10.7 Applicable Requirements Flashcards
Maintenance programmes and schedules outline a list of tasks with intervals specified in terms of flight hours, flight cycles, or calendar time. These intervals are determined based on hard time, on-condition, or condition monitoring criteria.
The operator selects a maintenance schedule that aligns with its operations, choosing either a Block (Pyramid) system or an Equalised (Progressive) system
In the Block (Pyramid) maintenance system, often represented by letter checks A, B, C, and D, tasks are grouped together. For instance, a basic set of tasks may be performed every 200 hours, with additional sets added at multiples of this interval, such as 400, 600, 800 hours, and so on. As the flight hours increase, the number of tasks required also increases. This approach is suitable for
long-haul carriers and/or older aircraft that can be scheduled for longer periods on the ground. Benefits include consistent preparation and completion times, a relatively stable workload, fixed content, and efficient planning and control.
However, there are some drawbacks to the Block (Pyramid) system. It involves relatively large gaps between checks, potentially leading to uneven workloads for staff and other resources. Additionally, the aircraft may be out of service for extended periods
the Equalised (Progressive) system employs shorter and equally sized checks that are conducted more frequently. These checks, sometimes referred to as E‑checks, contain the same tasks as in the Block system but are packaged differently. For example, the work involved in a D‑check could be distributed across multiple C‑checks (C1, C2, C3, C4), which progressively involve deeper inspections or component replacements.
The Equalised (Progressive) system is suitable for short-haul, low-cost carriers, and/or newer aircraft that require minimal downtime. Many types of checks can be completed overnight when the aircraft is not in use.
Benefits of the Equalised (Progressive) system include the balancing of resources and a more consistent workload for maintenance personnel. However, there are some disadvantages, such as additional costs due to repeated access work on the aircraft and the challenge of addressing emergent work that may require immediate attention upon discovery.
A- Check
This check is performed approximately every 500 to 800 flight hours or 200 to 400 cycles. The duration of the check requires about between 20‑50 man‑hours and is usually performed overnight at an airport terminal/gate or hangar.
The actual scheduling of this check varies by aircraft type, the cycle count (takeoff and landing is considered an aircraft ‘cycle’), or the number of hours flown since the last check.
The schedule can be delayed by the operator if certain predetermined conditions are met.
B- Check
This check is performed approximately every four to six months. The duration of the check requires about approximately 150 man‑hours and is usually performed within one and three days within a hangar environment.
A similar schedule applies to the B‑Check as to the A‑check. B‑Checks may be incorporated into successive A‑checks:
A‑1 through A‑10 complete all the B‑Check items.
C- Check
This check is performed approximately every 20 to 24 months or a specific amount of actual flight hours (FH) as defined by the manufacturer.
This maintenance check is more extensive than a B‑Check, requiring a large majority of the aircraft’s components to be inspected.
C‑Checks will require the use of a hangar facility at a maintenance base. The time required to complete the check is generally one to two weeks and can require up to 6000 man‑hours.
D- Check
This is the most comprehensive and demanding check. It is also known as a Heavy Maintenance Visit (HMV). This check occurs approximately every five years.
Such a check can usually demand up to 50 000 man‑hours and it can generally take up to two months to complete.
This check will also require the use of a hangar facility at a maintenance base. Due to the requirements of this check, it’s also the most expensive maintenance check to perform. Due to the complexity and the cost of a D‑Check, most operators (especially those with a large fleet) have to carefully schedule the D‑Checks for their aircraft years in advance.
On average, a commercial aircraft undergoes 2‑3 D‑Checks before it is retired
An airworthiness directive means a document issued or adopted by the CAA which mandates actions to be performed on an aircraft to restore an acceptable level of safety, when evidence shows that the safety level of this aircraft may otherwise be compromised.
The CAA shall issue an airworthiness directive when:
an unsafe condition has been determined by the CAA to exist in an aircraft, as a result of a deficiency in the aircraft, or an engine, propeller, part or appliance installed on this aircraft; and
that condition is likely to exist or develop in other aircraft.
