Advisory Circular (AC)

From: Transport Canada

Certification of Large Aeroplanes in the Restricted Category, Used for Special Purpose Operations

File No. 5009-6-525 AC No. 525-012
RDIMS No. 1140123-V2 Issue No. 02
Issuing Branch Aircraft Certification Effective Date 2005-04-11

1.0 Introduction

1.1 Purpose
1.2 Guidance Applicability
1.3 Description of Changes
1.4 Termination

2.0 References

2.1 Reference Documents
2.2 Cancelled Document

3.0 Background

4.0 Requirements

4.1 Performance
4.2 Changes to Performance Standards
4.3 Credit For Jettison of Disposable Load
4.4 Take-Off Requirements
4.5 Climb Requirements
4.6 Position Errors
4.7 Flight Characteristics
4.8 Structure
4.9 Design and Construction
4.10 Equipment
4.11 Operating Limitations and Information
4.12 Markings and Placards
4.13 Airplane Flight Manual
4.14 Operating Limitations
4.15 Normal, Abnormal and Emergency Procedures
4.16 Performance
4.17 Systems Description

5.0 Maintenance Manual Supplement

6.0 Headquarters Contact

Appendix A - Additional Technical Conditions for Aeroplanes used in Firefighting Role

1.0 Introduction

1.1 Purpose

The purpose of this Advisory Circular (AC) is to provide information on the requirements for the certification of aeroplanes having a maximum certificated take-off weight (MCTOW) exceeding 5,700 kg (12,566 pounds) in the restricted category for special purpose operations.

Additional technical conditions are also provided for the certification of aircraft in the fire prevention and suppression role in Appendix A to this advisory.

The requirements contained in this AC will be issued as Special Conditions in accordance with either section 511.07 (1)(b) or 513.07(1)(b) of the Canadian Aviation Regulations (CAR).

1.2 Guidance Applicability

This document is applicable to all Transport Canada personnel, delegates and industry.

1.3 Description of Changes

Minor editorial changes, identified by a revision bar in the right margin, have been made to the content of this AC.

1.4 Termination

This document does not have a terminating action. It will however, be reviewed periodically for suitability of content.

2.0 References

2.1 Reference Documents

It is intended that the following reference materials be used in conjunction with this document:

  1. Part V Subpart 11 of the Canadian Aviation Regulations (CAR) - Approval of the Type Design of an Aeronautical Product;
     
  2. Part V, Subpart 13 of the CAR - Approval of Modification and Repair Designs;
     
  3. Chapter 511 of the Airworthiness Manual (AWM) - Approval of the Type Design of an Aeronautical Product,
     
  4. Chapter 513 of the AWM - Approval of Modification and Repair Designs; and
     
  5. Chapter 525 of the AWM - Transport Category Aeroplanes.

2.2 Cancelled Document

As of the effective date of this document, AC 525-012 Issue 01 dated 2004-12-01 is cancelled.

3.0 Background

CAR Part 5, subpart 11, section 511.11(5) and subpart 13, section 513.11(3) state that a Type Certificate, a Supplemental Type Certificate or a Limited Supplemental Type Certificate shall be issued to an aeroplane in the Restricted Category for special purpose operations provided that the applicant demonstrates that:

  1. No feature or characteristic of the aircraft makes it unsafe when it is operated within the limitations specified for its intended use; and
     
  2. The aircraft meets the applicable standards specified in section 511.07 or 513.08, whichever is applicable, except those standards that are inappropriate for the special purpose operation.

In this case, the AC provides guidance on those requirements that are appropriate for the special purpose operations, including the fire prevention and suppression role (firefighting role).

CAR 511.11(5)(b)(ii) also states that a Type Certificate shall be issued if the aeroplane is of a type that has been manufactured in accordance with the requirements of, and accepted for use by, the Department of National Defence and has been modified for a special purpose operation.

In this case, the AC provides guidance on the appropriate flight requirements for assessing the aircraft in the absence of a civil basis of certification.

4.0 Requirements

4.1 Performance

The performance requirements shall be the current AWM Chapter 525 requirements or those applicable to the original design. Alternatively the minimum performance requirements below are an acceptable means of compliance.

