What is safe? Most programmes nowadays are multinational and sometimes the design is not conducted in accordance with recognised standards. In the modern (post Haddon-Cave) era of Type Certification and regulation, how do we deliver a safe FMS programme for a new, but 60-year-old capability, accommodating new technology and systems without asking everyone to start from scratch? In this lecture, as well as considering the philosophy of safety delivery, I look at how we are developing the equipment contribution to the Air System Safety Case for the new Chinook H47 (Extended Range) helicopter for the RAF to enable our Chief Engineer to understand and transfer risk to the ultimate risk taker. The presentation looks at the drive for proportionality and pragmatism whilst retaining appropriate levels of rigour, and why that matters.