{"id":"F2005B00782","name":"Civil Aviation Order 20.7.1B - Aeroplane weight & performance limitations - Aeroplanes above 5 700kg - All operations (turbine & piston-engined) (02/12/2004)","slug":"civil-aviation-order-20-7-1b-aeroplane-weight-performance-limitations-aeroplanes-above-5-700kg-all-o","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":32213,"registerId":"commonwealth-F2005B00782-current","compilationNumber":null,"startDate":"2026-04-01","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"Civil Aviation Order 20.7.1B - Aeroplane weight & performance limitations - Aeroplanes above 5 700kg - All operations (turbine & piston-engined) (02/12/2004)","content":"Civil Aviation Order 20.7.1B – Aeroplane weight and performance limitations – specified aeroplanes above 5 700 kg, or 2 722 kg if driven by 2 or more jet engines – all operations \nas amended\n\nmade under subregulation 235 (2) of the Civil Aviation Regulations 1988.\n\nThis compilation was prepared on 28 May 2014 taking into account amendments up to Civil Aviation Order 20.7.1B Amendment Instrument 2014 (No. 1).\n\nPrepared by the Legislative Drafting Section, Legal Branch, Legal Services Division, Civil Aviation Safety Authority, Canberra.\n\nContents\n\nPage\n\n2...Application........................................................\n\n3...Definitions........................................................\n\n4...Take-off weight limitations.............................................\n\n5...Landing weight limitations.............................................\n\n6...Accelerate-stop and take-off distance required..............................\n\n7...Take-off climb performance............................................\n\n8...En-route climb performance............................................\n\n9...Approach climb performance...........................................\n\n10..Landing climb performance............................................\n\n11..Landing distance required.............................................\n\n12..Obstacle clearance requirements........................................\n\n12A.Alternative take-off area requirements....................................\n\n14..Aeroplane configuration and procedures...................................\n\nNotes to Civil Aviation Order 20.7.1B.....................................\n\nSection 20.7.1B\n\nCivil Aviation Order 20.7.1B – Aeroplane weight and performance limitations – specified aeroplanes above 5 700 kg, or 2 722 kg if driven by 2 or more jet engines – all operations\n\n2 Application\n\n2.1 Subject to paragraph 2.2, this section applies to:\n\n(a) all aeroplanes driven by 2 or more jet engines having a maximum take‑off weight in excess of 2 722 kg; and\n\n(b) all aeroplanes driven by 2 or more turbine propeller engines having a maximum take-off weight in excess of 5 700 kg; and\n\n(c) all new types of aeroplanes first registered in Australia after 1 June 1963, driven by 2 or more piston engines and having a maximum take-off weight in excess of 5 700 kg.\n\n> Note Aeroplanes of maximum take-off weight exceeding 2 722 kg and not subject to Civil Aviation Order 20.7.1, 20.7.1B or 20.7.4 remain subject to subregulation 235 (2) of the Civil Aviation Regulations 1988.\n\n2.2 For paragraph 2.1:\n\n(a) a certificate of airworthiness for the aircraft must be in force; and\n\n(b) the certificate must include a statement to the effect that the certificate is issued in the transport, commuter or normal category.\n\nNote 1 The only normal category aeroplanes with maximum take-off weights exceeding 5 700 kg are SFAR 41 aeroplanes. See paragraph 7.6.\n\nNote 2 Aeroplanes of maximum take-off weight exceeding 5 700 kg and not subject to sections 20.7.1 or 20.7.1B of the Civil Aviation Orders remain subject to subregulation 235 (2) of the Regulations.\n\n3 Definitions\n\n3.1 In this section:\n\n> accelerate-stop distance available means the sum of:\n\n(a) the length of the take-off run available; and\n\n(b) if stopway is provided — the length of the stopway.\n\n> actual landing distance means the landing distance required for the actual conditions, using the deceleration devices planned to be used for the landing.\n\n> Note Actual landing distance required is explained in Safety Alert for Operators, SAFO 06012 published by the USA Federal Aviation Administration.\n\n> approved foreign flight manual, in relation to an aeroplane, means a flight manual for the aeroplane approved by the relevant regulatory aviation authority of the country where the aeroplane is, or was, manufactured.\n\n> Arinc 424 RF path terminator means a segment of a flight path known as radius-to-fix, terminating as specified in Aeronautical Radio Incorporated Specification 424-17.\n\n> clearway means a defined rectangular area at the end of a strip centrally located about the extended centre-line of its associated runway and declared to be available as a suitable area over which an aircraft taking off can continue to climb to the minimum height required to establish obstacle clearance.\n\n> contaminated runway means a runway that has more than 25% of the runway surface area within the required length and width being used covered by:\n\n(a) water, or slush, more than 3 mm deep; or\n\n(b) loose snow more than 20 mm deep; or\n\n(c) compacted snow or ice, including wet ice.\n\n> FMS means the flight management system of an aeroplane.\n\n> gross flight path means the flight path it is assumed an aeroplane will follow when flown in a particular configuration in accordance with specified procedures in ambient conditions and that is established from the aeroplane’s certification performance data representing the average fleet performance of the aeroplane type.\n\n> landing distance available means the length of the runway declared to be available and suitable for the ground run of an aeroplane landing.\n\n> manufacturer’s data manual, in relation to an aeroplane, means a publication (however described) produced by the manufacturer of the aeroplane as a guide for the flight crew in the operation of the aeroplane.\n\n> net flight path means the gross flight path of an aeroplane reduced in elevation or extended in length by margins specified in this section. The margins are to allow for factors such as deterioration in aeroplane performance and variations in pilot techniques in relating aeroplane performance to obstacle clearance.\n\n> RF leg means a radius-to-fix leg encoded in the navigation database for an approved RNP operation.\n\n> RNP means required navigation performance as displayed to the flight crew by the FMS.\n\n> RNP type means a level of navigation performance capability expressed in nautical miles and specified in the aeroplane’s flight manual to indicate the minimum navigation system requirements needed to operate in an area, on a route or on a procedure.\n\n> RNP-capable aeroplane means an aeroplane:\n\n(a) that is approved for area navigation (RNAV); and\n\n(b) that meets the RNP capability necessary for an approved RNP operation in accordance with the aeroplane’s flight manual; and\n\n(c) whose FMS permits the RNP type to be selected and displayed to the flight crew.