Climatologies of convective flight environments for use in the development of a storm penetrating aircraft

In 2005, the T-28 SPA (Storm-Penetrating Aircraft), operated by the Institute of Atmospheric Sciences (IAS) at the South Dakota School of Mines and Technology in cooperation the National Science Foundation (NSF), was retired, leaving a critical gap in the atmospheric science community's ability to obtain in situ microphysical and electrical measurements in harsh convective environments. The IAS, Naval Postgraduate School, and the NSF propose to fill this gap with the Next-Generation SPA, a Fairchild Republic A-10A Thunderbolt II (Warthog). Before the A-10A can be put into service as a SPA-10A, modifications must be made so that the aircraft can safely travel through, and obtain measurements in the extreme conditions associated with convection. The engineers planning the modification process will need to know the range of meteorological hazards the aircraft is likely to encounter, including severe aircraft icing, turbulence, and other processes leading to aircraft flight control problems. This information will allow them to formulate a proper modification scheme for the aircraft so that the SPA-10 will be capable of safely traversing and taking measurements in such hazardous conditions.

This study serves as a comprehensive survey of the convective flight environments in which the aircraft will operate. The meteorological flight hazards and their magnitude are identified and analyzed. The hazards considered in this work include supercooled liquid water content, vertical motions, and turbulence. The study includes data from convective environments in several key regions such as continental mid-latitudes, oceans, and polar regions. The analyzed data originates from three primary sources: T-28 data collected during various research projects, in situ data available from other airborne platforms, and results from various convective storm simulations. The result of the study is a comprehensive description of the convective storm environment compiled into a single source. The results are organized to give engineers designing and implementing the A-10A modification process a quantitative characterization of the range of conditions that the aircraft will be required to fly through. A direct impact of this study will be a minimization of modification time and cost, and maximization of performance and safety of the modified aircraft.