IN A NEW blow to Russian tourism - and still worse, to Russian national pride - the State Department has taken the unusual step of publicly warning Americans to avoid flying on domestic Russian airlines, whose reputation for poor safety and service now exceeds even that of their infamous predecessor Aeroflot.

The move follows instructions to US Government officials, including embassy staff in Moscow, to avoid using Russian airlines wherever possible. Only air travel deemed 'important and absolutely necessary' will be approved, say the new rules. As alternatives, the State Department recommends trains or international airlines via connections outside the country.

The warning to the general public is not binding. In practice it is only a recommendation, designed to remove any suggestion of a 'double standards policy' whereby information available to government employees is kept from the public. In extreme cases such as an air crash, this could lead to costly and embarrassing legal claims.

Concern about the safety of air travel inside Russia has risen sharply this year after several highly publicised disasters. In April the International Airline Passengers' Association advised travellers not to take any flights within the former Soviet Union. Already some Western countries have quietly urged their diplomats to do the same. But it is the stance of its erstwhile superpower rival which will sting the Russians most.

Yuri Tarshin, head of flight operations at the Russian Transport Ministry in Moscow, was quoted by the Associated Press as describing the State Department edict as offensive, and 'an insult to our professional abilities'. Other Russian officials claim the move is part of a conspiracy to shift business to rival foreign airlines.

In Washington, the State Department said no particular incidents had led to its recommendation. But travel within Russia was often 'unreliable, with unpredictable schedules and difficult conditions.' These latter - as anyone who has sampled the experience needs no reminding - include poor maintenance, ageing planes and gross overloading.

The new rules will apply at least until the US Federal Aviation Administration has made a formal assessment of the Russian civil aviation system. Part of the problem is the lack of a separate regulatory Russian agency along the lines of the FAA. That job was technically done by the Soviet, now Russian, civil aviation ministry - to all intents and purposes by Aeroflot itself.