Consolidated XB-24

XB-24 / LB-30
Rare color photograph of an RAF LB-30
Role	Bomber
Manufacturer	Consolidated Aircraft Corporation
Designer	Isaac M. Laddon
First flight	1939
Introduction	1941
Retired	1946,UK 1946, BOAC
Status	Retired
Primary user	RAF
Number built	8
Unit cost	$ 258,074.67
Variants	B-24 Liberator

Main article: B-24 Liberator

The Consolidated Preproduction B-24 aircraft began in the fall of 1938 when the United States Army Air Corps (USAAC) approached Consolidated Aircraft Corporation (CAC) with the intent of starting a second Boeing B-17 Flying Fortress production line. The president of Consolidated Aircraft, Reuben H. Fleet, as well as the Chief Designer Isaac M. Laddon after reviewing the Seattle production lines felt that Consolidated Aircraft could build a better, more modern bomber than the B-17.

Background

Using a highly advanced wing airfoil design created by David Davis as well as the twin tail design from the Consolidated Model 31 flying boat, both were mated to new fuselage. This new fuselage was intentially designed around the twin bomb bays, each one being the same size and capacity of the B-17.

Based on several mock-ups, the issued Type Specification # C-212 on 1 February 1939, which was specifically designed for the Consolidated Model 32 to be the winning design.

History

On 30 March 1939, the formal contract for the initial B-24 was signed.

After initial testing, the XB-24 was found to be deficient in several areas. One major failure of the prototype was that it failed to meet the top speed requirements specified in the contract. As built, the XB-24 top speed was only 273 mph instead of the specified 311 mph. As a result, the mechanically supercharged Pratt & Whitney R-1830-33s were replaced with the turbo-supercharged R-1830s. Additionally, the tail span was widened by 2 feet (0.61 m) 2 feet and the pitot-static probes were relocated from the wings to the fuselage. The XB-24 was then redesigned XB-24B – these changes became standard on all B-24’s built starting with the B-24C model.

The USAAC initially ordered 7 YB-24s under CAC contract # 12464 in April 1939, but like the prototype these aircraft were being built by hand and were not considered combat ready. Since both the Royal Air Force and French were shopping for aircraft the first 6 YB-24 were released for direct purchase under CAC contract # F-677 on 9 November 1940. These aircraft were redesigned LB-30A. The seventh aircraft was used by Consolidated and the USAAC to test armor installations as well as self-sealing fuel tanks. Initially, these aircraft were to be given USAAC serials 39-618 to 39-687 however, delays with the actual purchase the serials numbers were changed to 40-696 to 40-702. When the RAF purchased the first 6 YB-24 aircraft, the serial numbers were reassigned to a later block of B-24Ds.

The RAF like the USAAC found the LB-30A unsuitable for combat and had them assigned to the transatlantic Ferry Service between Canada and Prestwick, Scotland. The aircraft were all modified in Montreal and included the removal of all armaments, provision for passenger seating, and a revised cabin oxygen & heating system.

The Aircraft

XB-24

• 39-556
  • 29 October 1939 fuselage to wing mated.
  • 29 December 1939 first flight (CAC Chief Pilot Bill Wheatley).
  • 17 February 1940, first flown by USAAC (Major Umstead).
  • 18 March 1940, first official USAAC flight.

In the spring of 1940, the XB-24 was modified with turbo-supercharged engines (P&W R-1830-41) wider horizontal tail plane, moved pitot static ports and redesigned XB-24B.

XB-24B

• 39-680
  • 13 August 1940 accepted by the USAAC.
  • 1944 Modified as VIP transport for CAC personnel
  • 20 June 1946, Scrapped at Brookley Field, Mobile, Alabama.

YB-24 / Liberator LB-30A

• AM258 (ex 40-696) s/n 167. Delivered December 1940. Assigned as a transport with No.1425 Flight on the transatlantic ferry routes.
  • 25 June 1946 Scrapped Albuquerque, New Mexico.

• AM259 (ex 40-697) s/n 168. Delivered December 1940. Assigned as a transport with No.1425 Flight RAF on the transatlantic ferry routes.
  • Assigned to BOAC with registration G-AGCD.
  • 5 January 1943 midair collision with USSR A-20 Havoc.

• AM260 (ex 40-698) s/n 169. Delivered December 1940. Assigned as a transport with No.1425 Flight on the transatlantic ferry routes.
  • June 1941 Ferry Flight (Pilot F/L Spencer Leonard Ring).
  • 14 August 1941 Crashed and burned on takeoff at RAF Heathfield Airfield, Ayr, Scotland, after veering off the runway and striking a small building, then an embankment. (22 Killed))^[1] (Pilot was Captain Stafford) Arthur Blaikie Purvis Head of the British Purchasing Commission was one of those killed as a passenger on transit to Canada.

• AM261 (ex 40-699) s/n 170. Delivered December 1940. Assigned as a transport with No.1425 Flight on the transatlantic ferry routes.
  • 02 August 1941 flew the Duke of Kent across the Atlantic.
  • 10 August 1941 Crashed on Goat Fell, Isle of Arran, Scotland (BOAC Pilot Ernest Robert White^[2]

• AM262 (ex 40-700) s/n 171. Delivered December 1940. Assigned as a transport with No.1425 Flight on the transatlantic ferry routes.
  • June 1941 Ferry Flight (Pilot F/L Spencer Leonard Ring).
  • Assigned to BOAC with registration G-AGHG.
  • 30 May 1946 SOC

• AM263 (ex 40-701) s/n 172. Delivered December 1940. Assigned as a transport with No.1425 Flight on the transatlantic ferry routes.
  • Assigned to BOAC with registration G-AGDS.
  • 15 February 1942, crashed Eddystone

• YB-24 40-702 s/n 173. Delivered December 1940
  • Assigned to Wright Field, Dayton, Ohio. Codes MD 120
  • 28 March 1944 surveyed and scrapped at MacDill Field, Tampa, Florida

Notes

1. ^ Plane Crash Info 1941
2. ^ Peak District Air Crashes of the UK

References

• Birdsall, Steve. B-24 Liberator In Action. Carrollton, Texas: Squadron/Signal Publications, 1975. ISBN 0-89747-020-6.
• Blue, Al. Pictorial History of the B24 Liberator Bomber. New York: Simon & Schuster, 1985. ISBN 0-68414-508-1.
• O'Leary, Michael. Consolidated B-24 Liberator: Production Line to Front Line. Botley, UK: Osprey Publishing, 2002. ISBN 1-84176-023-4.
• Pearcy, Arthur. Lend-Lease Aircraft in World War II: An Operational History. St. Paul, Minnesota: MBI Publishing Company LLC, 1996. ISBN 0-76030-259-6.

See also

• Consolidated Liberator I
• XB-41 Liberator
• C-87 Liberator Express
• Consolidated PB4Y-2
• Consolidated B-24 Survivors
• List of B-24 Liberator operators