The US Air Force offers cash bonuses to all multilingual aircrew - with Russian listed as one of the most important languages.

High fliers get a bonus if they speak a bit of Russian - at least in the US Air Force.

Any airman can now bag a language proficiency payment worth up to $1,000 a month, depending on the tongues he has mastered and the level he has reached, Air Force Times reports.

Russian, along with Spanish, French and - somewhat surprisingly - Turkmen, is on the "critical languages" list.

A second list of "languages needed for crisis or potential threat" includes Georgian, Azerbaijani, Kazakh, Uzbek and Czech, while other CIS countries - and Russian regional languages like Chechen - are on a third list.

The precise sums depend on the language skills of the serviceman and the usefulness of the language studied, up to a total of $1,000 a month for proficiency in two "critical languages."

Most airmen who qualify for the bonuses - which are awarded on completion of an annual exam - speak French, Italian, Russian, German and Spanish.

The new bonus reflect a change in policy: previously only translators and secret service agents were eligible for these payments, but now anyone from pilots to ground crew can apply.

Lt. Col. Paul Valenzuela, head of Air Forces language and cultural programme office overseeing the bonuses, told the Air Force Times that 4,300 airmen are currently taking part in the programme, the majority receives about $500, and 13,000 more employees could be eligible.

To encourage recruits to learn a foreign language a training centre at Maxwell Air Force Base is offering a $3,000 incentive for students to go back to school.

"We are talking about the human aspect of the mission. In order to be successful as the human aspect, being able to understand the culture and speak its language is vital." Valenzuela told Air Force Times.