The Hump

"The Hump" was the name given by Allied pilots in the Second World War to the eastern end of the Himalayan Mountains over which they flew from India to China to resupply the Flying Tigers and the Chinese Government of Chiang Kai-shek. The region is noted for high mountain ranges and huge parallel gorges, and transverses the upper regions of the larger rivers of South-East Asia: Mekong, Irrawaddy, Salween, etc.

Allied pilots began flying cargo resupply missions over the Hump in April 1942, after the Japanese blocked the Burma Road. Missions continued until near the end of the war, when the Ledo Road opened.

The Burma Road Dilemma

Initially, the Burma Road was used to ferry military supplies, gasoline, and other goods by vehicle to China. However, in April and May of 1942, the Japanese seized several areas of Burma that effectively cut Allied access to the Burma Road. To maintain an uninterrupted supply to China of strategic materials requested by the Kuomintang government, U.S. and other allied leaders agreed to organize an continual aerial resupply effort, or air bridge. The U.S. responsibilities were assigned to the United States Army Air Corps, and in July 1942, the USAAF's new Ferrying Division of the Air Transport Command was assigned the task of organizing the airlift and providing planes and logistical support. The Ferrying Division, commanded by Col. William H. Tunner, assumed the task of organizing the airlift and providing logistical support. Most of the officers, men, and equipment were provided by the USAAF, augmented by British, Indian Army, and Commonwealth forces, Burmese labor gangs, and an air transport section of the Nationalist Chinese Air Company.

Flight Operations

Slowly, an airlift of unprecendented scale began to take shape, transiting the nations of India, Burma, and China. In the west, the air route commenced in India from a series of airfields strung out along the Assam section of the north east Indian railways, [William Slim. "Defeat into Victory", Chapter IX: The Foundations] and passed over the mountains of Yongnan and a series of spines to Sichuan Province. After the opening of the air bridge, the resupply effort became a literal "road of life" for the Nationalist Chinese war effort. Chiang Kai-shek had argued that at least 7,500 tons per month were needed to keep his field divisions and a 500-plane airforce in operation, though this figure proved unattainable for the first several months of the Hump airlift. [CBI Background, "CBI Order of Battle, Lineages and History: China Defensive Campaign, 4 July 1942-4 May 1945" http://www.cbi-history.com/part_xii_china_def.html]

A critical problem proved to be finding a cargo transport aircraft capable of carrying heavy payloads at the high altitudes required. Initially the Hump was flown with the C-39, the Douglas C-47, the Douglas DC-3 (converted to carry cargo), and the C-53, a troop transport variant of the C-47. However, these aircraft were ill-suited to high-altitude operation with heavy payloads, and could not normally reach an altitude sufficient to clear the mountainous terrain, forcing the planes to attempt a highly dangerous route through the maze-like Himalayan passes. [Gann, Ernest, Fate Is The Hunter, New York: Simon & Schuster (1961), ISBN 0-671-63603-0, p. 263]

The arrival of the Consolidated C-87 Liberator Express and its fuel transport variant, the C-109, in December 1942 boosted tonnage figures, and their high-altitude capability enabled them to surmount the lower mountains (15,000-16000 feet MSL) without resorting to the passes, but the planes had a high accident rate and were unsuited to the airfields then in use. Despite the C-87's four engines, the planes climbed poorly with heavy loads, and often crashed on takeoff after losing an engine. [Gann, Ernest, "Fate Is The Hunter", New York: Simon & Schuster (1961), ISBN 0-671-63603-0, p. 256] They also had a unfortunate tendency to spin out of control when encountering mild icing conditions over the mountains. [Gann, Ernest, "Fate Is The Hunter", New York: Simon & Schuster (1961), ISBN 0-671-63603-0, p. 256] The C-109s were dedicated fuel transport aircraft converted from existing B-24 bombers. All armament and bombardment equipment was removed, and eight fuel tanks were installed inside the fuselage that could carry 2,900 U.S. gallons of high-octane aviation gasoline. Many of the 218 C-109 fuel transports built were sent to the CBI. Like the C-87, they were not popular with their crews, since they were very difficult to land when fully loaded, especially at airfields above 6000 feet in elevation, and often demonstrated unstable flight characteristics with full tanks. A crash landing of a loaded C-109 inevitably resulted in a fireball and crew fatalities. ["Consolidated C-109", http://home.att.net/~jbaugher2/b24_27.html]

