AFRL Team Spearheads Redesign of B-2 Nozzle Bay Doors Published Dec. 28, 2006 By HQ AFRL HQ AFRL WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- A team of AFRL engineers successfully resolved a design problem affecting the performance of the B-2 aircraft's nozzle bay doors (NBD). The NBD redesign effort improved mission-capable rates for the B-2 fleet. The Advanced Composites Office worked with the AFRL team and the B-2 Systems Group to identify a timely and cost-effective solution. The engineering team thoroughly tested the redesigned door in the laboratory and on the aircraft. With full production now under way, about half of the B-2 fleet's NBDs have undergone modification according to the new design. AFRL's modification will generate an estimated savings of more than $20 million. As a result of this success, the B-2 Systems Group has requested further AFRL assistance to adapt the modification to other, similar doors on the aircraft. Prior to AFRL's redesign and transition effort, B-2 NBD repairs required multiple days and extensive use of costly materials. Focused on improving this situation, the engineering team established procedures for ensuring that the bond between the composite seal and the parent material of the door met all design requirements. In addition, the engineers developed nondestructive inspection standards and procedures for flight testing the new design, designing these standards and procedures into a door section, manufacturing the modification, and subsequently inserting various flaws into the modified product for test purposes. The team then conducted laboratory testing to simulate both thermal- and stress-loaded flight conditions. The AFRL engineers provided a strong, sustainable capability, as well as a methodology for rapidly resolving complex technical issues and problems while keeping the fleet flying. The team corrected defects found in operational flight systems and played a major role in identifying unexpected problem areas that can benefit from corrective action before major damage occurs. This proactive approach will help minimize future repairs. AFRL provides prompt support for a wide range of potential materials-related problem areas, including metals and composites, electronic material devices, corrosion control, nondestructive evaluation, and failure analysis (a technological approach used to determine a problem's root cause).