An airworthiness directive shall contain at least the following information
an identification of the unsafe condition;
an identification of the affected aircraft;
the action(s) required;
the compliance time for the required action(s);
the date of entry into force.
Part f to M.A.301 requires the accomplishment of any applicable
Continuing airworthiness tasks
airworthiness directive (AD);
operational directive with a continuing airworthiness impact;
continuing airworthiness requirement established by the CAA ;
measures required by the CAA in immediate reaction to a safety problem
Applicants seeking AMOC to an AD approval need to ensure and demonstrate that an equivalent level of safety is achieved compared to the compliance with the original AD. An AMOC to an AD linked to a minor or major change or a supplemental type-certificates (STC) will be approved after the related change is approved.
if an AD is superseded, all AMOCs related to the AD are automatically invalidated. In these cases, a new application is required to ascertain that compliance with the new AD is achieved. A new application is not required when an AD is revised.
Sensitive Security Airworthiness Directives (SSAD)
An SSAD is an AD issued or adopted by UK CAA that mandates certain corrective actions, the content of which includes security-sensitive information.
An SSAD is disseminated by UK CAA to those states having affected aircraft on the register. Further distribution of the SSAD to operators of the affected aircraft or other concerned parties remains under the State of Registry’s responsibility and must be done on a “need to know” basis only.
An SSAD record is uploaded in the UK CAA AD publishing tool, but only after the end of the SSAD compliance time and without attachments.
Service Bulletins (SBs)
With increasing in‑service experience, the type certificate holder of the aircraft can find ways to improve on the original design which can result in lower maintenance costs or increased performance. These improvements (can require alterations to the aircraft) are suggested and circulated through service bulletins (SBs) to the Operators as optional items.
The Operators can use discretion on whether or not to incorporate the bulletins. SBs can sometimes become mandated by relevant Airworthiness Directive (AD).
The SB include one of these four compliance recommendation categories in the service bulletin:
Service Bulletin must be accomplished
Service Bulletin recommended to be accomplished to prevent significant operational disruptions
Service Bulletin to introduce improvements
Service Bulletin for convenience or option
SBs are issued to cover each subject and describe the changes that fall into the following categories:
Modifications to the aircraft, engine or accessory including embedded software.
Modifications, which affect performance, improve reliability, increase safety of operation, provide improved economy, or facilitate maintenance or operation.
Special functional checks of an urgent nature required to detect an incipient failure, such as pressure checks, functional checks, etc.
Reduction of existing life limits or establishment of first time life limits for components.
Conversions from one engine model to another.
Changes affecting the interchangeability or intermix of parts.
Special inspections/checks required to be performed until a corrective action can be taken
Substitution of one embedded software program by another which changes equipment function and the part number of the programmed memory device, requiring a record of accomplishment.
Special inspections/checks required to maintain the aircraft, engine, or accessories in safe operating condition.
One time inspections/checks to detect a flaw or manufacturing error.
Substitution of one embedded software program by another which changes equipment function and the part number of the programmed memory device, requiring a record of accomplishment.
Special inspections/checks required to maintain the aircraft, engine, or accessories in safe operating condition.
One time inspections/checks to detect a flaw or manufacturing error.
If a new Service Bulletin is issued, then a revision to the invalidated Service Bulletin must also be issued, in order to stop its progression. Even though there are many other publications and correspondences available to the airframe, engine and component manufacturers, they are not allowed to be used to transmit actions which require a record of accomplishment.
Service Bulletins must not be used to cover routine recommended inspections/checks, standard repairs, or revisions to maintenance practices or shop procedures.
These must be covered as revisions to the manufacturer’s Aircraft Maintenance Manual, Structural Repair Manual, or Component Maintenance Manual as appropriate.
ALERT SB
Alert Service Bulletins are issued on all matters requiring the urgent attention of the operator and are limited generally to items affecting safety. Matters of extreme urgency with compliance recommendations are transmitted by suitable media, such as telegraph, cable, and facsimile or in some cases, by telephone.
These are identified as Alert Service Bulletins and must contain a Service Bulletin Number. A complete Alert Service Bulletin is prepared and distributed promptly to confirm and elaborate upon such messages.
