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Civil Aviation Authority advisory circular contains information about standards, practices, and procedures that the Director has found to be an acceptable means of compliance with the associated rules and legislation.
However the information in the advisory circular does not replace the requirement for participants to comply with their own obligations under the Civil Aviation rules, the Civil Aviation Act 1990 and other legislation.
An advisory circular reflects the Director’s view on the rules and legislation. It expresses CAA policy on the relevant matter. It is not intended to be definitive. Consideration will be given to other methods of compliance that may be presented to the Director. When new standards, practices, or procedures are found to be acceptable they will be added to the appropriate advisory circular. Should there be any inconsistency between this information and the rules or legislation, the rules and legislation take precedence.
An advisory circular may also include guidance material generally, including guidance on best practice as well as guidance to facilitate compliance with the rule requirements. However, guidance material should not be regarded as an acceptable means of compliance.
An advisory circular may also include technical information that is relevant to the standards or requirements.
This advisory circular provides guidance material about fire prevention measures in respect of aircraft fuelling and safety measures to be observed by a person involved in fuelling (or defueling) an aircraft.
It is intended for general information, and does not override those procedures developed by recognised and certificated fuel company suppliers.
This advisory circular relates to Civil Aviation Rules 91.15, 121.91, 125.73, 135.73 and Part 139. It would also be of interest to adventure aviation aeroplane and helicopter operators, agricultural aircraft operators, and aerodrome operators.
Revision 2 restructures and expands this advisory circular to provide greater guidance for industry on the requirements for and implications associated with remote fuelling operations. TAIC report AO-2016-008 found and outlined various gaps in NZCAA advisory material, and subsequent industry practice regarding control of fuel contamination during field operations. This revision addresses those findings.
This advisory circular cancels AC91-22 Revision 1 dated 7 December 2018.
This revision history log contains a record of revision(s) made to this advisory circular.
Summary of Changes
14 October 2015
This is the initial issue of this advisory circular.
7 December 2018
Title of the advisory circular is amended
Version history log is inserted
Numbering system is revised.
Inserted new definitions for Class 3.1A—Flammable liquid and Class 3.1C—Flammable liquid
Paragraphs 1.2, 1.3(c), 1.5(d), 1.5(g), 4.1.1, 4.1.2, 4.1.14, 4.2.4, 4.2.5, 4.2.7(a), 4.3.1, 4.3.2, 4.4.2(e), 4.5.1, 4.5.2, 4.5.7, 4.7.1, 4.7.2, 4.7.3(a), 4.7.3(b), 4.7.3(c), 4.7.4, 5.1.1, 5.2.2, 5.3.2, 6.6.4(b), 6.6.4(c), 6.6.7, 6.6.9, 7.1.1, 7.1.3(e), 7.1.3 (f), 7.1.3(g), 8.3.1, 8.4.2 (c), 8.5.3, 8.7.5 are amended.
New paragraphs 1.5(h), 4.7.6, 4.8, 5.4.4(f), 6.3.1(d)(8), 6.4.1(e), 6.6.2,6.6.3, 6.6.8, 6.8.1(h), 7.1.3(a)(3), 8.6.1(f), 9 are inserted
New explanatory notes are inserted under paragraphs 4.2.6, 4.5.5, 4.6.2, 7.1.3(g)
Headings 6.8 and 8.6 are amended
End note 5 is amended
Appendixes 1 and 2 are revoked and replaced
25 September 2019
Revision 2 restructures and expands this advisory circular to provide greater guidance for industry on the requirements for and implications associated with remote fuelling operations to address the findings of TAIC report AO-2016-008.
Inserted new definitions for Bonding and Grounding
Paragraph 4.7 and 4.9 are inserted. Previous 4.7 becomes 4.8 and previous 4.8 becomes 4.10
Paragraphs 6.6 and 6.7 removed and inserted in 4.9.
Paragraph 6.8 amended to 6.6
Paragraph 6.7 reinserted with new material
Headings 4.8, 4.9 and 9 are subsequently amended.
Headings 4.7, 6.7 and 9.4 are subsequently inserted
Paragraphs 4.1.17, 4.2.1, 4.2.7, 4.4.2, 4.5.7, 4.7.1, 4.8.3, 4.8.5, 4.8.8, 4.9.4, 5.2 note 1, 6.7.7, 7.1.3 are subsequently amended
New paragraphs: 4.1.18, 4.1.19, 4.5.9, 4.5.10, 4.7.5, 4.7.6, 4.8.2, 4.8.4, 4.9.1, 4.9.2, 4.9.3, 4.9.6, 4.10.3, 4.10.4, 4.10.5, 6.7.1, 6.7.2, 6.7.3, 6.7.4, 6.7.5, 9.4 are subsequently inserted
1.1 Any person engaged in the fuelling of aircraft is advised to take account of the guidance material set out in this advisory circular.
1.2 An airport authority or aerodrome operator is responsible for providing a safe environment for the fuelling of aircraft at its airport.
1.3 This advisory circular incorporates many of the provisions of:
1.4 The fuel supply companies also have jointly agreed guidelines for fuel handling procedures to be used for into-plane fuelling services and many of the provisions of these guidelines have been included into this advisory circular.
1.5 Other sources for this advisory circular include the:
2.1 This advisory circular provides advisory material/guidelines or information regarding safe practices/procedures, in respect of aircraft fuelling as per Parts 91, 121, 125, 135 and 139
requirements for aircraft fuelling and ground fire precautions. Applicable regulations made under the Hazardous Substances and New Organisms Act 1996 also apply (refer to rule 91.15).
2.2 Coverage of the different aspects of aircraft fuelling and ground fire precautions is not exhaustive in this advisory circular. This advisory circular sets out the main elements.
Certified handler is someone who has been certified to handle very hazardous substances as defined by Worksafe New Zealand .
