The Russian air force is undertaking a decade-long program to replace its aging transports.

More than 100 new transport jets are scheduled to be purchased.

The problem facing Russian air force commanders is whether they should buy indigenously built Russian aircraft or include in the purchase order Antonov transports, now built in the neighboring country of Ukraine.

Russian-Ukrainian relations have been strained since the December 1991 collapse of the Soviet Union, with two major issues being the final disposition of Russian Black Sea Fleet continuing to use the Ukrainian Crimean naval port of Sevastopol and Gazprom natural gas deliveries to Ukraine and Gazprom's use of Ukraine's soviet-era pipeline network to reach lucrative European markets.

The dispute over Sevastopol, the finest deep-water port in the Black Sea, is ongoing and the issue of Gazprom natural gas deliveries to Ukraine has been vexed by Moscow's determination gradually to raise gas prices to world prices. There are also accusations by the Russian side of Ukrainian diversions of significant amounts of gas.

In the last several years unresolved issues have resulted in Gazprom arbitrarily reducing shipments via the Ukrainian Druzhba pipeline network, much to the consternation of European customers.

For the Russian air force, the problem is whether it should buy 40 Ilyushin-476 transports, the latest modification of the Ilyushin-76, assembled at the Russian Federation's aviation plant in Ulyanovsk, with the remainder to come from Ukraine's Antonov aircraft manufacturing works, or seek alternatives, Zhurnal BSR website reported Thursday.

When the Soviet Union collapsed in 1991, it left the country's military industrial complex split among 15 new countries.

Antonov, formerly the Antonov Aeronautical Scientific/Technical Complex, is a state-owned commercial company, which has headquarters in Kiev. Antonov is the most common aircraft worldwide, with thousands of planes operating in the former Soviet Union and the Third World.

The company's website states, "Our enterprise built more than 22,000 units of more than 100 types and passenger, transport and special-purpose aircraft models."

The Russian air force is interested in acquiring Antonov-70s and heavy-lift Antonov-124s.

The Antonov An-70 is a high-wing monoplane with four wing-mounted propfan engines with fly-by-wire controls medium-range transport aircraft, and the first large aircraft to be powered by propfan engines, with the maiden flight of the first prototype taking place in Kiev nearly three years after the dissolution of the Soviet Union.

The Antonov An-124 (NATO codename "Condor"), is a strategic heavy airlift jet aircraft and is the world's second largest serially manufactured cargo airplane and world's third largest operating cargo aircraft, having received civil certification on Dec. 30.

More than 40 An-124s are in service in Ukraine, Russia, the United Arab Emirates and Libya.

In a rare example of bilateral Russian-Ukrainian cooperation in late 2008 Russia and Ukraine agreed joint to the manufacture of a new AN-124 variant, to be known as the An-124-150, which would incorporate several improvements, including a maximum lift capacity of 150 tons, with the Russian Federation expected to purchase 20 of the aircraft in the coming years.