Final answer:
Boeing's appointment of an engineer as a go-between between R&D and a government contractor is an example of a liaison role. This role involves communicating and coordinating effectively between both parties.
Step-by-step explanation:
When Boeing appoints an engineer to act as a "go-between" for its R&D department and the government contractor for the creation of a new fighter airplane, the role is best described as a liaison. This role is integral in facilitating communication and coordination between two different organizations or departments to ensure that project requirements are met and progress is smooth. A liaison would be responsible for managing relationships and relaying information effectively between the company and the external party.