Class 3.1A—Flammable liquid means a liquid that has a flash point of below 23ºC and has an initial boiling point (IBP) of a maximum 35ºC, and includes petrol based products.
Class 3.1C—Flammable liquid means a liquid that has a flash point at or above 23ºC, but at or below 60ºC, and includes kerosene based products.
Bonding means the electrical connecting of two or more conducting objects not otherwise adequately connected .
Grounding means the electrical connecting of conducting object to primary structure. The main frame, fuselage, and wing structure of the aircraft (commonly referred to as ground) or earth electrode, for return of current.
Fuelling includes refuelling and defueling aircraft, and the draining of aircraft fuel tanks .
Fuel has the same classification as those classified by the Hazardous Substances and New Organisms Act 1996 as listed at http://www.legislation.govt.nz/(external link).
Fuelling safety zone/area means any area within a radius of at least 3 metres (10 feet), or as specified by local regulations, from filling and venting points on the aircraft, hydrant pits, fuelling vehicle and its hoses in use.
Overseer means a person appointed by an operator to ensure that the fuelling procedures are complied with.
NOTE: See also Civil Aviation Rules Part 1 for other terms.
4.1.1 Personnel engaged in the fuelling of aircraft must not carry matches, cigarette lighters, two-way radios,or any other item which may cause a fire during the fuelling or defueling of an aircraft. Mobile phones are not to be used in the vicinity of an aircraft whilst it is being refuelled or defueled.
4.1.2 Do not carry out fuelling during an electrical storm or other hazardous conditions such as excess wind, fog, during aircraft de-icing procedures, etc. Each location should develop extreme weather or other extreme event guidelines on realistic scenarios relative to each location.
4.1.3 Do not operate a cell phone, radiotelephone device, pager device, portable electronic device (PEDs), electronic flash equipment, or photographic flash bulb within 8 metres of the fuelling tanker or 3 metres from aircraft fuel points and vents unless certified intrinsically safe or flameproof.
4.1.4 Maintain a clear path from the aircraft for quick removal of aircraft fuelling equipment in an emergency. This may not apply to aircraft fuelling dispensers if agreed by the fuelling agency, aircraft operator and airport authority.
4.1.5 Fuelling equipment access to and exit from fuelling operations should also be kept free of power units and associated cabling.
4.1.6 Vehicles and equipment should be kept clear of aircraft passenger exits to allow for quick evacuation of passengers and crew members in an emergency.
4.1.7 Trolleys, handcarts or any vehicle used within 15 metres of the aircraft or the fuelling equipment should be fitted with non-metal tyres/wheels.
4.1.8 In-ground power units located within 5 metres of an aircraft vent should have electrical compliance certificates, or meet the requirements of a class one, zone one installation, or both.
4.1.9 Electrical hand lamps or flashlights used directly in the fuelling operation should be flame proof and safe for use.
4.1.10 Hoses should be run out on selected routes which will prevent them from being run over by aircraft-servicing vehicles. Kinking and twisting of hoses should be avoided. Pressure fuelling couplings and overwing nozzles should not be dragged over the ground. Dust caps should be fitted if required or the coupling stowed so as to reduce the risk of damage or the entry of dirt and water into the nozzle. Fuelling hoses and bonding wires should not be allowed to come into contact with a fixed ground power unit or in-ground power unit (IGPU) or associated electrical cables and should be kept as far away from them as practicable.
4.1.11 Before fuelling, the fuelling vehicle system should be checked for leaks, the filter differential pressure should be observed as normal, and any pressure control equipment should be checked for correct action by observing the reading of the appropriate pressure gauges on the vehicle.
4.1.12 Clear lines of communication should be established between the operator delivering the fuel, and any other person(s) directly associated with the fuelling operation. For example: pilot/maintenance personnel monitoring cockpit fuel contents gauges.
4.1.13 When delivering fuel, the operator should be positioned at a point where a clear view of the vehicle control panels and aircraft fuelling points is available. Deadman control should always be used for pressure refuelling and should never be wedged open.
4.1.14 During fuelling, do not perform any aircraft maintenance which may cause a fire with fuel vapours or movement of control surfaces that may cause injury to refuelling personnel or equipment.
4.1.15 Fuel spills are fire hazards and cause environmental damage. Aircraft engines when hot can be a fire ignition source. Therefore take extra care not to spill fuel when an aircraft engine is hot, particularly when fuelling equipment is close to the aircraft.
4.1.16 If fuel spills, fuelling should stop and the spillage covered immediately with materials such as sand, sawdust, dry earth, or an agent such as foam or dry chemical extinguisher powder, to reduce the fire hazard. The aircraft should be moved clear of the contaminated area before any engine is started. Local airport regulations may also be applicable.
4.1.17 Prior to fuelling, personnel should ensure that all equipment used in the fuelling operation is clean and free from contamination.
4.1.18 Fuel filler caps should not be opened until the area surrounding the filler cap is completely clean. Filler cap configurations where the cavity opening is flush with the exterior skin are particularly vulnerable to contamination and strict cleanliness standards should be adhered to at all times.
4.1.19 Fuel that is not adequately labelled, is from an unknown source or is stored in containers or tanks that show visible signs of deterioration should not be used.
4.2.1 The published procedures on bonding contained within this advisory circular should be strictly followed. The aircraft and fuelling equipment should be electrically bonded together throughout the fuelling operation to ensure that no difference in electrical potential exists between the units.
4.2.2 Bonding requirements and electrical continuity checks should be in accordance with AS/NZS 60079.14 Explosive Atmospheres Pt 14 Design Selections Erection and Initial Specification. CASA advisory circular AC21-99 provides further guidance also.
4.2.3 Bonding leads should be examined for security of connections and damage prior to use. Clips should be intact and undamaged.
