NASA and the US Air Force plan to take the active aeroelastic wing (AAW) Boeing F/A-18A research testbed beyond Mach 1 by 1 December to prepare for wing-warping flights next year.

The AAW testbed has more flexible wings than a conventional F/A-18 and will be fitted with a modified flight-control system (FCS) featuring AAW software developed from data collected during the current flight tests. The aircraft is flying with the revised wing structure and modified flight-control surfaces, but lacks the FCS to manoeuvre through aerodynamically induced wing twist.

The research is aimed at developing thinner, higher aspect-ratio wings for lower drag, and improved efficiency and manoeuvrability for future high-performance combat aircraft. To induce the twist, the aircraft has modified additional actuators, a split leading-edge flap actuation system and thinner wing-skin panels to allow the outer wing section to twist up to 5°.

The first flight on 15 November was restricted to 350kt (650km/h) and altitudes up to 30,000ft (9,150m). The envelope has since been expanded to include 5g turns and speeds up to M0.95 at higher density altitudes of 15,000ft.

Source: Flight International