\n\n> speeds:\n\nV1 means the take-off decision speed;\n\nV1 (wet) means a reduced V1 established for use on a wet or contaminated runway;\n\nV2 means the initial climb out speed which is not less than the take-off safety speed;\n\nVR means the speed at which aeroplane rotation is initiated by the pilot during take-off;\n\nVS means the minimum speed in a stall or the minimum steady flight speed.\n\n> stopway means a defined rectangular area at the end of a runway, centrally located about the extended centre-line of its associated runway, declared to be available as a suitable area in which an aeroplane may be stopped after an interrupted take-off.\n\n> suitable aerodrome means an aerodrome approved for normal operations and which is forecast not to require an alternate during the period nominated for possible use. Operational requirements for suitable aerodromes are as promulgated by CASA.\n\n> take-off distance available means the sum of:\n\n(a) the length of the take-off run available; and\n\n(b) if clearway is provided — the length of the clearway.\n\n> take-off run available means the length of runway declared to be available and suitable for the ground run of an aeroplane taking off.\n\n> Note If any part of the take-off run available is lost due to the alignment of the aircraft at the start of the take-off run, account must be taken of the loss.\n\n> the Regulations means the Civil Aviation Regulations 1988.\n\n> wet runway means a runway that:\n\n(a) is covered by surface water not more than 3 mm deep; or\n\n(b) is covered by slush or loose snow equivalent to surface water not more than 3 mm deep; or\n\n(c) has sufficient moisture on the surface to cause it to appear reflective, but without significant areas of standing water.\n\nNote The distances and areas mentioned in the above definitions are normally declared to be available by the national aviation authority. In Australia, they are specified in Aeronautical Information Publications but may be the subject of a separate approval from CASA.\n\n4 Take-off weight limitations\n\n4.1 For the purposes of paragraph 235 (2) (a) of the Regulations, the maximum weight that an aeroplane to which this section applies may not exceed at take‑off is the least of the weights determined in accordance with subparagraphs (a) to (d):\n\n(a) a weight at which the take-off distance and accelerate-stop distance required under subsection 6 for the aerodrome elevation, ambient temperature, wind component along the runway, runway slope and runway surface conditions at the time of take-off are equal to or less than the take-off distance and accelerate-stop distance available in the direction of take-off. Approved declared conditions may be used instead of the ambient temperature and aerodrome elevation;\n\n(b) a weight that will permit compliance with the take-off climb requirements mentioned in subsection 7 taking into account either ambient temperature and aerodrome elevation, or approved declared conditions;\n\n(ba) for aeroplanes with maximum take-off weight in excess of 5 700 kg, a weight that will permit compliance with the obstacle clearance requirements mentioned in paragraph 7.5 and subsection 12 for take-off from a dry runway (whether it is dry or not) and taking into account either wind conditions, ambient temperature and aerodrome elevation, or wind conditions and approved declared conditions;\n\n(c) a weight which will permit compliance with the en-route obstacle clearance requirements specified in subsection 12;\n\n(d) a weight which, allowing for normal consumption of fuel and oil in flight to the destination and alternate aerodrome, will permit compliance with the landing weight limitations mentioned in subsection 5.\n\n5 Landing weight limitations\n\n5.1 For the purposes of paragraph 235 (2) (b) of the Regulations, the maximum weight which an aeroplane to which this section applies may not exceed at landing is the least of the weights determined in accordance with subparagraphs (a) to (c):\n\n(a) a weight at which the landing distance required in accordance with subsection 11 for the aerodrome elevation, wind component along the runway, runway slope (when exceeding 1%) and runway surface conditions at the time of landing, is equal to or less than the landing distance available in the direction of landing;\n\n(b) a weight which will permit compliance with the approach climb requirements specified in subsection 9, taking into account forecast or ambient temperature and aerodrome elevation or approved declared conditions;\n\n(c) a weight which will permit compliance with the landing climb requirements specified in subsection 10 taking into account forecast or ambient temperature and aerodrome elevation or approved declared conditions.\n\n6 Accelerate-stop and take-off distance required\n\n6.1 For subparagraph 4.1 (a), and subject to paragraphs 6.3.4 and 6.4, the accelerate-stop distance required is the distance set out in the flight manual.\n\n6.2.1 For subparagraph 4.1 (a), and subject to paragraphs 6.3.4 and 6.4, the take-off distance required is the distance set out in the flight manual.\n\n6.2.2 Subject to paragraph 6.4, if the take-off distance required at the take‑off weight selected by the pilot in command is greater than the take-off run available, the pilot in command must ensure that:\n\n(a) if the flight manual sets out information about take-off run required — the take-off run required does not exceed the take-off run available; or\n\n(b) if the flight manual does not set out information about take-off run required — the take-off distance required does not exceed the take-off run available by more than the lesser of 60 metres or the length of clearway included in the take-off distance available.\n\n6.3.1 For a take-off from a wet or contaminated runway, V1 may be less than V1 appropriate to a dry runway but not less than V1 (wet).\n\n6.3.2 V1 (wet) must:\n\n(a) allow the aeroplane to reach a height at least 15 feet above the runway after the aeroplane has:\n\n(i) suffered an engine failure that is recognised by the pilot at V1 (wet); and\n\n(ii) travelled a distance along the runway equal to the take-off distance required; and\n\n(b) subject to paragraph 6.4, be determined from the flight manual or the operations manual for the aircraft; and\n\n(c) not be less than the minimum control speed on the ground (Vmcg).\n\n6.3.3 For a take-off from a wet runway:\n\n(a) the take-off weight must not exceed that permitted for take-off from the runway when dry under the same conditions of ambient temperature and wind component along the runway; and\n\n(b) either:\n\n(i) if the flight manual or the operations manual allows the take-off distance available to include clearway — the take‑off run required must not exceed the take-off run available; or\n\n(ii) in any other case — the take-off distance available must not include clearway.