ATA 33 Lights

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:  33-10-1  FLIGHT DECK AND INSTRUMENT PANEL LIGHTING SYSTEM

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Flight Deck and Instrument Panel Lighting System C - -  

Individual lights may be inoperative provided remaining lights are:

a) Sufficient to clearly illuminate all required instruments, controls and other devices for which it is provided,

b) Positioned so that direct rays are shielded from flight crew member’s eyes, and

c) Lighting configuration and intensity is acceptable to the flight crew.

D - 0   May be inoperative for day operations.

DISCUSSION:

References:  AWM 523.1381, AWM 525.1381, FAA PL 77 (Rev. 1, 15 Aug. 1997)

Due to higher workload considerations, extra care may be required in permitting dispatch with reduced lighting for single pilot aircraft.

Consideration must be given such that adequate lighting will be available following any subsequent single in-flight electrical or lighting failure.

FAA  Differences:  TCCA adds cat D relief.

ITEM:  33-20-1  PASSENGER COMPARTMENT LIGHTING

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Passenger Compartment Lighting C - -   Must be sufficient for crew members to perform their duties.

DISCUSSION:

References:  nil

For cargo and non-passenger carrying operations there must be sufficient lighting for the inspection of cargo for the verification of cargo restraint or for fire fighting purposes.
Passenger compartment means all except flight deck and cargo areas.

FAA  Differences:  FAA has no guidance but relief is similar.

ITEM:  33-20-2  NO SMOKING/FASTEN SEAT BELT/RETURN TO CABIN LIGHTS

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
No Smoking/Fasten Seat Belt/Return to Cabin Lights C - - (M)(O) Passenger seats, flight attendant seats or lavatories from which a light is not readily legible shall not be occupied and must be blocked and placarded ”DO NOT OCCUPY”.
C - - (O)

The affected seats or lavatories may be occupied provided:

a) The crew call/cabin interphone system including associated chimes and PA system are operative, and

b) Procedures are established and used to alert flight attendants and notify passengers when seat belts should be fastened, return to seat is requested and smoking prohibited.

For aircraft with 19 or fewer seats (e.g. Beech BE-300) only the b) proviso is necessary.

A - - (O)

May be inoperative for one flight day for non-passenger carrying operations provided:

a) Crew members are the only occupants of the aircraft, and

b) Alternate procedures are established and used.

Aural Tone Function C - 0 (O) May be inoperative provided alternate procedures are established and used.
Automatic Function C - 0 (O)

May be inoperative provided:

a) Manual control function is operative, and

b) Alternate procedures are established and used.

All Cargo Operations D - 0   May be inoperative provided all crew members are on the flight deck.

DISCUSSION:

References:  CAR 705.16(3)(c) and (d), AWM 523.791, AWM 525.791

For non-passenger carrying flights conducting operations in an air transport service pursuant to Airline Operations regulated by CAR 705, alternate procedures referred to in proviso b) must be in compliance with the requirements of CAR 705.16(3)(c) and (d).

Consideration should be given to the applicability of this requirement to the Crew Rest Facility - Bunk as a crew member may be changing clothes, etc.

For clarification it is noted that this item refers to lights whereas item 25-20-4 addresses signs and placards.

FAA  Differences:  FAA relief is similar to TCCA.

ITEM:  33-20-3  CREW REST FACILITY - BUNK INTERIOR LIGHTING

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Crew Rest Facility - Bunk Interior Lighting C - -  

One or more lights may be inoperative provided:

a) Sufficient lighting is available in common area, main entry and aisle, and

b) Emergency lighting system operates normally.

DISCUSSION:

References:  nil

FAA  Differences:  No FAA PL exists for this item.

ITEM:  33-40-1  LANDING/TAXI LIGHTS

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Landing/Taxi Lights C - -   As required by regulations.
D - 0   May be inoperative for day operations.

