BAE Systems today issued an upbeat description of progress with the previously troubled upgrade of the Nimrod MRA.4 maritime patrol plane for the UK Royal Air Force (RAF). Two development aircraft have now logged 70 hours on 30 test flights, and RAF aircrew have flown in every position onboard.

The Nimrod upgrade was restructured in 2003 after BAE ran into trouble on the original fixed-price development and production contract. The company now must complete and demonstrate the required capability on three aircraft, prior to negotiation of a separate production contract later this year. The number of aircraft to be upgraded was reduced to 12 in a recent UK defence review. The third development aircraft will fly later this year.

BAE reported that the longest flight to date has been four hours and 12 minutes, with the aircraft achieving a top speed of 250 knots and an altitude of 31,800 feet. The MRA.4 is an extensive remanufacture of the current Nimrod MR.2, with new wings, tailplanes, Rolls-Royce BR710 turbofans and Boeing mission system.