embraer towing and brake riding overview

EMBRAER Towing and Brake Riding

1 This training document for training purposes only.

Embraer Towing Remember to consult the Control Manual for the towing procedure as they apply to Air Canada. The following information is for the Embraer technical aspects of the tow and not the procedural requirements as they are covered in the Control Manual.

Pushback and Tow 1. Make sure that the towing-indication light box (3) shows the red light on. 2. Open the access door 125AL Ramp Panel. Item B on next page 3. Set the steering switch (1) to the DISENGAGED position. On the EICAS display, make sure that the

STEER OFF status message comes into view. 4. Make sure that all external doors and panels are closed and correctly installed, except access door

125AL Ramp Panel. 5. Install the towbar to the towing attachment on the NLG. 6. Install the other end of the towbar to the tow tractor. 7. Remove the wheel chocks from all tires. 8. In the cockpit, release the emergency/parking brake handle (2) (brakes off). 9. Make sure that the towing indication light box (3) shows the green light on. 10. Make sure that all steps above are obeyed. Then do the towing as per the Control Manual.



Green Nose wheel steering is in the free-castor mode and the aircraft can be towed. Towing Indication Lights.

Located on Towing Indication Light Box (#3) Red Nose wheel steering is in the set mode and

the aircraft cannot be towed. Emergency/Parking Brake Handle ON Gives mechanical operation of the Dual

Emergency/Parking Brake-Valve. Power- Switch for Towing Indication Lights (item 2) Up Makes a selection of an alternate source of

electrical power for the towing indication lights.

Pushed Nose wheel steering is in the set mode. STEERING Switch (Ramp panel 125AL item 1.) Pushed Nose wheel steering is in the free-castor

mode.



The following information is provided for systems understanding that pertain to Brakeman functions. Remember to follow the checklists on the “175/190 AIRCRAFT BRAKE OPERATOR GUIDE “.

APU SYSTEM OPERATION

Moving the APU MASTER switch from ″OFF″ to ″ON″ causes: • The energization of the APU control panel. • The energization of the FADEC. • The opening of the shutoff valve of the APU fuel-feed line in the aircraft fuel system.

APU STARTING CYCLE Momentarily moving the APU MASTER switch from ″ON″ to ″START″ causes the FADEC to receive the APU starting input. As a result, the FADEC will: • Energize the APU starter. • Energize the APU ignition system and control the APU fuel system to supply metered fuel flow to the APU, which will accelerate it. • De-energize the stater/ignition systems when the APU has self sustaining rpm. • Control the APU fuel system to keep the APU rpm stable in reference to the operating requirements.

APU RUNNING CONDITION During the APU running condition, the FADEC monitors the APU operation. If a failure occurs, the FADEC automatically shuts down the APU, supplies a fuel cut-off signal to the APU fuel system, and displays a fault message on the EICAS (Engine Indicating and Crew Alerting System). The APU BLEED pushbutton on the cockpit air conditioning/pneumatic control panel controls the APU bleed air operation. A venturi installed in the bleed air duct keeps the bleed airflow to a limit.

APU NORMAL SHUTDOWN Moving the APU MASTER switch to ″OFF″ causes:

• The de-energization of the FADEC. • The de-energization of the APU control panel. • The closure of the shutoff valve of the APU fuel-feed line in the aircraft fuel system.

APU EMERGENCY SHUTDOWN Two modes permit the shutdown of the APU in an emergency: 1. Pushing the APU EMERGENCY STOP pushbutton on the cockpit APU control panel which:

• Overrides the APU MASTER switch. • Signals the APU stop function of the FADEC (ref. APU NORMAL SHUTDOWN). • Closes the APU fuel shutoff valve.

2. Pushing the APU FIRE EXTINGUISHING pushbutton on the cockpit fire control panel which:

• Overrides the APU MASTER switch. • Closes the APU fuel shutoff valve. • Discharges the fire extinguishing bottle.



