Abstract: A vehicle with wings and a mechanism for causing a flapping motion in wings. Each wing structure comprises a wing and a wing spar coupled to a follower via a resilient member. Each wing carrier is pivotally connected to the body and is configured to restrain lateral movement and permit rotation of the wing spar about a feathering axis. A biasing member provides torsional bias to each wing spar. A linkage, driven by an actuator, transmits cyclic motion that rotates the wing carrier about a flapping axis, which moves the follower along a follower path. A guide attached to the vehicle body lies in the path of each follower, and the follower and guide are shaped such that each wing spar has a first rotational position about its axis along a first portion of the follower path and a second rotational position along a second portion of the follower path.