\n\n6.3.4 Subject to paragraph 6.4, for a take-off from a contaminated runway:\n\n(a) the accelerate-stop distance required and the take-off distance required must be:\n\n(i) the distances set out in the flight manual or the operations manual for operations conducted on contaminated runways; or\n\n(ii) the distances approved by CASA for operations conducted on runways covered by slush, snow or a depth of water; and\n\n(b) the take-off weight must not exceed that permitted for take-off from the runway when wet under the same conditions of ambient temperature and wind component along the runway; and\n\n(c) either:\n\n(i) if the flight manual or the operations manual allows the take-off distance available to include clearway — the take-off run required must not exceed the take-off run available; or\n\n(ii) in any other case — the take-off distance available must not include clearway.\n\n6.4 For subparagraph 4.1 (a), paragraph 6.2.2 and paragraph 6.3.1, an aeroplane engaged in private operations must be operated so that compliance with the runway length requirements is demonstrated using data set out in:\n\n(a) the flight manual; or\n\n(b) the manufacturer’s data manual; or\n\n(c) the approved foreign flight manual.\n\nNote The data contained in some manufacturers’ data manuals is unfactored and makes no allowance for degraded aircraft performance.\n\n6.5 Nothing in paragraph 6.4 affects subsections 7 and 12.\n\n7 Take-off climb performance\n\n7.1 In the take-off configuration assuming failure of the critical engine so that it is recognised at V1, an aeroplane must be able to climb without ground effect at the speed established as the speed at which the aeroplane becomes airborne and in this configuration, without landing gear retraction, achieve a gross gradient of climb which is positive for two-engined aeroplanes, 0.3% for three-engined aeroplanes and 0.5% for four-engined aeroplanes.\n\n7.2 In the take-off configuration that exists with the critical engine inoperative and the landing gear fully retracted, the aeroplane at speed V2 must be able to achieve a gross gradient of climb of at least:\n\n(a) if the aeroplane is a commuter type aeroplane — 2%; and\n\n(b) if the aeroplane is not a commuter type aeroplane:\n\n(i) if it has 2 engines — 2.4%; and\n\n(ii) if it has 3 engines — 2.7%; and\n\n(iii) if it has 4 engines — 3%.\n\n7.3.1 An aeroplane may be accelerated in level flight from V2 speed to final take-off climb speed at a height above the take-off surface that is the greater of:\n\n(a) 400 feet; or\n\n(b) the height necessary to achieve obstacle clearance in accordance with paragraphs 12.1 and 12.2.\n\n7.3.2 During any such level flight acceleration manoeuvre, an aeroplane with the critical engine inoperative must have an available gross gradient of climb of at least:\n\n(a) for a twin-engined aeroplane — 1.2%; or\n\n(b) for a 3-engined aeroplane — 1.4%; or\n\n(c) for a 4-engined aeroplane — 1.5%.\n\n7.4.1 In the en-route configuration existing at the end of the level flight acceleration manoeuvre, an aeroplane must be able to achieve a gross gradient of climb of at least:\n\n(a) for a twin-engined aeroplane — 1.2%; or\n\n(b) for a 3-engined aeroplane — 1.4%; or\n\n(c) for a 4-engined aeroplane — 1.5%.\n\n7.4.2 The gradient of climb must be achievable at final take-off climb speed with the critical engine inoperative and the remaining engines at maximum continuous power or thrust.\n\n7.5 In determining the net flight path of an aeroplane to show compliance with subsection 12, the gross gradients of climb achieved in paragraphs 7.2 and 7.4.1 must be reduced by 0.8% for twin-engined aeroplanes, 0.9% for three‑engined aeroplanes and 1.0% for four-engined aeroplanes. Similarly the horizontal distance to accelerate in compliance with paragraph 7.3.1 must be increased due to the acceleration reduction equivalent to the climb gradient reductions specified in this paragraph.\n\n> Note The net flight path and the gross flight path may be considered identical when the aeroplane is in the take-off configuration described in paragraph 7.1.\n\n7.6 In this section:\n\n> commuter type aeroplane means:\n\n(a) a SFAR 41 aeroplane; or\n\n(b) an aeroplane that is certificated as a commuter category aircraft.\n\n> SFAR 41 aeroplane means an aeroplane that:\n\n(a) is certificated as a normal category aircraft; and\n\n(b) is such that an applicant under part 4 (c) of SFAR No. 41 would be entitled to a type certificate amendment or a supplemental type certificate that shows compliance with Annex 8 to the Chicago Convention in relation to the aeroplane; and\n\n(c) is operated in accordance with a flight manual that specifies performance standards that are at least equivalent to the standards set out in Annex 8 to the Chicago Convention.\n\n> SFAR No. 41 means Special Federal Aviation Regulation No. 41 of the United States of America.\n\n8 En-route climb performance\n\n8.1 The en-route climb performance of an aeroplane with the critical engine inoperative is to be determined taking into account all normal operating altitudes, operating weights, and anticipated temperatures.\n\n8.2 The en-route climb performance of a three- or four-engined aeroplane with the 2 most critical engines inoperative is to be determined taking into account all normal operating altitudes, operating weights, and anticipated temperatures.\n\n8.3 In determining the net flight path of an aeroplane to show compliance with subsection 12, the gross climb gradients established in accordance with paragraph 8.1 must be reduced by 1.1% for twin-engined aeroplanes, 1.3% for three-engined aeroplanes and 1.4% for four-engined aeroplanes. Similarly the gross climb gradients established in accordance with paragraph 8.2 must be reduced by 0.3% for three-engined aeroplanes and 0.5% for four-engined aeroplanes.\n\n9 Approach climb performance\n\n9.1 For paragraph 5.1 (b), the approach climb requirements are met if, in the approach configuration with the critical engine inoperative at a speed not more than 1.5 VS, an aeroplane has a gross gradient of climb of at least:\n\n(a) for a twin-engined aeroplane — 2.1%; or\n\n(b) for a 3 engined aeroplane — 2.3% or\n\n(c) for a 4 engined aeroplane — 2.4%.\n\n10 Landing climb performance\n\n10.1 For the purposes of subparagraph 5.1 (c), the landing climb requirements are met if, in the landing configuration an aeroplane has a gross gradient of climb of not less than 3.2% at a climbing speed not in excess of 1.3 VS with all engines operating.\n\n11 Landing distance required\n\n11.1 When determining the maximum weight for take-off of a jet-engined aeroplane of maximum take-off weight greater than 5 700 kg for the purpose of subparagraph 4.1 (d), the landing distance required is:\n\n(a) for an aeroplane engaged in regular public transport operations when the appropriate weather reports and forecasts, or a combination, indicate that the runways will be dry at the estimated time of arrival, or in charter operations — 1.67 times the distance required to bring the aeroplane to a stop on a dry runway; or\n\n(b) for an aeroplane engaged in regular public transport operations when the appropriate weather reports and forecasts, or a combination, indicate that the runways may be wet at the estimated time of arrival:\n\n(i) 1.92 times the distance required to bring the aeroplane to a stop on a dry runway; or\n\n(ii) the distance set out in the flight manual or operations manual for operations conducted on wet runways.