The East Turkistan leaders boarded the aeroplane, optimistic about negotiations with Chairman Mao. But the plane mysteriously crashed. Whether by design or accident almost the whole of the republic's leadership was wiped out, and with them the only hope of quasi-independence for Xinjiang's minorities.
"Uighur people these days still cry about this ... Young people today still revere the [East Turkistan] leaders," said Justin Rudelson, a specialist on Xinjiang at Tulane University in the United States.
Since 1949, the Turkic-Muslim nationalities of Xinjiang, China's far north-western province, have been ruled with varying degrees of brutality by Peking. The separatist movement has never died, erupting regularly and violently against Han Chinese domination, but it has been quashed by the Chinese authorities.
During the past few weeks, however, the authorities have shown unusual alarm over a perceived "splittist" threat in Xinjiang, just as a number of violent incidents, including political assassinations, have come to light. It is difficult to gauge what is going on in Xinjiang, a vast territory of just 16 million people which accounts for one-sixth of China's land mass. Large areas are closed to foreigners and journalists are unwelcome.
Unlike Tibet there is no powerful lobby group outside China and no figure such as the Dalai Lama to provide information. But, judging by the recent official pronouncements, something is amiss.
During the first week in May, Xinjiang party leaders held a meeting on how to fight separatism. "Local ethnic splittist activities have entered a period of revived dynamism", backed by "hostile" foreign forces, said the Xinjiang Daily, the regional party mouthpiece. Subsequent reports revealed that during the last six days of April, 1,700 suspected "terrorists, separatists and criminals" were arrested in Xinjiang, coinciding with the national "Strike Hard" crackdown on crime.
Then, on 2 May, in Kuqa town, nine alleged Muslim separatists were killed in a shootout with police. They were accused of "bombings, murders and other violent terrorist activities". According to the official accounts, the men were armed with home-made bombs intended for an attack in Kuqa. Two weeks later, in the provincial capital of Urumqi, an activist, Abduwayiti Aihemaiti, was jailed for three years allegedly for writing "reactionary articles" calling for the independence of Xinjiang.
Much official media coverage has been devoted this month to warnings by the hardline Xinjiang party secretary, Wang Lequan, who is Chinese. "We must be aware that Uighur nationalism and illegal religious activities pose the greatest dangers to the stability of Xinjiang," he said.
New regulations require all books on Islam to be published by the Xinjiang People's Publication House. Last week, Peking ordered that "party members and officials ... implicated in political bombings, assassinations or other violent terrorist activities, must be immediately investigated and punished with due severity".
This week there have been reports of six or seven murders by Muslim separatists. Among the victims were a vice-chairman of Xinjiang's political consultative conference, killed at the end of April, and two policemen and a pro-Peking Muslim Imam who were killed in February.
Last year five Muslims were executed for their part in a series of bombings in February 1992 and 19 were convicted for counter- revolutionary activities in Khotan city.
It all suggests that ethnic strife has been suppressed but not tamed. The question is how serious the separatist threat really is, and why officials appear so worried now. According to most Western analysts, although Uighur nationalism is strong, the separatists backing an armed struggle are a minority. Mr Rudelson said: "There are those who are calling for separatism and independence, but for the most part it is not seen as a sensible thing to try to push."
But there are serious grievances, especially the massive influx of Han Chinese which has made the Uighur people a minority in their own land. Some 38 per cent of Xinjiang's population are now Han Chinese, and 47 per cent Uighur. The rest are Kazakhs, Hui, Kirzhis, Mongols and other minorities. "Now a lot of Han are coming in to Xinjiang to make money. It causes a lot of friction," said Mr Rudelson.
The Uighurs resent the way Peking has exploited Xinjiang's vast oil reserves,with little benefit for the local population. "China views Xinjiang as a natural resources deposit; it is a storehouse for extraction," said Mr Rudelson.
The oil companies do not even hire local labour, preferring immigrant Han. Xinjiang remains one of the poorest parts of China and is used as China's nuclear test site. It is also host to a large number of Chinese convicts in numerous labour camps.
Professor June Teufel Dreyer, at the University of Miami, who studies China's ethnic minorities, believes the crackdown may be tied to Peking's recent border agreements with Kazakhstan, Kyrgystan, and Tajikistan. After seeing the emergence of these new Muslim republics, Peking fears cross- border links with Uighur nationalists in these states. "There is infiltration of weapons and Islamic fundamentalist propaganda," said Ms Dreyer. But she judges the Uighur threat to Peking as "mainly of nuisance value at the moment".
Peking, however, has considered desperate measures. According to Ms Dreyer, in 1990 they were willing to arm Han Chinese convicts in labour camps in the event of an Uighur uprising.