DISCUSSION:

References:  AWM 523.1383, AWM 525.1383, CAR 605.16(1)(j), CAR 702.42, CAR  703.64, CAR 704.62(3), CAR 705.68

CAR 705 requires two landing lights for night operations whereas the other referenced CARs require only one light.  The design standard does not require landing and taxi lights but only addresses what needs to be accomplished for certification.  During certification it must be demonstrated by flight test that the lighting configuration (landing and/or taxi lights) anticipated for dispatch is acceptable.  There is no need to cater in the MMEL to the next failure after dispatch since the consequences will be different depending on the type of operation.  The MEL may need to be more restrictive (e.g. dispatch for 705 operator would require three lights and for the other operations would require two) depending on the operation, i.e. operating into poorly lit airports.  Manufacturers may also wish to limit the dispatch configuration for reasons such as reliability.

FAA  Differences:  FAA relief is similar to TCCA.

ITEM:  33-40-2  ANTI-COLLISION LIGHT SYSTEM

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Anti-Collision Light System, Lights C 4 2   Either upper and lower red fuselage strobe lights or white wing tip strobe lights may be inoperative.
C 4 0   May be inoperative for day operations.

DISCUSSION:

References:  AWM 523.1401, AWM 525.1401, CAR 605.17

It is general practice to use the rotating beacon type anti-collision light(s) as an indication of engine(s) running on the ground. The example relief is from the B767 which TCCA has accepted unchanged.
Some aircraft may have strobe lights installed that are equivalent to an approved rotating beacon system. These aircraft may also have a rotating beacon(s) with the strobe, where the rotating beacon(s) does not meet the anti-collision lighting requirements.  Relief will be granted accordingly.

FAA  Differences:  FAA relief is identical to TCCA.

ITEM:  33-40-3  POSITION LIGHT SYSTEM

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Position Light System Light Bulbs C - 3   One bulb at each position (wing tips and aft) must be operative.
C - 0   May be inoperative for day operations.

DISCUSSION:

References:  AWM 523.1385 to AWM 523.1397, AWM 525.1385 to AWM 525.1397, CAR 605.17, FAA PL 91 (Rev. 1, 14 Nov. 2003)

Relief may be given for one bulb (of 2) for each of the position lights (left/right wingtip plus tail).  Relief may be worded differently to reflect a specific aircraft configuration, e.g. B767.

A strobe light in close proximity to the tail position light may not be an acceptable substitute, since strobes are often turned OFF on the ground because of their high intensity.

FAA  Differences:  The FAA PL only addresses the issue of substituting a strobe light for an inoperative wing/tail position light.

ITEM:  33-40-4  STROBE LIGHT (OR HIGH INTENSITY) SYSTEM

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Strobe Light (or High Intensity) System C - 0   May be inoperative.

DISCUSSION:

References:  FAA PL 91 (Rev. 1, 14 Nov. 2003)

Although there is no Canadian operational regulation, once installed it is in the interest of safety to have the system operative.  A category C is considered an acceptable compromise in order to not discourage such an installation.

FAA  Differences:  FAA does have an operational requirement for strobes, therefore is more restrictive for night operations; and assigns a cat C.

ITEM:  33-40-5  WING INSPECTION (ICE) LIGHTS

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Wing Inspection (Ice) Lights C 2 0   One or both may be inoperative provided a portable lamp/light of adequate capacity for wing and/or control surface inspection is available for night operations in icing conditions.
C 2 0   One or both may be inoperative provided flight is not conducted in known or forecast icing conditions at night.
C 2 0   One or both may be inoperative for day operations.
For passenger and cargo airplanes where view of the wing surfaces from the flight deck is restricted C 2 0   One or both may be inoperative provided ground deicing procedures do not require their use.
C 2 0   One or both may be inoperative for day operations.

DISCUSSION:

References:   AWM 525.1403, FAA PL 72 (Rev. 3, 24 Mar. 2008)

FAA  Differences:  FAA relief is identical to TCCAFAA PL 72 only applies to air carrier aircraft.

ITEM:  33-40-6  LOGO LIGHTS

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Logo Lights D - 0   May be inoperative.

DISCUSSION:

References:  nil

FAA  Differences:  FAA relief is identical to TCCA.

ITEM:  33-50-1  FLOOR PROXIMITY EMERGENCY ESCAPE PATH MARKINGS

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Floor Proximity Emergency Escape Path Markings   1 1   System must be operative.
Electrical Lighting Systems C - -   Individual lights may be inoperative provided compliance is shown with minimum acceptable lighting as required by certification documents.
Photoluminescent Systems C 1 -   Specified sections of the photoluminescent system may be inoperative provided compliance is shown with minimum acceptable lighting as required by certification documents.
All Cargo Operations C 1 0   May be inoperative.