\n\n11.2 When determining the maximum weight for landing of a jet-engined aeroplane of maximum take-off weight greater than 5 700 kg for the purpose of subparagraph 5.1 (a), the landing distance required is 1.67 times the distance required to bring the aeroplane to a stop on a dry runway or, if actual landing distance data is supplied by the aircraft’s type certificate holder, 1.15 times the actual landing distance.\n\n> Note Subparagraph 4.1 (d) refers to determining the permissible landing weight before take‑off and subparagraph 5.1 (a) refers to re-assessing the permissible landing weight after take-off.\n\n11.3 For subparagraphs 4.1 (d) and 5.1 (a), when determining the maximum weight for take-off and landing, respectively, of a jet-engined aeroplane of maximum take-off weight not greater than 5 700 kg engaged in regular public transport operations, the landing distance required is 1.43 times the distance required to bring the aeroplane to a stop on a dry runway.\n\n11.4 When determining the maximum weight for take-off of a propeller-driven aeroplane for the purpose of subparagraph 4.1 (d), the landing distance required in regular public transport operations and charter operations is:\n\n(a) when the appropriate weather reports and forecasts, or a combination, indicate that the runways will be dry at the estimated time of arrival — 1.43 times the distance required to bring the aeroplane to a stop on a dry runway; or\n\n(b) when the appropriate weather reports and forecasts, or a combination, indicate that the runways may be wet at the estimated time of arrival:\n\n(i) for a landing at a destination aerodrome — 1.67 times the distance required to bring the aeroplane to a stop on a dry runway; or\n\n(ii) for a landing at an alternate aerodrome — 1.43 times the distance required to bring the aeroplane to a stop on a dry runway.\n\n11.5 When determining the maximum weight for landing of a propeller-driven aeroplane for subparagraph 5.1 (a), the landing distance required in regular public transport operations and charter operations is 1.43 times the distance required to bring the aeroplane to a stop on a dry runway.\n\n11.6 Subject to paragraph 11.8, the distance required to bring the aeroplane to a stop on a dry runway must be the horizontal distance necessary to land and come to a complete stop from a point 50 feet above the landing surface using information set out in the flight manual.\n\n11.7 Subject to paragraph 11.8, for a landing on a contaminated runway, the landing distance required is:\n\n(a) the distance set out in the flight manual or the operations manual for operations conducted on contaminated runways; or\n\n(b) the distance approved by CASA for operations conducted on runways covered by slush, snow or a depth of water; or\n\n(c) if actual landing distance data is supplied by the holder of the aircraft’s type certificate — 1.15 times the actual landing distance.\n\n11.8 For subparagraph 4.1 (d) and paragraph 5.1, an aeroplane engaged in private operations or aerial work operations, or a jet-engined aeroplane of maximum take-off weight not greater than 5 700 kg engaged in charter operations, must be operated so that compliance with the landing requirements is demonstrated using data set out in the flight manual or the manufacturer’s data manual.\n\n> Note The data contained in some manufacturers’ data manuals is unfactored and makes no allowance for degraded aircraft performance.\n\n11.9 Paragraphs 11.2, 11.3, 11.5, 11.7 and 11.8 do not apply in the case of an emergency.\n\n12 Obstacle clearance requirements\n\n12.1 For the purposes of subparagraph 4.1 (ba), the take-off obstacle clearance requirements are met if the net flight path of the aeroplane, following failure of the critical engine so that it is recognised at V1 appropriate to a dry runway, would clear by at least 35 feet vertically all obstacles in the take-off area. For the purpose of meeting this requirement, the planned departure procedure may include a change of heading but, in that event, the change of heading must not be initiated before a point where the net flight path clears all obstacles by at least 50 feet and, for the duration of the turn, the net flight path must clear by at least 50 feet vertically all obstacles in the take-off area. The planned angle of bank must not exceed 15°, except that in an approved RNP operation the planned angle of bank must not exceed 25° subject to the aeroplane’s flight manual containing data that supports the planned angle of bank. The data must provide an increased take-off safety speed V2 when planning an angle of bank greater than 15°. It must also contain data to allow construction of the net flight path when using an increased take-off safety speed V2 and when planning to use an angle of bank greater than 15°.\n\nNote If an engine failure is recognised at or after V1 (wet) during take-off from a wet or contaminated runway, the net flight path may clear obstacles by less than 35 feet, or, during a turn, by less than 50 feet.\n\n12.1A In paragraph 12.1, take-off area means the area calculated by the operator in accordance with paragraph 12.1.1 or subsection 12A, at the operator’s discretion.\n\n12.1B However, the operator is not required to calculate the area beyond the point on the planned flight path at which the net flight path complies with paragraph 12.4.\n\n12.1.1 Unless determined in accordance with subsection 12A, the take-off area is:\n\n(a) in the case of V.M.C. operations by aeroplanes below 22 700 kg maximum take-off weight — the area on either side of the planned flight path within a lateral distance of 150 feet plus 0.125D where D is distance measured horizontally along the planned flight path and commencing at the end of the take-off distance available. Despite this requirement, the area more than 1 000 feet either side of the planned flight path need not be considered unless the planned flight path involves a change of heading in excess of 15o. In this latter event the lateral area will continue to expand throughout the turn and the limiting lateral distance shall become the greater of 1 000 feet or the distance represented by 150 feet plus 0.125D where D is measured to the point of completion of the turn;\n\n(b) in the case of V.M.C. operations by aeroplanes at or above 22 700 kg maximum take-off weight and all I.M.C. operations — the area on either side of the planned flight path within a lateral distance of 250 feet plus 0.125D where D is distance measured horizontally along the planned flight path and commencing at the end of the take-off distance available. If the aircraft is equipped and approved to conduct RF legs and any turns, and the departure procedures are constructed using ARINC 424 RF path terminators, then the lateral expansion of the take-off area may be discontinued when the perimeter of the take-off area reaches:\n\n(i) RNP set equal to, or greater than, 0.5 — 900 metres either side of the defined flight path; or\n\n(ii) RNP set equal to, or less than, 0.2 — 370 metres either side of the defined flight path; or\n\n(iii) RNP set to more than 0.2 but less than 0.5 — a distance either side of the defined flight path derived by linear interpolation between 370 metres and 900 metres according to the RNP.