Oxygen.docx

2A-36-10: General Oxygen The aircraft has a dual tank oxygen system to provide an alternate breathing source to the flight crew and passengers in the event of a cabin pressunzation failure or the presence of smoke or fumes within the aircraft. Both tanks are identical, each with a capacity of 123.4...

2A-36-10: General Oxygen The aircraft has a dual tank oxygen system to provide an alternate breathing source to the flight crew and passengers in the event of a cabin pressunzation failure or the presence of smoke or fumes within the aircraft. Both tanks are identical, each with a capacity of 123.4 ft3 normally pressurized to 1,800 ±50 psi. The tanks are plumbed together to form a single oxygen source that is available to boththe cockpit and cabin.The tanks are physically located beneath the cabinfloor in the vicinity of the main entrance doorway. The tanks are serviced through a panel on the aircraft exterior onthe right side, beneath the first two cabinwindows. The service panel contains a single filler connection for both tanks and a pressure gage for each tank. Each cylinder has two pressure relief ports, one for high pressure and low pressure. Each cylinder's relief ports are teed together and connected to the overboard discharge indicator on the right hand side of the aircraft. Each cylinder vents low pressure relief when regulator supply pressure exceeds 90 psig.The cylinder regulator vents high pressure relief when cylinder pressure exceeds 2775 psig. Cockpit indicators and controls enable monitoring the fill levels of the tanks, and activating the masks stowed in the cabinoverhead, initiating the flow of oxygen to the cabin masks with a manual switch command or automatically in the event of depressurization. An additional therapeutic oxygen outlet is installed in the cabin interior with mask and hoseto provide for medical emergencies. Thelocation of the outlet is determined by the interior furnishings arrangement selected by the customer. Each crew member, induding the occupant of the observer seat, has a dedicated oxygen mask with integrated microphone that provides uninterrupted communications through the Audio Control Panels (ACPs). 2A-36-20: Passenger and Crew Oxygen System General Description: (See Figure 1.Oxygen System Diagram and Control Panels (1of 2).) The oxygen bottles are designated as crew and passenger supplies, but both bottles are plumbed together into a common supply line just prior to the oxygen system control panel on the copilot side console. Pressure regulators on the bottles reduce system pressure to 55-80 psi prior to the supply line to prevent the presence of high-pressure flow in the cockpit. Switches and selectors on the cockpit control panel open valves to supply a low-pressure flow of oxygen to either or both the cockpit and passenger compartments. Although both oxygen bottles act as a single system, each is equipped with a shutoff valve, dedicated pressure regulator, pressure transducer, direct reading gage, pressure and temperature relief valves and a low pressure switch that provide the following functions: Shutoff Valve - Shuts off the bottle ouUet for removal and installation of the bottles Pressure regulator - Reduces the bottle pressure from the maximum of 1,800 ±50 psi down to a supply pressure of 58-80 psi to conform to the structurallimits of the system plumbing and provide a comfortable pressure for human inhalation. The regulator will close the supply valve whenthe pressurewithin the tank drops to 200 psi, indicating that the tank is approaching depletion. When the supply valve closes, a low pressure switch in the supply line will detect the drop in pressure in the supply line and signal that line pressure is 45 psi or below. Pressure Regulator and Temperature Relief Valve Assemblies - There are two oxygen cylinder pressure regulator and temperature relief valve assemblies per aircraft. Each contains a high pressure and low pressure relief port. The assembly vents low pressure relief when low pressure supply exceeds 90 psig and is reset at 90 psig. The assembly vents high pressure relief when cylinder pressure exceeds 2775 psig and is reset at 2500 psig. For cylinder pressures between 250 and 1850 psig,low pressure supply is regulated to 55-80 psig. Each assembly also contains a refill port that is plumbed to the aircraft oxygen service panel, along with a port for remote indication of cylinder charge pressure. The vent line is capped with a