 MACON, Ga.--BUSINESS WIRE--Today, Blue Bird Corporation NASDAQ: BLBD, a leading manufacturer of school and activity buses, announced that it entered into a third amendment the Third Amendment to its credit facility, dated as of December 12, 2016 the Credit Agreement. The Third Amendment provides for covenant relief through Blue Birds second fiscal quarter of 2022. For the fiscal 2021 period, the net leverage ratio is replaced by a minimum trailing twelve-month EBITDA quarterly coven 