The “peculiar” YC-14 was the most radical of the two short take-off and landing (STOL) tactical transports that competed in the 1970s USAF’s Advanced Medium STOL Transport (AMST) competition to replace the Lockheed C-130 Hercules. The main feature of this prototype was its wing/engine configuration designed to produce an upper-surface blowing. The resultant “Coanda effect” made the jet exhausts “dope” the flaps, improving its low speed performances. As its competitor, the Boeing YC-15, the YC-14 proved to be more than a technical success, but changes in operational policy – a turn to strategic instead of tactical uses- condemned both designs; just the prototypes were built.
Gorgeous inlet vortex. These vortices form in turbine engines during its ground operations in high humidity and with certain wind conditions; nil or almost nil crosswind.