THREE ACCIDENTS within a month have prompted the US Navy to proceed with an upgrade to the flight-control system of the Grumman F-14. Funds had previously not been available for the $80 million programme to install a digital flight-control system (DFCS) in the F-14 to prevent flat spins and improve carrier approach handling qualities.

The DFCS, developed by the UK's GEC-Marconi Avionics, has been flight-tested by the USN under the US Foreign Comparative Test programme. Testing will be extended to October, and a production contract awarded to upgrade 211 aircraft - 80 F-14As, 80 F-14Bs and 51 F-14Ds. The triplex-redundant DFCS replaces the F-14's analogue stability-augmentation system.

In the clean configuration, at low airspeed and high angle of attack, the system reduces pilot inputs, slowing aircraft response, and giving the pilot more time to recognise and counteract an impending spin.

In the power-approach configuration, with the gear and flaps down, the DFCS provides a lateral-stick to rudder interconnect, to reduce yawing in response to roll inputs, thereby reducing pilot workload.

The upgrade will include the installation of a pressure-indicator light to warn of engine air-starvation caused by blanking of either inlet during turns. The flight-control upgrade was requested in 1994, but turned down by the US Department of Defense (DoD). Now the DoD has agreed to reprogramme funds to pay for it. See Defence Analysis, P21.

Source: Flight International