The Curtiss C-46 Commando began to fly Hump missions in April 1943. The C-46 was a large turbo-supercharged twin-engine aircraft capable of flying faster and higher than any previous twin-engine cargo aircraft, and was capable of carrying heavier loads than either the C-47 or the C-87. [Gann, Ernest, "Fate Is The Hunter", New York: Simon & Schuster (1961), ISBN 0-671-63603-0, p. 263-264] [CBI Hump Pilots Association, "Flying the Hump: A Fact Sheet for the Hump Operations During World War II" (USAAF) China-Burma-India (CBI) Theater of Operations http://www.cbi-history.com/part_xii_hump5.html] With the C-46, aircraft loads increased significantly the Hump reached 12,594 tons in December, 1943. Loads continued to increase throughout 1944 and 1945, reaching an all-time maximum tonnage in July, 1945. [CBI Hump Pilots Association, "Flying the Hump: A Fact Sheet for the Hump Operations During World War II" (USAAF) China-Burma-India (CBI) Theater of Operations http://www.cbi-history.com/part_xii_hump5.html] [Background Information, Curtiss C-46 Commando, http://www.ruudleeuw.com/c46_tech.htm]

Flying over the Hump proved to be a nearly suicidal endeavour on the part of Allied flight crews. The air route first crossed the Himalayan foothills and wound its way into the high mountains between north Burma and west China, where violent turbulence, gales, icing, and instrument weather conditions were a regular occurrence. From the beginning, a lack of experienced personnel and resources hampered the mission. In the first months of the operation, inexperienced supply officers often ordered planes loaded until they were 'about full', heedless of gross weight limitations. Lack of suitable navigational equipment, radio beacons, and inadequate numbers of trained personnel (there were never enough navigators for all the groups) continually affected airlift operations. While there were some experienced civilian airline and military transport pilots in the ATC, many others were just out of flight school with relatively little instrument time and minimal experience in flying multi-engine cargo planes in extreme conditions. Chinese pilots, while used to a variety of aircraft, also had little instrument flying experience, and most were unfamiliar with the large American transport aircraft used in the airlift. Still, American and Chinese pilots flew their heavily-loaded planes daily on round-trip flights to Chengdu, Kunming, and other cities. Transport planes flew around the clock from any of thirteen bases in northeastern India, landing about 800 kilometres away at one of six Chinese airfields. Some exhausted crews flew as many as three roundtrips every day. Mechanics serviced planes in the open, using tarps to cover the engines during the frequent downpours. There were never enough mechanics or spare parts to go around; maintenance and engine overhauls were often deferred. Many overloaded planes crashed on takeoff after losing an engine or otherwise encountering mechanical trouble. Author and ATC pilot Ernest K. Gann recalled flying into Chabua airfield in India and witnessing four separate air crashes in one day - two C-47s and two C-87s. Three flight crews were killed, all before five o'clock in the afternoon. [Gann, Ernest, "Fate Is The Hunter", New York: Simon & Schuster (1961), ISBN 0-671-63603-0, pp. 265-271] Due to the isolation of the area, as well as the lower priority of the CBI theater, parts and supplies to keep planes flying were in short supply, and flight crews were often sent into the Himalayan foothills to cannibalize aircraft parts from the numerous crash sites in order to repair the remaining aircraft in the squadron. A byproduct of the tragic, near daily air crashes was a local boom in native wares made from aluminum crash debris.

