VC-25B is the official Air Force designation for the two modified Boeing 747-8s that will replace the current presidential aircraft fleet, designated VC-25A. “The design maturity for the aircraft interior continues to lag due to numerous technical and certification issues,” the report said. Boeing has also agreed with the Air Force to shift the aircraft from FAA certification to a military certification process. Earlier Air Force reports had already identified wiring, interior work, worker shortages and slow modification rates as major risks. The Air Force plans to keep both aircraft available until the replacements can carry out the full presidential airlift mission.