Air/Ground system These are the systems/components controlled by the proximity switch electronics unit (PSEU): * Landing gear transfer valve (SECTION 32-31) * Landing gear position indicating and warning (SECTION 32-61) * Speedbrake deployed indication (SECTION 27-62) * Takeoff warning (SECTION 31-53) * Airstairs control/warning (SECTION 52-71) * Door warning (SECTION 52-71) * Air/ground relays.
Purpose The air/ground system supplies air mode and ground mode signals to airplane systems. Components * Nose landing gear compressed sensors * Left main landing gear compressed sensors * Right main landing gear compressed sensors Two compressed sensors are on each landing gear. One sensor sends inputs to air/ground system 1 and the other sensor sends inputs to air/ground system 2. * Proximity switch electronics unit (PSEU) * Air/ground relays * PSEU fault light. There are 2 air/ground systems!!! 接近电门电子组件 (PSEU) 目的 接近电门电子组件控制六个飞机系统并为多个飞机系统提供空/地继电器信号和离散信号输出。PSEU还提供的故障指示并维护 BITE。 位置 PSEU位于前设备舱内。维护人员可通过飞机起落架轮舱前底部的接近门来接近PSEU。 具体介绍 PSEU是一个具有两个内部电路板和前部BITE面板的航线可换件(LRU)。BITE面板下的两盏红灯显示空/地系统是否处于空中模 式。PSEU前面的标牌上标有操纵BITE的程序。 PSEU有七个电气接头: — 系统1为J1—J4 — 系统2为J5—J7 功能介绍 PSEU为空/地系统执行下列功能: — 监控起落架压缩传感器 — 操纵空/地继电器 — 发送空/地离散信号 PSEU处理来自空/地传感器的信号,并向飞机系统和空/地继电器发送空/地信号。 PSEU还执行下列功能: — 起落架位置指示和警告 — 起落架转换活门控制 — 起落架未放下警告 — 速度刹车伸出琥珀色灯控制 — 起飞(音响警告) — 舱门警告 为得到关于起落架位置指示和警告的详细信息,可参阅起落架位置指示和警告系统部分。(AMM 第I 部分32—61) 为得到关于起落架转换活门的详细信息,可参阅起落架控制系统部分。(AMM 第I 部分32—31) 为得到关于速度刹车伸出琥珀色灯的详细信息,可参阅速度刹车控制系统部分。(AMM 第I 部分27—62) 为得到关于舱门警告的详细信息,可参阅舱门警告系统部分。(AMM 第I 部分52—71)
Main Landing Gear Compressed Sensors Physical Description The landing gear compressed sensors are inductance type sensors. Each sensor has a metal target and a sensor. Location The main landing gear compressed sensors are on the lower area of the outer cylinder of the main landing gear. The targets are on each side of the upper torsion link where the link attaches to the outer cylinder of the main landing gear. Main Landing Gear Compressed Sensors The targets are near the sensors when the main landing gear shock strut compresses and the airplane is on the ground. This sends signals to the air/ground systems in the proximity switch electronic unit (PSEU). The PSEU detects the change in sensor inductance and considers the sensor status as target near. If the target is outside the sensing range, the status of the sensor is set to target far. If the PSEU detects a failed sensor, the sensor status is set to target far.
Nose Landing Gear Compressed Sensors Location The nose landing gear compressed sensors are on each side of the upper torsion link where the link attaches to the outer cylinder of the nose landing gear. The targets are on the lower area of the outer cylinder of the nose landing gear.