APU FIRE/OVERHEAT DETECTION SYSTEM Introduction The function of the APU (Auxiliary Power Unit) fire and overheat detection system is to monitor the APU for fire and overheat conditions. If a fire or overheat is detected, the system alerts the crew by means of CAS (Crew Alerting System) messages, aural warning bell, and visual indications (lights). General Description The APU fire detection system comprises two pneumatic fire detectors installed in the tail cone structure. The fire detectors are electrically connected in two loops (4 detectors each loop) which interface directly with the MAU (Modular Avionics Unit) that process the signals and provides the related EICAS (Engine Indicating and Crew Alerting System) and CMC (Central Maintenance Computer) messages. The dual loop configuration provides system redundancy, once each detector of loop A will have a correspondent detector of loop B protecting the same area. In normal operation, crew messages will be generated only if both loops detect fire. In case of one defective loop, its signals will not be considered, and the MAU will use only the operative loop to provide fire message to crew. Thus, the aircraft can be dispatched with one loop inoperative. Each dual loop has different set points based on its location. Components The APU fire protection system comprises two DRH pneumatic type fire detectors which use connector for electrical connection. Operation If fire is detected: • The fire detector sends a discrete signal to the MAU. • The MAU provides a fire message to the EICAS. • The master warning light starts to flash and the aural warning fire bell is activated. • The APU fire extinguishing switch light comes on. A dedicated APU FIRE message comes into view on the EICAS display. When the aircraft is on the ground and fire on the APU is detected, the MAU sends to the APU FADEC (Full-Authority Digital Engine- Control) an auto-shutdown command after ten seconds. If only one loop provides a fire alarm (considering that both loops are in good condition), after ten seconds, the MAU considers the loop failed. If only one loop fails, a maintenance message is recorded on the CMCM (Central Maintenance Computer Module). The APU FIRE DET FAIL fault message comes into view on the EICAS display only if the dual loop fails.



Electrical Power External Power The external AC power is routed through the aircraft plug to the EPAC (External-Power Alternating-Current Contactor) and provides the aircraft with power when the IDG (Integrated Drive Generator) or APU generator power is not being utilized. The external AC power is monitored by the EPM (External Power Module). To provide external AC power to the aircraft, the AC ground power supply plug should be connected to the aircraft AC external power receptacle. The external DC power is routed through the aircraft DC power receptacle to the EPDC (External-Power Direct-Current Contactor) and is used for powering the APU START BUS upon an APU start attempt. The external DC power is controlled by dedicated system relay logic. To provide external DC power to the aircraft, the DC ground power supply plug should be connected to the aircraft DC external power receptacle. Operation of the GPU switch on the ELECTRIC control panel or the GROUND SERVICE SW on the AC GPU flight attendant’s panel in flight will not cause any contactors or breakers to change status, or inhibit in-flight operation of any system. Note: A caution message ″GPU CONNECTED″ is shown on the EICAS (Engine Indicating and Crew Alerting System) display when the AC GPU is connected and the parking brake is released.

GPU Switch



Operation EXTERNAL AC POWER - NORMAL MODE The cockpit control panel GPU switch provides an ability to manage the external AC power through EPM logic. If external AC power quality requirements are satisfied but the GPU switch is in the unlatched position, then the GPU AVAIL lamp is ON. Selecting the GPU switch to the latched position allows automatic EPGDS operation through the EPM for powering with external AC power. Once the EPAC closes, the GPU AVAIL lamp goes OFF and the GPU IN USE lamp comes ON. If no other source of power is available on the aircraft, a backup source of 28 VDC (Volt Direct Current) is routed from the EPM to the AGCU (Auxiliary Generator Control Unit) so that BTC 1 and BTC 2 control can be properly coordinated. With the EPAC closed and power on the tie bus, the AGCU will accordingly close BTC 1 and BTC 2, provided the AC BUS TIES switch is in the AUTO position so that the AC BUS1 and AC BUS 2 can by powered. This allows the AETC (Alternating-Current Essential Transfer-Contactor) to be energized to the AC BUS 2 position for feeding power to the AC ESS BUS and STANDBY AC BUS. TRU (Transformer Rectifier Unit) 1, TRU 2, and the TRU ESS (Essential) converts the three-phase AC input power and provides a +28 VDC output to feed the DC BUS 1, DC BUS 2, DC ESS BUS 1, DC ESS BUS 2 and DC ESS BUS 3. Also, if the BATT 1 switch is in the ON position and the BATT 2 switch is in the AUTO position, battery 1 and battery 2 will be in a charging mode through the associated BC (Battery Contactor) 1 and BC 2 contactors.



