The G-1 is a large twin turboprop with performance characteristics of contemporary production aircraft. It is capable of measurements to altitudes approaching 30,000 feet over ranges of 1500 nautical ... miles, and can be operated at speeds that enable both relatively slow sampling and rapid deployment to field sites throughout the world. The aircraft is configured for versatile research applications. It accommodates a variety of external probes for aerosol, radiation, and turbulence measurements and internal sampling systems for a wide range of measurements. The G-1 has sufficient cabin volume, electrical power and payload capabilities, and flight characteristics to accommodate a variety of instrument systems and experimental equipment configurations. Internal instrumentation is mounted in removable racks to enable rapid reconfiguration as necessary. Data from most systems are acquired on a central computer that is tailored to airborne research data acquisition. In addition to acquiring the various analog and digital input signals, it can be configured to communicate with and/or control other systems onboard, and to provide time synchronization to other computers.