Aircraft market is estimated to be worth 2.6 trillion dollars over the next two decades so the fight is on to secure a share The Boeing and Airbus duopoly is coming under threat from China and Russia as both countries seek ways to clinch a share of a a market that is forecast to be worth $2.6 trillion over the next two decades. China said this weekend that it would invest $7 billion (£3.6 billion) to build a commercial jet to rival the offerings of manufacturers Boeing, of the United States, and Airbus, of Europe. Russia is also planning to revitalise its aerospace industry and is encouraging Western companies to invest there. The antique Tupolevs and other Russian-built aircraft that fly in both countries need to be replaced before they fall out of the skies, but neither the Kremlin or Beijing wants to hand billions of dollars to Boeing or Airbus without attempting to develop their own industries first. Both countries face enormous barriers to entry, with each type of aircraft costing up to $10 billion to develop. They will also have to overcome the stigma of having "made in Russia" and "made in China" on their products. Boeing and Airbus have spent decades improving their safety records and aircraft are now safer and more reliable than ever. Given the reputation on quality control of Chinese and Russian manufacturing, there are questions to be asked about whether passengers will want to fly on aircraft built in these countries. The risks may be worth the investment if either country can break the lucrative Boeing-Airbus duopoly, but, even if a Chinese-built jet sold only to domestic airlines, the potential would be enormous, with the market for new aircraft there estimated to be worth $350 billion by 2025, according to Airbus. The Russian industry could be worth $70 billion. One theory is that Chinese manufacturers might imitate their domestic automotive industry, using old designs to build cheap products that sell well domestically and in developing countries. This could create a two-tier industry, with rich passengers flying Boeing and Airbus and the less well off using Russian and Chinese aircraft. China already plans to enter the regional jet market - aircraft with up to 100 seats. The China Aviation Industry Corporation is expected to launch the ARJ21 next year, while Russia's Sukhoi is developing the similar Superjet 100. China's announcement that it will build a 150-plus-seat jet is the first move by either country into territory dominated by Boeing and Airbus. This will be particularly bitter news for Airbus, which is building an assembly plant in China in order to position itself better in that country. Russia has limited itself to taking a stake in EADS, Airbus's parent company, so far, but the Kremlin is merging a number of companies into the United Aircraft Corporation and, once this is complete, it may seek to relaunch its aerospace industry. The medium size ailiner market is apparently going into a concurrential phase again after decades of domination by Boeing, challenged by Airbus. Brazilian Embraer is developing also its own 100-some carrier. All this happens against a backdrop of air transport being questioned on enviromental grounds. On the other hand, low cost airlines widely demand these sort of planes.