Never mind the systems issues, having the engines buried in the wing root creates significant design, performance and maintenance challenges. Going from a turbojet to a turbofan and increasing the space required just exacerbated those issues. During the upgrade program it was discovered that no two airframes were alike, despite BAE's claim of Nimrod "being the best understood airframe in service". The design was flawed from the start, and the Ostrich mentality that ignored the obvious was responsible for the cost and delay still impacting the maritime capability today.