In 2002, the Defence Advanced Research Projects Agency awarded Northrop Grumman two contracts for continuation of conceptual studies for a future Quiet Supersonic Platform (QSP). The first contract, valued at US$2.7 million, will permit Northrop Grumman to validate earlier studies and undertake wind-tunnel testing of a scale model of its preferred QSP design. At least a dozen different concepts were considered after work began in 2000, culminating in selection of the so-called 'dual relevant' approach, whereby the 'joined wing' or 'strut-braced wing' configuration could be adapted into either a strike/attack platform or an executive jet.
In its current guise, the QSP utilises a slender fuselage that can accommodate side-by-side weapons bays some 8.3 m (27 ft) in length or a 6.9 m (23 ft) long cabin. The main wing is shoulder-mounted and has a sharply swept cranked arrow planform with a straight trailing-edge; inboard leading-edge sweep is 84°, reducing to 71.5° outboard. The QSP is approximately 47.5 m (156 ft) long with a span of 17.6 m (57 ft 9 in); max T-O weight will be about 45,360 kg (100,000 lb), including payload of approximately 9,072 kg (20,000 lb). Project objectives include a very low sonic boom signature, range of 6,000 n miles (11,112 km; 6,904 miles) and maximum cruise speed of M2.4. Two General Electric GE449 engines are located at the rear of the aircraft, with a single vertical tail protruding above the engine nacelles. No recent news received of this concept.
The second contract received by Northrop Grumman was worth US$3.4 million and scheduled to involve flight trials of a modified Northrop F-5E Tiger II; these were expected to take place in the latter half of 2002, but did not begin until 24 July 2003. This aircraft has a revised forward fuselage that produces a shaped sonic boom, which is significantly quieter.