Standard SB
Standard Service Bulletins are issued where the use of Alert Service Bulletins is not required
Engine Conversion SB
Conversion Service Bulletins will be issued to provide operators with the information necessary to convert engine models from one designation level to another.
Service Bulletin Contents
Service Bulletins must contain a title. It contains the chapter name keyword, and a brief statement of the work involved.
The body of the Service Bulletin can be preceded by a summary. The summary contains an overview of the information contained in the Service Bulletin.
The body of Service Bulletins is to be prepared in the following sections:
Planning Information
Material Information
Accomplishment Instructions and optional Appendices.
Service Information Letter (SIL)
The SIL is the document used by the manufacturers of aircraft, their engines, or their components to communicate details to the Operators of advisory action or other ‘useful information’ about their products which can enhance safety, reliability or reduce repetitive costs.
SILs are for information only, they do not contain any mandatory instructions.
A person or organisation repairing an aircraft or a component must assess any damage against published approved repair data.
Modifications and repairs must be carried out using, as appropriate, the following data:
Approved by the UK CAA
Approved by a design organisation complying with Annex I (Part-21) to Regulation (EU) No 748/2012
Contained in the requirements referred to in point 21.A.90B (Standard Changes) or 21.A.431B (Standard Repairs) of Annex I (Part-21) to Regulation (EU) No 748/2012.
The action to be taken if the damage is beyond the limits or outside the scope, can involve any one or more of the following options:
Repair by replacement of damaged parts (classified as maintenance)
Requesting technical support from the following:
Type Certificate holder
An approved Part-21 Organisation
A UK CAA approval of the particular repair data
Part-M 304 states “Damage shall be assessed and modifications and repairs carried out using data approved by the UK CAA or by an approved Part-21 design organisation, as appropriate.”
The maintenance data is:
The applicable instructions for continuing airworthiness and other maintenance instructions that are issued by the type-certificate holder, supplementary type-certificate holder and any other organisation that publishes such data following Annex I (Part‑21) to Regulation (EU) No 748/2012.
For components approved for installation by the design approval holder, the applicable maintenance instructions published by the component manufacturers and acceptable to the design approval holder.
ATA iSPEC 2200 reduced dependence on paper by providing a common way to enable the electronic use of maintenance and engineering information in the aerospace industry. Its application moved maintenance and engineering documentation from paper to electronic format and it has been the dominant specification used in the aerospace industry for the past 2 1/2 decades.
S1000D is an international specification for technical publications, utilising a Common Source Database.
The purpose of the ATA e-Business Programmes Civil Aviation Working Group (CAWG) is to develop the necessary modifications to enable S1000D to be the world-wide accepted future Technical Data exchange standard for the Civil Aviation Industry
The AMM is produced by the aircraft design authority and applies to one aircraft type only. The manuals can then be customised for a particular operator’s aircraft.
The manual indicates which aircraft operator it applies to, and it lists the effectiveness on each page.
The effectivity allows the user to ensure whether a particular procedure applies to a particular aircraft. If the wrong effectivity or the wrong manual is used, then the work can be illegal, and the aircraft must not be released back to service until the correct procedure has been carried out.
ATA = Air Transport Association
AMM comes in various forms paper-based volumes, online and DVD formats
AMM
in each chapter, there is a description of the system to allow the reader to gain an understanding of the operation of that system.
In each sub-section, there is information relating to the servicing, repair, replacement, adjustment, inspection and testing of a particular component or system.
The manual contains a set of preliminary pages at the very start of the book containing the following information:
List of chapters
record of revisions
list of temporary revisions = This list details all the temporary revisions which must be removed from the manual, and which must remain effective.
service bulletin list = The service bulletin list details all the service bulletins and Customer Originated Changes (COCs) which apply to at least one aircraft of the fleet.
De-activation/Re-activation index=
The de-activation and re-activation index shows in numerical sequence all the MMEL and CDL items which require a maintenance action with the corresponding AMM task number.
Preliminary Pages of Each AMM Chapter
Highlights: The highlights provide the reason for revision issues and list the temporary revisions which are fully incorporated into the chapter at this revision.
