave a reasonable arc of fire, elevation and depression were very limited, while drag was considerable, and disturbance of the slipstream adversely affected the tailplane and elevators. As protection against attacks from astern they were ineffective, as even at maximum traverse they left a considerable arc uncovered, while the tailplane shielded a significant area.

Boeing Y1B-17 Flying Fortress, “61.”

Part of the 2nd Bomb Group over New York City on its way to Buenos Aires in February 1938.

A Y1B-17 of the 49th Bombardment Squadron with designator numbers (“80”) on nose and tail. Front portion of cowlings were painted yellow. This is an enlargement of the plane at lower left in the above photo.

Boeing Y1B-17 Flying Fortress, “80,” as seen in the previous two photos.

Y1B-17 “80,” at the 1937 Cleveland Air Race.

Y1B-17 repainted in wartime camouflage colors on exhibit at the Golden Gate international Exposition, Treasure Island, 1940.

Boeing Y1B-17 Flying Fortress over Washington, D.C. Aircraft number 60 from the 96th Squadron. First YB-17 flew 2 December 1936.

General Frank M. Andrews, commander of General Headquarters (GHQ) Air Force, wanted heavy bomber techniques developed as quickly as possible, so 12 of 13 Y1B-17s built were assigned to the 2nd Bomb Group, Langley Field, Virginia, beginning in March 1937. In addition to long-range bombardment, the Army was assigned coastal defense duties as outlined in the MacArthur-Pratt agreement of 1931. This allowed the U.S. Navy to assume long-range sea offensive operations. Colonel Robert Olds, commander of the 2nd Bomb Group, developed a “training mission” in which a flight of B-17s (the Y1B-17 was redesignated B-17 when assigned to the 2nd Bomb Group) would intercept a ship at sea to demonstrate the long-range bomber’s capabilities. The ship selected for intercept was the Italian liner Rex. On the morning of 12 May 1938, three B-17s took off from Langley Field under the command of Maj. Caleb Hayes. Lieutenant Curtis LeMay was lead navigator for the flight and charged with finding the liner, which was about 800 miles east of New York City. Although the weather was bad, the B-17s successfully intercepted the Rex after a four-hour flight. The B-17s made several passes over the ship to allow for still and motion picture photography. The U.S. Navy protested that the flight was not coastal defense, but the U.S. Army made the most of the flight and heavily publicized it in newsreels and newspaper stories.

Y1B-17A Flying Fortress (37-269).

Boeing Y1B-17 on public exhibit in front of the Federal Building on Treasure Island during the 1939 Golden Gate International Exposition.

Boeing Y1B-17.

Boeing Y1B-17.

YB-17 prototype being refueled on 4 June 1937.

Boeing YB-17 Flying Fortress.

YB-17 in flight over Mount Rainier.

Boeing YB-17.

A giant of the skyways poises for flight, Langley Field, Virginia. The four powerful engines of a YB-17 bomber are warmed up before a takeoff; May 1942.

U.S. Army Air Forces pilot in front of a YB-17 bombing airplane, probably Langley field, Virginia; May 1942.

A combat crew receives final instructions just before taking off in a mighty YB-17 bomber from a bombardment squadron base at the field, Langley Field, Virginia; May 1942.

Boeing YB-17A Flying Fortress.