BUCS | ||
---|---|---|
(AH-64D Apache) Back-Up Control System Normally, the pilot and CPG flight controls are mechanically linked. The mechanical linkages are protected by shear pins and mis-track sensors to prevent a control jam or severance from affecting both sets of flight controls. If the flight controls are decoupled by the shear pin, or a mis-track is otherwise sensed, the Back-Up Control System is automatically activated. The BUCS is a single-channel, four-axis, non-redundant electric fly-by-wire (FBW) system. The FBW system is designed to replicate the feel of the hydromechanical controls but does not replicate SCAS functionality. BUCS can only be active for the pilot or the CPG station. Either the pilot or the CPG can transfer BUCS control to their station if necessary, depending on the nature and location of the jam or severance within the flight controls. | ||
ECU | ||
---|---|---|
(AH-64D Apache) Electronic Control Unit Detects overspeed and overcurrent anomalies, as well as abnormal oil pressure. The ECU will automatically shut down the APU when an anomaly is detected. The ECU also controls the power takeoff (PTO) clutch engagement to the accessory section of the main transmission. | ||
IPAS | ||
---|---|---|
(AH-64D Apache) Integrated Pressurized Air System The IPAS provides pressurized air to aircraft pneumatic systems. Bleed air is drawn from two ports: a high-pressure port is exclusively used to pressurize the hydraulic systems, and a low-pressure port is used by all other consumers. Low-pressure air is used by the engine air turbine starters, fuel boost and transfer pumps, anti-ice system, ice detection probe, nitrogen inerting unit, vapor cycle cooling system, and environmental control system. IPAS bleed air can be provided by one or both engines, the APU, or an external source such as an AGPU. | ||
M-TADS | ||
---|---|---|
(AH-64D Apache) Modernized Target Acquisition Designation Sight The M-TADS is a long-range, precision engagement and pilotage solution for day, night, and adverse weather missions. | ||
SCAS | ||
---|---|---|
(AH-64D Apache) Stability and Control Augmentation System Hydraulic augmentation, which consists of hydraulic actuators controlled by the FMC. The command augmentation system provides consistent control feel across the full range of helicopter airspeeds. The SCAS also provides automatic turn coordination for turns above 40 knots airspeed. | ||