\n\n12.2 In the application of paragraph 12.1, it is to be assumed that the point on the net flight path where a horizontal flight segment commences is the same horizontal distance from the end of the runway as the point where the gross flight path intersects the height selected for the level flight acceleration manoeuvre.\n\nNote This paragraph requires the height selected by the operator for the level flight acceleration manoeuvre to be more than 35 feet higher than the height of the highest obstacle in the take-off area.\n\n12.3.1 For paragraph 12.1, an obstacle-clear take-off gradient, for a runway and a direction, published in Aeronautical Information Publications, may be used for the part of the take-off area commencing at the end of the take-off distance available and extending for the length of the surveyed area on which the gradient is based, despite the fact that the rate of divergence of the surveyed area may be less than 0.125D and that the length of the inner edge of the surveyed area may be less than 300 feet.\n\n12.3.2 The requirements mentioned in paragraph 12.1 are met for a part of the take‑off area if the gradient of the net flight path in that part is not less than the obstacle-clear take-off gradient.\n\n12.3.3 The obstacle-clear take-off gradient is taken to be zero at the height of the highest obstacle within the take-off area.\n\n12.4 For the purposes of subparagraph 4.1 (c), and subject to paragraph 12.5, the en-route obstacle clearance requirements are met if, in the en-route configuration with the critical engine inoperative the net flight path of an aeroplane under V.M.C. clears by 1 000 feet vertically all obstacles within 5 nautical miles of the aeroplane’s track or, under I.M.C., by such greater distance as is determined by the accuracy of the navigation aid(s) used. At the pressure altitude required to achieve this clearance of the critical en-route obstacles the net flight path must have a positive slope.\n\n12.5 If compliance with paragraph 12.4 is not possible, a “drift down” procedure may be planned. For this purpose it must be established that, following failure of the critical engine at any point during climb or cruise, a net flight path from that point to a suitable aerodrome will clear, by 2 000 feet vertically, all obstacles within 5 miles laterally of the aeroplane’s track under V.M.C. or, in the case of I.M.C., obstacles within such greater lateral distance from the aeroplane’s track as is determined by the accuracy of the navigation aid(s) used.\n\n12.6 The net flight path in the en-route configuration must have a positive slope at 1 500 feet above the aerodrome where a landing is assumed to be made following engine failure. If the aeroplane is to be landed at other than the destination or alternate aerodrome following an engine failure that aerodrome must be specified in the operational flight plan and be suitable for landing.\n\n12.7 The following factors must be taken into account when determining the net flight path in the en-route configuration:\n\n(a) the effect of wind;\n\n(b) temperature (forecast temperature may be used in the determination of en-route net flight paths);\n\n(c) pressure altitude;\n\n(d) fuel and oil consumption;\n\n(e) fuel jettisoning — in accordance with an approved procedure, consistent with reaching an aerodrome;\n\n(f) the effect of ice protection systems when anticipated weather conditions along the route indicate possibility of icing conditions.\n\n12A Alternative take-off area requirements\n\n12A.2 Subject to paragraphs 12A.3, 12A.4 and 12A.5, the take-off area consists of the area on either side of the planned flight path within a lateral distance calculated using the formula:\n\n90 metres + 0.125D\n\nwhere D is the distance measured horizontally along the planned flight path and commencing from the end of the take-off distance available.\n\n12A.3 Obstacles at a distance greater than 600 metres on either side of the planned flight path need not be cleared:\n\n(a) if the planned flight path does not include a change of heading of more than 15o; or\n\n(b) in the case of operations conducted in V.M.C. by day.\n\n12A.4 If paragraph 12A.3 does not apply, obstacles at a distance greater than 900 metres on either side of the planned flight path need not be cleared.\n\n12A.5 Despite paragraphs 12A.3 and 12A.4, for an RNP-capable aeroplane engaged in an approved RNP operation, the expansion of the take-off area may be discontinued when the perimeter of the take-off area reaches:\n\n(a) if RNP is set equal to or greater than 0.5 — 900 metres on either side of the defined flight path; or\n\n(b) if RNP set to or less than 0.2 — 370 metres on either side of the defined flight path; or\n\n(c) if RNP is set to more than 0.2 but less than 0.5 — a distance on either of the defined flight path, derived by linear interpolation, between 370 metres and 900 metres according to RNP.\n\n14 Aeroplane configuration and procedures\n\n14.1 Paragraph 14.1A applies if:\n\n(a) the manufacturer of, or the holder of the type certificate for, an aeroplane has published advice, recommendations or guidance (the information) about the performance of the aeroplane in an emergency, unusual operating conditions or an abnormal configuration; and\n\n(b) the aeroplane is in the emergency, conditions or configuration.\n\n14.1A The pilot in command of the aeroplane must take the information into account when planning the take-off or landing of the aeroplane.\n\n14.1B In subparagraph 14.1 (a), type certificate includes foreign type certificate within the meaning of paragraph 21.041 (1) of the Civil Aviation Safety Regulations 1998.\n\n14.2 Procedures to be followed consistent with this Order, including procedures anticipating engine failure at any time between the commencement of take-off and completion of landing, must be specified in the Operator’s Operation Manual. The procedures so specified must be such that they can be consistently executed in service by flight crews of average skill and they must also be such that the take-off flight path with all engines operating is above the one-engine inoperative take-off flight path.\n\n> Notes to Civil Aviation Order 20.7.1B\n\n> Note 1\n\n> Note: The Civil Aviation Order (in force under the Civil Aviation Regulations 1988) as shown in this compilation comprises Civil Aviation Order 20.7.1B amended as indicated in the Tables below.\n\n> Note: > Note: Table of Orders\n\n| Year andnumber | Date of notificationin Gazette/registration on FRLI | Date ofcommencement | Application, saving ortransitional provisions |\n| ---------------------- | --------------------------------------------------- | -------------------------- | --------------------------------------------- |\n| 2004 No. R7 | 8 December 2004 | 8 December 2004 (see s. 2) | |\n| 2005 No. 1 | FRLI 10 June 2005 | 11 June 2005 (see s. 2) | |\n| CAO 20.7.1B 2014 No. 1 | FRLI 23 May 2014 | 24 May 2014 (see s. 2) | |\n\n```html\n

