Aircraft maker Boeing violated the terms of a US agreement that has so far protected it from prosecution following two fatal plane crashes, according to the US Department of Justice. Boeing had not implemented a programme to prevent violations of US fraud laws as agreed, according to court documents filed on Tuesday. The government says it has not yet decided how to proceed in the matter. Boeing was given until June 13 to provide an official response. In an initial reaction on Tuesday, the company emphasized that, in its own estimation, it had complied with the agreement. The crashes of two Bo…