4.2 Changes to Performance Standards

The performance standards will be those of AWM section 525.101 to 525.125 inclusive at Change 525-1, and 525.1581(g), with the exceptions listed hereunder and the addition of the climb requirements given in paragraphs 4.3 and 4.5 of this AC:

525.101 (f)

Reference to take-off flight paths is not applicable.

525.101 (g)

References to 525.119 and 525.121(d) are not applicable.

525.105 (a)

References to take-off path described in 525.111, take-off run are not applicable.

525.107 (c)

Reference to 525.121(b) is not applicable.

525.107 (c)(2)

Reference to 525.111(c)(2) is not applicable.

525.107 (d)

Not applicable.

525.107 (e)(1)(iii)

Not applicable.

In lieu of this requirement substitute: VR may not be less than 1.1 VS.

525.107 (e)(1)(iv)

Not applicable.

525.107 (e)(2)

Reference to one-engine-inoperative is not applicable.

525.107 (e)(3)

Not applicable.

525.107 (f)

Not applicable.

525.109 (a)(1)

Not applicable.

525.109 (d)

Not applicable.

525.111

Not applicable

525.113 (a)(1)

Not applicable.

525.113 (a)(2)

Reference to 525.111 is not applicable.

525.113 (b)

Not applicable.

525.115

Not applicable.

525.117

References to 525.119 and 525.121 are not applicable.

525.119

Not applicable. See paragraph 4.5(e).

525.121

Not applicable. See paragraph 4.3 and 4.5(a), (b), (c).

525.123

Not applicable. See paragraph 4.5(d).

525.125(f)

Not applicable. In lieu of this requirement a one-engine-inoperative landing distance may be established and presented in the Aeroplane Flight Manual (AFM).

525.1581(g)

Not applicable.

4.3 Credit For Jettison of Disposable Load

In meeting the one-engine-inoperative take-off and final take-off climb requirement it is permissible to take credit for jettisoning of a disposable load, such as water or fire retardant, following engine failure. For the purpose of take-off, load jettison does not include fuel.

To be considered jettisonable 90% of the load must leave the aircraft in 5 seconds or less. Use of the load jettison system must be safe and reliable and be such that consistent results can be expected without requiring exceptional skill to control the aeroplane. The aeroplane weight at which the one-engine-inoperative climb requirement must be met is the take-off weight less the jettisonable load.

Performance credit for load jettison will not normally be given unless the normal and emergency drop systems are sufficiently segregated with respect to electrical supply, hydraulic supply and any other system that is required for drop system operation.

For aeroplanes taking performance credit for load jettison the following flight characteristics should be demonstrated:

  1. Load jettison following engine failure during take-off, with rejected take-off.
     
  2. Load jettison following engine failure during take-off, with continued take-off.

In addition, if credit is taken for load jettison, the steady gradient of climb may not be less than 6%, with:

  1. All engines operating;
     
  2. Not more than maximum take-off power or thrust;
     
  3. Landing gear retracted, if applicable;
     
  4. Wing flaps in the take-off position;
     
  5. A speed selected by the applicant which is not less than: 
     
    1. 1.3 VS;
       
    2. 1.1 VMC in the selected configuration;
       
  6. At the maximum take-off weight for the ambient temperature and altitude (Without jettisoning load).

4.4 Take-Off Requirements

The all-engines-operating take-off distance must be determined in accordance with AWM 525.113 (a)(2). Similarly, the all-engines-operating accelerate-stop distance must be determined in accordance with AWM 525.109 (a)(2). For the accelerate stop distance, it is permitted to take credit for jettisoning a disposable load in the rejected take-off, provided that sufficient flight tests are conducted to demonstrate that the procedure:

  1. Is able to be consistently executed in service by crews of average skill;
     
  2. Uses methods and devices that are safe and reliable; and
     
  3. Includes allowance for any time delays in the execution of the procedures that may reasonably be expected in service.

4.5 Climb Requirements

The following are climb requirements:

  1. Take-Off Climb, One-Engine-Inoperative - The steady gradient of climb may not be less than 1%, with:
     
    1. The critical engine inoperative and its propeller, if applicable, in the position it normally takes after engine failure without any pilot action;
       
    2. Remaining engine(s) at not more than maximum take-off power or thrust;
       
    3. Landing gear retracted, if applicable;
       
    4. Wing flaps in the take-off position;
       
    5. A speed selected by the applicant which is not less than: 
       
      1. 1.2 VS;
         
