Advisory Circulars

Commercial & Business Aviation


No. 0108


Protective Breathing Equipment Requirements


This Air Carrier Advisory Circular (ACAC) is intended to provide clarification and additional information to air operators, operating aircraft with one or more flight attendants, in regard to options which may be applied to satisfy the protective breathing equipment requirements under the Canadian Aviation Regulations. This Circular may provide some relief in the total number of protective breathing equipment units installed on board an aircraft.


Air operators operating under Canadian Aviation Regulations (the Regulation) subpart 705, Airline Operations, are required to operate in accordance with Section 705.71 of the Regulation, Protective Breathing Equipment.

Subsection 705.71(1) of the Regulation states:

"No air operator shall operate a pressurized aircraft unless, at each station listed in paragraph (3)(b), protective breathing equipment with a 15-minute supply of breathing gas at a pressure-altitude of 8,000 feet is provided in accordance with this section."

Paragraph 705.71(3)(b) of the Regulation further states:

"(3) Protective breathing equipment shall be conveniently located and readily available ...

(b) with a portable breathing gas supply for use by crew members in combatting fires, as follows:

  1. one unit for use in each Class A, B and E cargo compartment that is accessible to crew members in the cabin during flight,
  2. one unit for each hand-held fire extinguisher located in each isolated galley,
  3. one unit on the flight deck,
  4. one unit located within one metre of each hand-held fire extinguisher required in the passenger compartment by section 705.93, except if the Minister has authorized the location of protective breathing equipment more than one metre from each hand-held fire extinguisher where special circumstances exist that make compliance with this subparagraph impractical and that location provides an equivalent level of safety, and
  5. the number of units of protective breathing equipment used to satisfy the requirements of this paragraph shall not be less than the number of flight attendants required for the flight."

The locations of the protective breathing equipment (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 CAR 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.

The number of PBE units required under Section 705.71 of the Regulation may appear over abundant 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.

In order to effectively outline an option to reduce the number of PBE units, a specific aircraft example is given.

Scenario: In the case of a Hawker Siddley 748 combi aircraft, operating with one flight attendant, the main deck is comprised of:

the flight deck - one PBE unit;
the forward cargo compartment - one PBE unit;
the aft cargo compartment - one PBE unit; and
the passenger compartment - two PBE units; one for each hand-held fire extinguisher as required by Section 705.93, unless otherwise approved by the Minister.

Installing a separate PBE unit for each requirement as shown above results in a total of five PBE units for this aircraft.

Option: Placing one PBE unit on the forward cabin bulkhead in this aircraft covers both the requirements for a PBE unit accessible and readily available for the cargo area and one 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 and one PBE unit next to the halon extinguisher for the aft cabin.

Consequently, the appropriate location of PBE units in this situation has reduced the number of PBE units installed from five to three, while satisfying all requirements under Section 705.71 of the Regulation.

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


The compliance plan described above can be applied to other aircraft types where cargo compartment PBE requirements can be combined with cabin PBE requirements to reduce the number of PBE units installed on board an aircraft while upholding all aspects of the regulatory requirements.

In addition, a similar compliance plan can be applied to combi aircraft operating with more than one flight attendant provided the number of PBE units installed are not less than the required number of flight attendants for the flight, as outlined in subparagraph 705.71(3)(b)(v) of the Regulation.

A.J. LaFlamme
Commercial and Business Aviation

Commercial & Business Aviation Advisory Circulars (CBAAC) are intended to provide information and guidance regarding operational matters. A CBAAC may describe an acceptable, but not the only, means of demonstrating compliance with existing regulations. CBAACs in and of themselves do not change, create any additional, authorize changes in, or permit deviations from regulatory requirements.

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