ATA 35 OXYGEN

LEGEND

Procedures Required

(O) – An operational procedure
(M) or (M#) – A maintenance procedure
(O)(M) or (O)(M#) – Both operational and maintenance procedures

Repair Interval Categories

Category A

Items in this category shall be repaired within the time interval specified in the "Remarks or Exceptions" column of the air operator's approved MEL. Whenever the proviso in the "Remarks or Exceptions" column of the MMEL states cycles or flight time, the time interval begins with the next flight. Whenever the time interval is listed as flight days, the time interval begins on the flight day following the day of discovery.

Time Limited Dispatch - Some MMEL's for aircraft that are equipped with FADEC engines have relief that is subject to time limited dispatch expressed as a specific number of engine hours, and will start in accordance with the times established by the engine manufacturer or as indicated in the remarks column of the MMEL. Time limited relief cannot be extended.

Category B

Items in this category shall be repaired within 3 consecutive calendar days excluding the day of discovery.

Category C

Items in this category shall be repaired within 10 consecutive calendar days, excluding the day of discovery.

Category D

Items in this category shall be repaired within 120 consecutive calendar days, excluding the day of discovery. To be considered for placement in Category D, the item must be of an optional nature, or excess equipment which an air operator may, at his/her discretion, deactivate, remove from or install on an aircraft.

To be approved for Category D, the item must meet the following criteria:

  1. the absence of the item does not adversely affect crew member's workload;
  2. the crew members do not rely on the function of that item on a routine or continuous basis; and,
  3. the crew members' training, subsequent habit patterns and procedures do not rely on the use of that item.

Category D relief will generally not be approved for equipment which is considered to increase the level of safety, even if that equipment is of an optional nature.

ITEM:  35-10-1  FLIGHT DECK OXYGEN SYSTEM

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Flight Deck Oxygen System
Bottle Pressure Indication C 1 0 (M) May be inoperative provided an acceptable method is used to confirm that adequate oxygen is available for the intended flight.
EICAS (or equivalent) Pressure Indication C 1 0 (M) May be inoperative provided an acceptable method is used to confirm that adequate oxygen is available for the intended flight
Observer Seat B/D 1 0  

May be inoperative provided it is selected OFF and the seat is not occupied.

NOTE:
This relief must be checked because there may be designs where shutting off the Observer oxygen disables the supply to one of the flight crew members.

DISCUSSION:

References:  CAR 605.31

Although the oxygen system is not required by CARs below 10,000 ft MSL, because of the oxygen requirements of smoke removal emergency procedures, it is not appropriate to grant relief for the flight crew members’ equipment.

Category B/D is consistent with observer’s seat dispatch relief (see item 25-10-3).

FAA Differences:  Observer seat relief may differ.

ITEM:  35-20-1  PASSENGER OXYGEN SYSTEM

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Passenger Oxygen System
Entire System B 1 0 (O)

May be inoperative provided:

a) Minimum en route altitude does not exceed 13,000 ft above MSL,

b) All air conditioning packs are operative,

c) Pressurization system is operative,

d) Flight remains at or below FL 250,

e) Portable oxygen units are provided for all crew members and 10% of the passengers for half an hour (supplemental oxygen), and

f) Passengers are appropriately briefed.

Automatic Presentation System B 1 0  

May be inoperative provided:

a) The alternate flight deck deployment system is operative, and

b) Flight remains at or below FL 300.

Individual PSUs         Refer to item 35-20-2.
All Cargo Operations D 1 0  

May be inoperative provided:

a) Portable oxygen bottles are available to all crew members required to be off the flight deck, and

b) An automatic warning system is installed in the cargo area to alert of a decompression, if crew members are required to be in the cargo area during flight.

D 1 0   May be inoperative provided all crew members are on the flight deck.

DISCUSSION:

References:  CAR 605.31, CAR 605.32, (First Aid Oxygen in CAR 703.68, CAR 704.67, CAR 705.72), AWM 523.1447, AWM 525.1447

Total amount of supplemental oxygen required in Portable Passenger Oxygen units (e) is in addition to the amount required for first aid oxygen in the CARs.

For the cat D relief, the automatic warning system should be aural, visual, or both depending on the flight deck warning system.  The automatic warning system must be available in the cargo compartment and any other compartment such as a lavatory where the cargo compartment warning system may not be heard or seen.

FAA Differences:  FAA identifies automatic deployment system under Passenger Service Units, does not specify a time under e).