Table of Amendments

ad. = added or inserted am. = amended rep.= repealed rs. = repealed and substituted

Provision affected

How affected

s. 20.7.1B

rs. 2004 No. R7

title

rs. 2005 No. 1

am. CAO 20.7.1B 2014 No. 1

subs. 2

am. 2005 No. 1, CAO 20.7.1B 2014 No. 1

subs. 3

am. 2005 No. 1, CAO 20.7.1B 2014 No. 1

subs. 4

am. 2005 No. 1, CAO 20.7.1B 2014 No. 1

subs. 5

am. 2005 No. 1

subs. 6

rs. 2005 No. 1

subs. 7

am. 2005 No. 1

subs. 8

am. 2005 No. 1

subs. 9

rs. 2005 No. 1

subs. 11

am. 2005 No. 1

rs. CAO 20.7.1B 2014 No. 1

subs. 12

am. 2005 No. 1, CAO 20.7.1B 2014 No. 1

subs. 12A

am. 2005 No. 1, CAO 20.7.1B 2014 No. 1

subs. 14

am. 2005 No. 1

\n```\n\n> Note 2\n\nTransitional and savings provisions\n\nClause 5 of Civil Aviation Amendment Order (No. 2) 2002 reads as follows:\n\n5 Transitional\n\n5.1 An approval given under paragraph 13.3 of section 20.7.1B of the Civil Aviation Orders (the Orders) to operate a twin-engined aeroplane on passenger carrying regular public transport operations that was in force immediately before the commencement of subsection 3B of section 82.0 of the Orders is taken to continue in force as if subsection 13 of section 20.7.1B and Appendixes I and II to that section were still in force.\n\n5.2 A twin-engined aeroplane that was being operated in accordance with paragraph 13.4 of section 20.7.1B, but not in accordance with an approval given under paragraph 13.6, immediately before the commencement of subsection 3B of section 82.0, may continue to be operated in accordance with paragraph 13.4 as if subsection 13 of section 20.7.1B and Appendixes I and II to that section were still in force.\n\n5.3 A twin-engined aeroplane that was being operated in accordance with an approval given under paragraph 13.6 of section 20.7.1B, that was in force immediately before the commencement of subsection 3B of section 82.0, may continue to be operated in accordance with that approval as if subsection 13 of section 20.7.1B and Appendixes I and II to that section were still in force together with the airworthiness directive issued by CASA and known as AD/General/69.","sortOrder":0}],"analysis":{"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"flash_summary":{"complexity_score":8,"scope_assessment":{"changed":true,"description":"Since its original form the Order has been expanded and updated with technical detail and alternative compliance pathways. Amendments introduced: RNP‑based allowances and ARINC RF leg considerations (s.12, s.12A.5), explicit treatment of manufacturer/foreign flight manuals and advice (s.3; s.14.1A), alternative take‑off area calculations (s.12A), and clarified distinctions between jet/propeller and operation types (regular public transport, charter, private) in landing distance multipliers (s.11). These changes broaden the Order from a prescriptive set of weight/ performance limits into a more technical instrument that: (a) accommodates modern navigation capabilities (RNP/FMS); (b) specifies multiple data sources and approval routes; and (c) creates differentiated requirements by operation type. The core safety aim (weight/performance limits to ensure obstacle clearance and safe climb/landing performance) remains, but the practical scope has grown to include equipment‑based exemptions/allowances and more detailed data‑and‑approval workflows, increasing regulatory reach into equipment standards, operations manuals and performance data approvals."},"complexity_factors":["Numerous technical defined terms in s.3 (e.g. net/gross flight path, RNP, RF leg, actual landing distance), increasing interpretive burden","Multiple weight thresholds and applicability rules (2,722 kg vs 5,700 kg; different engine types; historic registration date) (s.2)","Cross‑references to many external documents: flight manual, manufacturer’s data manual, approved foreign flight manual, Aeronautical Information Publications, CASA approvals (s.3 definitions; s.6.4; s.11.7)","Layered conditional logic: different formulas and factors for jet vs propeller, regular public transport vs private/charter, dry/wet/contaminated runways (s.6, s.11)","Numeric performance margins and reductions applied differently by engine count (twin/tri/quad) across multiple provisions (s.7, s.8, s.12.3)","Nested exceptions and special cases (e.g. wet runway rules, contaminated runway approvals, emergency exceptions in s.11.9)","Alternative calculation path (s.12A) with RNP thresholds and interpolation rules (technical mathematics and navigation performance implications)","Operational-documentation requirement and human factors standard (procedures must be executable by crews of average skill) adding subjective compliance assessment (s.14.2)","Multiple amendment layers and transitional/saving provisions in Notes (table of amendments and transitional clauses), increasing historical interpretive complexity"],"plain_english_summary":"**What this Order does (mechanically)\n\n- Sets mandatory weight and performance limits for a defined group of aeroplanes (mostly multi‑engine and heavier types). (See s.2 and s.4–s.5.)