Boeing XB-15 (XC-105, EC-105)
Technical Information

Background
Designed and built by Boeing in Seattle. In 1933, the Model 294 (Boeing 294) was design and development began as "Project A" in conjunction with the U.S. Army Air Corps (USAAC) as an experimental aircraft to test the viability of building a heavy bomber with a 2,000 pound bombload at 200 mph over a distance of 5,000 miles. In April 1934, the U.S. Army contracted with both Boeing and Martin to design such a bomber designated the XB-15 (XC-105, EC-105).

Delivered to the U.S. Army Air Corps (USAAC) as XB-15 as an experimental aircraft to test the viability of building a heavy bomber with a 5,000 mile range. The XB-15 was designed to be powered by four liquid-cooled 1,000 hp engines. Before these were developed, air cooled radial engines rated at 850 hp (637 kW) were used instead. These engines left the bomber significantly underpowered; with a top speed of 200 mph or only 145 mph carrying a bomb load and was deemed to be too slow for a modern combat aircraft and the project as canceled after only one prototype XB-15 35-277 was built.

Prototype
The only prototype, XB-15 35-277 made a first flight on October 15, 1937. converted into a transport, designated "XC-105" and later designated "EC-105" which carried freight around the Caribbean during World War II with the 6th Air Force. In service for eight years, the XB-15 carried more than 5,200 passengers, 440,000 pounds of cargo and 94,000 pounds of mail. It flew 70 cargo trips and 60 missions including anti-submarine patrol. Scrapped 1945.

Production
Only one prototype XB-15 35-277 was ever built.

Technical Details XB-15 (XC-105, EC-105)
Crew  Ten
Engine  4 × 14-cylinder Pratt & Whitney R-1830-11 after modification at Panama Air Depot (PAD) at Albrook Field
Span  87' 7"
Length  149'
Height  18' 1"
Maximum Speed  200 mph at 5,000'
Range  5,130 miles
Armament  3 x .30 caliber machine guns, 3 x .50 caliber machine guns
Bombload  12,000 pounds of bombs