4.2.4 Bonding between the fuelling vehicle and the designated bonding point of the aircraft should be completed before any hoses are connected or tank filler caps opened. Bonding should be maintained until all hoses have been finally disconnected or tank filler caps replaced.
4.2.5 When grounding aircraft, the fuelling equipment and aircraft should be grounded by means of a “Y” grounding cable and not through the fuelling vehicle. Hydrant pits or hydrant pit internals should not be used as bonding connections. Where bonding is carried out, it should be completed before connecting hoses or opening filler caps.
4.2.6 When overwing fuelling, make sure to follow the correct procedure for inserting the nozzle into the tank filler. If the filler caps have been previously removed to dip the tank contents, the caps should be replaced and any vapour allowed to disperse before starting any fuelling operation.
NOTE: In some installations a dipstick can be used to confirm fuel quantity in the aircraft’s tank – see Appendix 2.
4.2.7 The fuelling procedure may vary with aircraft type, but the following additional steps are recommended—
4.3.1 Personnel engaged in the fuelling of aircraft should be dressed in protective clothing that does not cause static electricity build-up to prevent a flashback. The European standard EN 1149-5 is an acceptable reference for assessement of clothing suitability, if needed.
4.3.2 Personnel should wear non-slip semi-conductive footwear, safety glasses and fuel resistant gloves.
4.3.3 Personnel should be instructed in the procedure for alerting local fire services in an emergency.
4.4.1 Fuelling operations should be carried out by competent personnel, thoroughly trained in aircraft fuelling procedures, the operation of fuelling equipment, the action to be taken if an emergency occurs, and safety procedures for storing, handling, and dispensing fuel, lubricants, and oxygen.
4.4.2 Training of personnel should also include—
NOTE: Operational knowledge of system components such as self-closing valves, internal valves, and vents will reduce uncertainty and avoid delay and error.
4.5.1 Vehicles driven in airside operations should comply with local aerodrome procedures in condition and operation, and should, especially, in fuelling/defueling operations, be driven with care.
4.5.2 When driving a vehicle, always move forward into the fuelling position and exit in a forward direction, without reversing, if practicable. If the vehicle has to be reversed into position, a guide should be stationed at the rear of the unit to direct the manoeuvre. It is recommended that the driver of the refuelling vehicle walk around the vehicle completely before departing the aircraft. This gives opportunity to ensure that everything is completely stowed, and that nothing external has changed, such as aircraft flaps being lowered. Also, loose fuel caps, fuel doors, errant dipsticks should be checked for, prior to driving away from the aircraft already refuelled/defueled.
4.5.3 Truck and trailer combinations should not be reversed into position. Once the vehicle is in position, the driver should not leave the cab until the parking brakes have been applied and locked in position.
4.5.4 The vehicle should be positioned at a safe and convenient distance from the fuelling points on the aircraft to permit—
4.5.5 Special precautions should be taken to ensure that vehicles used for underwing fuelling have a sufficiently low profile for this purpose. Vehicles should be positioned so as to avoid the aircraft wing, winglets or other surfaces bearing down onto the vehicle as the aircraft settles under increased fuel load. The position of aircraft flap tracks in case of unheralded flaps extension should be taken into account.
NOTE: Slats and flaps may be extended as part of an aircraft overheat protection system on some aircraft such as the Airbus A320 family of aircraft).
4.5.6 Aircraft servicing vehicles must not be driven at excessive speed around fuelling operations and care must be taken to avoid contact with the fuelling vehicle, hoses and couplings, bonding wires, and any associated appliances. The operator or the overseer should ensure that such vehicles should not be driven at excessive speeds and airside driving rules and speed limits imposed by the aerodrome should be adhered to. If no regulations exist, a limit of 25km/h should be enforced on apron roads and less than 10 km/hr when in proximity to aircraft.
4.5.7 Any person engaged in fueling operations must ensure that all hoses and fueling equipment are disconnected from the aircraft and stowed safely, prior to aircraft departure. Operators certificated under various rule parts should include their method for ensuring this happens in their fuel management processes.
4.5.8 The fuelling vehicle - either a hydrant dispenser or a tanker/fueller - should be positioned so that it can be driven away quickly in an emergency. For this reason it is imperative that other ramp users do not obstruct the exit route of a fuelling vehicle.
4.5.9 During fuelling at remote locations, care should be taken to ensure that vehicles and trailers are positioned well clear of rotating blades and in clear vision of the pilot.
4.5.10 Regardless of vehicle positioning, no member of the fuelling team may stand on either the vehicle or fuelling equipment during fuelling operations, unless the vehicle concerned has been specifically designed or modified to be so used.
4.6.1 Fuelling/defueling is generally not permitted in hangars or similar enclosed buildings, except by special agreement with the respective operators and the appropriate airport authorities, and in accordance with relevant and approved special procedures which should include satisfactory liability or indemnification protection.
4.6.2 Fuelling vehicles involved in such operations should remain outside the hangar.
NOTE: See part 7 of this advisory circular for defueling.
4.7.1 Use only Jerry Cans specifically manufactured as fuel containers. The traditional metal Jerry Cans are preferable to the plastic versions available on the market. Plastic Jerry Cans intended for use with fuels will have been manufactured to a recognised standard. In New Zealand, for cans up to 25L in size, this is Australian/New Zealand standard 2906:2001 and this identification is embossed permanently on the side of the container. Each Jerry Can manufacturered to this standard will have a date of manufacture also printed on the can. Cans manufactured in excess of five years prior to to date of fuelling should not be used and the fuel discarded.
4.7.2 Do not use plastic containers not designed for fuel, as their deficiencies may pose hazards such as—
4.7.3 In particular, the cap gaskets have been identified as an actual hazard. The standard requires that these be physically restrained in the cap by a retaining ring, or other means of preventing accidental loss. Obviously, the gasket itself should also be fuel resistant.
4.7.4 Apart from simply falling out of the cap and preventing proper sealing, two ways in which the gasket can be hazardous.