\n- Specifies how to calculate the maximum permitted take‑off and landing weights by reference to: runway lengths (take‑off/landing distance available), accelerate‑stop/run requirements, climb performance with an engine out, en‑route obstacle clearance, and anticipated fuel burn. (See s.4.1, s.5.1, s.6, s.7, s.12.)\n- Lays down numeric climb‑gradient and speed targets (V1, V2, VR, VS) to be met after a critical‑engine failure for two‑, three‑ and four‑engine aeroplanes in specified configurations. (See s.7–s.10.)\n- Prescribes how to treat wet and contaminated runways, including reduced V1 (V1 (wet)), and the sources of approved performance data to be used (flight manual, manufacturer’s data, CASA approvals). (See s.6 and s.11.)\n- Defines obstacle‑clearance areas for departures and en‑route flight (including an alternate method for calculating take‑off area and allowances for RNP‑capable aircraft). (See s.12, s.12A.)\n- Requires pilots to take published manufacturer/type‑certificate emergency or abnormal‑configuration guidance into account when planning take‑offs or landings. (See s.14.1A.)\n\nWho this affects\n\n- Aircraft operators and flight crews of aeroplanes to which the Order applies: broadly, two or more jet‑engined aeroplanes over 2,722 kg, turbine‑prop aeroplanes over 5,700 kg, and certain piston‑engined types first registered after 1963 over 5,700 kg. (See s.2.)\n- Regulators (CASA) and type‑certificate holders who provide the data and approvals relied upon by operators (flight manuals, approved performance data, CASA approvals for special runway conditions or RNP operations). (See s.3 definitions; s.6.4; s.11.7.)\n- Airports and air navigation service providers indirectly, because declared runway lengths, clearways/stopways and published obstacle‑clear take‑off gradients are inputs to the calculations. (See notes to definitions and s.12.3.)\n\nWhy it matters (official purpose claim and testing it)\n\n- Officially: the Order implements minimum weight/ performance rules so aeroplanes can safely take off, climb, navigate en route and land even after engine failure, and clear obstacles. (See s.4–s.12.)\n\nTesting that claim against practical costs, incentives and trade‑offs:\n\n- Who pays: Operators bear the direct compliance costs — performing weight/performance calculations, limiting payload or fuel when necessary, training crews in the procedures and maintaining or updating operations manuals to reflect required data sources (s.6.4, s.14.2).\n\n- Behavioural incentives: The Order creates incentive for operators to plan more conservative weights (less payload or more fuel stops) where runway length, runway contamination, high temperature, elevation or obstacle environment restrict allowable weight (s.4.1(a), s.6.3, s.11). It also incentivises adoption of approved performance data, better flight manuals, and navigation capability (RNP) because those can ease some lateral/area requirements (s.12.1, s.12A.5).\n\n- Trade‑offs and opportunity costs: Meeting the standards can reduce commercial payload or require diversion/alternate planning, increasing operating costs per flight. Operators may need to choose between upgrading avionics/FMS (to gain RNP advantages) or accepting more restrictive departure/weight limits.\n\n- Implementation and data risks: The Order depends heavily on external documents (flight manual, manufacturer’s data manual, approved foreign flight manual, Aeronautical Information Publications and CASA approvals). Some manufacturer data may be \"unfactored\" (not adjusted for in‑service degradation), which the Order flags as a risk for private operators (s.6.4 note, s.11.8 note). Reliance on approved data and CASA approvals creates administrative and potential timing bottlenecks.\n\n- Compliance burden and discretion: Operators must document procedures in the operations manual and ensure flight crews can consistently execute them (s.14.2). CASA retains discretion to approve alternative distances or procedures (s.6.3.4(b), s.11.7(b)), and to accept RNP‑based reductions (s.12A.5), creating paths for both prescriptive compliance and administrative approvals.\n\n- Effects on competition and fleet choice: Smaller operators or those flying older types without modern FMS/RNP capability may face relatively higher costs or capacity restrictions; operators investing in equipage and approved data may gain operational flexibility (s.12A.5).\n\n- Concentrated benefits, diffuse costs: Safety gains from stricter, technical limits are concentrated (reduced accident risk) while the costs (payload restrictions, compliance work, potential avionics upgrades) are diffuse across operators and passengers.\n\nConcrete mechanisms (who decides, who pays, what changes)\n\n- Who decides: Pilot‑in‑command selects the actual take‑off and landing weight within the statutory limits, using approved/manual data; operators choose procedures and whether to pursue CASA approvals for special operations (s.6.2.2, s.14.2). CASA approves or accepts performance data and special procedures (s.6.3.4, s.11.7, s.12A.5).\n\n- Who pays: Aircraft operators (airlines, charter companies, private owners) pay through operational restrictions, paperwork, training and possible equipage/aircraft performance data purchases.