APU AC GENERATION Introduction The APU (Auxiliary Power Unit) generation system is used primarily when the aircraft is on the ground for aircraft maintenance or flight preparation. This system can also be used to let the aircraft be dispatched with an altitude restriction or as a backup source of electric power in flight. The APU AC (Alternating Current) generation system uses an APU driven auxiliary generator to supply 30/40 kVA, 115/200 VAC, three phase, 400 Hz to the aircraft.

CONTROL/INDICATOR POSITION/INDICATION FUNCTION

Latched in (on)

This is the usual position. This position allows the APU generator to automatically provide power to the aircraft after APU start. The striped bar is off in this position

APU GEN switch

Latched out (off)

This position gives the flight crew personnel the option to manually de-energize the APU generator and open ALC and the GCR (Generator Control Relay). This position also resets the APU generator protective trip. The striped bar is on in this position.

APU GEN Pushbutton



APU-PNEUMATIC BLEED SYSTEM

General Description The APU is a source of pneumatic power to the aircraft on the ground or in flight. The APU bleed system supplies air to the aircraft pneumatic system for engine starting, air conditioning operation and ground maintenance operations. The APU bleed flow control is made by the APU bleed shutoff valve and the APU bleed check valve. The APU bleed check valve allows for APU bleed supply to enter the bleed manifold. It is closed by engine bleed pressure when APU is not running. Operation To activate the APU pneumatic bleed system, the BLEED APU switch can be set to AUTO or OFF. When set to OFF - manual override mode: • APU bleed system is continuously OFF. • On the AIR COND/PNEUMATIC control panel, the BLEED APU switch is illuminated (a white colored striped bar comes into view). When set to AUTO - APU bleed system is enabled:



• APU bleed activation will be subjected to normal system control laws: – The APU bleed request is determined by the AMS (Air Management System) controller. – The AMS controller communicates with the FADEC (Full-Authority Digital Engine-Control) (through the SPDA (Secondary Power Distribution Assembly)) to open the APU bleed valve when exists demand.

• On the AIR COND/PNEUMATIC control panel, The BLEED APU switch will be dark.

AIR CONDITIONING Introduction The air conditioning system supplies airflow to the cockpit and passenger cabin for ventilation and pressurization. It also controls the temperature and decreases the humidity of the air. The air conditioning controls and indicators are: • 1 - PRESSURIZATION control panel - Controls the pressurization of the aircraft • 2 - PACK 1 switch - Controls the left cooling pack (AUTO - OFF) • 3 - CKPT knob - Controls the cockpit temperature • 4 - RECIRC switch - Controls the recirculation system (AUTO - OFF) • 5 - PAX CABIN knob - Controls the passenger cabin temperature • 6 - PACK 2 switch - Controls the right cooling pack (AUTO - OFF) • 7 - EICAS (Engine Indicating and Crew Alerting System) display - Shows the system failure messages and the pressurization data • 8 - MFD (Multi-Function Display) Synoptics Page - Shows the synoptics of the environmental control system. Data is provided for the air conditioning, pressurization, bleed and oxygen systems • 9 - CABIN TEMPERATURE knob - Enabled by the PAX CABIN knob on the cockpit, this knob controls the temperature of the cabin when the ENABLE LED is on



