Northrop Grumman B-2 Spirit Refueling

KC-135 Stratotanker doing an Aerial Refueling to a US Northrop Grumman B-2 Spirit over Salt Lake City in USA. The Northrop Grumman B-2 Spirit (also known as the Stealth Bomber) is a strategic bomber versatile developed in the US by Northrop Corporation with stealth technology ‘low visibility’ able to penetrate air defenses to deploy both conventional and nuclear attacks. It is the most expensive airplane ever built. The manufacturing cost of each B-2 was about 737 million US $ in 1997. The total costs of purchasing the bomber reached an average of 929 million per aircraft, including spare parts, equipment upgrades and support software.