Air/Ground Relays Purpose The air/ground relays supply air/ground signals to airplane systems. Physical Description The air/ground relays are hermetically sealed units, with a mounting bracket attached. Air/Ground Relays Location Air/Ground Relays Location
Proximity Switch Electronics Unit Purpose The proximity switch electronics unit (PSEU) controls six airplane systems and provides air/ground relay and discretre outputs for multiple airplane systems. The PSEU also provides fault indication and maintenance BITE. Location The PSEU is in the forward equipment compartment. You get access to the PSEU through the access door on the bottom on the airplane, forward of the nose landing gear wheel well. Proximity Switch Electronics Unit Proximity Switch Electronics Unit Physical Description The PSEU is an LRU with two internal circuit cards and a BITE panel on the front. Two red lights below the BITE panel show if the air/ground systems are in the air mode. A placard on the front of the PSEU has instructions to operate the BITE. The PSEU has these seven electrical connectors: * J1-J4 are for system 1 * J5-J7 are for system 2. Proximity Switch Electronics Unit Functional Description Monitors the landing gear compressed sensors Operates the air/ground relays Sends air/ground discrete signals. The PSEU also does these functions: * Landing gear position indication and warning * Landing gear transfer valve control * Landing gear not down warning * SPEEDBRAKES EXTENDED amber light control * Takeoff (aural) warning * Airstair control/warning * Door warning. Air/Ground Discretes - System 1 These are the multiple use systems/units that use air/ground discretes from system 1: * Antiskid/autobrake control unit (AACU) * Auto speedbrake control module * Flap/slat electronics unit (FSEU) * Stall management yaw damper (SMYD) * AC indication * Cabin pressurization system * Ram air door control * Anti-ice Air/Ground Discretes - System 1 These are the multiple use systems/units that use air/ground discretes from system 1 (continue): * Pitot heat * Bus power control unit (BPCU) * Generator control unit (GCU) * Auxiliary power unit (APU) start * Auxiliary power unit (APU) warning * Thrust reversers system * Common display system (CDS) * VHF communications system * HF communications system Air/Ground Discretes - System 1 These are the multiple use systems/units that use air/ground discretes from system 1 (continue): * Aircraft communications addressing and reporting system * Voice recorder system * Flight data recording system * Passenger entertainment video system * Air data inertial reference system (ADIRU) * Integrated flight system accessory unit (IFSAU) * Radio altimeter system * Weather radar system Air/Ground Discretes - System 1 These are the multiple use systems/units that use air/ground discretes from system 1 (continue): * Instrument landing system (ILS) * VHF omnidirectional ranging (VOR) system * Marker beacon system * Distance measuring equipment (DME) system * Automatic direction finder (ADF) system * Air traffic control (ATC) system * Traffic collision avoidance system (TCAS) * Ground proximity warning system (GPWS) * Flight management computer system (FMCS) * Digital flight control system (DFCS) * Autothrottle system
Air/Ground Discretes - System 2 These are the multiple use systems/units that use air/ground discretes from system 2: * Antiskid/autobrake control unit (AACU) * Stall management yaw damper (SMYD) * Cabin pressurization system * Ram air door control * Bus power control unit (BPCU) * Generator control unit (GCU) * Auxiliary power unit (APU) start * Auxiliary power unit (APU) warning * Common display system (CDS) Air/Ground Discretes - System 2 These are the multiple use systems/units that use air/ground discretes from system 2 (continue): * Aircraft communications addressing and reporting system (ACARS) * Flight data recording system * Air data inertial reference system (ADIRU) * Integrated flight system accessory unit (IFSAU) * Voice recorder system * Radio altimeter system * Instrument landing system (ILS) * VHF omnidirectional ranging (VOR) system Air/Ground Discretes - System 2 These are the multiple use systems/units that use air/ground discretes from system 2 (continue): * Distance measuring equipment (DME) system * Automatic direction finder (ADF) system * Air traffic control (ATC) system * Flight management computer system (FMCS) * Digital flight control system (DFCS) Air/Ground Discretes - System 2 Air/Ground Relays - System 1 System 1 relays receive configuration signals from the PSEU and electrical power from either BUS 1 or the BAT BUS. The PSEU also provides the electrical ground source to energize the relays in an air or ground mode. These are the air mode relays: * R584 for the left thrust reverser * R593 for the control display unit (CDU)/mode control display unit (MCDU) data loader interface, and door area heaters. These are the ground mode relays: * R587 for the power transfer unit (PTU) * R589 for the weather radar system * R592 for the overboard exhaust valve control * R594 for the forward and aft drain mast heaters, and the cargo compartment fire extinguishers.
Air/Ground Relays - System 2 System 2 relays receive configuration signals from the PSEU and electrical power from either BUS 2 or the BAT BUS. The PSEU also provides the electrical ground source to energize the relays in an air or ground mode. These are the air mode relays: * R585 for the right thrust reverser * R588 for standby rudder control, the gray water drain valve, and automatic ground speedbrake control. These are the ground mode relays: * R590 for the exterior logo lights * R591 for the automatic ground speedbrake control * R595 for the pitot and probe heaters, the left and right pack valves, and power transfer unit (PTU) * R596 for the nose wheel steering actuator.
Functional Description - Pseu Fault Light Logic |