It said that hot refuelling with engine running is not available with other turboprop aircraft

The HAL developed Hindustan Turboprop Trainer (HTT 40) aircraft program which is aiming to get certification prior to its induction into the Indian Air Force (IAF) has completed hot refuelling with engine running.

The PSU said that the hot refuelling with engine running has been successfully completed and that the refuelling technique is unique.

Hot Refuelling is a single point pressure refuelling of the aircraft with the engine in operation. It is a process by which an aircraft is refuelled in between sorties while its engine is in operation, thereby cutting down the refuelling time by half and turn-around time significantly.

The (HTT-40) is a tandem seat trainer aircraft with advanced features like zero-zero ejection seats and multi-function displays, it can also be adapted as a light attack aircraft. Its role includes basic flying training, aerobatics, instrument flying, navigation, night flying, close formation, etc.

A few months ago the aircraft prototype had undergone the spin testing six turn spin test to both right and left the aircraft.

During the spin turn the aircraft enters in two or three or five and subsequently recovers with the appropriate controls.

That apart the HTT 40 has completed all major test points and meets the Preliminary Staff Qualitative Requirements (PSQR) issued by Air Headquarters for the Basic Trainer Program.

HTT-40 has also successfully completed stalls, engine relights, inverted flying, acrobatic flying and systems testing. The Basic Operational clearance and user evaluation trials readiness is expected soon, HAL said. The production clearance for HTT 40 is expected to be accorded by the end of this year. The HTT-40 program can be counted as one the quickest indigenous defence program to have evolved from the drawing board and to have takes to the skies. The project started its detail design in August 2013 and the HTT-40 had its maiden flight three years later and the spin tests was started last year.