4.7.5 All mobile tanks used to store and transfer fuel by road must have been designed and built in accordance with the relevant provisions of a standard commensurate with: Health and Safety at Work (Hazardous Substances) Regulations 2017, Part 16.
4.7.6 Storage of fuel in drums falls under the same graded set of requirements as for larger, above ground storage facilities. Worksafe New Zealand has published advisory material called Good Practice Guidelines: Above Ground Fuel Storage on Farms. That document should be referenced when installing, inspecting and using storage facilities of those types. Specific requirements for the use of drums to store fuel are identified in section 6 of that document.
4.8.1 Contaminants (especially water or incorrect fuel grade) in the fuel have been known to cause engine failures – usually just after the aircraft has become airborne. Fuel contamination could also be in the form of solid contaminants such as sand, corrosion products, or other debris. Water contamination in fuel continues to be a major source of fuel related incidents.
4.8.2 Below are common examples of ways that contaminants can enter fuel.
4.8.3 Some fuelling practices are likely causes of contamination, particularly when undertaking remote fuelling operations, such as when fuelling helicopters whilst the main rotor is turning, or when transit of fuelling equipment along dirt roads has allowed contaminants to build up on fuelling equipment. Under these conditions, particles of foreign material (dust and grass) are likely to be introduced into the fuel system through the tank filler.
4.8.4 The specific types of fuel contamination are many and varied, however can be grouped into the following broad categories:
In particular, particles held in suspension pose a serious threat to flight safety as they may be so fine that they are not captured by filtration elements in the fuelling equipment. Fine particles then enter tanks and may cause contamination of fuel nozzles or injectors as the fuel is atomised and burnt. Dissolved water may also be present in fuel without being visibly obvious and whilst dissolved, it is not a hazard to aircraft operation. However, temperature changes may cause the water to separate out of the fuel and become free water, which can cause catastrophic risk to aircraft safety. Entrained water is similarly difficult to identify as it consists of tiny droplets that have been agitated into fuel by pumps etc. This water will separate into droplets with settling time, which may mean that water is only obviously identifiable long after the fuel transfer operation took place. General settling times to be applied are 1 hour per vertical foot of tank space for Jet fuel and 15 mins per vertical foot of tank space for AVGAS.
NOTE: Go/No go filters that snap shut when water is sensed in the fuel are not to be considered fail safe. Many instances have been reported that indicate water has been allowed to pass through these types of filters without being detected.
4.8.5 To minimise the risks of this happening, a fuel sample should always be taken from the refueller and tested for solid particle contamination, undissolved water and appearance of fuel. This test should be carried out at any time fuel is transferred between any of the storage vessels identified in paragraph 6.7.2 of this advisory circular and at scheduled times for stored fuel. In addition, fuel drain checks from the aircraft should be carried out by the aircraft operator before the first flight of the day – and after refuelling. In general, any form of contaminated fuel should not be used and reference should be made to the aircraft type-specific documentation, such as maintenance manuals, task cards or the aircraft flight manual. Additionally, fuel that is not adequately labelled, is from an unknown source or is stored in containers or tanks that show visible signs of deterioration should not be used.
4.8.6 Water finding paste can be used for identifying free water for either Jet A1 and Avgas. A water detector capsule can be used to identify suspended water in Jet A1, a fresh capsule must be used for each check. In cases where fuel contamination persists frequently then the source of the contamination needs to be investigated.
4.8.7 Nozzle size of the refuelling equipment versus the aircraft tank aperture size, is not a guarantee against misfuelling. It is of the utmost importance that the appropriate markings or decals are maintained and regularly checked for presence, to show the type of fuel, grade and capacity of the tank, visible to the refueller.
4.8.8 The following general considerations apply to taking a fuel drain sample when required.
4.8.9 Always confirm that each spring-loaded drain valve (if such a type is fitted) shuts securely afterwards, as any leaks will result in higher than normal in-flight fuel consumption and possible external venting of fuel vapour. Take care with remotely-operated fuel drains, and make sure that they also close properly after operation.
4.8.10 If the sample tests positive for water or other contaminants, empty the sample vessel and continue draining until a clean sample is obtained. Be sure to empty the sample into a fuel disposal container as fuel can also degrade bitumen surfaces. Never tip the sample back into the aircraft tank, even if it appears clean.
4.8.11 Tipping samples of drained fuel into ground support equipment is not recommended.
NOTE: If any person or organisation that is storing fuel for the purposes of resale or reuse by another person or organisation, then the provisions of Civil Aviation Rule Part 19F must be complied with.
4.9.1 The risks of contamination noted in paragraph 4.8 of this advisory circular, raise various instances where contamination of stored fuel can occur. For that reason, it is important that the following precautions are noted and complied with when storing fuel.
4.9.2 Operators of aircraft must nominate who is to be responsible for the inspection and maintenance of aircraft fuel storage and transfer equipment and for the routine testing of stored fuel. These responsibilities should include.
4.9.3 Whilst each operator is responsible for determining their own inspection schedules for fuelling equipment that identify when checks are be conducted and by who, the following general areas should be covered.
4.9.4 Fuels such as Avgas and two stroke mixes will store for up to one year in a sealed container. After that period the fuel may still be fit for purpose but problems such as hard starting and spark plug fouling may occur due to lack of light components. Once the seal is broken then lighter components evaporate and the storage life is best assumed to be 6 months at ambient temperatures of 20º C and 3 months at ambient temperatures of 30º C or more. Aviation turbine fuel should not be stored for longer than 12 months. After these periods, aging tests should be carried out.
4.9.5 Reference to (Energy Institute) EI 1550 (Handbook on equipment used for the maintenance and delivery of clean aviation fuel), as at latest revision can be made for more information on filtration.
