Abstract: An engine fuel control system includes a metering valve to control fuel flow between the supply and delivery line with a pressure drop control regulating the pressure across the valve and maintain a substantially constant pressure across the valve. The fuel control system includes a backup system controllable by a pullback signal to operate the pressure control, thus increasing the pullback signal reducing the fuel flow between the supply and delivery line. The fuel control system detects a start of an engine overthrust event, and when the upward runaway is caused by the arrested overthrust event. The fuel control system's controller which (i) determines the overthrust detection, the pullback signal increase rate and the pullback signal offset, (ii) sends the pullback signal to the backup system at the rate of increase, and (iii), reduces the pullback signal to the backup system when the upward runaway is arrested by the offset.

Abstract: An engine fuel control system includes a metering valve to control fuel flow between the supply and delivery line with a pressure drop control regulating the pressure across the valve and maintain a substantially constant pressure across the valve. The fuel control system includes a backup system controllable by a pullback signal to operate the pressure control, thus increasing the pullback signal reducing the fuel flow between the supply and delivery line. The fuel control system detects a start of an engine overthrust event, and when the upward runaway is caused by the arrested overthrust event. The fuel control system's controller which (i) determines the overthrust detection, the pullback signal increase rate and the pullback signal offset, (ii) sends the pullback signal to the backup system at the rate of increase, and (iii), reduces the pullback signal to the backup system when the upward runaway is arrested by the offset.

Abstract: A shut-down arrangement comprises a shut-off actuation device operable under the control of a control unit, a switch whereby a first shut-down signal can be supplied to the control unit and whereby a second shut-down signal can be supplied to the shut-off actuation device, and delay means whereby the transmission of the second shut-down signal to the shut-off actuation device is delayed relative to the transmission of the first shut-down signal to the control unit.

Abstract: A shut-down arrangement comprises a shut-off actuation device operable under the control of a control unit, a switch whereby a first shut-down signal can be supplied to the control unit and whereby a second shut-down signal can be supplied to the shut-off actuation device, and delay means whereby the transmission of the second shut-down signal to the shut-off actuation device is delayed relative to the transmission of the first shut-down signal to the control unit.

Abstract: A fault diagnostics technique for use with an engine controller and a hydromechanical device including a memory device comprises the steps of using diagnostics characteristics data stored in the memory device to modify a fault diagnostics algorithm of the engine controller, and using the modified fault diagnostics algorithm in conjunction with real time operating data from the hydromechanical device to determine whether the hydromechanical device is operating correctly.

Abstract: A controller is provided in which an independent protection controller is provided in a casing, which casing is disposed within the casing for the main controller, such that the protection controller is provided as a box within a box. This allows the casing for the main controller to provide extra protection to the protection controller against mechanical stress and damage. The independent protection module is directly connected to a pilot operated “shut down” demand and in response to such a demand assumes authority to shut the engine down.