      2. 1.1 VMC in the take-off configuration;
         
    6. Pressure altitude and ambient temperature at airfield altitude;
       
    7. Take-off weight (or take-off weight less jettisonable load).
       
  2. Final Take-Off Climb, One-Engine-Inoperative - The steady gradient of climb may not be less than 1%, with:
     
    1. The critical engine inoperative and its propeller, if applicable, in the minimum drag position;
       
    2. Remaining engine(s) at not more than maximum continuous power or thrust;
       
    3. Landing gear retracted, if applicable;
       
    4. Wing flaps position selected by the applicant (not necessarily the take-off position);
       
    5. A speed selected by the applicant which is not less than:
       
      1. 1.2 VS;
         
      2. 1.1 VMC in the applicable configuration;
         
    6. Pressure altitude and ambient temperature at 1000 ft above airfield altitude;
       
    7. Take-off weight (or take-off weight less jettisonable load).
    8.  
  3. Take-off Weight (WAT) Limit - The maximum take-off weight (as limited by climb requirements) must be established as the weight at which compliance is shown with the most restrictive of paragraph 4.3 (a) and paragraphs 4.5 (a) and (b). The climb limited maximum take-off weight must be presented in the AFM.
  4.  
  5. En route Climb, One-Engine-Inoperative - The aeroplane one-engine-inoperative enroute net climb performance represents the gross climb performance as determined below reduced by a gradient of 0.5%.
     
    The gross climb performance is determined with:
     
    1. Critical engine inoperative and its propeller (if applicable) in the minimum drag position;
       
    2. Remaining engine(s) at not more than maximum continuous power;
       
    3. Landing gear retracted, if applicable;
       
    4. Wing flaps in the enroute position;
       
    5. A speed selected by the applicant which is not less than:
       
      1. 1.2 VS;
         
      2. 1.1 VMC in the applicable configuration;
         
    6. Pressure altitudes and ambient temperatures within the operational limits selected by the applicant;
       
    7. The weight of the aeroplane taking into account progressive consumption of fuel; and
       
    8. The weight of the aeroplane resulting from fuel jettison, and/or load jettison, if such a system is approved.
    9.    
  6. Balked Landing Climb, All Engines Operating - The steady gradient of climb may not be less than 2.5%, with:
     
    1. Take-off power on each engine;
       
    2. The landing gear extended;
       
    3. The wing flaps in the landing position;
       
    4. A speed selected by the applicant which is not less than:
       
      1. 1.2 VS;
         
      2. VMCL in the applicable configuration;
         
    5. Pressure altitude and ambient temperature at 1000 ft. above airfield altitude.
    6.    
  7. Maximum Landing Weight - The maximum landing weight (as limited by climb requirements) must be established as the weight at which compliance is shown with paragraph 4.5(e) and must be presented in the AFM.

4.6 Position Errors

Position errors may change if external modifications to an aircraft are made. Any changes from the AFM position error values of the unmodified aircraft should be taken into consideration for performance analysis and airspeed limitations.

4.7 Flight Characteristics

The modified aeroplane should meet the applicable flight requirements to its original basis of certification, and any special conditions applied to the modification. Any non-compliant characteristics with the original certification basis must be assessed to determine whether complete compliance with the requirement is appropriate to the proposed operation.

Criteria to be used include:

  1. Nature and degree of non-compliance;
     
  2. Comparison with unmodified aeroplane;
     
  3. Other design features, which may impact or be impacted by the non-compliance;
     
  4. Compensating features;
     
  5. Operational role;
     
  6. Qualitative assessment by Transport Canada, Aircraft Certification, Flight Test Division.

4.8 Structure

The structural requirements of the original basis of certification shall apply, except where deviations from these requirements are acceptable to Transport Canada.

4.9 Design and Construction

Fatigue Evaluation

Consideration shall be given to the ability of the structure to resist and/or tolerate fatigue damage in the environment peculiar to the special purpose role. All information relating to fatigue resistance such as test reports, existing fatigue life limitations, fatigue oriented maintenance and inspection schedules, must be investigated. If fatigue life limitation has been established it may remain in force for a limited period not to exceed one year, until more appropriate fatigue life limitations have been substantiated and approved. These limitations may be based on a damage-tolerance of the identified principal structural elements and may consist of an appropriate combination of structural inspections and component life limits.

