An aircraft assembly may have a drag-inducing discontinuity 112. A seal assembly 101 includes a seal body 110 arranged to fair and/or seal the discontinuity 112; and a sealed chamber 114, wherein the sealed chamber 114 being pressurised such that in response to changes in the ambient pressure relative to the internal pressure of the chamber 114 the sealed chamber 114 alters the behaviour of the seal body 110.