In this paper, we propose an architecture that uses a tender protocol, the Contract Net Protocol (CNP), to let human operators express their consent about the allocation of goals to Unmanned Aerial Vehicles (UAVs) in a constrained environment. The CNP has several well-known properties : it has an appropriate level of automation; it is simple; it spares the bandwidth. But if bids are evaluated solely on the base of a numerical payoff, the CNP cannot fully convey human preference in complex situations. Thus, we extended and implemented the CNP within our framework, Aerial, to enable a more subjective human feedback. We detail how we build the bids and how we filter them to not flood the user. We also explain how we enable a dependable commitment in a dynamic context when the award time is not accurately foreseen.