List of Effective Pages (LEP): The LEP lists all effective pages in the chapter at a given revision issue.
Table of Contents (TOC): Each chapter in the AMM begins with the table of contents which lists every section of the chapter and the subject material contained in the sections
Illustrated Parts Catalogue (IPC)
It consists of exploded drawings showing every area of the aircraft and associated pages listing the illustrated parts and giving the part numbers of parts, assemblies, and sub-assemblies.
Every component on the aircraft which can be replaced must be listed in the IPC, although in some cases not all the components are illustrated.
The effectivity can normally be found on the bottom left-hand corner of the page with the revision status on the bottom right-hand side.
Structural Repair Manuals (SRM)
The Structural Repair Manual (SRM) contains information and specific instructions for the repair of primary and secondary structures of the aircraft. It also provides structure identification and recommended repairs to perform to damaged structures.
The information contained allows the engineer to assess the damage to the aircraft, identify the allowable limits for damage at that point, and carry out the appropriate repair if necessary.
The SRM contains information for all aircraft of the type and is not customised to a particular operator.
SRM
Also included are material and fastener substitution as well as specific repair techniques. SRMs are usually applicable to large or complex aircraft.
Wiring Diagram Manual (WDM)
The Wiring Diagram Manual (WDM) covers the documentation of all aspects of the wiring on the aircraft, engine, and components.
The purpose of the manual is to permit a full understanding of electrical and electronic systems, operation, troubleshooting and maintenance.
The Wiring Diagram Manual (WDM) is subdivided into three parts:
Aircraft Schematic Manual (ASM)
Aircraft Wiring Manual (AWM)
Aircraft Wiring List (AWL)
CMM
The manual contains sufficient information to return the component to a serviceable condition. Also included are the test and inspection techniques to verify the condition of the component
The manual is annotated with the customer code and the revision date, and each page is annotated with its effectiveness. The effectivity must be checked before the work is carried out to ensure that the correct drawings are used.
The wiring manual is used with other manuals for circuit diagnosis and fault finding. A wiring diagram can be a block diagram or a schematic or another type. It shows the complete electrical circuit for the aircraft system or subsystem and lists the specifications for looms, cables, and wires.
The Component Maintenance Manual (CMM) contains the information required for the maintenance, repair, and overhaul of aircraft components.
The manual is intended for use in a workshop environment by overhaul engineers rather than by an aircraft engineer, but the information is useful to the aircraft engineer because it provides detailed information on the assembly and operation of the component
Trouble Shooting Manual (TSM) or Fault Isolation Manual (FIM)
The purpose of the Trouble Shooting Manual (TSM) and Fault Isolation Manual (FIM) is to allow the systematic identification, isolation, and rectification of aircraft faults.
The manuals detail the most likely faults on the aircraft and give the procedure to isolate and rectify the fault.
Normally, this is in the form of a flow chart which follows a logical progression through isolation of the fault with references made to the relevant AMM chapters and subsections as necessary.
The TSM is the term used by Airbus and FIM is the term used by Boeing
Normal revision of documentation
Normal revision of technical documentation is issued by the aircraft manufacturer or design authority and has the same approved status as the original manual. Normally, these revisions are released quarterly, but may also be released at the time of major changes to the manual. Dates on the amended pages will be changed to reflect the date of amendment, but the remaining pages will be reprinted with their original date.
Each revision will be consecutively numbered and the revision will carry the same date of issue as the amended pages. The revision will be accompanied by a letter of transmittal which will carry details of the revision number, effective date and instructions for the removal and replacement of pages
Temporary Revision
If there is an instance where the manufacturer decides to release an amendment at short notice and there is not time to prepare a complete revision, then a temporary revision may be released. These are normally printed on yellow paper to draw the user’s attention to the revision.
Each temporary revision has its own unique reference number within a particular ATA chapter and they are released consecutively. The temporary revision will be accompanied by instructions for the insertion of pages and for the removal of superseded temporary revisions if applicable. Temporary revisions may not themselves be revised, if there is a change to a temporary revision then it must be replaced in its entirety by another temporary revision with a new number.
