F-16 touches 110` angle-of-attack By Guy Norris in Los Angeles A Lockheed F-16 equiped with a General Electric thrust-vectoring nozzle has achived a transient angle of attack (AoA) of 110` and a sustained AoA of 80`. Programme sources say the high tranisent AoA was attained during emulation of the "Cobra: manoeuvre which "...made the Sukhoi Su-27 look boring". The tests are being undertaken as part of the US Air Force's multi axis thrust-vectoring (MATV) project,in which the effect of picth/yaw thrust-vectoring on combat capabilities and high AoA characteristics is being assessed. The two-seat testbed F-16 is the specially adapted variable-stability inflight simulator aircraft (VISTA),fitted with a GE F110-100 engine and pitch/yaw axisymmetric vectoring engine nozzle (AVEN).More than 30h of a test programme of about 116h have already been amassed.The first 25h were dedicated to subsonic high manoeuvrability tests at altitudes starting at 30000 ft (9200 m). A low-altitude phase,covering,work in the 20000-25000 ft area of the flight envelope,began in mid-August and should be completed around mid-October.This phase also examines the performance of the engine under high AoA conditions. "The engine is performing flawlessly with no stalls or afterburner blow-outs," says the engine maker.The USAF adds:"We could have expected at least some sort of 'pop' stall,but it has been fine,even when we have taken air up the tail pipe during the Cobra." Concurrent with envelope expansion during phase two,the MATV programme is also expected to move to a third phase covering the military utility of the AVEN nozzle.Pilots from the test team as well as from the 416th test squadron at Edwards AFB,and the 422nd test and evaluation squadron,based at Nellis AFB,Nevada,will fly the aircraft against the conventional F-16s in simulated combat conditions. MATV programme officials hope the AVEN nozzle can be used by the pilots to demonstrate several new combat techniques including an unusual evasive maneouvre called the "hammer-head",wich forces the pursuing aircraft to overshoot. Other exercises to be attempted will include a gun-tracking rates, allowing an aircraft to track an opponent inside his turning circle;and a moneouvre known as a "J turn",calling for decelerations from 300 kt to around 0 tk in 5-10 s. The programme is expected to be completed by the end of November so that the aircraft can be returned to the VISTA configuration by 1 January next year. Preuzeto iz Flight International , 8-14 Septebmer 1993