green overboard discharge disc located on the exterior of the airplane above and to the right of the oxygen service panel. If any of the relief valves opens to discharge excess pressure, the green disc will rupture, indicating the loss of oxygen. One relief valve will open if pressure inthe supply lines exceeds 90 psi,another valve will open if pressure inthe bottle exceeds 2,775 psi. Pressure Transducer - An electrical sensor powered by 28V DC is mounted onthetank regulator totransmit pressure readingstothe cockpit oxygen pressure gages Direct Reading Gage- Eachtank hasa direct readinggage onthe oxygen service panel that is connected by tubing to the oxygen tank Pressure andTemperature Relief Valves - All reliefvalves are plumbed to a common overboard vent line. The vent line is capped with a green overboard discharge disc located on the exterior of the airplane above and to the right of the oxygen service panel. Ifany of the relief valves opensto discharge excess pressure, thegreen discwill rupture, indicating the loss of oxygen. One relief valvewill open if pressure inthe supply lines exceeds 90 psi,another valve will open if pressure in the bottle exceeds 2,775 psi or if the bottle temperature exceeds 225°F. Low Pressure Switch - Each low pressure supply line from each cylinder has a pressure switch and a check valve. The pressure switch is located upstreamof the check valve and provides asignal to trigger either a Ml§.C.Hr (caution) or (caution) CAS message. Sincethe cylinder vents the low pressure supply line (upto the check valve) when the cylinder is in the OFF position,and the pressure switch is upstream of the check valves, there is no false indication from trapped oxygen in the line if the bottle is inadvertently left in the OFF position. The therapeutic oxygen line for the passenger compartment is teed from the low pressure supply line from the passenger oxygen cylinder. Although both the flight crew and passengers share the common oxygen system, the methods of delivery are different because of the disparate usage requirements. The passenger oxygen supply is provided to maintaincabin occupant respiration untilthe airplane is able to descend to an altitude where ambient air is dense enough that oxygen is no longer required. The flight crew can be supplied with either supplemental oxygen that is combined with ambient airto provide a breathable mixture to sustain extended flight at high cabin altitudes, normal one hundred percent (100%) oxygen inhaled on demand in the event of depressurization, or emergency pressurized flow of one hundred percent (100%) oxygen if depressurization occurs at very high altitudes or if there is toxic smoke or fumes in the cockpit. Description of Subsystems, Units and Components: Passenger Oxygen Supply: The Passenger Oxygen Control Panel (POCP) provides the crew with AUTO I MAN I OFF functionality for the passenger oxygen system in the cabin. It is capable of providing two auto-deployment set points, one for normal field operations (14,750 +/- 250 feet) and one for high field operations (15,750 +/- 250 feet). It also controls both automatic and manual deployment of passenger oxygen masks and retains OFF functionality I selection. The panel provides test function capability, indication to the crew when oxygen is being delivered to the passengers, indication to the crew when set point is set (normal vs. high field) and is ARINC 429 capable. Oxygen is delivered to the occupants of the cabin through yellow flexible cup-like masks commonly used in airline operations. The masks are stowed in compartments overhead of each seat and are deployed either automatically if the cabin is depressurized or through manual command by a switch on the cockpit oxygen control panel. The number of masks installed on the airplane is dependent upon the seating configuration of the particular aircraft, but will always exceed the number of occupants by at least 10% to provide a margin for mask inoperability or for small children not assigned a seat. In addition to above the passenger seats, masks are also installed in lavatory and galley areas. Note The flight crew must ensure that the rotary switch is selected back to the appropriate AUTO or OFF position when passenger oxygen is no longer required. Flight Crew Oxygen: (See Figure 2. Aircrew Oxygen Masks (Pilot, Copilot, Observer) .) The oxygen system is designed to provide the flight crew and observer with low pressure oxygen via three mask