4.10 Equipment

  1. Location of Emergency Controls - Each emergency control (for example, emergency load jettison) must be in a position that can readily be accessed by both crewmembers from the normal seated position.
     
  2. Circuit Breakers - If the ability to reset a circuit breaker or replace a fuse is essential to safety in flight, that circuit breaker or fuse must be located and identified so that it can be readily reset or replaced in flight.
     
  3. Occupant Provisions - If provisions for transporting occupants associated with the operation are included, the crash protection and emergency exit requirements which apply will be established by Transport Canada.

4.11 Operating Limitations and Information

The following are Operating Limitations:

  1. Type of Operation - The type of operation in the restricted category shall be defined, for example, day, night, VFR, IFR.
     
  2. Minimum Crew - The minimum crew required to operate the aeroplane, including any onboard special equipment shall be presented. In addition the maximum number of additional crew onboard for training purposes should also be established.
     
  3. Occupants - Procedures and limitations for carriage of occupants in addition to crew are to be established. With an approved seating configuration the carriage of personnel associated with the operation or role may be permitted in accordance with the operating rules.
     
  4. Cargo - Procedures and limitations for carriage of cargo in addition to aeroplane support equipment are to be established.
     
  5. Airspeed Limitations - Airspeed limitations if changed from the original aeroplane shall be presented (consideration must also be given to any changes in position errors).
    Airspeed limitations in the special purpose operation must be presented.
     
  6. Altitude Limitations - Altitude limitations if changed from the original aeroplane shall be presented.
     
  7. Weight and CG limitations - Any changes to normal operating weights and or CG limits shall be presented.
     
  8. Configuration Limitations - Aeroplane configurations during the special purpose operation are to be defined, For example, acceptable flap and gear configurations, position of tank doors for take-off and landing.

4.12 Markings and Placards

The following are markings and placards:

  1. Control Markings - Each cockpit control must be plainly marked as to its function and method of operation. Each emergency control (for example emergency suppressant jettison) must be red in colour.
     
  2. Circuit Breakers - Circuit breakers must be clearly and consistently marked.
     
  3. Airspeed Placards - An airspeed placard showing the special purpose configurations and associated maximum speeds must be installed in clear view of each pilot.

4.13 Airplane Flight Manual

A Flight Manual Supplement will be required detailing the limitations, procedures, and performance for operating the aeroplane in the special purpose operation.

4.14 Operating Limitations

Operating limitations must be presented.

4.15 Normal, Abnormal and Emergency Procedures

Procedures for operating the aircraft and its associated equipment in the special purpose role, including any changes to the basic aeroplanes operating procedures must be published. (For example, emergency procedures for engine failure during take-off with load jettison may need to be addressed).

4.16 Performance

The performance data required by the certification basis shall be used, or the following if the Minimum Performance criteria of paragraph 4.1 is utilised.

  1. Position errors;
     
  2. Take-off distance;
     
  3. Accelerate-stop distance;
     
  4. Take-off WAT limit, based on climb requirements;
     
  5. Take-off rate climb gradient, one-engine-inoperative;
     
  6. Final take-off climb gradient, one-engine-inoperative;
     
  7. Take-off climb gradient, all engines operating, if applicable;
     
  8. Enroute net climb gradient, one-engine-inoperative;
     
  9. Landing WAT limit, based on climb requirements;
     
  10. Landing distance (all engines operating and one-engine-inoperative);
     
  11. Stall speeds.

Note:

It may be acceptable to present performance in terms of an assumed weight increment on the base aircraft, or a percentage change to the original AFM data.

4.17 Systems Description

A detailed description of the system, its operation, and the significance of the associated annunciatons should be presented.

5.0 Maintenance Manual Supplement

A Maintenance Manual Supplement approved by Transport Canada may be required that describes additional systems system in detail and sets out the maintenance procedures and schedules.

6.0 Headquarters Contact

For more information please contact:

Policy Standards Coordinator (AARDH/P)
Phone: (613) 990-3923
Facsimile: (613) 996-9178
E-mail: AARDH-P@tc.gc.ca

Original signed by Eric Lucas
for

Maher Khouzam
Chief, Regulatory Standards
Aircraft Certification Branch

Appendix A - Additional Technical Conditions for Aeroplanes used in Firefighting Role

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