(TEMPORARY REVISION)
In the case of documents on microfiche, microfilm or CD-ROM the temporary revisions must be kept in a file adjacent to the reader or computer and the fiche, film or CD will be annotated to draw attention to the presence of the temporary revisions.
(NORMAL REVISION)
In the case of microfiche, microfilm or CD-ROM the amendment is made by the replacement of the fiche, film or disc.
The temporary revisions are normally replaced by being fully incorporated in the next normal revision.
The Master Minimum Equipment List (MMEL) is a document that lists the equipment that may be temporarily inoperative, subject to certain conditions while maintaining an acceptable level of safety of an aircraft.
Each MMEL is specific to an aircraft type. All items related to the airworthiness of the aircraft and not included in the list are automatically required to be operative. UK CAA will only accept an application for MMEL approval from the Type Certificate Holder (designer).
The Minimum Equipment List (MEL) is an approved document, prepared by the operator, taking into account the relevant operational and maintenance conditions they operate under. It lists items from the MMEL which may be temporarily inoperative, subject to certain conditions, at the commencement of the flight. The MEL may not be less restrictive than the MMEL on which it is based.
The MMEL and associated MEL are alleviating (dispatch friendly) documents; their purpose is not to encourage the operation of aircraft with inoperative equipment as it is undesirable for aircraft to be dispatched with inoperative equipment.
Dispatch is permitted only as a result of careful analysis of each item to ensure that an acceptable level of safety is maintained.
The continued operation of an aircraft in this condition should be minimised. There are limitations governing rectification intervals for inoperative equipmen
In most cases, multiple unserviceabilities of unrelated aircraft systems cannot be addressed by the MMEL nor consequently by the MEL. The decision as to whether or not to dispatch with multiple unserviceabilities, which individually would be allowed by the MEL, will ultimately rest with the Aircraft Commander, taking into consideration advice from the operator’s specialists where available.
MEL Rectification Intervals
Inoperative items or components, deferred in accordance with the MEL, must be rectified at or prior to the rectification intervals established by the following letter designators:
Category A - No standard interval is specified. However, items in this category shall be rectified in accordance with the conditions stated in the MMEL.
Where a time period is specified in calendar days or flight days, the interval excludes the day of discovery.
Where a time period is specified other than in calendar days or flight days, it shall start at the point when the defect is deferred in accordance with the operator’s approved MEL.
MEL Rectification Intervals (2)
Inoperative items or components, deferred in accordance with the MEL, must be rectified at or prior to the rectification intervals established by the following letter designators:
Category B - Items in this category shall be rectified within three (3) calendar days, excluding the day of discovery.
Category C - Items in this category shall be rectified within ten (10) calendar days, excluding the day of discovery.
Category D - Items in this category shall be rectified within one hundred and twenty (120) calendar days, excluding the day of discovery.
Remarks or Exceptions include statements either prohibiting or allowing operation with a specific number of items inoperative, provisos (conditions and limitations), notes, (M) and/or (O) symbols, as appropriate for such operation.
Dispatch Deviation List (DDL)
The Dispatch Deviation List (DDL), also called Dispatch Deviation Guide (DDG), is the overall document, and within that, there are two ‘sub’ documents, specifically the MEL and CDL.
The DDG contains operational and maintenance procedures for the MEL and CDL. This document must be carried on the flight deck of large transport category aircraft. It is an approved publication subject to review and amendment.
The MEL and CDL are relieving documents and their purpose is not to encourage the operation of aircraft with inoperative equipment.
Configuration Deviation List (CDL)
Configuration Deviation List (CDL) identifies any external parts of an aircraft which may be missing at the commencement of flight. The CDL contains information associated with operating limitations and aircraft performance corrections where necessary.
The CDL is established by the holder of the type design and approved by the State of Design.
The CDL is published as part of the Aircraft Flight Manual and is found in the Dispatch Deviation Guide (DDG).
