Civil Aviation Order 108.26 (as amended) made under subregulations 207 (2) and (3) of the Civil Aviation Regulations 1988. This compilation was prepared on 2 November 2007 taking into account amendments up to Civil Aviation Order 108.26 Amendment Order (No. 1) 2007. Prepared by the Legislative Drafting Branch, Legal Services Group, Civil Aviation Safety Authority, Canberra. Contents System specification — oxygen systems Page 1 Application 2 Abbreviations 3 Oxygen specifications 4 System arrangements 5 Dispensing units 6 Minimum mass flow of supplemental oxygen 7 Protective breathing equipment Appendix II Notes to Civil Aviation Order 108.26 Section 108.26 System specification — oxygen systems 1 Application 1.1This section of Civil Aviation Orders contains specifications for aircraft oxygen systems intended for operation at altitudes up to 40 000 feet and is applicable in such circumstances as may be specified by CASA or an authorised person under the Civil Aviation Regulations 1988. Note Specifications for oxygen systems in aircraft intended for operations at altitudes above 40 000 feet are subject to separate determination by CASA. 2 Abbreviations BTPD means body temperature and pressure dry. BTPS means body temperature and pressure saturated. STPD means standard temperature and pressure dry. (0C. at 760 mm Hg, dry) 3 Oxygen specifications 3.3 (1) Oxygen used in gaseous oxygen systems must comply with a specification acceptable to CASA. The following specifications are acceptable: C.I.G. Gas Code 420 or 430; RAAF Specification G172; U.K. Ministry of Defence DEF STAN 68-2 1/1; U.S. Military Specification MIL-0-272 10. (2) Oxygen produced by chemical means in an aircraft oxygen system must comply with a specification acceptable to CASA. The following specifications are acceptable: U.S. Military Specification MIL-E-83252; Scott Engineering Report 1024. 4 System arrangements 4.3Portable oxygen units may be used to meet the crew or passenger breathing requirements. 5 Dispensing units 5.1An individual dispensing unit must be installed for each occupant for whom supplemental oxygen is to be supplied. A unit must be equipped with a suitable means to retain the unit in position on the face. 5.1.1A unit: (a) must not adversely affect a person's ability to use the aircraft's electronic communication equipment while using the unit; or (b) must provide alternative electronic communication equipment that the person can use while using the unit. 5.1.2The units provided in an aircraft operating at or below flight level 180 must include at least 1 unit designed to cover the nose and mouth for every 15 units provided. 5.1.3Every unit provided in an aircraft operating above flight level 180 must be designed to cover the nose and mouth. 5.1.4Every unit installed in an unpressurised aircraft on or after 10 January 1996 must meet the requirements of paragraph 5.1.6. 5.1.5On and after 10 January 1999, every unit provided in an unpressurised aircraft must meet the requirements of paragraph 5.1.6. 5.1.6For the purposes of paragraphs 5.1.4 and 5.1.5, a unit meets the requirements of this paragraph if the following information is clearly visible on it: (a) a notice prohibiting smoking while the unit is used; (b) an illustration showing how to put the unit on; (c) a notice describing the dangers of flying with any kind of nasal obstruction or congestion. 5.2For operations at altitudes up to and including 25 000 feet where section 20.4 of the Civil Aviation Orders requires the use of oxygen, each crew member must be provided with and have readily available, an oxygen supply terminal and dispensing unit. For other occupants under these same circumstances, the supply terminals and dispensing equipment must be located to allow the use of oxygen as required by section 20.4 of the Civil Aviation Orders. 5.3For operations above 25 000 feet, the provision of oxygen dispensing equipment must meet the following requirements: (a) an oxygen dispensing unit which is connected to oxygen supply terminals must be immediately available to each occupant, wherever seated. The total number of dispensing units and outlets must exceed the number of seats by at least 10%. The extra units must be as uniformly distributed throughout the cabin as is practicable; (b) crew members on flight deck duty must be provided with demand equipment. In addition, an oxygen dispensing unit connected to an oxygen supply terminal, must be immediately available to each flight crew member when seated at his station. Where a quick-donning type of oxygen mask is used to meet the requirements of section 20.4 of the Civil Aviation Orders, it must be demonstrated to the satisfaction of CASA that: (i) the mask is capable of being placed on the face from the ready position, properly secured, sealed, and supplying oxygen on demand, with 1 hand within 5 seconds; and (ii) the mask can be donned without disturbing eye glasses and without delaying the flight crew member from proceeding with his assigned emergency duties; and (iii) immediately the donning action is completed, the flight crew member can communicate with other crew members over the aircraft intercommunication system; (d) portable oxygen equipment must be immediately available for each cabin attendant. 6 Minimum mass flow of supplemental oxygen 6.1If continuous flow equipment is installed for the use by flight crew members, the minimum mass flow of supplemental oxygen available for each crew member must not be less than the flow required to maintain, during inspiration, a mean tracheal oxygen partial pressure of 149 mm Hg when breathing 15 litres per minute, BTPS and with a maximum tidal volume of 700 cc with a constant time interval between respirations. The flow rates and mask efficiencies in Appendix II may be used instead of the above flow rates. 