4.9.6 When storing drums of fuel, drums should be oriented on their side with bungs located at 3 and 9 o’cloock positions and the bung end of the drum at a lower level than the other end. This is to decrease the risk of breathing between the fuel inside the drum and the atmosphere outside.
4.10.1 To comply with fuel specification traceability and quality control requirements, all checks and tests on aviation fuel and fuelling equipment should be recorded.
4.10.2 Effective records should detail what was first observed (e.g. volume of contaminant, colour, type, location), what actions were taken to rectify the situation and what the final result was. Detailed records are valuable.
4.10.3 Records should also include a list of all fuel storage and transfer installations and vessels in the organisation’s possession and the current condition of each. Inspections of equipment must also be recorded.
4.10.4 Scheduled and incidental fuel drain testing must be recorded.
4.10.5 Records must be kept of any training conducted with staff on fuelling or inspection activities. FAA advisory circular 150/5230-4B provides guidelines as to the possible content of a fuel safety training programme.
5.1.1 During fuelling operations, air and fuel vapour are displaced from the aircraft fuel tanks. This potentially explosive mixture is expelled via tank vents and the fill point(fuel vapour is heavier than air. The fuel vapour can accumulate in low points, and may "flow" downhill for quite some distance) . This combined air (oxygen) and fuel vapour forms an explosive mixture quite capable of causing fatalities or destroying an aircraft or hangar.
5.1.2 An explosive fuel-air mixture can also be formed by splashing a volatile fuel in an open container, as in washing oily components, or by pouring fuel from a sample container into another open container. All it takes to initiate a fuel explosion is just a small spark or a hot surface - not necessarily in the immediate vicinity, given the ability of fuel vapour to flow long distances. If a fire breaks out, extinguish using dry powder, foam or carbon dioxide extinguishers, or a water fog. Do not use a water jet, as this will spread the burning liquid and may make matters worse. Fires in confined spaces should be dealt with by trained personnel wearing appropriate breathing apparatus. Ensure an escape path is always available from a potential fire.
5.2.1 Commonly referred to as ‘static’, this is one of the most hazardous sources of ignition. Fuel is an extremely flammable liquid and explosive fuel/vapour mixtures may form at ambient temperatures. The presence of an ignition source can spell disaster. So static and aviation fuel is a bad mix. The risk is always present, and must be managed, even in seemingly innocuous situations. The considerations apply equally to gasoline fuels and Jet A-1.
5.2.2 Static can be generated from a number of sources, typically by the flow of fuel from the fuelling equipment to the aircraft, and by the wearing of synthetic clothing (high-visibility vests can be a hazard in this case – see 4.3 above regarding clothing). A resultant electrical charge can build up on an aircraft, the fuelling equipment, or a human body, and when two unequally-charged objects are brought close enough together, the charge will equalise by means of a spark. Static sparks can be of the order of thousands of volts and combined with the presence of fuel vapour of sufficient concentration will result in a potentially catastrophic explosion. This can be avoided by the use of the proper bonding leads or cables, coupled with procedures to equalise any electrical potential, before any hazardous vapour is introduced into the surrounding areas.
NOTE: The grounding of helicopter skids does not necessarily equalise the electrical potential between fuelling equipment and the helicopter – bonding the helicopter is an acceptable means to achieve a safe state for fuelling. Helicopters with wheeled landing gear and those parked on trolleys are particularly suceptable to electrical potential to be present.
NOTE: Further information on bonding may be found in FAA advisory circular 25.899-1 “Electrical bonding and protection against static electricity”
5.3.1 The most important thing to do before fuelling is to correctly bond the pump or fuelling equipment to the aircraft. When fuelling from drums, always ensure that there is a bonding lead connected to both the aircraft and the drum in use and make the necessary connections before removing any fuel caps. Additionally, it is good practice to keep the fuelling nozzle in physical contact with the filler aperture at any time fuel is being pumped. This also applies to the filling of portable containers – place the container on the ground, and maintain contact between the fuel nozzle and the container. Containers complying with Australian/ New Zealand standard 2906:2001 have this instruction on the label. Also check the bonding to the aircraft of any stands or ladders used to gain access to any overwing fuelling point.
NOTE: Should the bonding cable be accidently disconnected during the fuelling process, stop fuelling immediately and wait for any static to dissipate before reattaching the bonding cable.
5.3.2 Despite the traditionally accepted practice of filtering fuel through chamois leather, this is now not recommended. Studies have found that the use of a chamois can be a static hazard in itself, synthetic chamois even more so. Any drum pump should be more preferably fitted with an appropriate in-line filter, and the delivery hose must be fuel-specific. The fuel supplier should be able to advise on the correct equipment, and it is very important that the correct equipment is used, inspected and maintained in accordance with manufacturer's recommendations.
5.4.1 Spillage and leakage of fuel should be avoided at all times. Every spill is a fire hazard as well as an environmental pollutant, and should be dealt with immediately. Each spill presents a different situation involving many variables, such as size of spill, weather conditions and location of spill.
5.4.2 Action required will depend on each particular situation, so no one set of instructions will apply in every case. Prompt action, good judgement and initiative by well-trained personnel are important to prevent hazards arising from fuel spills.
5.4.3 The overseer is responsible for ensuring that the local and national regulations relating to environmental pollution are fully met. This includes keeping an up-to-date spillage emergency plan and ensuring that all staff are aware of the plan and what must be done if fuel spills.
5.4.4 The following general procedures should be adopted into the plan for any spillage:
5.4.5 Smaller spills should be immediately soaked up using non-combustible absorbent material, such as sand or dry earth while someone stands by with a dry powder or foam extinguisher in case a fire breaks out. This also applies to places where fire services are not stationed. Be sure to dispose of the contaminated material in a safe place afterwards and any tools used for this purpose must be non-flammable.
