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Division V - Aircraft Equipment Requirements

745.71  Protective breathing Equipment

R745.71 - Protective breathing Equipment (PBE)

Protective breathing equipment is defined in CAR 101.01 as equipment designed to cover the eyes, nose and mouth of the wearer, or the nose and mouth where accessory equipment is provided to protect the eyes, and to protect the wearer from the effects of smoke, carbon dioxide or other harmful gases. NOTE: the PBE must provide a minimum 15 minute supply of breathing gas at a pressure altitude of 8,000 feet.

The locations of the PBE units are intended to allow immediate access of a PBE unit by the crew member to maintain a safe environment on board the aircraft. Placing a PBE unit in a Class A, B or E cargo compartment to satisfy subparagraph 705.71 (3)(b)(i) of the regulation would require the crew member to don the PBE in a less than ideal environment during a potential fire. Common sense prevailing, the PBE unit should be located in close proximity to the entrance outside the cargo compartment to allow the crew member immediate access to the PBE unit and to don the equipment in the cabin environment. The crew member would then proceed into the cargo compartment to monitor and/or combat the fire.

For aircraft operating in a combined cargo/passenger configuration (combi), especially those aircraft operating with one flight attendant, some relief in the total number of PBE units installed on board an aircraft may be achieved by placement of PBE units in appropriate locations. More than one requirement set out in Section 705.71 of the regulation can be satisfied by combining the cargo fire fighting PBE requirements with the cabin PBE requirements. For example, on an a combi aircraft operating with one flight attendant, with the main deck comprised of the flight deck, forward cargo compartment, aft cargo compartment and passenger compartment, placing one PBE unit on the forward cabin bulkhead can cover both requirements for a PBE unit accessible and readily available for the cargo area and for a PBE unit next to the halon extinguisher on the forward bulkhead in the cabin. Similarly the placement of a PBE unit next to a halon extinguisher in the aft galley area would also satisfy the requirement to have a PBE unit accessible and readily available for the aft cargo compartment.

A PBE unit is required for each hand-held fire extinguisher located in each isolated galley. An isolated galley is defined as a galley that is isolated from the normal working environment in such a way that fire extinguishers in the passenger cabin are not readily available for use in the galley area. For example, the DC-10 lower lobe galley is an isolated galley; the galleys on the B737 are not isolated.

745.72 First Aid Oxygen

R745.72 - First Aid Oxygen

The purpose of First Aid Oxygen is to provide oxygen for those passengers who may have suffered a respiratory or cardiac emergency as a result of a decompression or a medical condition. A passenger may not necessarily have the same fitness level as a crew member and may not be accustomed to the normal cabin pressure altitudes of 6,000 to 8,000 feet. For some passengers, the decrease in pressure at altitude can aggravate or trigger an existing medical condition necessitating the need for supplemental oxygen.

There must be first aid oxygen for a minimum of one person, or, when 2% of the occupants (crew and passengers) total more than one person, there must be sufficient first aid oxygen for 2% of the occupants.

To determine the period of time for which first aid oxygen must be provided, calculate which of the following is the longer period with respect to the particular flight operation/routing:

(a) one hour; or

(b) the duration of the flight, following depressurization of the cabin, that is operated at a cabin altitude above 8,000 feet. (When making this calculation, assume that the cabin depressurization occurs at the “worst case” point along the route.)

The requirement for sufficient first aid oxygen for “…the entire duration of flight at a cabin pressure altitude above 8,000 feet” does not mean that sufficient first aid oxygen is required for the duration of the originally planned flight. Rather, that the supply is sufficient for the period of time following a cabin depressurization, that the aircraft will be operated with the cabin pressure above 8,000 feet. This time period will vary according to the flight routing, possible en route alternates and the planned altitude of operation either to the original destination or to an alternate airport if a diversion is necessary. For example, on one route the terrain being overflown may preclude descent to levels that would allow operation at a cabin pressure altitude below 8,000 feet, while on another route this may not be a factor.

However, the one hour requirement is not predicated on cabin pressure altitude. Therefore, if the period of flight (following depressurization) that would have to be operated at a cabin pressure-altitude of above 8,000 feet is determined to be less than one hour, then the one hour supply is the minimum required.

745.73 Interphone System

R745.73 - Interphone System

The interphone system and the public address system must be able to be operated independently. The exceptions are the handsets, headsets, microphones and selector switches that can be common to both systems. For example, the switch that enables the user to go from public address to intercom may be defective; however, this does necessarily prevent the operator of the system from making a public address announcement. Similarly, if the public address handset becomes defective (e.g. the press bar or its connection has a short in it), that defect may not prevent the operator of the system from using the same handset to operate in the intercom mode. The aircraft cannot be dispatched with both the passenger address system and intercom system inoperative.

745.76 Lavatory Fire Protection

R745.76(e) - Lavatory Fire Protection

The Non Smokers Health Act prevents smoking on a scheduled commercial flight and thus it is possible that an aircraft may never be used for smoking flights. Nonetheless, there remains a requirement for ashtrays to be installed where such installation is required by the aircraft design standards to comply with Airworthiness Directive (AD) 74-08-09 (02) issued by the FAA and adopted by Transport Canada. This AD provides for some time limited relief for ashtrays required for lavatory fire protection and Transport Canada is currently reviewing Transport Canada Supplements to ensure that the relief is included in MMELs where appropriate. Where such MEL relief is sought but not yet provided for in the MMEL, or Transport Canada Supplement, the air operator is advised to submit a formal request to Transport Canada Aircraft Certification (Flight Test) for consideration.

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