The C-23B Sherpa, based on the Shorts 330 regional airliner which first flew on 22 August 1974, is a light military transport aircraft designed to operate efficiently, even under the most arduous conditions, in a wide range of mission configurations. The large square-section cargo hold, with excellent access at both ends, offers ready flexibility to perform ordnance movement, troop and vehicle transport, airdrops, aeromedical evacuation and is suitable for conversion to other specialist duties such as maritime or land surveillance.
Configured as a troop transport, the Sherpa provides comfortable, air-conditioned seating for 30 passengers in airline-type seats, features "walk about" headroom, a removable latrine unit, and has a 500-pound capacity (345 cubic feet) baggage compartment located in the nose of the aircraft. Additional space for a 600-pound capacity optional baggage pallet is provided on the rear ramp of the aircraft. The Sherpa can also accommodate four small pallets or 18 litter patients plus their medical personnel. Through-loading is provided via a large forward freight door, and via a full-width, hydraulically operated rear ramp/door assembly with removable roller conveyors.
The major military customer was the U.S. Air Force, which bought 18 C-23As for its European Distribution System Aircraft (EDSA) requirement, these being used to shuttle spare parts between the USAFE maintenance and distribution centers and the front-line bases. Based with the 10th MAS at Zweibrücken AB, Germany, the C-23As served from November 1984 until 31 October 1990, when the EDSA program was ended.
Four C-23As remained in USAF hands at Edwards AFB, where they were used for the USAF Test Pilots' School, but these have since been retired. Eight were diverted to the U.S. Forestry Service, and six were transferred to the Army National Guard, which also ordered 10 more new-build C-23Bs, distinguished by their cabin windows.
The C-23B meets Army Short TakeOff and Landing (STOL) guidelines, can operate from unpaved runways and is equipped with self-contained ground handling equipment. The Army National Guard has procured 44 C-23B/B+ Sherpas to support theater airlift, airdrop, and aeromedical evacuation for both state and federal wartime missions. Operational experience with this remarkable aircraft has proven it to have low maintenance costs and low fuel consumption.