Structural health monitoring has recently been applied to Aircraft and Launchers, in which the number of interconnected devices is constantly increasing. Up to now, wired networks have been used, but their high mass leads to increased fuel consumption and high carbon emissions. Wireless sensor networks would certainly reduce the mass and complexity of wiring, yet the essential question is: are they able to meet the requirements of non-critical and health monitoring applications in the specific environment of Aircraft and Launchers? First, we unify the requirements of non-critical and health monitoring applications in Aircraft and Launchers, and we show that such requirements impose the choice of multichannel mesh wireless networks. Multichannel networks bring many advantages in terms of latency, throughput and robustness. However, they do raise a number of challenges, some of which are general, while others are specific to supporting data gathering applications. Different solutions from the state-of-the art are given. These solutions, whether designed to take into account the specificities of data gathering or not, range from medium access control to multihop routing. The best performances are obtained when both problems are tackled together. We establish bounds on the minimum number of time slots needed by a raw data convergecast, taking into account the number of available channels, the number of children of the sink in the routing tree, as well as the number of radio interfaces in the sink. We propose SAHARA, a solution that provides an adaptive multichannel collision-free protocol for data gathering and we present many performance results obtained by simulation