Flight testing of the Lockheed Martin/Boeing F-22 Raptor has passed the critical 183h mark, clearing the way for the US Congress to release $800 million in funding for two production representative test vehicles (PRTVs) and long-lead items for the initial Lot I batch of six fighters.
The first two F-22 test aircraft have cleared Congressional and Department of Defense (DoD) mandated initial development and flight test targets. "We completed all flight criteria in October and the last one prior to Thanksgiving [26 November]. We've now met all Secretary of Defense criteria to go on contract for PRTV and advance Lot 1," says F-22 programme manager Tom Burbage.
As of 1 December, flight testing had achieved an altitude of 50,000ft (15,250m), exceeding the DoD goal of 30,000ft, reached a speed of Mach 1.4 without augmented power and attained a 26° angle-of-attack (AoA), surpassing the stipulated goal of 18°. Other criteria met include the first flight of a second prototype, air-to-air refuelling and the completion of vibration tests.
Two non-flight test milestones were met by 23 November, with the delivery of Block 1 avionics software and the completion of a critical design review of Block 2 software. Congress has also requested that the programme accumulate a minimum flight test time of either 433h or 183h, if accompanied by a supporting report from the defence secretary.
The F-22's flight test envelope has been divided into 10 separate zones, with one aircraft instrumented for high speed testing and the second for low speed. The former will be used for M1.5 plus supercruise tests, while the latter will be fitted with a spinchute in March for increased AoA flights.
The DoD is expected to award Lockheed Martin and Pratt & Whitney a $600 million contract for two PRTV aircraft and a $200 million advance contract for Lot I, subject to a defence acquisition board formal review. A full contract for Lot 1 is due in December 1999, along with an advance contract for a follow-on ten aircraft in Lot 2.
The first F-22 integrated avionics software package has been delivered by Boeing for installation in the 757 Flying Test Bed, which will begin testing the suite in early 1999.
It includes software for the radar, mission systems, inertial reference system, pilot vehicle interface and cockpit displays.
Source: Flight International
