Air forces will buy some $28 billion worth of aircraft engines through the end of the decade. American manufacturers will supply $16 billion worth of of these engines. European manufacturers will supply $8 billion worth, Russian manufacturers 2.3 billion worth and various other manufacturers the rest. These estimates were based on current and projected orders. The ability to design and build powerful jet engines is essential for producing effective warplanes. For the last seventy years, warplane design has been described as finding the most powerful engine you can and then building an aircraft around it.