I regulator assemblies. The crew and observer masks are quick-donning masks which include a diluter I demand-type regulator, microphone, oxygen supply hose, a mouth-nasal mask shellwith inflatable harness and integral detachable smoke goggles (goggle option on pilot and copilot masks only).A manual inflation control to operate the inflatable harness is located on the regulator. The regulator is integrated into the masks to provide on-demand oxygen flow that is combined with ambient cabin air, only pureoxygen, or positive pressurized pure oxygen flow. The masks are stowed in readily-accessible compartments and are quick-donning, requiring only one hand to grasp and put in place over the face. Once in position, they are held securely over the nose and mouth by a harness of elastic inflatable tube-type straps. The masks are pulled out of their storage compartment by the hose on the front of the mask. When the tabs are squeezed, the inflatable tubes are expanded with system oxygen, allowing the mask to be positioned over the head. Once in position, the red tabs are released and the tubes deflate, allowing the elastic of the tubes to hold the mask securely over the face. The tension in the mask harness can be adjusted with a comfort toggle on the front of the mask. The toggle is pulled up and a roller beneath the toggle is rotated to adjust the tension with which the mask is held against the face. Once the mask leaves the storage compartment, two gate-type doors on the endosure are pushed aside, starting the flow of oxygen to the mask. A push lever on the right side of the front of the mask is used to select either normal (supplemental) oxygen or a supply of 100% oxygen to the mask. Normal or 1OC°Ai oxygen is furnished on demand - i.e. by normal inhalation. A rotary knob on the front of the mask can be used to select emergency oxygenthat provides a positive pressurized oxygen flow to the mask instead of on demand inhalation.The masks are certified to a cabin altitude of 40,000 ft and the masks will automatically switch to positive pressurized flow if the cabin altitude exceeds 35,000 ft. Each mask has an integrated microphone installed within the breathing area of the mask. The microphone is activated by selecting the MIC button on the Audio Control Panel (ACP)to the extended or mask position (if the button is depressed only the headset boom microphone hasinputs to the ACP). The microphone is keyed using the normal RADIO / ICS toggle switch on the control yoke or the PTT button on the CCD. The observer position uses the RADIO / ICS toggle switch on the radio jack box beneath the ACP. The masks have a deflector on the top to direct a small flow of oxygen to the interior of the smoke masks when they are in use to prevent condensation on the interior of the plastic lens. Oxygen is available to the flight crew at any time provided the ON I OFF toggle switch (located directly below the CREW I PASSENGER quantity gages) is positioned to ON. With the switch in the ON position, valves open to allow oxygen to the masks and to the rotary selector knob on the PASSENGER section of the panel. Crew masks may be tested without extracting them from the storage containers by depressing a PRESS TO TEST AND RESET button beside the mask on the face of the container. When the button is depressed, a blinking "cat-eye• indicator above the button will open showing a yellow background to indicate flow of oxygen to the mask. When the mask is in use, the indicator will blink open whenever oxygen is inhaled. When the test button is held in, the "cat-eye• should dose, showing no yellow background.If the indicator does not close, a leak in the mask should be suspected. The emergency oxygen flow function can also be tested with a pushbutton on the face of the mask, but requires that the mask be extracted from the storage container. There is no indication of emergency flow other than the noise associated with the pressurized release of oxygen. After oxygen is no longer needed, the masks are stowed back to their respective container by first squeezing the red harness inflation tabs on the side of the mask to inflate the harness so that it can be removed from the head.After the mask and harness are removed, the tabs are released to deflate the harness, allowing the mask to fit back within the storage compartment. The mask should always be stowed with the selector to the 100% position so that the mask is configured for any subsequent immediate