[3] Two weeks later on 17 April, the Nationalists entered into a service contract with an American firm, Aviation Exploration Inc which was to establish air routes between a few of the major treaty ports and manage all operations.

[5] This new Sino-American venture faced acute resistance from military factions in South China: warlords had their own small air forces which had ambitions to earn income from airmail service between the treaty ports.

Even more ominous was the opposition from Wang Po-chun the Minister of Communications; in July 1929, he went ahead and set up an airmail service, Shanghai-Chengtu Airways, owned entirely by his ministry.

It continued to face overwhelming political and financial difficulties, not least from the Ministry of Communications which not only collected airmail revenue from its own service but from that of China Airways Federal.

By the start of 1930 China Airways Federal was at the point of bankruptcy and threatened to stop operations altogether unless the Ministry of Communications released its revenue.

[6] From 1931 until 1948 William Langhorne Bond was operations manager and vice-president of China National Aviation Corporation By 1933, Keys had retired under a cloud of scandal and near bankruptcy.

After a series of disastrous accidents and disagreements with Chinese leaders, Morgan decided to sell the 45 percent stake held by Intercontinent in CNAC to Pan American Airways: on 1 April 1933.

Initially, the Nationalists maintained contact with the outside world through the port of Hanoi in French Indo-China, but the Japanese put pressure on the new pro-Vichy regime there to cut off relations with them in 1940–41.

[citation needed] By fall 1940, CNAC operated service from Chongqing (via Kunming and Lashio) to Rangoon, Chengdu, Jiading (via Luzhou and Yibin) and Hong Kong (via Guilin).

Despite the large casualties inflicted by the Japanese and more significantly, the ever-changing weather over the Himalayas, the logistics flights operated daily, year round, from April 1942 until the end of the war.

Moon Fun Chin, who flew supplies over the dangerous Hump Campaign to resupply the Chinese during World War Two, was the last surviving CNAC pilot.