Airworthiness Manual Chapter 522 Subchapter E - Powerplant - Canadian Aviation Regulations (CARs)

Content last revised: 2012/06/01


  • A (522.1-522.3)
  • B (522.21-522.255)
  • C (522.301-522.597)
  • D (522.601-522.885)
  • E (522.901-522.1193)
  • F (522.1301-522.1449)
  • G (522.1501-523.1589)
  • H (522.1801-523.1857)
  • J (522.1901-523.1947)


F, G, I, J, K


Subchapter E - Powerplant


522.901 Installation

  • (a) For the purpose of this Chapter 522, the glider powerplant installation includes each component that -

    • (1) is necessary for propulsion; and

    • (2) affects the safety of the propulsive unit.

  • (b) The powerplant must be constructed, arranged and installed to-

    • (1) insure safe operation; and

    • (2) be accessible for necessary inspections and maintenance.

(Change 522-1 (87-08-31))

522.902 Installation: Gliders with Retractable Powerplants or Propellers

Powered gliders with retractable powerplants or propellers must comply with the following:

  • (a) Retraction and extension must be possible without risk of damage and without the use of exceptional skill or effort or excessive time.

  • (b) It must be possible to secure the retraction (extension) mechanism in the extreme positions. There must be a means to inform the pilot that this mechanism is secured in the fully retracted or extended position.

  • (c) Any doors associated with extension and retraction must not impair extension and retraction and they must be restrained against spontaneous opening.

  • (d) The installation must be so designed as to prevent the heat of the engine from causing a fire or other hazardous condition.

  • (e) Fuel or lubricant must not discharge in dangerous quantities from the engine, its components or accessories, when the powerplant is in the retracted position and during extension and retraction.

522.903 Engines

  • (a) The engine must be type approved or otherwise approved in accordance with Subchapter H.

  • (b) Restarting of the engine in flight must be possible.

522.905 Propellers

The propeller must be type approved or otherwise approved in accordance with Subchapter J.

522.925 Propeller Clearance

If an unshrouded propeller is to be installed, propeller clearances with the powered glider at maximum weight, with the most adverse c.g. and with the propeller in the most adverse pitch position, may not be less than the following:

  • (a) Ground clearance. There must be a clearance of at least 180 mm (for a powered glider with a nose-wheel landing gear) or 230 mm (for a powered glider with a tail-wheel landing gear) between the propeller and the ground, with the landing gear statically deflected and in the level attitude, normal take-off attitude or taxiing attitude, whichever is most critical. In addition, there must be positive clearance between the propeller and the ground in the level take-off attitude, with:

    • (1) the critical tire completely deflated and the corresponding landing gear strut statically deflected; and

    • (2) the critical landing gear strut bottomed and the corresponding tire statically deflected.

  • (b) Structural clearance. There must be:

    • (1) At least 25 mm radial clearance between the blade tips and the glider structure, plus any additional radial clearance necessary to prevent harmful vibration;

    • (2) At least 13 mm longitudinal clearance between the propeller blades or cuffs and stationary parts of the glider; and

    • (3) Positive clearance between other rotating parts of the propeller or spinner and stationary parts of the glider.

(Change 522-1 (87-08-31))

Fuel System

522.951 General

  • (a) Each fuel system must be constructed and arranged to ensure a flow of fuel at a rate and pressure established for proper engine functioning under any normal operating condition.

  • (b) Each fuel system must be arranged so that no fuel pump can draw fuel from more than one tank at a time. Gravity feed systems may not supply fuel to the engine from more than one tank at a time, unless the air spaces are interconnected in a manner to ensure that all interconnected tanks feed equally.

522.955 Fuel Flow

  • (a) Gravity systems. The fuel flow rate for gravity systems (main and reserve supply) must be 150% of the take-off fuel consumption of the engine.

  • (b) Pump systems. The fuel flow rate for each pump system (main and reserve supply) must be 125% of the take-off fuel consumption of the engine at the maximum power established for take-off.

522.959 Unusable Fuel

The unusable fuel supply for each tank must be established as not less than that quantity at which the first evidence of malfunctioning occurs under the most adverse fuel feed conditions occurring during take-off, climb, approach and landing involving that tank.

522.963 Fuel Tanks: General

  • (a) Each fuel tank must be able to withstand, without failure, the vibration, inertia, fluid and structural loads that it may be subjected to in operation.

  • (b) Each flexible fuel tank must be of an acceptable kind.

522.965 Fuel Tank Tests

  • (a) Each fuel tank must be able to withstand the following pressures without failure or leakage;

    • (1) for each conventional metal tank and non-metallic tank with walls not supported by the glider structure, a pressure of 0.25 bar;

    • (2) for each non-metallic tank with walls supported by the glider structure and constructed in an acceptable manner using acceptable basic tank material, and with actual or simulated support conditions, a pressure of 0.14 bar for the first tank of a specific design.