General Description The TEMPERATURE CONTROL includes these subsystems: • COCKPIT-ZONE TEMPERATURE CONTROL • PASSENGER-CABIN-ZONE TEMPERATURE CONTROL The temperature control system provides independent temperature control for the cockpit zone and the passenger cabin zone. During normal operation, the cockpit and passenger cabin zones receive air flow from the air conditioning packs and recirculation fans. The cockpit and passenger cabin zone temperatures are electronically controlled by the AMS (Air Management System) controller. The AMS controller interfaces with the cockpit and passenger cabin zone temperature potentiometers to determine the desired cockpit and passenger cabin temperatures. Components COCKPIT-ZONE TEMPERATURE CONTROL The cockpit zone temperature control adjusts the temperature of the cockpit to meet the selected temperature. The temperature is selected by the flight crew using the CKPT selector. PASSENGER-CABIN-ZONE TEMPERATURE CONTROL The passenger zone temperature control adjusts the temperature of the passenger cabin to the selected value. Operation The cockpit temperature is selected by the flight crew using the CKPT selector. The passenger cabin temperature can be selected by the flight crew using the PAX CABIN selector or by the flight attendants, using the CABIN TEMPERATURE selectors.



HYDRAULIC POWER Introduction This aircraft is provided with a hydraulic power system designed to supply power sufficient to meet the performance and redundancy requirements of safe flight. Hydraulic power is used to operate the following aircraft systems and components that require high power and accurate control: • Primary Flight Controls • Spoilers • Landing Gear • Nose Wheel Steering • Main Landing Gear Brakes • Thrust Reversers

General Description The HYDRAULIC POWER includes these subsystems: • MAIN HYDRAULIC POWER • INDICATING The aircraft hydraulic power is supplied by three independent hydraulic systems. Systems No. 1 and No. 2 use EDP (Engine Driven Pump)s as a primary source of hydraulic power and an electric pump as a standby source of hydraulic power. System No. 3 has one electric pump for regular use and a second electric pump available for periods of high flow requirements. A PTU (Power Transfer Unit) is available to transfer power between systems in the event of a right engine EDP failure.



The indicating subsystem provides hydraulic power system status information to the flight crew. Temperature, pressure, quantity, and pump status are continuously displayed on the hydraulic synoptic page of the MFD (Multi-Function Display). Abnormal conditions are reported to the flight crew by the CAS (Crew Alerting System) which generates messages, aural tones, and flashing indicators to alert the flight crew. Operation The hydraulic power necessary for aircraft operation is supplied by the EDPs when the engines are in operation. Operation of the hydraulic system is essentially automatic with little flight crew intervention required. Abnormal hydraulic system conditions generate system responses that allow continued aircraft operation. Any necessary load shedding is pre-programmed and automatically accomplished. There are three independent hydraulic systems, with no fluid intermixing, identified as No. 1, No. 2, and No.3. The PTU provides emergency hydraulic pressure from the No. 1 hydraulic system to the No. 2 hydraulic system without mixing their fluids.



REF CONTROL/INDICATOR POSITION/INDICATION FUNCTION

1 SYS 1 ENG PUMP SHUTOFF switch

OFF Closes the No. 1 hydraulic system firewall shutoff valve.

2 SYS 2 ENG PUMP SHUTOFF switch

OFF Closes the No. 2 hydraulic system firewall shutoff valve.

OFF De-energizes ACMP 1B. AUTO Automatically energizes ACMP 1B if EDP

pressure decreases during take-off or landing.

3 SYS 1 ELEC PUMP switch

ON Energizes ACMP 1B. OFF De-energizes ACMP 2B.

AUTO Automatically energizes ACMP 2B if EDP pressure decreases during take-off or landing.

4 SYS 2 ELEC PUMP switch

ON Energizes ACMP 2B. OFF De-energizes ACMP 3A. 5 SYS 3 ELEC PUMP switch ON Energizes ACMP 3B. OFF De-energizes ACMP 3B.

