I want to know the answer to the following question:
When did the USAF have several missteps of aircraft procurement projects?
All the background I'm provided with is that "As a result, the USAF fleet is setting new records for average aircraft age and needs to replace its fleets of fighters, bombers, airborne tankers, and airborne warning aircraft, in an age of restrictive defense budgets.". Is that enough to answer the question?