522.967 Fuel Tank Installation

  • (a) Each fuel tank must be supported so that the loads resulting from the weight of the fuel are not concentrated. In addition:

    • (1) there must be pads, if necessary, to prevent chafing between each tank and its supports; and

    • (2) materials employed for supporting the tank or padding the supporting members must be non-absorbent or treated to prevent the absorption of fuel.

  • (b) Each tank compartment must be ventilated and drained to prevent accumulation of flammable fluids and vapors. Each compartment adjacent to a tank must be treated in a similar manner.

  • (c) No fuel tank may be located on the engine side of the firewall. There must be at least 15 mm of clearance between the fuel tank and the firewall.

  • (d) If the fuel tank is installed in the personnel compartment, it must be demonstrated that adequate ventilation and drainage are provided, that the presence of the tank will in no way interfere with the operation of any part of the powered glider, or the normal movement of occupants, and that no leaking fuel will fall directly on to any occupant.

  • (e) Fuel system components which could cause leakage of fuel as a result of a wheels-up landing must be suitably protected from damage.

522.969 Fuel Tank Expansion Space

Each fuel tank must have an expansion space of sufficient capacity, but of not less than 2% of the tank capacity, to prevent spillage of fuel onto the surfaces of the glider due to thermal expansion, sloping ground or any normal ground attitude or manoeuvre, unless the design of the venting system precludes such spillage. it must not be possible to fill the expansion space inadvertently with the powered glider in any normal ground attitude.

(Change 522-2 (93-06-30))

522.971 Fuel Tank Sump

  • (a) Each fuel tank must have a drainable sump with an effective capacity, in the normal ground and flight attitudes, of 0.10% of the tank capacity, or 120 cm3, whichever is the greater, unless -
    (amended 2007/07/16)

    • (1) the fuel system has a sediment bowl or chamber that is accessible for drainage and has a capacity of 25 cm3;

    • (2) Each fuel tank outlet is located so that, in the normal ground attitude, water will drain from all parts of the tank to the sediment bowl or chamber.

  • (b) The drainage system must be readily accessible and easy to drain.

  • (c) Each fuel system drain must have manual or automatic means for positive locking in the closed position.

522.973 Fuel Tank Filler Connection

Fuel tank filler connections must be located outside personnel compartments, except where the fuel tank must be taken out of those compartments for refuelling. Spilled fuel must be prevented from entering the fuel tank compartment or any part of the powered glider other than the tank itself.

(Change 522-2 (93-06-30))

522.975 Fuel Ttank Vents

Each fuel tank must be vented as close as practicable to the highest point of the tank installation, or from the top part of the expansion space where this is required to be provided. In addition:

  • (a) Each vent outlet must be located and constructed in a manner that minimizes the possibility of its being obstructed by ice or other foreign matter.

  • (b) Each vent must be constructed to prevent siphoning of fuel during normal operation.

  • (c) Each vent must discharge clear of the powered glider.

(Change 522-2 (93-06-30))

522.977 Fuel Strainer or Filter

  • (a) There must be a fuel filter between the fuel tank outlet and the carburettor inlet (or an enginedriven fuel pump, if any).

  • (b) There must be a finger strainer with 3 to 6 meshes per cm at the outlet of each fuel tank. The length of each strainer must be at least twice the diameter of the fuel tank outlet.

  • (c) Each filter or strainer must be easily accessible for drainage and cleaning.

522.993 Fuel System Lines and Fittings

  • (a) Each fuel line must be installed and supported to prevent excessive vibration and to withstand loads due to fuel pressure and accelerated flight conditions.

  • (b) Each fuel line connected to components of the glider between which relative motion could exist must have provisions for flexibility.

  • (c) Each flexible hose must be approved or must be shown to be suitable for the particular application.

  • (d) Each fuel line and fitting in any area subject to engine fire conditions must be at least fire-resistant.

522.995 Fuel Valves and Controls

  • (a) There must be a means to allow the pilot to shut off rapidly in flight the fuel to the engine.

  • (b) No shut-off valve may be on the engine side of any firewall.

  • (c) The portion of the line between the fuel cock and the carburettor must be as short as possible.

  • (d) Each fuel tank selector must
    (amended 2007/07/16)

    • (1) Require a separate and distinct action to place the selector in the “OFF” position; and
      (amended 2007/07/16)

    • (2) Have the tank selector positions located in such a manner that it is impossible for the selector to pass through the “OFF” position when changing from one tank to another.
      (amended 2007/07/16)

Oil Systems

522.1011 General

  • (a) If an engine is provided with an oil system, it must be capable of supplying the engine with an appropriate quantity of oil at a temperature not exceeding the maximum established as safe for continuous operation.

