The Air Force Research Lab, in conjunction with Boeing’s Phantom Works and Aeronautical Systems Center’s Aging Aircraft Systems Squadron, has developed a new environment-friendly, corrosion resistant aircraft coating. AFRL scientists have been searching for a new coating because the existing chromate-based coating—which has excellent corrosion inhibiting properties—is known to be hazardous. The result is AC-131BB, a zirconium alkoxide-based coating. Researchers have completed 1,000 hours of salt-spray testing, adhesion experiments, and corrosion tests—all showing that the new coating works—on aluminum test panels of an F-15 and a KC-135.
The rate of building B-21 bombers would speed up if the fiscal 2026 defense budget passes. But it remains unclear how much capacity would be added, and whether the Air Force would simply build the bombers faster, or buy more.