CAUTION: If any fuel spills onto your body or clothing, do not remove your clothing except under shower. If you take off your clothing without first dousing under water, you could create a static spark and set yourself on fire.
5.4.6 In any case, take great care to prevent the spillage, as far as possible, from entering into the drainage system.
5.5.1 Appropriate fire extinguishers should always be readily available. They may remain on the fuelling vehicle, if they are carried in open housings or in racks with quick opening fastenings.
5.5.2 The recommended fire extinguisher is a 9kg BC dry powder extinguisher – sodium or potassium bicarbonate powders. These are the most suitable for liquid and gas fires and are therefore recommended for most fuelling applications.
NOTE: ABC type multi-purpose mono ammonium phosphate powders are not recommended for aviation fuelling operations, as they can leave sticky and corrosive residue on surfaces when discharged.
Extinguishers should be maintained and certified serviceable in accordance with the relevant recognised standards. Fuelling personnel should be trained on how to use extinguishers effectively and know where they are located.
NOTE: Any published procedures by the fuelling company and any manufacturer’s manual instructions on fuelling must be strictly followed.
6.1.1 The operator or the overseer should ensure that the following precautions are observed during the fuelling of any aircraft—
6.2.1 Personnel responsible for fuelling aircraft should take into account the following general procedures—
6.3.1 In addition to the ‘general procedures’ in paragraph 6.2, the following sequence is recommended when the hydrant pit cover is removed—
6.4.1 In addition to the general procedures in paragraph 6.2, the following sequence is recommended—
6.5.1 In addition to the procedures for underwing fuelling, the following further measures are required to ensure that the correct grade of fuel is delivered when using an overwing (trigger) nozzle.
NOTE: (i) if there is no grade marking on the aircraft, fuelling should not start until the pilot or responsible ground servicing personnel has confirmed the grade of fuel required
(ii) if the grade marking on the aircraft is different to that of the fuelling equipment, fuelling should not start until the discrepancy has been fully investigated and resolved.
NOTE: Certain jet fuel (Class 3.1C) aircraft types may have filling orifices which are too small to accept the standard diameter Jet A-1 nozzle, necessitating the use of a smaller diameter nozzle adapter.
6.5.2 The following additional precautions are applicable for overwing fuelling.
6.6.1 During the fuelling operation, the pilot-in-command or overseer, as appropriate, should only permit maintenance, testing, servicing or cabin replenishment within the fuelling area subject to the following conditions.
6.7.1 Refuelling in remote locations exposes operators to increased risk in various areas, such as:
6.7.2 Multi transfer fuelling cycles may consist of transferring fuel between any of the following storage methods:
6.7.3 Each time a fuel storage tank is opened for the purpose of fuel transfer operations, it represents an opportunity for contamination to occur. No storage tank should be opened prior to ensuring that comprehensive cleaning of the area surrounding the filler port is carried out. All operations where fuel is decanted between storage containers should be carried out using a suitable pump and preferably through micronic filtration. Further, anytime fuel is transferred between storage tanks or to an aircraft, operators are to check for fuel contamination in accordance with the guidance material provided in paragraph 4.8 of this advisory circular.
6.7.4 Prior to filling or using the fuel contained within, ensure that all equipment that is used to store or transport fuel in remote locations is of the appropriate standard and is checked for serviceability and cleanliness in accordance with the relevant parts of this advisorycircular.
6.7.5 Fuelling equipment that is used to facilitate easy transfer of fuel, such as Jerry Can filler extension tubes, must be of an appropriate standard, configuration and cleanliness. In particular, tubes that are held to Jerry Cans with tape of any kind are prohibited as they have been known to detach and be found later in tanks. In an effort to ensure that any contaminants are cleared from the fuelling equipment nozzle prior to fuelling, fuelling staff should discharge the first fuel out of the nozzle into a container to be discarded.
6.7.6 Take care to correctly identify the type and quality (fuel does go stale) of the fuel before refuelling from drums. Ensure that the pump is fitted with a clean and serviceable filter (one that will filter particulate matter, as well as absorbing water). Corrosion products (rust), water and dirt can all be a problem when fuel is stored in drums. It is most important that the fuel delivery line incorporates a filter of five microns for avgas or 1 micron for jet fuel or less with the ability to separate both water and other contaminants. Fuel suppliers can provide or recommend suitable filters for this purpose.
NOTE: A chamois cloth, once traditionally used as a filter, should not be used, as it can be a potential source of static charge. Fuel drums should be stored on their side with bungs and vents at three o’clock and nine o’clock positions, with the top of the drum (with the openings) lower than the bottom. This will minimise any ‘breathing’ (air and moisture exchange from outside) through the bungs and vents. A partly filled drum is more likely to contain moisture because of increased ‘breathing’.
6.7.7 When opening a drum—
6.7.8 The practice of using bleed air from the compressor of an aircraft turbine for the purpose of pressurising the fuel drum can only be considered safe if the following points are observed—
6.7.9 Take care not to exceed the allowable maximum differential pressure across the filter element so that the excessive pressure does not render the filter ineffective. It is therefore important to ensure that the stand pipe is positioned clear of water deposits which may be presented in the bottom of drums.
6.7.10 Fuel suppliers are well aware of the problems of refuelling from drums in remote areas and have indicated their willingness to assist operators in the adoption of safe refuelling practices. Technical information in the form of bulletins and leaflets is readily available from most suppliers.
NOTE: Any published procedures by the fuelling company and any manufacturers’ manual instructions must be strictly followed.
7.1.1 It may, from time to time, be necessary either to off-load fuel from an aircraft after completing fuelling for subsequent aircraft fuel load adjustment, or to completely off-load all fuel, usually at the airline overhaul base, to permit maintenance work to be carried out.
7.1.2 Both operations are designated defueling and the procedures to be followed during defueling are similar to those which apply to fuelling.
