ATA 30 Ice and Rain Protection

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:  30-00-1  ANTI-ICE/DE-ICE SYSTEM TEST

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Anti-ice/De-ice System Test
a) Airframe and Engine C 1 0 (M) May be inoperative provided an alternate means is used to confirm the system is operative prior to dispatch into known or forecast icing conditions.
b) Windows and Probes C - 0 (M) or (O) Flight or maintenance crew must physically verify window/probe heat operates normally before each departure.

DISCUSSION:

References:  nil

FAA  Differences:  FAA relief is identical to TCCA.

ITEM:  30-00-2  ICE AND RAIN PROTECTION

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Ice and Rain Protection
Airframe Anti-icing and/or De-icing System C 1 0   Except for ETOPS beyond 120 minutes, may be inoperative provided flight is not conducted in known or forecast icing conditions.
Elevator Horn Heaters C 1 0   Except for ETOPS beyond 120 minutes, may be inoperative provided flight is not conducted in known or forecast icing conditions.
Propeller Anti-icing and/or De-icing System C 1 0   May be inoperative provided flight is not conducted in known or forecast icing conditions.

DISCUSSION:

References:  FAA PL 40 (Rev. 1, 15 Aug. 1997), FAA PL 94 (Rev. 1, 8 Oct. 2004)

The above-mentioned alleviations must be considered in the context of each aircraft and may not be applicable in all cases.  For example, at a NASA/FAA Tailplane Icing Workshop in Cleveland, Ohio (4-6 Nov. 1991), which TC attended, it was recommended that inoperative deicing equipment on turbo-prop aircraft be category B versus C.  This policy was implemented on the Jetstream 3101, 3201 in the Original TC Supplement, Feb. 1992 in view of a Jetstream accident that was caused by tailplane icing.

Propeller or liquid paste deicer shall not be used in lieu of an operative Propeller Anti-icing and/or De-icing System except where the AFM specifically approves its use.

FAA  Differences:  FAA relief is similar to TCCA, except that the FAA PL does not address relief specifics such as category.

ITEM:  30-10-1  WING DEICER BOOT ADVISORY INDICATIONS

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Wing Deicer Boot Advisory Indications C - 0  

May be inoperative provided:

a) Boot operation is monitored visually from the flight deck, and

b) The appropriate wing inspection light(s) (or alternate means) are operative for night operations.

DISCUSSION:

References:  nil

FAA  Differences:  No FAA PL available for this item.

ITEM:  30-20-1  POWERPLANT ICE PROTECTION

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Engine Intake Anti-icing and/or De-icing System C - -   One engine system may be inoperative provided flight is not conducted in known or forecast icing conditions

DISCUSSION:

References:  Letter 5011-1 (AARDD) dated 9 Nov. 1988, TC TP 6327 (ETOPS), FAA PL 40 (ETOPS) (Rev. 1, 15 Aug. 1997)

Relief for the Engine Intake Anti-icing and/or De-icing System can only be permitted if satisfactory resistance to icing with the protection system inoperative has been demonstrated during the certification program.  Powerplant instrument probes requiring ice protection must also be considered.

No relief for ETOPS if inoperative closed.  Relief has been granted for a valve open with several performance related provisos (see B767).

FAA  Differences:  FAA relief is identical to TCCA.

ITEM:  30-30-1  PITOT HEATERS

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Pitot Heaters B 2 1  

Except where enroute operations and/or ETOPS beyond 120 minutes require its use,one may be inoperative provided:

a) Flight is conducted in day VMC,

b) Flight is not conducted in visible moisture, and

c) Flight is not conducted in known or forecast icing conditions.

B 3 2    

DISCUSSION:

References:  AWM 523.1419(b), AWM 525.1323(i), TP 1490E, Manual of All Weather Operations (Cat II and III), FAA PL 40 (Rev. 1, 15 Aug. 1997)

The 3/2 relief applies in the case where the three referenced pitot systems feed the primary airspeed and altitude indication system and not the standby instruments (i.e. The standby pitot heaters are considered a fourth system for this case).  Consideration may also need to be given for architectures where there is more than one heating system for each pitot system.

This system may be part of the air data system function that is required to support the RVSM certification of the aircraft.  With this item inoperative, RVSM qualification may be invalid and the MMEL will need a proviso for addressing the loss of RVSM capability.  In the case that only one air data side is RVSM qualified, the proviso will specifically identify that side is affected only.

FAA  DifferencesFAA relief is identical to TCCA.

ITEM:  30-30-2  PITOT HEAT INDICATING SYSTEM

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Pitot Heat Indicating System B - 0 (M)

Except for ETOPS beyond 120 minutes, may be inoperative provided:

a) Flight is not conducted in known or forecast icing conditions, and

b) All elements of the pitot heat system are verified to be operative.

DISCUSSION:

References:   AWM 525.1326 (no AWM 523 equivalent), FAA PL 40 (ETOPS) (Rev. 1, 15 Aug. 1997), FAA PL 90 (Rev. 1, 20 Sep. 2001)

AWM 525.1326 requires an indication of pitot heat operation if that pitot system is a source for flight instruments. There is no need to check that “other elements of the pitot heat system are operative” if relief has been granted for those other elements (see Item 30-30-1).

FAA  Differences:  FAA relief is identical to TCCA.

ITEM:  30-30-3  STATIC SOURCE HEATERS

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Static Source Heaters B 2 1   Except where enroute operations and/or ETOPS beyond 120 minutes require its use, one may be inoperative provided flight is not conducted in known or forecast icing conditions.