AUTO Automatically energizes ACMP 3B if ACMP 3A pressure decreases.

6 SYS 3 ELEC PUMP B switch

ON Energizes ACMP 3B. OFF De-energizes the PTU select valve.

AUTO Automatically energizes the PTU select valve, which causes the PTU to operate, if the right engine or EDP stops during take-off or landing.

7 PTU switch

ON Energizes the PTU select valve, which causes the PTU to operate.



Communications General Description The aircraft has three VHF COMM systems: • VHF COMM 1 system • VHF COMM 2 system • VHF COMM 3 system The VHF COMM system can be tuned by the MCDU (Multifunction Control Display Unit) or by the CCD (Cursor Control Device) and PFD (Primary Flight Display). The MCDU is the primary controller and the CCD and PFD are the secondary controllers. The DAP (Digital Audio Panel) controls the radio selections and audio outputs of the VHF COMM system.

VHF COMM SYSTEM TUNING AND CONTROL – MCDU The MCDU supplies the primary controls for radio tuning and other system functions. It has LSK (Line Select Key)s, function keys, and an alphanumeric keypad that let you make selections and changes from different pages shown on its display. It also has a dual concentric knob that lets you change the parameters. The inner knob makes small changes, and the outer knob makes large changes. On the MCDU, the COM detail pages give access to all available functions and selections for the VHF COMM system. To get access to the initial RADIO 1/2 page, push the RADIO key. Then, push the LSK 1L for COM1 or LSK 1R for COM2 to move the cursor to that line. To see the COM1 detail page, push the LSK 1L again. To see the COM2 detail page, push the LSK 1R again. From the COM1 or COM2 detail page, you can make these selections:



• LSK 1L - With the cursor box on line 2L, push the LSK 1L to interchange the ACTIVE and PRESET frequencies. When the semicircular arrow symbol shows, use the tuning knob to change the preset frequency to a new value. With the cursor box on line 3L, push the LSK 1L to copy the stored frequency (shown on line 3L) to the ACTIVE line. If you write a new ACTIVE frequency on line 1L (through a scratchpad entry), the old ACTIVE frequency replaces the PRESET frequency. • LSK 2L - Gives access to the VHF COMM PRESET frequency. • LSK 3L - Gives access to the MEM TUNE function. Turn the tuning knob to see the sequence of available frequency values and related labels kept in memory. • LSK 6L - Gives access to the MEMORY 1/2 page. This page shows a maximum of six frequency values that you can tune or write into memory. • LSK 1R - Lets you set the SQUELCH function to ON or OFF. • LSK 2R - Lets you set the MODE function to DATA or VOICE. • LSK 3R - Lets you set the FREQ function (channel separation) to 8.33 or 25 (kHz). • LSK 6R - Shows the RADIO 1/2 page again. The RADIO 2/2 page on the MCDU LSKs 5L and 6L give access to the COM3 ACTIVE and PRESET frequencies. To access the RADIO 2/2 page, from the RADIO 1/2 page, push the NEXT key.

VHF COMM TUNING FIELD PFD DISPLAY SETUP - MCDU The PFD RADIO SETUP 1/1 page on the MCDU lets the pilot and co-pilot set the secondary radio tuning displays that show on each of the PFDs. To see the PFD RADIO SETUP 1/1 page, the pilot or co-pilot pushes the MENU key on the MCDU, then pushes the LSK 1L for the MISC menu. On the MISC menu, the pilot or co-pilot pushes the LSK 2L to show the SETUP page. The LSK 6L on the SETUP page is used to access the PFD RADIO SETUP 1/1 page. LSK 5L on the PFD RADIO SETUP page puts the cursor in the radio select field. The tuning knob on the MCDU changes the radio that shows in the radio select field. The pilot or co-pilot turns the tuning knob until



the correct radio shows in the radio select field and then pushes the LSK for Pilot L (left), Pilot R (right), Co-pilot L (left), or Co-pilot R (right) to set the secondary radio tuning display for the pilot or co-pilot PFD as follows: • 1L sets Pilot L secondary radio tuning display; • 2L sets Pilot R secondary radio tuning display; • 1R sets Co-pilot L secondary radio tuning display; • 2R sets Co-pilot R secondary radio tuning display.