use. c. OXYGEN SYSTEM and PASSENGER OXYGEN Control Panels: (See Figure 1. Oxygen System Diagram and Control Panels (1of 2) Details A and B to view both panels.) The OXYGEN SYSTEM control panel is located on the copilot side console and contains two electrically-powered gages that show the amount of oxygen in each crew and passenger bottle, indexed in pounds per square inch (psi). When full, each bottle pressure should read 1,800 ±50 psi. Above the gages is the notation: GAGE PRESS DOES NOT BLEED TO ZERO (0) WITH SYS INOFF POSITION. Since the gages are electrical and not direct reading, turning off the system selector switch does not affect gage readings. The system selector switch is a toggle switch located below the gages. The switch has two positions: OFF and ON and is labeled CREW I PASSENGER since it controls the flow from both bottles as both are plumbed together. Note The system selector switch should be selected to the ON position during all flight operations to allow oxygen to be supplied to the flight compartment masks andto the rotary mode control switch for passenger compartment oxygen. The PASSENGER OXYGEN control panel (located directly aft of the OXYGEN SYSTEM control panel), indudes a gage indicating the pressure of the oxygen available to the passenger oxygen system, an annunciator that illuminates the text label PASS OXYGEN ON when the control panel detects oxygen flowing to the passenger oxygen masks and a three-position rotary mode control switch to select the desired operation of the passenger oxygen system. Passenger Oxygen System Test Switch: A pushbutton on the SYSTEM TEST panel on the cockpit overhead will test the indications of the passenger oxygen system operation. The pushbutton, labeled PASS OXYGEN, willilluminate with the legend TEST when the button is depressed, and cause the green PASS OXYGEN ON light on the PASSENGER OXYGEN control panel to illuminate, the Passenger Oxygen On (caution) CAS message to appear on the CAS display and the NO SMOKING signs I icons to illuminate accompanied by an aural chime I tone over the airplane speaker system. Oxygen Service Panel: The oxygen service panel is located on the airplane exterior on the right hand side approximately below the first two cabin windows (see Figure 3. Oxygen Servicing Panel and Overboard Discharge Disk, Detail A). The panel is accessible by releasingthe locking tabs holding the panel door shut. V\lithin the panel is a direct reading gage for the crew and passenger bottles and a filler adapter. Both bottles are serviced by connecting an oxygen servicing cart to the filler adapter. The bottles are filled by usinganambient temperature vs. pressure chart. The nominalfull level is 1,800 psi at 70°F (21°C). Oxygen System Overpressure Discharge Disc: A green plastic disc (see Figure 3.Oxygen Servicing Panel and Overboard Discharge Disk,Detail B) is installed on the skin of the airplane above and forward of the oxygen service panel beneath a label reading CAUTION VENT - DO NOT BLOCK. The disc seals the overpressure discharge vent line of the oxygen system. If pressure within the bottles exceeds 2,600 psi through overfilling or if the temperature of the bottles reaches 225°F, an overpressure valve on the tanks will open, releasing oxygen into the overpressurevent line and rupturingthe green plasticdisc sealing the line. The excess pressure limit is to protect the structural integrity of the bottles and the temperature limit is to ensure that the bottles are emptied if there is a fire aboard the airplane so that the contents of the bottles do not contribute to the severity of the flames. Protective Breathing Equipment: The crewmember Essexx Protective Breathing Equipment (PBE) is a self-contained, portable, personal breathing device designed to safeguard the wearer from the effects of smoke, carbon dioxide, harmful gases and oxygen deficiency while managing in-flight fire, smoke orfume emergencies. The equipment improves the wearer's visibility in smoke-filled compartments, protects the head and face from melting or dripping plastics, and shields the head against brief exposure to heat and flame. One PBE is installed in the flight deck and the other is installed in the vicinity of the baggage compartment (see Figure 1. Oxygen System Diagram and Control Panels (1 of 2)). The PBE features a battery-powered green and red light Service I End-of-Service indicator.Mounted slightly below eye level onthe left inner side of the