Calendar Day
A 24-hour period from midnight to midnight based on usually UTC
Commencement of flight
The point when an aircraft begins to move under its own power for the purpose of preparing for take-off
Day of discovery
The calendar day that a malfunction was recorded in the aircraft maintenance record/log book
Flight Day
Means a 24-hour period (from midnight to midnight) usually UTC during which at least one flight is initiated for the affected aircraft
If installed
Means that the equipment is either optional or is not required to be installed on all aircraft covered by the MMEL
The ICAO Airworthiness Manual, Volume 1, states the purpose of airworthiness Check Flights is to ensure that the aircraft’s flight characteristics and its functioning in flight do not differ significantly from the normal characteristics for the type and to check the flight performance against the appropriate sections of the flight manual.
Flight testing of aircraft provides a basis to establish compliance with certification requirements for new aircraft and changes to aircraft.
Check Flights or in-flight surveys, can be carried out periodically on in-service aircraft as one of the processes to ensure that an aircraft continues to comply with the applicable airworthiness requirements. Additionally, maintenance Check Flights may be carried out following a maintenance activity on an aircraft to provide reassurance of performance or establish the correct functioning of a system that cannot be fully established during ground checks
Check Flight Report
After each Check Flight, the pilot who conducted the flight should complete the post-flight certificate, which lists all the defects found during the flight. This together with the completed Schedule comprises the Check Flight Report. Each defect should be classified according to its impact on safety. Items requiring rectification should be marked ‘R’. Those items that require re-checking in-flight following rectification (such as inadequate climb performance) should, in addition, be marked ‘FT’.
Flight Test Manual (FTM)
The FTM shall describe the organisation’s policies and procedures in relation to flight testing. The FTM should include a chart indicating the structure of the organisation and, more specifically, the functional links of the people in charge of flight test activities. It should also mention the coordination between all departments affecting flight testing (e.g. Design, Production and Maintenance), in particular coordination for the establishment and update of a Flight Test Programme.
According to the flight test category, the FTM should describe the organisation’s policy on crew composition (including the need to use a Lead Flight Test Engineer (LFTE)). This should include the competency of the flight test crew members and procedures for appointing crew members for each specific flight.
Test Flights
these flights must only be conducted in accordance with schedules that have been reviewed and accepted by the manufacturer or an organisation approved in accordance with CAA Part 21 Subparts G or J or CAP 533 Chapter A8-21 (Approval Organisations Responsible for Design or Production (annex 1 aircraft)).
The applicant shall allow the authorities to review any report and make any inspection and to perform or witness any flight and ground test necessary to check the validity of the declaration of compliance and to determine that no feature or characteristic makes the product unsafe for the uses for which certification is requested.
Flight Test Manual
The FTM shall include procedures to identify the instruments and equipment to be carried. The FTM should list, depending on the nature of the flight, the specific safety-related instruments and equipment that should be available on the aircraft or carried by people on-board.
The FTM should contain provisions to allow flights to take place in case of defective or missing instruments or equipment. Under regulations two distinct areas are addressed, flight test instrumentation and safety equipment.
‘Safety Equipment
standard’ fit of the aircraft, such as lifejackets, oxygen masks, emergency escape slides, first aid kits, and so on. However, it may also include extra devices fitted to reduce the risk in particular circumstances. This may include non-standard escape hatches, parachutes, anti-spin parachutes, life rafts or flame-retardant flight suits for the crew. The maintenance of such equipment should also be considered.
consideration needs to be given to when items of safety equipment will be mandatory for a given flight and when they are optional. This needs to be clearly recorded and implemented so that the aircraft is not inadvertently dispatched with inadequate safety equipment and so that the flight crew is clear on what is necessary for both crew and non-crew members. Limitations may need to be imposed in the event of equipment unserviceability (e.g. flight over land only in the event of life raft unserviceability).
Flight Test Equipment
The organisation should also consider what Flight Test Equipment needs to be fitted to the aircraft. This will be driven primarily by the data-recording requirements of the flight test activity. The FTM should describe the process for deciding the Flight Test Equipment fit, the links to the risk assessment process, and the personnel involved.
Extended Range Twin Operations (ETOPS).
In 2012 ICAO standards made the decision through amendment 36 to replace the term ETOPS with the term Extended Diversion Time Operation (EDTO)
ETOPS approval allows operators to operate an aircraft over a route that contains a point further than one hour’s flying time from an adequate airport at the approved one-engine inoperative cruise speed for twins and 180 minutes for quads: regardless of whether such fields are separated by water or land.