  • (b) Each oil system must have a usable capacity adequate for the endurance of the powered glider.

522.1013 Oil Tanks

  • (a) Each oil tank must be installed to:

    • (1) meet the requirements of 522.967(a), (b) and (d); and

    • (2) withstand any vibration, inertia and fluid loads expected in operation.

  • (b) The oil level must be easy to check without having to remove any cowling parts (with the exception of oil tank access covers) or to use any tools.

  • (c) If the oil tank is installed in the engine compartment it must be made of fireproof material.

522.1015 Oil Tank Tests

Oil tanks must be subjected to the tests specified in 522.965 for fuel tanks, except that in the pressure tests a pressure of 0.35 bar must be applied.

522.1017 Oil Lines and Fittings

  • (a) Oil lines must comply with 522.993 and each oil line and fitting must be made of fireproof material.

  • (b) Breather lines. Breather lines must be arranged so that:

    • (1) condensed water vapour or oil that might freeze and obstruct the line cannot accumulate at any point;

    • (2) the breather discharge will not constitute a fire hazard if foaming occurs or cause emitted oil to strike the pilot's wind shields;

    • (3) the breather does not discharge into the engine air induction system;

    • (4) if the engine is retractable, there must be no discharge of oil from the breather line when the engine is completely retracted.


522.1041 General

The powerplant cooling provisions must be able to maintain the temperatures of powerplant components and engine fluids within the temperature limit established by the engine constructor during all likely operating conditions.

522.1047 Cooling Test Procedure for Reciprocating Engine Powered Gliders

  • (a) To determine compliance with the requirement of 522.1041, a cooling test must be carried out as follows:

    • (1) Engine temperatures must be stabilized in flight with the engine at not less than 75% of maximum continuous power.

    • (2) After temperatures have stabilized, a climb must be begun at the lowest practical altitude and continued for one minute with the engine at take-off power.

    • (3) At the end of one minute, the climb must be continued at maximum continuous power for at least 5 minutes after the occurrence of the highest temperature recorded.

  • (b) The climb required in (a) must be conducted at a speed not more than the best rate-of-climb speed with maximum continuous power.

  • (c) The maximum anticipated air temperature (hot-day conditions) is 38°C at sea-level. Above sea-level, the temperature decreases with a temperature gradient of 6.5°C per 1000m altitude. If the tests are conducted under conditions deviating from this value, the recorded temperatures must be corrected according to (d), unless a more rational method is applied.

  • (d) The temperatures of the engine fluids and of the powerplant components (with the exception of cylinder barrels) must be corrected by adding to them the difference between the maximum ambient anticipated air temperature and the temperature of the ambient air at the time of the first occurrence of the maximum recorded component or fluid temperature.

Induction System

522.1091 Air Induction

The air induction system for the engine must supply the air required by the engine under all likely operating conditions.

522.1093 Induction System Icing Protection

  • (a) Except as permitted by (b), each engine having a conventional venturi carburettor must be provided with a pre-heater capable, in air free of visible moisture at a temperature of -1°C, of increasing the intake air temperature by 50°C with the engine at 75% of maximum continuous power.

  • (b) Where the intake air is continuously heated, and it is demonstrated that the temperature rise is adequate, a pre-heater need not be provided.

522.1103 Induction System Ducts

  • (a) Each induction system duct must have a drain to prevent the accumulation of fuel or moisture in the normal ground and flight attitudes. No drain may discharge where it will cause a fire hazard.

  • (b) Each duct connected to components between which relative motion could exist must have means for flexibility.

(Change 522-1 (87-08-31))

522.1105 Induction System Screens

If induction system screens are used -

  • (a) each screen must be upstream of the carburettor;

  • (b) it must be impossible for fuel to strike the screen.

Exhaust System

522.1121 General

  • (a) The exhaust system must ensure safe disposal of exhaust gases without fire hazard or carbon monoxide contamination in any personnel compartment.

  • (b) Each exhaust system part with a surface hot enough to ignite flammable fluids or vapours must be located or shielded so that leakage from any system carrying flammable fluids or vapours will not result in a fire caused by impingement of the fluids or vapours on any part of the exhaust system, including shields for the exhaust system.

  • (c) Each exhaust system component must be separated by fireproof shields from adjacent flammable parts of the glider that are outside the engine compartment.

  • (d) No exhaust gases may discharge dangerously near any oil or fuel system drain.

  • (e) No exhaust gases may be discharged where they will cause a glare seriously affecting pilot vision at night.

  • (f) Each exhaust system component must be ventilated to prevent points of excessively high temperature.