VHF COMM SYSTEM TUNING AND CONTROL - CCD AND PFD The CCD and PFD operate together to supply the secondary controls for radio tuning and other system functions. The CCD has a touch pad, a range control knob, and keys that operate as follows: • The touch pad lets you use your finger to move the cursor on the PFD. The touch pad has six ″hot″ fields that, when touched, instantly move the cursor to the related position on the PFD page. The ″hot″ fields of the touch pad are in each corner and at the top and the bottom center.



• The range control knob is a dual concentric knob. The outer knob changes the integer part of the frequency, and the inner knob changes the decimal part of the frequency. • There are three display format keys, one each for the PFD, MFD (Multi-Function Display), and EICAS (Engine Indicating and Crew Alerting System) DU (Display Unit). There are also two ENTER keys that make the selections. On the PFD, each bottom left and right corner of the display has a box that contains two frequencies. The active frequencies are green and the standby frequencies are white. When you make a selection of one or the other, the PFD cursor shows around that box and the active frequencies become green. You can now adjust these values. When you make selections with the CCD, it transmits the radio control data on the ARINC-429 bus to the PFD. The PFD changes the ARINC-429 data to ASCB data, then transmits it on the ASCB. The NIM in the MRC receives the ASCB data and transmits it on the RCB to the applicable VHF COMM module. The NIM also digitizes the analog audio signals, then transmits the data on the digital audio bus to the DAP. To tune the VHF COMM radio, push the applicable format key on the CCD to make a selection of a PFD. On the touch pad, touch the ″hot″ field that is related to a secondary tuning field on the PFD. For your selection, the cursor shows around the window which then becomes larger. Use the range control knob to change the frequency, then push the ENTER key to interchange the active and standby frequencies. The radio frequency and function select controls for the VHF communication module 3 come from the generic I/O module in MAU 3 on ARINC-429 bus. The RADIO 2/2 page on the MCDU LSK 5L and 6L on the RADIO 2/2 page give access to the COM3 active and preset frequencies. VHF COMM SYSTEM AUDIO CONTROL - DAP The DAP supplies the manual controls that let you make radio selections and set volume levels into different audio output devices (such as headphones and loudspeakers). The NIM digitizes and transmits the audio signals from the VHF COMM radio through the digital audio bus to the DAP. The DAP digitizes and transmits the microphone audio to the NIM through the digital MIC bus.



STEERING The steering subsystem is a steer-by-wire subsystem, which has four modes of operation. These are: • Pedal steering • Handwheel steering • Free-castoring • Rigging/Trimming When the subsystem is in the pedal steering mode (which is the usual mode of operation), a RVDT (which is connected to the rudder bar) transmits the mechanical input from the pilot to the NWSCM. In this mode, the maximum steering angle is ± 7 degrees. When the subsystem is in the handwheel steering mode a RVDT (which is connected to the nose-wheel steering handwheel) transmits the mechanical input from the pilot to the NWSCM. In this mode, the maximum steering angle is ± 76 degrees. When the NWSCM receives a control input, it operates the steering manifold to supply hydraulic pressure to the steering motor. This then turns the sliding tube (of the NLG) to the correct position. When the subsystem is in the free-castor mode, the steering is disconnected, and the maximum steering angle is ± 170 degrees. In this mode, the green towing light is on to show that the aircraft can be towed (in the other modes, the red towing light is on). In the rigging/trimming mode, the NWSCM operates with the CMC (Central Maintenance Computer), to store the rigging and trimming values.

embraer towing and brake riding overview

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