In this piece from The Washington Post, the crash of a V-22 Osprey aircraft that killed four Marines in December was caused by a design flaw that had been known for months but went largely uncorrected. According to pilots interviewed by the paper anonymously, all current or former officers in the Marines 1st Osprey Squadron, they said the design flaw in the aircraft’s hydraulic system was compounded by a software glitch that could have been detected by more rigorous testing, but, they said, they believe both problems slipped by because the Marine Corps wanted to win Pentagon funding for full production of the plane. The production decision was postponed after two Osprey crashes last year killed 23 Marines, raising questions about the safety of the aircraft.