The US Air Force is testing a new stealth coating for B-2 bombers that could seriously reduce maintenance time. On any aircraft, key elements are located behind removable panels. Accessing and servicing these components involves unbolting a hatch, working on the component, then replacing the hatch. On a stealthy aircraft, doing this is a problem since the gaps around the edges of each panel become reflectors for radar signals. To avoid this problem, each crack around each hatch must be covered with tape and special coatings. Accessing an internal component takes 36 hours, most of which involves removing the old tape and installing new tape. The new Alternate High-Frequency Material reduces this service time to less than an hour. The material reduces the width of the gap around the edges of these panels to the point it does not reflect radar. If the new coating holds up in flight tests, all 21 bombers will have this material installed during routine depot-level maintenance.--Stephen V Cole