U.S. Air Force Global Strike Command wants a contractor to help renovate the ducts on the Boeing [BA] B-1B bomber’s engine bleed air distribution system (EBADS).
“Hydrogen embrittlement is common in the titanium [EBADS] ducting on the B-1,” an Oct. 4 EBADS performance work statement (PWS) said. “Ruptures in these titanium ducts in unmonitored areas can cause substantial damage to the aircraft due to heat soaking from prolonged exposure to high temperature bleed air, and are a safety concern.”
“Due to the brittle overload fracture failure mechanism, visual inspection is believed to be ineffective in the detection of an imminent rupture,” per the PWS. “The B-1 System Program Office (SPO) [at Tinker AFB, Okla.] is evaluating an improvement to aircraft safety by addressing the titanium embrittlement issue in a timely and cost effective manner to include weld repairs/refurbishments which may be a more cost effective approach when compared to replacement of the ducts.”
The refurbishment of the EBADS ducts is to take place at Aircraft Ducting Repair Inc. (ADR) in Forney, Texas, and the repaired ducts are then to be shipped to Ellsworth AFB, S.D., for installation on the B-1Bs.
The EBADS duct repair is to use “a process which involves welding a new titanium section into the existing ducting by means of a shielded fusion welding process, developed by the B-1 SPO,” the Oct. 4 PWS said. “This will increase service life of the EBADS and become a long-term solution to the hydrogen embrittlement issue.”
This summer at the Air Force Life Cycle Management Center’s annual industry days in Dayton, Ohio, Brig. Gen. William Rogers, AFLCMC’s program executive officer for bombers, said that the Air Force is looking to sustain its B-1Bs and the 20 Northrop Grumman [NOC] B-2A Spirit stealth bombers until B-21 production scales up in the next decade.
The Air Force may use the B-1B for hypersonic weapons testing through the addition to the B-1B of a Boeing-developed Load Adaptable Modular (LAM) pylon, Rogers said.