In addition to losses from weather and mechanical failure, the unarmed and unescorted transport aircraft flying the Hump were occasionally attacked by Japanese Army fighters in the dry (winter) season. [Background Information, Curtiss C-46 Commando, http://www.ruudleeuw.com/c46_tech.htm] While piloting a C-46 on one such mission, Captain Wally A. Gayda returned fire in desperation against a Nakajima fighter by pushing a Browning BAR automatic rifle out the forward crew cabin window and emptying the magazine, killing the Japanese pilot. [Curtiss C-46 Commando http://www.faqs.org/docs/air/avc46.html] [American Aircraft of World War Two, "Curtiss Commando" http://www.century-of-flight.net/Aviation%20history/photo_albums/timeline/ww2/2/Curtiss%20Commando.htm] Some 468 American and 46 Chinese flight crews perished from all causes, totaling over 1500 personnel. At times, monthly aircraft losses totalled 50% of all aircraft then in service along the route.

In 1944 CBI Pilot Major Robert K. Chittle of Flint, Michigan was flying a C-46 over the Hump when approached from the east by a Japanese Zero. With no defenses, he brought the heavily laden aircraft down to the deck (ground level) and flew as close to the ground as possible. The Zero hovered above for some time, before leaving the area. Major Chittle earned the Distinguished Flying Cross for this and other heroic flying.Fact|date=September 2008

Chinese pilots made a key contribution to Hump flight operations. During 1942 to 1945 the Chinese received from the U.S. exactly 100 transport aircraft: 77 C-47 Dakotas and 23 C-46 Commandos. According to some sources, from May 1942 to September 1945, a total of 650,000 tons were transported via the Hump, of which Chinese pilots accounted for 75,000 tons (about 12%). This figure does not include passengers, of which 33,400 persons were transported, in one or both directions.

In 1944, Air Transport Command was tasked with the mission of supporting B-29 Superfortress missions being flown from China against Japan. From February to October 1944, ATC flew nearly 18,000 tons over the Hump in support of the B-29 strategic offensive bombing campaign, when B-29 operations were transferred from China.

In August 1944, USAAF General William H. Tunner took command of the India-China Division of Air Transport Command. By this time, the arrival of increased numbers of Douglas C-54 Skymaster four-engine transport planes greatly increased tonnage levels flown to China from India. [Glines, C.V., "Flying the Hump", Air Force Association Magazine (March 1991) Vol. 74 http://www.afa.org/magazine/1991/0391hump.asp] In order to improve efficiency, General Tunner changed the C-54's air routing to a more direct route to China, using escort from Eastern Air Command fighter squadrons to prevent interception by Japanese aircraft. The C-54, which could carry three times the cargo load of the C-47, replaced both the latter transport as well as the C-46 in the last months of the airlift. [Glines, C.V., "Flying the Hump", Air Force Association Magazine (March 1991) Vol. 74 http://www.afa.org/magazine/1991/0391hump.asp]

The Hump's air bridge operation continued until the end of the war. Though it declined in importance with the opening of the Ledo Road network in January 1945 and in particular, the recapture of Rangoon, the airlift's total tonnage (650,000 tons) dwarfed that of the Ledo Road (147,000 tons). [Air Force Association, "Flying The Hump" http://www.afa.org/magazine/1991/0391hump.asp] The final summary of flight time in the airlift totalled 1.5 million flight hours. The Hump ferrying operation was the largest and most extended strategic air bridge in the world, only exceeded in 1949 (in volume of cargo airlifted) by the West Berlin air bridge.

ee also

*General William H. Tunner
*General Albert Coady Wedemeyer
*Robert Lee Scott, Jr.
*Fort Hertz
*China Burma India Theater of World War II
*South-East Asian Theatre of World War II
* [http://www.flickr.com/photos/denalidog1/2544902059/in/photostream M. Kelly Gardner]

References

Further reading

* Jon Latimer, "Burma: The Forgotten War", London: John Murray, 2004 ISBN 0-7195-6576-6
* http://www.palletmastersworkshop.com/hump.html
* http://www.nimitz-museum.org/cbiprimer.htm
* http://www.usaaf.net/ww2/airlift/airliftpg7.htm
* http://www.comcar.org/comcarhome.htm