The operator requires an ETOPS approval and so does the aircraft type, not all aircraft are used for ETOPS because there is an extra maintenance implication for additional safety.
The concept of the ETOPS approval is to maintain a high level of safety level for twin, tri, and quad-engine aircraft.
When a two-engine aeroplane is intended to be used in extended range operations, a determination should be made that the design features are suitable for the intended operation. The ETOPS significant system for the particular airframe/engine combination should be shown to be designed to fail-safe criteria and it should be determined that it can achieve a level of reliability suitable for the intended operation. In some cases modifications to systems may be necessary to achieve the desired reliability.
There are two methods for obtaining an ETOPS approval, depending on the availability and amount of prior experience with the candidate airframe/engine combination:
“Accelerated ETOPS approval”, does not require prior in-service experience with the candidate airframe/engine combination;
“In-service ETOPS Approval”, based on a pre-requisite amount of prior in-service experience with the candidate airframe/engine combination. Elements from the “accelerated ETOPS approval” method may be used to reduce the amount of prior in-service experience.
ETOPS Approval Categories
There are 4 approval categories:
Approval for 90 minutes or less diversion time
Approval for diversion time above 90 minutes up to 180 minutes
Approval for diversion time above 180 minutes
Approval for diversion times above 180 minutes of operators of two-engine aeroplanes with a maximum passenger seating configuration of 19 or less and a maximum take-off mass less than 45 360 kg
The CAMO should develop appropriate procedures to be used by all personnel involved in the continuing airworthiness and maintenance of the aircraft, including supportive training programmes, duties, and responsibilities.
The CAMO should specify the procedures necessary to ensure the continuing airworthiness of the aircraft particularly related to ETOPS operations
An ETOPS service check should be developed to verify the status of the aeroplane and the ETOPS significant systems. This check should be accomplished by an authorised and trained person prior to an ETOPS flight. Such a person may be a member of the flight crew
ETOPS Significant System means the aeroplane propulsion system and any other aeroplane systems whose failure could adversely affect the safety of an ETOPS flight, or whose functioning is important to continued safe flight and landing during an aeroplane diversion.
Each ETOPS significant system is either a Group 1 or Group 2 system based on the following criteria:
ETOPS Group 1 Systems :
Group 1 Systems are ETOPS significant systems that, related to the number of engines on the aeroplane or the consequences of an engine failure, make the systems’ capability important for an ETOPS flight. The following provides additional discriminating definitions of an ETOPS Group 1 Significant System:
A system for which the fail-safe redundancy characteristics are directly linked to the number of engines (e.g., hydraulic system, pneumatic system, electrical system).
A system that may affect the proper functioning of the engines to the extent that it could result in an in-flight shutdown or uncommanded loss of thrust (e.g., fuel system, thrust reverser or engine control or indicating system, engine fire detection system).
A system which contributes significantly to the safety of an engine inoperative ETOPS diversion and is intended to provide additional redundancy to accommodate the system(s) lost by the inoperative engine. These include back-up systems such as an emergency generator, APU, etc.
A system essential for prolonged operation at engine inoperative altitudes such as anti-icing systems for a two-engine aeroplane if single engine performance results in the aeroplane operating in the icing envelope.
ETOPS Group 2 systems:
Group 2 Systems are ETOPS significant systems that do not relate to the number of engines on the aeroplane, but are important to the safe operation of the aeroplane on an ETOPS flight. The following provides additional discriminating definitions of an ETOPS Group 2 Significant System:
A system for which certain failure conditions would reduce the capability of the aeroplane or the ability of the crew to cope with an ETOPS diversion (e.g., long range navigation or communication, equipment cooling, or systems important to safe operation on a ETOPS diversion after a decompression such as anti-icing systems)
Time-limited systems including cargo fire suppression and oxygen if the ETOPS diversion is oxygen system duration dependent.
A system specifically installed to enhance the safety of ETOPS operations and an ETOPS diversion regardless of the applicability of paragraphs (2)(i), (2)(ii) and (2)(iii) above (e.g. communication means).