6.1AIn spite of paragraph 6.1, flight crew members may use nasal cannula manufactured under the name "Oxymizer", subject to the following conditions: (a) the minimum flow of supplemental oxygen available for each flight crew member at various cabin pressure altitudes must not be less than 0.3 litre per minute at 10 000 feet altitude, increasing by 0.1 litre per minute for every 2 000 feet up to 18 000 feet altitude; (b) the flight crew members must use the nasal cannula only during private, aerial work, or charter, operations; (c) the aircraft must not operate above 18 000 feet altitude. 6.2If demand equipment is installed for use by flight crew members, the minimum mass flow of supplemental oxygen available for each crew member must not be less than the flow required to maintain, during inspiration, a mean tracheal oxygen partial pressure of 122 mm Hg, up to and including a cabin pressure altitude of 35 000 feet and 95 per cent oxygen between cabin pressure altitudes of 35 000 feet and 40 000 feet, when breathing 20 litres per minute BTPS. In addition, there must be means to allow the crew to use undiluted oxygen at their discretion. 6.3For passengers and cabin attendants using masks, the minimum mass flow of supplemental oxygen available for each person at various cabin pressure altitudes must not be less than the flow required to maintain, during inspiration and while using the oxygen equipment provided, the following mean tracheal oxygen partial pressures: (a) at cabin pressure altitudes above 10 000 feet up to and including 18 500 feet, a mean tracheal oxygen partial pressure of 100 mm Hg when breathing 15 litres per minute, BTPS, and with a tidal volume of 700 cc with a constant time interval between respirations; (b) at cabin pressure altitudes above 18 500 feet up to and including 40 000 feet, a mean tracheal oxygen partial pressure of 83.8mm Hg when breathing 30 litres per minute, BTPS, and with a tidal volume of 1100 cc with a constant time interval between respirations. The flow rates and mask efficiencies specified in Appendix II may be used at cabin pressure altitudes up to 25 000 feet instead of the above flow rates. 6.3.1For passengers and cabin attendants using nasal cannulas manufactured under the name "Oxymizer", the minimum flow of supplemental oxygen available for each person at various cabin pressure altitudes must not be less than 0.3 litre per minute at 10 000 feet altitude, increasing by 0.1 litre per minute for every 2 000 feet up to 18 000 feet altitude. 6.4If first-aid oxygen equipment is installed, the minimum mass flow of oxygen available to each user must not be less than 4 litres per minute, STPD. However, there may be a means to decrease this flow to not less than 2 litres per minute, STPD, at any cabin altitude. The quantity of oxygen required may be based upon an average flow rate of 3 litres per minute per person for whom first‑aid oxygen is required. 6.5If portable oxygen equipment is installed for use by crew members, the minimum mass flow of supplemental oxygen must be as specified in paragraph 6.1 or 6.2 of this section, whichever is applicable. 7 Protective breathing equipment 7.1Protective breathing equipment must be designed to protect the flight crew from smoke or toxic fumes and gases. 7.2Equipment must include: (a) masks either covering the eyes, nose, and mouth or covering the nose and mouth with accessory equipment to cover the eyes; and (b) at least 1 portable oxygen system of the demand type. 7.3The protective breathing equipment while in use, must allow the flight crew to use the radio equipment and to communicate with each other, while at their assigned duty stations. 7.4The part of the protective breathing equipment protecting the eyes must not cause any appreciable adverse effect on vision and must allow corrective glasses to be worn. 7.5The protective breathing equipment must supply protective oxygen of 15 minutes duration per crew member at a pressure altitude 0 feet with a respiratory minute volume of 30 litres per minute, BTPD. If a demand oxygen system is used, a supply of 300 litres of free oxygen at 20C and 760 mm Hg pressure is considered to be of 15 minute duration at the prescribed altitude and minute volume. If a continuous flow protective breathing system is used (including a mask with a standard rebreather bag) a flow rate of 60 litres per minute at 8 000 feet (45 litres per minute at sea level) and a supply of 600 litres of free oxygen at 20C and 760 mm Hg pressure is considered to be of 15 minute duration at the prescribed attitude and minute volume. Appendix II MINIMUM OXYGEN FLOW RATES FOR FLIGHT ALTITUDES NOT EXCEEDING 25 000 FEET WHEN USING MASKS WITH EFFICIENCIES EQUAL TO OR BETTER THAN THE A 8 B ORONASAL MASK, THE SCOTT 28302–11 SEMI-DISPOSABLE MASK OR THE K–S DISPOSABLE MASK Notes to Civil Aviation Order 108.26 Note 1 The Civil Aviation Order (in force under the Civil Aviation Act 1988) as shown in this compilation comprises Civil Aviation Order 108.26 amended as indicated in the Tables below. Table of Orders Year and Date of notification Date of Application, saving or number in Gazette/ commencement transitional provisions registration on FRLI CAO 2004 No. R95 23 December 2004 23 December 2004 (see s. 2) CAO 108.26 2007 No. 1 FRLI 2 November 2007 3 November 2007 (see s. 2) Table of Amendments ad. = added or inserted am. = amended rep. = repealed rs. = repealed and substituted Provision affected How affected s. 108.26 rs. CAO 2004 No. R95 subs. 6 am. CAO 108.26 2007 No.1