hood, this indicator functions as a secondary indicator for monitoring oxygen activation, reassuringthe wearer that the equipment is functioning property as well as indicating when the equipment's service life has ended. Controls and Indications: Circuit Breakers (CBs): The following CBs protect the crew I passenger oxygen system: Circuit Breaker Circuit Breaker Panel Location Power Source OXYGEN IND CREW MCDU SSPC (#3501) L DC MPT 2 OXYGEN IND PASS MCDU SSPC (#3502) L DC MPT 1 Crew Alerting System (CAS) Messages: The following GAS messages are associated with the crew I passenger oxygen system: Area Monitored CAS Message Crew oxygen bottle supply line pressure 45 psi or lower Crow Oxygen 0 (caution) Passenger oxygen bottle supply line pressure 45 psior lower Passenger Oxygen (caution) Passenger oxygen system pressurized Passenger Oxygen 0 (caution) Flight Manual Limitations: Oxygen Departure Pressures: The quantity of oxygen required varies with the flight profile. Use Figure 4. Oxygen Duration - Crew of 3 with Masks set to NORMAL to determine the required oxygen quantity fur each flight with the Oxygen masks set to NORMAL Figure 5. Oxygen Duration - Crew of 3 with Masks set to 1000.Ai is provided in the event the crew selects 100% on the Oxygen masks. Refer to GC61468M001, Airplane Interior AFM Supplement, Appendix 0, to compute oxygen departure pressures for flights including passengers. Additional Certification Requirements: The following airplane certification requirements are in addition to the requirements of applicable operating rules. The most restrictive requirements (certification or operating) must be observed. Availability Of Crew Masks: Above Flight Level (FL) 250, crew masks must be in the quick-donning position which allows donning withinfive seconds. Use of Crew Masks: On airplanes equipped with EROS MLD 20 Series Full Face Mask with detachable goggles, hats and "earmutr type headsets must be removed prior to donning crew oxygen masks. Maximum Cabin Altitude For Use: Crew and passenger oxygen masks are not approved for use above 40,000 ft cabin altitude. Note Headsets and eyeglasses worn by crewmembers may interfere with quick-donning capabilities. WARNI NG _ PASSENGER MASKS ARE INTENDED FOR USE DURING AN EMERGENCY DESCENT TO AN ALTITUDE NOT REQUIRING SUPPLEMENTAL OXYGEN. WARNI NG _ PASSENGER MASKS WILL NOT PROVIDE SUFFICIENT OXYGEN FOR PROLONGED OPERATION ABOVE 34,000 FT CABIN ALTITUDE. PROLONGED OPERATION ABOVE 25,000 FT CABINALTITUDE WITH PASSENGERS ABOARD IS NOT RECOMMENDED. OEM Provided Data Oxygen Revision B 2019..Q6-13 2A-35-00: 8 of 14 Figura 1.Oxygen System Diagram and Control Panels (1 of 2) MASK STOWAGE """ SEE DETAILA O\IBll DISCHARGE/ INJICA.TIJR SMOKE HODD MASK 9TOWAClE BOX OXYGEN Born.E WITH REGULATOR OXYGEN Born.E WITH REGULATOR ll_H_.P '!_RJ;.!:' 1_!_p _!lE- _!_E£_1:!E_!.'._) LOW-PRE88URE UNE (!(11" DIA) LOW-PREBBURE UNE-TlERAPEUTIC (5111!1• DIA) Ew:TRICALLINE TIL.--003856 Figure 1.Oxygen System Diagram and Control Panels (2 of 2) SEE DETAILA SEE DETAIL B DETAIL A PASSENGER OXYGEN Controller PASS OXYGEN ON OXYGEN SUPPLY PRESSURE Three position switch: OFF: Oxygen flow to the passenger oxygen system is inhibited. AUTO: PASSENGER OXYGEN control panel will automatically deploy passenger oxygen masks when sensed cabin altitude reaches 14,750! 250 feet. Oxygen flow is based on cabin altitude. MAN: Manually deploys passenger oxygen masks. Oxygen flow is provided at a constant pre-set flow. Indicator Indicates oxygen is flowing to the deployed passenger oxygen masks (indicates green). Displays oxygen system supply pressure available to the passenger oxygen system. DETAIL B TIL-003855A Figura 2. Aircrew Oxygen Masks (Pilot, Copilot, Observer) SEE DETAILA RIGHT ELECTRONIC EQUIPMENT RACK PRESS TO TEST I EMERGENCY When knob is pressed momentarilly, oxygen is supplied under constant pressure. When placed in NORMAL,oxygen is supplied in diluter demand flow. When placed in EMERGENCY, undiluted oxygen is supplied under constant pressure. DETAIL B TIL-003875A Figure 3. Oxygen Servicing Panel and Overboard Discharge Disk SEE DETAIL A SEE DETAIL B OXYGEN FILLER VALVE PASSENGER OXYGEN INDICATOR GAGE DETAIL A CREW OXYGEN INDICATOR GAGE DETAIL B OVERBOARD DISCHARGE DISK TIL-003863 0 m "'IJ < c !!I. a-n· c iii (j) ::::J 0 ::::J c lJ "U m a (") ll -§·l.a ... "' ... ....... .,. TIL-013982 iz 0 Q t.> )> =r s::: QI) r QI) 0 z 0 ;;ti )> r 0 Iii! 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