ITEM:  35-20-2  PASSENGER SERVICE UNITS (DROP DOWN OXYGEN)

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Passenger Service Units (Drop Down Oxygen)
Automatic Opening Feature of Door Latches B - - (M)(O)

May be inoperative provided:

a) The PSU oxygen system is operative,

b) The flight remains at or below FL 300,

c) The alternate flight deck deployment system is operative,

d) No more than two consecutive banks of seats and their adjacent banks of seats have an inoperative automatic opening feature, and

Individual PSUs D - - (M)(O)

May be inoperative with no flight altitude restriction provided:

a) Affected seats or banks of seats are blocked and placarded INOPERATIVE to prevent occupancy,

b) No more than two consecutive banks of seats and their adjacent banks of seats have an inoperative PSU, and

c) Units at assigned flight attendant locations are operative.

DISCUSSION:

References:  CAR 605.31, AWM 525.1441 to AWM 525.1453

The first aid NOTE may not be applicable to all aircraft depending on the source/location of the first aid oxygen outlet.

Proviso d) in the cat B relief and b) in the cat D relief are only applicable on aircraft when flight attendants are carried.  The reason that no more than two consecutive banks (a bank of seats is a grouping of two or more seats) of seats and their adjacent (cross aisle) banks of seats may have an inoperative automatic opening feature or an inoperative PSU is to enable flight attendants to carry out their immediate action procedure during a decompression.

The first (O) to establish procedures for no more than two consecutive banks of seats and their adjacent banks of seats to have a PSU with an inoperative automatic opening feature, and for occupants to be briefed on oxygen mask access.

The second (O) to establish procedures for no more than two consecutive banks of seats and their adjacent banks of seats to have an inoperative PSU.  The (M) to detail blocking and placarding affected seats.

Refer to item 35-20-3 for Lavatory Oxygen.

FAA Differences:  TCCA adds wording for clarification.  TCCA permits cat D for individual PSUs (FAA cat B).

ITEM:  35-20-3  LAVATORY OXYGEN

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Lavatory Oxygen C - 0 (M)(O)

May be inoperative provided:

a) The lavatory is not used for any purpose, and

b) The lavatory door is locked and placarded ”INOPERATIVE DO NOT ENTER”.

NOTE:
This does not preclude storage of in-flight service waste bags in the associated lavatory.

C - 0   May be inoperative provided the aircraft is not operated above FL 250.

DISCUSSION:

References:  CAR 605.31

FAA Differences:  No FAA Policy Letter exists for this item.

ITEM:  35-20-4  CREW REST FACILITY - BUNK DROP DOWN OXYGEN MASKS

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Crew Rest Facility - Bunk Drop Down Oxygen Masks C - - (M)(O) One or more may be inoperative provided the associated bunk is not occupied and placarded INOPERATIVE - DO NOT USE.
C - - (M)(O)

One or more may be inoperative and associated bunk may be occupied provided a portable oxygen bottle with mask attached is available for the associated bunk occupant.

NOTE:
Portable oxygen bottle must be properly secured in the associated bunk.

DISCUSSION:

References:  nil

FAA Differences:  FAA does not have a policy letter for this item.

ITEM:  35-30-1  PORTABLE OXYGEN DISPENSING UNITS (BOTTLE AND MASK)

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Portable Oxygen Dispensing Units (Bottle and Mask) D - - (M)(O)

Any in excess of those required by regulation may be inoperative or missing provided:

a) Required distribution of operative units is maintained throughout the aircraft,

b) The inoperative portable oxygen dispensing unit is removed from the passenger cabin and its location is placarded INOPERATIVE, or it is removed from the installed location, secured out of sight and the portable oxygen dispensing unit and its installed location are placarded INOPERATIVE, and

c) Procedures are established and used to alert crew members of inoperative or missing equipment.

DISCUSSION:

References:  CAR 605.31, CAR 703.68, CAR 704.67, CAR 705.72, CAR 705.94

For all cargo operations portable oxygen units would be required for crew members likely to be in the cargo area during flight.

FAA Differences:  FAA MMELs include provisions for requiring that the bottles to be serviced, replaced or removed at the next maintenance facility.

ITEM:  35-30-2  PROTECTIVE BREATHING EQUIPMENT

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Protective Breathing Equipment D - - (M)(O)

Any in excess of those required by regulation may be inoperative or missing provided:

a) Required distribution of operative units is maintained throughout the aircraft,

b) The inoperative protective breathing equipment unit is removed from the passenger cabin and its location is placarded INOPERATIVE, or it is removed from the installed location, secured out of sight and the protective breathing equipment unit and its installed location are placarded INOPERATIVE, and

c) Procedures are established and used to alert crew members of inoperative or missing equipment.

DISCUSSION:

References:  CAR 703.67, CAR 704.66, CAR 705.71, FAA PL 43 (Rev. 1, 15 Aug. 1997)

The (O) will establish procedures to alert crew members of the inoperative or missing equipment.  The (M) will provide instructions to placard the unit or remove it from the aircraft.

FAA Differences:  FAA relief is identical to TCCA.