An aircraft system intended for gliders and low power-to-weight aircraft, to aid the pilot in locating updrafts associated with the buoyancy of humid air in the convective layer of the atmosphere, namely moist thermals. The system comprises a pair of laterally spaced hygrometers, generally at the wingtips....http://www.google.co.uk/patents/US6012675?utm_source=gb-gplus-sharePatent US6012675 - Aircraft system monitoring air humidity to locate updrafts