522.1125 Exhaust Manifold

  • (a) The exhaust manifold must be fireproof and corrosion-resistant, and must have means to prevent failure due to expansion by operating temperature.

  • (b) The exhaust manifold must be supported to withstand the vibration and inertia loads to which it may be subjected in normal operation.

  • (c) Parts of the manifold connected to components between which relative motion could exist must have means for flexibility.

Powerplant Controls and Accessories

522.1141 General

The portion of each powerplant control located in the engine compartment that is required to be operated in the event of fire must be at least fire-resistant.

522.1145 Ignition Switches

  • (a) Each ignition circuit must be independently switched, and must not require the operation of any other switch for it to be made operative.

  • (b) Ignition switches must be arranged and designed to prevent inadvertent operation.

  • (c) The ignition switch must not be used as the master switch for other circuits.

522.1149 Propeller Speed and Pitch Controls

  • (a) Propeller speed and pitch must be limited to values that ensure safe operation under normal operating conditions. In addition:
    (amended 2003/01/15)

    • (1) If there are propeller speed or pitch controls, their operation must not require undue attention or exceptional skill.
      (amended 2003/01/15)

    • (2) For variable pitch propellers, provisions must be made for a positive indication that:
      (amended 2003/01/15)

      • (i) the allowable pitch range for engine start, and
        (amended 2003/01/15)

      • (ii) the takeoff pitch position has been reached.
        (amended 2003/01/15)

  • (b) Propellers that cannot be controlled in flight must meet the following requirements:

    • (1) during take-off and initial climb at VY, the propeller must limit the engine rotational speed at full throttle to a value not greater than the maximum allowable take-off rotational speed, and

    • (2) during a glide at VNE with throttle closed or the engine inoperative, provided this has no detrimental effect on the engine, the propeller must not permit the engine to achieve a rotational speed greater than 110% of the maximum continuous speed.

    • (3) For powered gliders capable of extending and retracting the powerplant during a glide at VPE with the throttle closed, the propeller must not permit the engine to achieve a rotational speed of more than 110% of the maximum continuous speed. VPE must not be less than 1•4 VS1 where VS1 is the stalling speed with the wing flaps neutral at maximum weight.
      (amended 2007/07/16)

  • (c) A propeller that can be controlled in flight but does not have constant speed controls must be so designed that -

    • (1) 522.1149(b)(1) is met with the lowest possible pitch selected, and

    • (2) 522.1149(b)(2) is met with the highest possible pitch selected.

  • (d) A controllable pitch propeller with constant speed controls must comply with the following requirements:

    • (1) with the governor in operation, there must be a means to limit the maximum engine rotational speed to the maximum allowable take-off speed, and

    • (2) with the governor inoperative, there must be a means to limit the maximum engine rotational speed to 103% of the maximum allowable take-off speed with the propeller blades at the lowest possible pitch and the powered glider stationary with no wind.

522.1163 Powerplant Accessories

  • (a) Each engine-driven accessory must -

    • (1) be satisfactory for mounting on the engine concerned; and

    • (2) use the provisions on the engine for mounting.

  • (b) Electrical equipment subject to arcing or sparking must be installed to minimize the probability of contact with any flammable fluids or vapours that might be present in a free state.

522.1165 Engine Ignition Systems

  • (a) Each battery ignition system must be supplemented by a generator that is automatically available as an alternative source of electrical energy to allow continued engine operation if any battery becomes depleted.

  • (b) The capacity of the batteries and generators must be large enough to meet the simultaneous demands of the engine ignition system and the greatest demands of any other electrical system components that draw from the same source.

  • (c) There must be a means to warn the pilot if, while the engine is running, malfunctioning of any part of the electrical system is causing continuous discharge of any battery used for engine ignition.

Powerplant Fire Protection

522.1191 Firewalls

  • (a) The engine must be isolated from the rest of the glider by a firewall, shroud or equivalent means.

  • (b) The firewall or shroud must be constructed so that no hazardous quantity of liquid, gas or flame can pass from the engine compartment to other parts of the glider.

  • (c) The firewall and shroud must be fireproof and protected against corrosion.

522.1193 Cowling and Nacelle

  • (a) Each cowling must be constructed and supported so that it can resist any vibration, inertia and air loads to which it may be subjected in operation.

  • (b) There must be a means for rapid and complete drainage of each part of the cowling in the normal ground and flight attitudes. No drain may discharge where it will cause a fire hazard.

  • (c) Cowling must be at least fire-resistant.

  • (d) Each part behind an opening in the engine compartment cowling must be at least fire-resistant for a distance of at least 600 mm aft of the opening.

  • (e) Each part of the cowling subjected to high temperatures due to its nearness to exhaust system ports or exhaust gas impingement, must be fireproof.