Systems whose failure would result in excessive crew workload or have operational implications or significant detrimental impact on the flight crew’s or passengers’ physiological well-being for an ETOPS diversion (e.g., flight control forces that would be exhausting for a maximum ETOPS diversion, or system failures that would require continuous fuel balancing to ensure proper CG, or a cabin environmental control failure that could cause extreme heat or cold to the extent it could incapacitate the crew or cause physical harm to the passengers)
The operator must develop a verification programme to ensure that the corrective action required is carried out after any of the following:
An engine shutdown
An ETOPS significant system failure
Any adverse trends
An event which requires a verification flight, or another verification action is established
A clear description of who must initiate these verification actions and the section or group responsible for the determination of what action is necessary must be identified in the verification programme. ETOPS significant systems or conditions requiring verification actions must be described in the Continuing Airworthiness Management Exposition (CAME).
Maintenance training focuses on the special nature of ETOPS. This programme is included in normal maintenance training. The goal of this programme is to ensure that all personnel involved in ETOPS are provided with the necessary training so that the ETOPS maintenance tasks are properly accomplished and to emphasise the special nature of ETOPS maintenance requirements.
Qualified maintenance personnel are those that have completed the operator’s extended-range training programme and have satisfactorily performed extended-range tasks under supervision, within the framework of the operator’s approved procedures for personnel authorisation.
An Instrument Landing System (ILS) is a highly accurate and dependable means of navigating an aircraft to the runway in Instrument Flight Rules (IFR) conditions. When using the ILS, the flight crew determines aircraft position primarily by reference to the flight deck instruments
For the flight crew to be able to make an approach to a runway in bad weather, the weather has to be at or above certain conditions and depends on the Category number of the ILS.
If the weather is worse than the categorisation of the runway then no approach can be made, unless the aircraft has dedicated certified equipment installed.
All commercial air transport aircraft are categorised according to their ability to land by utilising the Instrument Landing System (ILS).
The regulations for all weather operations are laid down in Air Ops Part-SPA and CS-AWO (Certification Specification - All Weather Operations).
They detail the requirements for operations where the operator wishes to carry out landings and take-offs in low-visibility with or without electronic guidance systems. AWOPS approvals allow aircraft to make low-visibility take-offs and landings.
Low-visibility operations are classified as:
Manual take-off (with or without electronic guidance systems).
Auto-coupled approach to or below Decision Height (DH), with manual flare, landing and roll-out.
Auto-coupled approach followed by auto-flare, auto-landing, and manual roll-out.
Auto-coupled approach followed by auto-flare, auto-landing, and auto roll-out, when the Runway Visual Range (RVR) is less than 400 metres.
All heights are referred to in feet while distances are referred to in metres.
Category One Operations (CAT I)
A CAT 1 operation is a precision instrument approach and landing using ILS (Instrument Landing System) or MLS (Microwave Landing System) with a decision height not lower than 200 feet and a Runway Visual Range (RVR) not less than 550 metres
Category Two Operations (CAT II)
A CAT 2 operation is a precision instrument approach and landing using ILS or MLS with a decision height below 200 feet but not lower than 100 feet and an RVR not less than 300 metres.
Category Three Operations (CAT III)
Category 3 operations are divided into 3 sections (A,B & C).
CAT 3A operation is a precision instrument approach and landing using ILS or MLS with a decision height lower than 100 feet and an RVR not less than 200 metres.
CAT 3B operation is a precision instrument approach and landing using ILS or MLS with a decision height lower than 50 feet and an RVR lower than 200 metres but not less than 75 metres.
CAT 3C operation is a precision instrument approach and landing using ILS or MLS with no decision height and no RVR.
If the aircraft is to be used for these operations, then particular attention must be paid when deferring faults in accordance with the MEL as the AWOPS certification status can be affected
Definition of Decision Height
A decision height is a specified lowest height in the approach descent at which, if the required visual reference to continue the approach (such as the runway markings or runway environment) is not visible to the flight crew, the flight crew must initiate a missed approach (go around).
