Boeing C-108 Flying Fortress

A rare Cargo modification based on the XC-108. This is CB-17G-50-DL, 44-6301, at Patterson Field, Ohio on January 1, 1946. (Bill Larkins)

The Boeing C-108 Flying Fortress was an American transport aircraft used during World War II. Four were converted from B-17 Flying Fortress heavy bombers.

Design and Development

The first C-108 built (designated XC-108) was a B-17E (41-2593) converted to a V.I.P. transport for General Douglas MacArthur in 1943. With the exception of the nose and tail turrets, all armament was removed, as was all armor. The interior of the plane was made into a flying office for MacArthur, with extra windows, cooking facilities, and living space. To facilitate entry and exit, a drop-down door with steps was installed in the rear fuselage. A similar conversion was later made on a B-17F-40-VE (42-6036), which was redesignated YC-108.

Between August 1943 and March 1944, another B-17E (41-2595) was converted to a cargo aircraft and designated XC-108A. Hoping to convert obsolete bombers into cargo aircraft, the United States Army Air Forces initiated a re-manufacturing station at Wright-Patterson Air Force Base. The plane was stripped of armament, armor, and other military equipment. Crew locations were shifted, and the nose was modified to provide space for cargo and/or personnel. The cockpit was accessed via the crawl way under it or through the hinged solid nose cone that had replaced the original glazed bombardier station. To increase cargo space, several bulkheads were removed and the bomb bay doors were sealed closed. This allowed much of the fuselage volume to be used to carry cargo or personnel.

A B-17F 42-30190 was converted (and given designation XC-108B) to tanker service. As in the XC-108A, it was devoid of armor and weapons, and the fuselage was modified to make space for its cargo. The fuselage was filled with fuel tanks.

Operational History

The XC-108 was personal VIP transport aircraft of General Douglas MacArthur in 1943.

The XC-108A was used to fly material and personnel over the Himalayas to the B-29 base in Chengdu, China. Due to chronic engine difficulties, it proved an impractical cargo aircraft. In October 1944, it was returned to the United States. By the end of the war, it was disassembled and left in a junkyard in Maine, where it suffered from some parts being scrapped and others salvaged from the airframe. Since then it has been rescued and is under restoration back to B-17E configuration.

Variants

XC-108: B-17E converted to VIP transport standard for General Douglas MacArthur. Originally B-17E s/n 41-2593.

YC-108: B-17F converted to VIP transport standard for General Douglas MacArthur. Originally B-17F s/n 42-6036.

XC-108A: B-17E converted to cargo or troop transport standard. Originally B-17E s/n 41-2595, known as "Desert Rat".

XC-108B: B-17F converted for service as a tanker. Originally B-17F s/n 42-30190.

Two other cargo transports and VIP transports were made from the B-17.

CB-17G:  Troop transport version capable of carrying up to 64 troops, 25 built.

VB-17G: VIP transport version for high level staff officers, 8 built. 

Operators

United States: United States Army Air Forces

Details (XC-108)

Role: Military transport aircraft

Manufacturer: Boeing / Lockheed-Vega / Wright-Patterson AFB

First flight: 1943

Introduction: 1943

Retired: 1945

Primary user: United States Army Air Forces

Number built: 4 conversions from B-17

Developed from: Boeing B-17 Flying Fortress

Crew: 5

Capacity: 64 troops or 8,000 lb (3.63 t) cargo

Length: 74 ft 4 in (22.66 m)

Wingspan: 103 ft 10 in (31.65 m)

Height: 19 ft 1 in (5.82 m)

Wing area: 1,527 sq ft (141.9 m2)

Empty weight: 32,250 lb (14,628 kg)

Gross weight: 40,260 lb (18,262 kg)

Maximum takeoff weight: 53,000 lb (24,040 kg)

Powerplant: 4 × Wright R-1820-65 9-cyl. turbo-charged air-cooled radial piston engines, 1,200 hp (890 kW) each

Maximum speed: 274 kn (315 mph, 507 km/h)

Cruise speed: 169 kn (195 mph, 314 km/h)

Range: 2,900 nmi (3,300 mi, 5,300 km)

Service ceiling: 36,600 ft (11,200 m)

Armament: 4 × 0.5 in (12.7 mm) M2 Browning machine guns in nose and tail turret

Survivors

XC-108A, 41-2595, "Desert Rat", survived in a New England junkyard and is undergoing restoration in McHenry County, Illinois, by a private individual to B-17E configuration.

Bibliography

Jablonski, Edward. Flying Fortress. Doubleday, 1965.

Johnson, E. R. (2013). American Military Transport Aircraft Since 1925. Jefferson, North Carolina: McFarland & Company, Inc.

Wagner, Ray. American Combat Planes. Doubleday, 1982.

Encyclopedia of American Aircraft

USAF Museum

Andrade, John M. . U.S Military Aircraft Designations and Serials since 1909. Leicester : Midland Counties Publications, First edition 1979.

The first C-108 built (designated XC-108) was a B-17E (41-2593) converted to a V.I.P. transport for General Douglas MacArthur in 1943. With the exception of the nose and tail turrets, all armament was removed, as was all armor. The interior of the plane was made into a flying office for MacArthur, with extra windows, cooking facilities, and living space. To facilitate entry and exit, a drop-down door with steps was installed in the rear fuselage. (Bill Larkins)

Boeing XC-108, the transport version of the B-17 Flying Fortress bomber, used as transport by General MacArthur, 29 November 1943. (USAAF)

Boeing XC-108 Flying Fortress (41-2593), the only one of its type modified from a B-17E, was the personal transport of Gen. MacArthur.

XC-108 41-24537 transported General Douglas MacArthur to observe a paratroop drop on Markham Valley.

XC-108A, serial number 41-2595, was a B-17F converted into a cargo transport.

YC-108 Flying Fortress (42-6036), used by Gen. Frank D. Hackett, India.