Routine, wide-scale offshore soundings within five years using second-generation Aerosondes

Early in the afternoon of 21 August 1998, a diminutive Aerosonde weather-reconnaissance aircraft landed into a brisk wind on South Uist in the Scottish Hebrides, and so became the first unmanned aircraft (and, at only 13.2 kg takeoff weight, by far the smallest aircraft) ever to have crossed the Atlantic. Its flight, of some 3200 km from Newfoundland in just under 27 hours, was a key advance in the burgeoning development of unmanned aircraft in general, but moreover it was a significant milestone for weather forecasting. The Aerosonde was conceived to eliminate the chronic dearth of in situ meteorological data over the oceans, and the Atlantic crossing combined dramatically with results of earlier field trials to demonstrate the unique potential of miniature aircraft for this role. These trials, encompassing hundreds of flight hours in Australia, Canada, the US, and the South China Sea, have shown the ability of Aerosondes to collect high-quality upper-air data on flights of long range and endurance; to operate autonomously, with limited supervision from the ground; to be accepted by regulatory and air-traffic authorities; to be satisfactorily segregated from other air traffic; and to operate effectively in hazardous weather, including severe tropical thunderstorms and midlatitude icing. In short the Aerosonde concept, originally proposed in 1991, has advanced to the point that feasibility is demonstrated. It is now seen by many meteorologists in the US and abroad (for example in the North American Observing System Council) as perhaps the only practical and affordable means in prospect for making wide-scale observations over the oceans.

That vision can be realised within five years. The essential next step is a long-planned redesign of the existing "first-generation" Aerosonde, which, having been built as a testbed, lacks the reliability, economy, and performance required for routine offshore service. Substantial improvements are well within reach of an effective engineering effort encompassing powerplant, airframe, flight control, software, avionics, communications, production engineering, and test operations. This work could be completed in about two years at a cost of $3.5M. Routine service could then commence, and expand as the world's weather services take up unilateral and cooperative Aerosonde observing programs.