7.1.3 To protect the quality of the fuel in the fuelling equipment from being contaminated by the fuel off-loaded from the aircraft, the following procedures should be adopted before defueling begins—
NOTE: The aircraft operator should supply this information.
NOTE: For compliance with aviation fuel specifications and standards, refuelling companies are not permitted to handle or dose fuels with biocides.
8.1.1 An auxiliary power units (APU) exhaust discharging outside fuelling zone—
8.1.2 An APU exhaust discharging into fuelling zone—
8.1.3 An APU in engine nacelle on fuelling side of aircraft—
8.2.1 Position the ground power units (GPU) and associated cabling at least 6 metres away from fuelling vehicles and clear of wing tank vents.
8.2.2 Do not start, connect, switch on, or disconnect the GPU during the refuelling process. These actions must be completed either before refuelling or after the refuelling process is completed.
8.2.3 If fuel spills, the GPU should be stopped immediately and should remain stationary with all electrical circuits and switches left untouched until the spillage is removed and there is no danger from inflammable vapours.
8.3.1 Fuelling operations may be carried out subject to the same conditions as those applicable to general aircraft servicing, with the exception that, if fuel spills, the unit should be switched off. This is to prevent the possibility of flammable vapours being drawn into the aircraft passenger compartment or avionics bay.
8.4.1 Fuelling of an aircraft, which has one propulsion engine running, is a non-routine operation and requires very strict safety precautions.
8.4.2 The following procedure applies specifically to underwing fuelling.
8.5.1 The pilot-in-command and/or overseer as designated by the aircraft operator should ensure that no hazard is presented to fuelling equipment, its operation or to fuelling personnel during the starting of engines or taxiing of aircraft, especially due to the efflux from turbine engines. In the case of the fuelling equipment or personnel to the rear of, and within a 15° arc either side of the exhaust outlet axis, the engines should not be operated unless the engine is at a minimum distance (listed in Appendix 1).
8.5.2 As aerodromes or airports serve a large variety of aircraft types, depending on prevalent aircraft engine type, the minimum distances may be increased or decreased if agreed by the affected parties.
8.5.3 The operation of aircraft engines including aircraft-borne APUs within the fuelling area is not recommended, except when the engines (or APUs) are tail-mounted and the fuel to be uplifted is class 3.1C, or the express approval of the relevant fuelling agency (or aerodrome (as applicable) and aircraft operator has been granted.
8.5.4 In addition, if the aircraft-borne APU is not tail-mounted, it may be operated within the fuelling area when the fuel to be uplifted is class 3.1C providing the APU is started before the filler caps are removed and fuelling connections made.
8.5.5 If an aircraft-borne APU is stopped for any reason during fuelling, it should not be restarted until the fuel has stopped flowing, the refuelling vehicle is disconnected and moved away, and there is no risk of igniting fuel vapours.
8.5.6 Operators are responsible for the following—
8.6.1 Fuelling or defueling involving passengers may be carried out following the accepted procedures in an aircraft operator’s exposition. Refer to Civil Aviation Rules 121.91, 125.73, and 135.73 provided the conditions listed below are satisfied—
8.7.1 Internal combustion engines used in association with auxiliary plant and vehicles powered by internal combustion engines should not be operated within the fuelling area unless—
8.7.2 Do not start, connect, switch on, or disconnect a GPU during refuelling. These actions must be completed before or after refuelling is completed.
8.7.3 Where an electric motor, portable electrical appliance or ground supply unit is operated within the fuelling area, all electrical apparatus on the unit should be flame proofed in accordance with AS/NZS 60079.14 Explosive Atmospheres Pt 14 Design Selections Erection and Initial Specification.
8.7.4 Operators should make sure that vehicles and fuelling equipment are maintained to satisfactory safety standards.
8.7.5 Do not start ground equipment engines in the vicinity of the aircraft being refuelled, during fuelling until the flow of fuel has ceased and there is no risk of igniting fuel vapours, venting from the aircraft.
8.7.6 Ground equipment engines should also not be operated within 3 metres horizontal radius of an aircraft fuel venting system. The area also includes all that space encompassed vertically below the horizontal exclusion zone.
8.8 Fuelling on aircraft having fuel tanks with inert gas system (nitrogen generation system)
8.8.1 Modern generation transport category aircraft may be fitted with fuel tanks having a nitrogen generating system. This nitrogen generating equipment is dangerous as nitrogen is colourless and odourless. The generated nitrogen decreases the oxygen in the air remaining within the tank, safeguarding against the likelihood of an explosive mixture. However, the resultant gaseous mixture when vented is unhealthy and may cause hypoxia, dizziness, nausea, and in extreme cases unconsciousness and possible death.
8.8.2 While fuelling or defueling aircraft which have fuel tanks fitted with nitrogen generating equipment, make sure that any warning instructions associated with such systems (typically in the main wheel well, centre fuel tank and air conditioning bay) are read and obeyed by fuelling operators. The aircraft operator should be approached to assist in identifying any hazards and procedures to be followed when dealing with such systems.
8.8.3 An aircraft operator is responsible for educating and training fuellers regarding features of the aircraft used by the operator relating to fuelling/defueling operations and special precautions to be taken during fuelling operations.
9.1.1 To reduce health hazards when handling aviation fuels, observe the following precautions.
9.2.1 It is important from a Health and Safety perspective that the correct personal protective equipment (P.P.E) is worn during any fuelling/servicing/defueling operations.
9.2.2 Wear a face visor or goggles in circumstances where eye contact can accidentally occur. If skin contact is likely, wear impervious protective clothing and/or gloves.
9.4.1 Management of risk is the responsibility of all industry participants, whether private or commercial operators. Many serious incidents or accidents that are caused by fuel contamination problems occur in a context of previous minor incidents going either unnoticed or unmitigated. Further, even when incidents are dealt with, often protective measures that are required to prevent reoccurrence are either insufficient or completely missing. A good example of this is when fuel tank contamination occurs, often the response is to make the necessary repairs to the aircraft, but neglect to look at what systems or processes failed to prevent the contamination in the first place.
