Redesign of Bomber's Aft Deck Promises to Reduce Maintenance Costs, Improve Aircraft Availability

http://www.irconnect.com/noc/press/pages/news_releases.html?d=185513

PALMDALE, Calif., March 2, 2010 (GLOBE NEWSWIRE) -- Northrop Grumman Corporation (NYSE:NOC) and the U.S. Air Force hope to soon resolve, once and for all, a technical issue that's challenged engineers and maintainers of the nation's fleet of B-2 stealth bombers for more than 20 years: cracking in the B-2's aft deck, a metallic panel on the bomber's upper surface that shields its composite airframe from the heat of engine exhaust.  

The team has just completed a paper "fly-off" between two alternate approaches for redesigning the aft deck. The goal of the program is to develop and produce a new aft deck that can span normal long-term B-2 maintenance cycles without needing additional service or repairs.

Northrop Grumman is the Air Force's prime contractor for the B-2, the flagship of the nation's long range strike arsenal, and one of the most survivable air systems in the world.

"Resolving the aft deck problem is an important part of guaranteeing the long term viability of the B-2," said Dave Mazur, Northrop Grumman's vice president of long range strike and B-2 program manager. "We are committed to helping the Air Force develop and implement the solution that is in the best long term interests of both the B-2 fleet and U.S. taxpayers."

Located behind the B-2's exhaust outlets, the aft deck is exposed to extreme temperatures and acoustic-induced vibrations, making it vulnerable to fatigue and cracking. 

"The key to producing a reliable, high performance aft deck is creating a balance between stiffness and flexibility," explains Chuck Osberg, Northrop Grumman's aft deck program manager. "If the deck is too flexible, high cycle fatigue will cause premature failure; if it's too stiff it can put undue stress on adjacent structures."

According to Osberg, the winning aft deck design – a fundamentally new approach – was selected on the basis of cost and performance.   It reflects many years of thermal and structural analysis of the aft deck, the structures to which it attaches and its operating environment by Northrop Grumman engineers.  It also includes new stiffening elements designed to significantly reduce the vibration and metal fatigue currently experienced in flight by the aft deck. 

The aft deck upgrade program is the latest in a series of modernizations that the Air Force, Northrop Grumman and its subcontractors have undertaken to ensure that the B-2 remains fully capable against evolving threats. 

The B-2 Spirit stealth bomber is one of the most survivable aircraft in the world. It remains the only long-range, large-payload aircraft that can penetrate deeply into protected airspace. In concert with the Air Force's air superiority fleet, which provides airspace control, and the Air Force's tanker fleet, which enables global mobility, the B-2 helps ensure an effective U.S. response to threats anywhere in the world. It can fly more than 6,000 nautical miles unrefueled and more than 10,000 nautical miles with just one aerial refueling, giving it the ability to reach any point on the globe within hours.