\n\n- Behaviour change: More conservative flight planning where runway, weather, obstacle environment or aircraft performance are limiting; possible trade‑offs between payload and fuel/alternate planning; incentive to obtain RNP approval or better documented performance data.\n\nKey sections to check if you operate or regulate these aeroplanes: Application (s.2), Definitions and data sources (s.3, s.6.4, s.11.8), Take‑off & landing weight tests (s.4–s.5), Specific runway/wet/contaminated rules (s.6, s.11), Climb and obstacle clearance (s.7–s.12), Alternative take‑off area and RNP treatment (s.12A), and operational documentation requirements (s.14)."},"kimi_summary":{"content_quality":"ok","complexity_score":8,"scope_assessment":{"changed":true,"description":"The original 2004 Order appears to have been a consolidation/replacement of earlier performance rules. The 2005 amendments significantly expanded scope by adding detailed contaminated runway provisions, wet runway V1 calculations, and RNP (Required Navigation Performance) operational approvals. The 2014 amendments further expanded scope to incorporate modern navigation database procedures (ARINC 424 RF path terminators) and refined landing distance calculations with actual landing distance data. The Order has evolved from basic weight/performance limits to a comprehensive framework integrating advanced avionics, precision navigation, and variable runway condition performance."},"complexity_factors":["19 defined technical terms in section 3, many cross-referencing aviation standards (ARINC 424, SFAR 41, RNP types)","Nested conditional logic throughout: different rules apply based on engine count (2/3/4 engines), aircraft weight thresholds (2,722 kg vs 5,700 kg vs 22,700 kg), runway condition (dry/wet/contaminated), and operation type (private/charter/regular public transport)","Mathematical formulas for obstacle clearance areas (e.g., '90 metres + 0.125D' and linear interpolation for RNP values)","Extensive cross-referencing between subsections (e.g., paragraph 4.1(ba) references paragraph 7.5 and subsection 12; subsection 12A provides alternative calculations for subsection 12)","Multiple amendment layers visible in the Table of Amendments (2004, 2005, 2014) with provisions being substituted, amended, and repealed","Technical aviation jargon requiring specialised knowledge (V1, V2, VR, VS, Vmcg, RNP, RNAV, FMS, RF legs)","Exception to exception structure: e.g., paragraph 12.1.1 has conditions for VMC vs IMC operations, with sub-conditions for RF leg capability, which themselves have RNP-based thresholds"],"plain_english_summary":"This Civil Aviation Order sets the safety rules for how heavy aeroplanes must calculate their weight limits and performance capabilities during take-off, flight, and landing.\n\n**Who it affects:**\n- **Large jet aeroplanes** (2,722 kg or heavier with 2+ jet engines)\n- **Large turboprop aeroplanes** (5,700 kg or heavier with 2+ turbine engines)\n- **Large piston-engine aeroplanes** (5,700 kg or heavier with 2+ engines, registered in Australia after 1 June 1963)\n\n**What it does:**\nThe Order requires pilots and operators to perform detailed calculations before every flight to ensure the aeroplane can safely:\n- **Take off** within the available runway length, even if an engine fails at the critical decision speed (called **V1**)\n- **Stop safely** if the take-off is aborted (called **accelerate-stop distance**)\n- **Climb** adequately with one engine failed, both immediately after take-off and during the flight\n- **Clear obstacles** (buildings, terrain) by specified safety margins during take-off and en-route\n- **Land safely** within the available runway distance, accounting for wet or contaminated runways\n\n**Key safety concepts:**\n- **Gross flight path**: The theoretical path the aeroplane should fly based on average performance data\n- **Net flight path**: The gross path reduced by safety margins to account for pilot variation and performance degradation\n- **Contaminated runway**: Runways covered by water, slush, snow, or ice deeper than specified limits\n\n**Why it matters:**\nThese rules prevent accidents by ensuring aeroplanes never operate at weights where they couldn't climb over obstacles or stop on the runway if something goes wrong. The Order distinguishes between different types of operations (regular public transport, charter, private) and applies stricter safety margins for passenger-carrying operations."}},"importantCases":[],"_links":{"self":"/api/acts/civil-aviation-order-20-7-1b-aeroplane-weight-performance-limitations-aeroplanes-above-5-700kg-all-o","history":"/api/acts/civil-aviation-order-20-7-1b-aeroplane-weight-performance-limitations-aeroplanes-above-5-700kg-all-o/history","analysis":"/api/acts/civil-aviation-order-20-7-1b-aeroplane-weight-performance-limitations-aeroplanes-above-5-700kg-all-o/analysis","conflicts":"/api/acts/civil-aviation-order-20-7-1b-aeroplane-weight-performance-limitations-aeroplanes-above-5-700kg-all-o/conflicts","importantCases":"/api/acts/civil-aviation-order-20-7-1b-aeroplane-weight-performance-limitations-aeroplanes-above-5-700kg-all-o/important-cases","documents":"/api/acts/civil-aviation-order-20-7-1b-aeroplane-weight-performance-limitations-aeroplanes-above-5-700kg-all-o/documents"}}