DISCUSSION:

References:   CAR 705.16, CAR 705.78, AWM 525.812(e)

As the proviso requires that the certification standard be met, category C is acceptable for either system.  For the electrical lighting systems, the MMEL and MEL must identify the lamps that may be inoperative based on the certification tests.

Similarly, for the photoluminescent systems, whether installed on the aircraft as a modification or during the aircraft certification process, certification information including the following must be determined and included in the MMEL and MEL: the maximum total length of the system that can be inoperative, the maximum length of each inoperative segment, the condition that the section on the adjacent side of the aisle must be operative, and the condition that the inoperative segment is not adjacent to the wing exit or door marking strip.

CAR 705.16 provides some exemptions to CAR 705.78 regarding the number and functions of crew members who may be carried on-board in addition to flight crew members.  In cases where additional crew members are carried on-board and cannot be accommodated in flight deck seats, then they shall have access to the most convenient, readily accessible and operative passenger emergency exit.  The internal emergency pathway lighting from the exit shall be operative and the emergency lights on the escape assist device (inflatable slide or stairs) shall be operative.

FAA  Differences:  This item will usually be included in a TC Supplement since the FAA wording refers to specific certification documents that may not be applicable in Canada.  However, the FAA certification findings are normally accepted when they are specific enough to identify which lights or tape sections may be inoperative.

ITEM:  33-50-2  EMERGENCY LIGHTING, INTERNAL

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Emergency Lighting, Internal         Must be operative.
C - -   Individual light bulbs, etc. may be inoperative provided compliance is shown with minimum acceptable lighting as required by certification documents.
Crew Rest Facility - Bunk D - - (M)

May be inoperative provided:

a) Crew Rest Facility - Bunk is not occupied, and

b) Crew Rest Facility - Bunk is placarded “INOPERATIVE - DO NOT USE”.

DISCUSSION:

References:  AWM 525.812

As the proviso requires that the certification standard be met, category C is acceptable.

Although it could be argued that crew familiarity with the aircraft and flashlight availability might compensate for inoperative emergency lighting, it is necessary that all on board be able to locate and operate exits, which might include a smoke filled aircraft during day operations.  Therefore, relief for all cargo operations has been deleted.

The certification documents referenced in the proviso must be obtained from the aircraft manufacturer or the holder of the Supplemental Type Certificate, whoever installed the lighting system.

FAA  Differences:  FAA relief is similar to TCCA.

ITEM:  33-50-3  EMERGENCY LIGHTING, EXTERNAL

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Emergency Lighting, External C - 0  

May be inoperative for day operations.

Some relief may be acceptable for night operations provided certification has been shown with the reduced lighting.

A - 0 (O)

May be inoperative for one flight day provided:

a) Aircraft crew are the only occupants of the aircraft, and

b) Alternate procedures for that aircraft type are established and used.

NOTE:
The operator’s MEL must state the maximum number of aircraft crew permitted.

DISCUSSION:

References:  AWM 525.812

The Note requires the operator to state the maximum number of aircraft crew permitted.  The maximum number of aircraft crew would be determined by adding the number of the operating crew members that would likely be scheduled on that aircraft type, plus the number of maintenance personnel who would likely be scheduled to remain with the aircraft when flying to destinations where the air operator does not have any contracted maintenance agreement, plus the maximum number of supervisory crew members who would likely be carrying out an in-flight check ride at one time.

For some northern operations, because of local geographical features and low light conditions, this relief may not be appropriate in that it would be too alleviating.  The MEL will need to provide the appropriate relief.

FAA  Differences:  FAA has no Policy Letter.  FAA assigns a category B whereas TC assigns a category C.  TC also permits more flexibility by granting one flight day relief with no provisos other than aircraft crew only. This is considered an acceptable risk in view of the aircraft crew’s familiarity with emergency exits and emergency procedures training.  While some might argue that a category D would be appropriate, the external emergency lighting is considered generally necessary for crew as well as passengers, hence the cat A relief.

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