9.4.2 All operators of aircraft are reminded of their obligations as aviation document holders to comply with section 13(a) of the Civil Aviation Act 1990.
13 Duties of pilot-in-command
The pilot-in-command of an aircraft shall—
(a) be responsible for the safe operation of the aircraft in flight, the safety and well-being of all passengers and crew, and the safety of cargo carried; and…
9.4.3 Appropriately managing the risk to the quality of fuel that enters the aircraft has a material impact on both the safe operation of the aircraft in flight and the safety and well being of all passengers and crew. Therefore, all pilots are expected to ensure that any instances of contaminated fuel entering an aircraft are appropriately reported and dealt with.
9.4.4 For operators that are obligated to have a safety management system (SMS) approved under Civil Aviation Rule Part 100, it is expected that any instances as described above are appropriately managed through the provisions in their SMS. Incidents of fuel contamination impact on virtually all of the SMS elements that are identified in advisory circular AC100-1 and it is expected that:
A1.1 An aircraft engine should not be started or operated whilst refuelling is underway:
A1.2 Turbine engines, in addition, should not be operated within the appropriate distance specified below of any other aircraft, fuelling equipment or exposed public areas which lie to the rear of and within a 15º arc either side of the exhaust outlet axis of that engine.
Minimum distance metres
At or below normal slow taxiing power
15 (50 ft)
At power used to initiate movement of a stationary aircraft
23 (75 ft)
At or below normal slow taxiing thrust
30 (100 ft)
At thrust used to initiate movement of a stationary aircraft
46 (150 ft)
NOTE: Fuelling equipment does not include equipment and outlet points of an installation located below ground level when the equipment is stowed and covering hatches are in place.
A2.1.1 Dipsticks should be fabricated from a non-magnetic material, finished so that they are unlikely to damage the fuel tanks or cells of the aircraft they are to be used on.
A2.1.2 Many dipsticks are fabricated out of wood. It is preferable the dipstick is not painted, however, if it is painted, ensure that it is a type of paint that will not be affected by the fuel and the paint is unlikely to chip or flake. Ensure that the surface finish will not facilitate excessive creeping of the fuel level which may lead to over indication of the fuel quantity.
A2.1.3 Many dipsticks are circular, however the use of a rectangular or square section may make it easier to mark and will more easily allow different units of measurement to be included.
A2.1.4 The top end of the dipstick should be fabricated so that the dipstick cannot fall into the tank, the dipstick should be fitted with a "REMOVE BEFORE FLIGHT" streamer.
A2.2.1 All dipstick markings should be permanent, preferably engraved, and should include the aircraft’s registration letters and the units of measurement. While the aircraft may appear to be the same, it is quite possible that the same type of aircraft may have different shaped or sized fuel tanks – therefore aircraft dipsticks should not be interchanged between aircraft.
A2.2.2 In addition to the manufacturer's preferred markings, complementary scales in differing units of volume or weight may be added on separate surfaces of the dipstick, providing no chance of confusion exists.
A2.2.3 If the aircraft has tanks with differing capacities, a separate dipstick should preferably be used for each tank location, rather than to calibrate a common dipstick. Each dipstick should be clearly marked to indicate which tank it relates to.
A2.2.4 The dipstick should be marked to indicate "empty" when the tank contains the unusable fuel quantity stated in the flight manual. In other words, the quantity indicated by the dipstick should be usable rather than total.
A2.2.5 To establish the "empty" mark, the fuel system should be drained at its lowest drain point. Allowing for any undrainable fuel, add the quantity of fuel required to make up "unusable" fuel. With the aircraft in the attitude that it would be in when the dipstick is used, mark the dipstick "empty" at the fuel level indicated. Calibrate the remainder of the scale by adding known additional quantities of fuel and marking the dipstick accordingly.
A2.3.1 For most aircraft the dipstick should be held vertically while making fuel quantity readings. However, some aircraft may have unusual filler neck geometry necessitating special techniques for which instructions should be supplied.
A2.3.2 The dipstick should never be forced or allowed to drop onto the bottom of the tank, as damage may occur or paint flakes may be dislodged.
A2.3.3 Dust and debris should be wiped off the dipstick with a clean cloth before its insertion into the fuel tank.
A2.4.1 When not in use, the dipstick should be kept in a stowage receptacle, where it cannot come adrift during flight.
A2.4.2 Stowage should preferably be in a specially made pocket so that the dipstick is protected from contamination and is readily accessible from the ground outside the aircraft. The stowage pocket should have suitable provision (e.g. a flap or straps) to retain the dipstick.
A2.4.3 Before stowage, the dipstick should be wiped dry so that residual fuel vapour will not cause discomfort or danger to the aircraft occupants.
 Aircraft fuel tank calibration, aircraft fuel flow tests, and the draining of aircraft fuel tanks which are normally conducted within hangars at engineering bases, are not deemed to be fuelling. Special procedures etermined by the aircraft operator, the airport authority, the fuel company, and the maintenance organisation and should be used for the protection of these operations.
Fuelling zone/area: This is made up of areas with a radius of at least 3 metres, or more (depending on the installation)authorities, from filling and venting points on the aircraft, hydrant pits, fuelling vehicle and its hoses in use.
 Overwing Class 3.1A fuelling with one engine running is not permitted under any circumstances. For other fuel types,the procedure should be used only when an aircraft engine cannot be restarted because of inoperative ground aircraft starting equipment.
The overseer should ensure that the fuelling operation with one engine running, as requested by the operator, is within the scope of the current airport regulations.
Under no circumstances may fuelling take place on the same side of the aircraft as that where an engine is running, or on a Class 3.1A fuel helicopter, with the engine running.