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 military transport
aircraft from India to China to resupply the Chinese war effort of Chiang
Kai-shek and the units of the United States Army Air Forces based in China.
The official Army Air Forces history of the airlift stated:
The Brahmaputra valley floor lies 90 feet (27 m) above sea level at Chabua.
From this level the mountain wall surrounding the valley rises quickly to 10,000
feet (3,000 m) and higher. Flying eastward out of the valley, the pilot first
topped the Patkai Range, then passed over the upper Chindwin River valley,
bounded on the east by a 14,000-foot (4,300 m) ridge, the Kumon Mountains. He
then crossed a series of 14,000—16,000-foot (4,300—4,900m) ridges separated by
the valleys of the West Irrawaddy, East Irrawaddy, Salween, and Mekong Rivers.
The main "Hump", which gave its name to the whole awesome mountainous mass and
to the air route which crossed it, was the Santsung Range, often 15,000 feet
(4,600 m) high, between the Salween and Mekong Rivers. East of the Mekong the
terrain became decidedly less rugged, and the elevations more moderate as one
approached the Kunming airfield, itself 6,200 feet (1,900 m) above sea
The airlift began in April 1942, after the Japanese blocked the Burma Road, and
continued on a daily basis from May 1942 to August 1945, when the effort began
to scale down. Final operations were flown in November 1945. The Hump airlift
delivered approximately 650,000 tons of materiel to China during its 42-month
In 1942 Chiang Kai-shek insisted that at least 7,500 tons per month were needed
to keep his field divisions in operation, but this figure proved unattainable
for the first fifteen months of the Hump airlift. The 7,500 total was first
exceeded in August 1943, by which time objectives had been increased to 10,000
tons a month. Ultimately monthly requirements surpassed 50,000 tons.
ATC operations accounted for 685,304 gross tons of cargo carried eastbound
during hostilities, including 392,362 tons of gasoline and oil, with nearly 60%
of that total delivered in 1945. ATC aircraft made 156,977 trips eastbound
between December 1, 1943, and August 31, 1945, losing 373 aircraft. Though
supplemented by the opening of the Ledo Road network in January 1945 and by the
recapture of Rangoon, the airlift's total tonnage of 650,000 net tons dwarfed
that of the Ledo Road (147,000 tons). In addition to cargo, 33,400 persons
were transported, in one or both directions.
CNAC pilots made a key contribution to Hump flight operations. During 1942 to
1945 the Chinese received 100 transport aircraft from the United States: 77
C-47s and 23 C-46s. Of the eventual 776,532 gross tons and approximately 650,000
net tons transported over the Hump, CNAC pilots accounted for 75,000 tons (about
12%). The Hump airlift continued beyond the end of the war. The final
missions of the ICD-ATC, made after most of its attached organizations had
departed, were the transporting of 47,000 U.S. personnel west over The Hump from
China to Karachi for return to the United States.
The maximum aircraft strength of the India-China Division, ATC (July 31, 1945)
was 640 aircraft: 230 C-46s, 167 C-47s, 132 C-54s, 67 C-87/C-109s, 33 B-25s,
10 L-5s, and 1 B-24.
Gen. Tunner's final report stated that the airlift "expended" 594
aircraft. At least 468 American and 41 CNAC aircraft were known lost
from all causes, with 1,314 air crewmen and passengers killed. In addition, 81
more aircraft were never accounted for, with their 345 personnel listed as
missing. Another 1,200 personnel had been rescued or walked back to base on
The final summary of logged flight time in the airlift totalled 1.5 million
hours. The Hump ferrying operation was the largest and most extended strategic
air bridge (in volume of cargo airlifted) in aviation history until exceeded in
1949 by the Berlin airlift, an operation also commanded by Gen. Tunner.
Tunner, writing in Over the Hump, described the significance of the Hump
"Once the airlift got underway, every drop of fuel, every weapon, and every
round of ammunition, and 100 percent of such diverse supplies as carbon paper
and C rations, every such item used by American forces in China was flown in by
airlift. Never in the history of transportation had any community been supplied
such a large proportion of its needs by air, even in the heart of civilization
over friendly terrain...After the Hump, those of us who had developed an
expertise in air transportation knew that we could fly anything anywhere