DISCUSSION:

References:   AWM 523.1325(b)(3), AWM 525.1325(b), FAA PL 40 (Rev. 1, 15 Aug. 1997)

At least one static source must be heated unless it was confirmed during icing certification that icing in flight had no effect on static sources.

The prohibition of flight into known or forecast icing conditions includes ground operations where ice and slush may be splashed onto the static sources. (See TCCA icing definition in applicable AFM).

AWM 525.1325(b) specifies that the instruments, which require static pressure, operate normally even when the airplane is exposed to icing conditions.  Because of their location and as determined during certification flight tests, it may be that static sources are unaffected by flight in icing.

This system may be part of the air data system function that is required to support the RVSM certification of the aircraft.  With this item inoperative, RVSM qualification may be invalid and the MMEL will need a proviso for addressing the loss of RVSM capability.  In the case that only one air data side is RVSM qualified, the proviso will specifically identify that side is affected only.

FAA  DifferencesFAA relief is identical to TCCA.

ITEM:  30-30-4  TOTAL AIR TEMPERATURE (TAT) PROBE HEATER SYSTEM

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Total Air Temperature (TAT) Probe Heater System C 1 0 (O) Except where enroute operations and/or ETOPS beyond 120 minutes require its use, may be inoperative provided flight is not conducted in known or forecast icing conditions.

DISCUSSION:

References:  FAA PL 40 (Rev. 1, 15 Aug. 1997)

This system may be part of the air data system function that is required to support the RVSM certification of the aircraft.  With this item inoperative, RVSM qualification may be invalid and the MMEL will need a proviso for addressing the loss of RVSM capability.  In the case that only one air data side is RVSM qualified, the proviso will specifically identify that side is affected only.

FAA  DifferencesFAA relief is identical to TCCA.

ITEM:  30-40-1  WINDSHIELD WIPERS

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Windshield Wipers C 2 0   One or both may be inoperative provided flight is not conducted in precipitation within five nautical miles of the airport of take-off or intended landing.
Low Speed C 1 0   May be inoperative provided high speed is operative.
High Speed C 1 0   May be inoperative provided the low speed is operative.
Park Function C 1 0   May be inoperative provided the wipers can be parked out of the pilots’ view.

DISCUSSION:

References:  AWM 523.773, AWM 525.773

If an alternate means was certified then the five nautical mile restriction may not apply.  For Airbus products relief for one inoperative on the pilot-not-flying side has been permitted for three flights with no ”five nautical mile restriction”.  However, this relief is not considered appropriate in view of the requirements of AWM 525.773 and has been deleted from this item.

FAA  Differences:  FAA has no Policy Letter but the FAA  airworthiness requirements for this item are identical to the TCCA requirements.

ITEM:  30-40-2  WINDSHIELD/WINDOW HEATERS

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Windshield/Window Heaters
Forward Facing Windows C - - (M)

Except for ETOPS beyond 120 minutes, one may be inoperative provided:

a) Flight is not conducted in known or forecast icing conditions,

b) Associated windshield pneumatic anti-fog system (if installed) operates normally, and

c) Associated window heat is deactivated.

Side Facing Windows C 2 0 (M) One or both may be inoperative provided the associated window heat is deactivated

DISCUSSION:

References:   AWM 523.773, AWM 523.775, AWM 525.773(b), AWM 525.775, FAA PL 40 (Rev. 1, 15 Aug. 1997)

If the pilot’s side window is not openable but has been shown during certification to be equivalent to a Direct Vision (DV) window, relief for its heating must not be permitted. (see RJ MMEL).

Relief has been permitted for all heaters to be inoperative with the defog system operative and no flight in icing.  This sort of relief will be aircraft dependant.

FAA  Differences:  FAA has no Policy Letter but relief appears to be identical to TCCA.

ITEM:  30-40-3  LIQUID RAIN REPELLANT SYSTEM

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Liquid Rain Repellant System         Relief not required if system has been deactivated or removed.

DISCUSSION:

References:  nil

In accordance with Canadian environmental regulations, the fluid used in rain repellant systems is banned and these systems are to be disabled accordingly.  Any associated MMEL relief must be deleted.

FAA  Differences:  FAA has never accepted a rain repellant system in lieu of a wiper system.  The FAA position regarding the environmental issue is not known.

ITEM:  30-80-1  ICE DETECTION SYSTEMS

System and Sequence No. Item Repair
Interval
Category
Number
Installed
Number
required
for
dispatch
Procedures
required
Remarks or Exceptions
Ice Detection Systems C 1 0   May be inoperative provided flight is not conducted in known or forecast icing conditions.
C 2 1 (O) May be inoperative provided wing and engine anti-icing equipment is turned on if the OAT on the ground is below +10 degrees C or in flight if the SAT is below +5 degrees C with visible moisture present.

DISCUSSION:

References:  FAA PL 40 (Rev. 1, 15 Aug. 1997)

Ice detection systems are not specifically required by airworthiness standards. However, aircraft design considerations have resulted in detection systems being fitted, e.g. where there is no reliable way for the pilot to visually determine the presence of ice.  In granting relief for ice detection systems, airplane service history and the effect of ice on performance and handling qualities should be considered.  Depending on the service history of the airplane an additional “no night flight” restriction may be appropriate.

Some Flight Manuals may have stricter temperature limits than those stated in the relief above, and thus may need to be evaluated depending upon the actual aircraft application.

FAA  Differences:  FAA relief is similar to TCCA, but the specific temperatures used in the TCCA icing definition are slightly higher than those used by the FAA.

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