ATA 31 Indicating/Recording Systems

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:  31-20-1  CLOCK

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Clock C - -   Aircraft clock may be inoperative provided a reliable and functioning timepiece is readily available to all flight deck crew members.

DISCUSSION:

References:   CAR 602.59(2)(f), AWM 525.1303(a)(2) (no AWM 523 requirement)

Consideration must be given to clock inputs into other aircraft systems.

FAA Differences:  FAA makes reference to VFR and IFR when granting relief.

ITEM:  31-30-1  FLIGHT DATA RECORDER

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Flight Data Recorder
If FDR and CVR required by regulations: A 1 0  

May be inoperative provided:

a) Cockpit Voice Recorder is operative, and

b) Repairs are made within three flight days.

If only FDR required by regulations: A 1 0   May be inoperative provided repairs are made within three flight days.
Digital FDR Recording Parameters required by regulations. A - -  

Up to three digital recording parameters may be inoperative provided:

a) Cockpit Voice Recorder is operative, and

b) Repairs are made within twenty calendar days.

Digital FDR Recording Parameters not required by regulations. A - -   May be inoperative provided repairs are made before the completion of the next heavy maintenance visit.
If not required by regulations: D 1 0    

DISCUSSION:

References:  CAR 605.33, CAR 605.34, CAR 625.33, FAA PL 87 (Rev. 8, 7 Oct. 2005)

The MMEL may contain all relief options.  The MEL shall reflect the correct situation for each specific aircraft/operation.

FAA Differences:  FAA PL 87 has incorporated the statement to the effect that dispatch is not permitted from an airport where repairs can be made, but TC does not wish to return to this convention.  The FAA PL also refers to air carrier.  TC includes some cat D relief for an FDR that is not required.

ITEM:  31-40-1  ENGINE INDICATING AND CREW ALERTING SYSTEM (EICAS)

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Engine Indicating and Crew Alerting System (EICAS)   - -   See DISCUSSION.

DISCUSSION:

References:  FAA PL 25 (Rev. 13, 11 Sep. 2006)

Relief for some aspects of the EICAS has been granted for aircraft such as the B 767 and B 747 as category A, one flight day.  This relief has been accepted unchanged by Transport Canada.  Relief for the RJ has been permitted for one of the two Engine Displays as a category B.

Relief will be aircraft specific depending on failure analysis, next failure, reversion capabilities, etc.

FAA Differences:  FAA relief is identical to TCCA.

ITEM:  31-50-1  AURAL WARNING SYSTEMS

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Aural Warning Systems         Must be operative.

DISCUSSION:

References:   nil

FAA Differences:  FAA relief is identical to TCCA.

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