Business Aviation Centre, Farnborough Airport, Hants. GU14 6XA
E2:0401
CERTIFICATE OF MAINTENANCE REVIEW
AIRCRAFT TYPE: REGISTRATION: CONSTRUCTION No.
BAe 125-700B G - BJDJ 257142
'Certified that a maintenance review of this aircraft and such of its equipment as is necessary for its airworthiness has been carried out in accordance with the requirements of the Air Navigation Order for the time being in force'.
Signed :
Approval Stamp
Name : Date: 29th October 2001
THE NEXT MAINTENANCE REVIEW IS DUE : 28th February 2002
For Minor Maintenance Status refer to the Supplementary Inspection Record Sheets in the front of the Aircraft Technical Log Book.
A.N. Other
CERTIFICATE OF MAINENTENANCE REVIEW JAR-OPS WAIVER
Approved Maintenance Programme
An Approved Maintenance Programme (AMP) is a plan for the regular and systematic maintenance of Civil Aircraft and components.
The maintenance requirements are dictated by an Approved Maintenance Schedule produced for each aircraft type.
Approved Maintenance Schedule (A.M.S.) The Approved Maintenance Schedule contains details of all the procedures by which it is proposed that the Airworthiness of an aircraft will be preserved on a continuing basis. The Manufacturer or Constructor produces a recommended AMS.
Note: The difference between a Maintenance Schedule and a Maintenance Manual is that the Schedule says What is to be done and When, while the Manual describes How each operation is to be carried out.
The Approved Maintenance Schedule specifies routine inspection and maintenance work to be carried out during a series of maintenance checks on an aircraft, at intervals defined as a number of flying hours completed or as a number of days elapsed (elapsed calendar time).
The AMS covers each part of the aircraft; its engine and auxiliary power unit (A.P.U.), propellers, components, accessories, equipment, instruments, electrical and radio apparatus, and all associated systems and installations. Certain components are given a limited ‘life’ on an aircraft. At the end of the specified time such components must be removed from the aircraft and replaced by new or overhauled items.
For all these items, the schedule specifies periods at which each shall, as appropriate, be checked, cleaned, lubricated, adjusted, tested and inspected or replaced. The type and degree of inspection is also stated.
A typical A.M.S. comprises the following parts:
Part 1 - General information – Introduction, CAA Approval Certificates, list of applicable aircraft registrations, Check Cycle, Inspection standards etc.
Part 2 - Ramp Maintenance - Lists the Transit and Ramp check tasks.
Part 3 - Aircraft Inspection Requirements – Zonal and Highlight inspections.
Part 4 Routine Maintenance Requirements -This part of the Schedule comprises all the routine maintenance work and includes servicing, functional checks and lubrication requirements.
Part 5 - Component Tasks - Lists all Maintenance Significant Items (M.S.I.) components. Contains all workshop scheduled and unscheduled tasks.
Part 6 - Structural Inspection Programme.
Part 7 - Corrosion Prevention Control Programme – Lists CPCP inspection and maintenance tasks.
Mandatory – Lists all the Mandatory tasks from Parts 2 – 5.
For aircraft with a maximum total weight authorised (MTWA) exceeding 2,730 kg the Maintenance Schedule used may be drawn up by either the Manufacturer or the Operator but must be submitted to the CAA for approval. For aircraft below this weight the Operator has the choice of either following the same procedure or using the generic Light Aircraft Maintenance Schedule (LAMS), produced by the CAA.
In respect of aircraft registered in the UK, the requirement for maintenance in accordance with Maintenance Schedules approved by the CAA applies to:
• all aircraft flying for the purpose of public transport or dropping or projecting any material for agricultural, public health or similar purposes.
• aeroplanes and rotorcraft not exceeding 2730 kg certified in the Transport Category (Passenger), Transport Category (Cargo), Aerial Work Category and Private Category.
Check Cycle
The Check Cycle in Part 1 of the AMS is the timetable of maintenance checks designed to ensure continuing airworthiness of the aircraft.
Like the AMS itself it may be developed by the operator to satisfy their particular operational requirements, but the trend is towards using the Manufacturers recommended cycle as the standard.
The Never Exceed Periods (NEPs) for each check may be specified in calendar time (years, months and days) flying time (thousands of hours) or cycles (flights or landings) or a mixture of all three. A typical Check Cycle for the Boeing 747-400 is shown below.
Check NEP
Transit Check After every flight
London Transit To be completed at each London Transit (LHR or LGW)
Ramp Check 1 50 hours or 7 landings, whichever is sooner Ramp Check 2 190 hours
Ramp Check 3 540 hours Service Check 1 99 days Service Check 2 190 days
Inter 1 24 months
Inter 2 48 months
Major 1 8 years from new,
thereafter 5 years
Major 2 13 years from new or 5 years from first Major, thereafter 10 years
0 100 200 300 400 500 600
= TRANSIT CHECK
= RAMP CHECK
= SERVICE CHECK
= INTER CHECK
= MAJOR CHECK
The repair of non-critical defects found during a check may deferred to a more appropriate length of check. For instance a structural crack discovered during a Service Check may require a longer period of time to repair than is available during the check. It will be assessed against criteria found in the Structural Repair Manual and, if found to be acceptable for further service, it will be classed as an Allowable Deferred Defect (ADD). The SRM may specify that a temporary repair and/or periodic inspection is required to assure continued airworthiness. Any additional inspection will be added to the aircraft Tech Log with instructions for the check period so it can be signed off at the appropriate intervals. At the next Inter check the repair will be carried out when it can be contained within the ‘downtime’
of the aircraft.
If, however, the defect is of a serious nature, deferment is not an option and rectification must be performed before release back to service.
This is the most common cause of maintenance overruns.
Maintenance Checks
As we have seen, the scheduled tasks to be performed in each check are dictated by the AMS. Additional non-AMS tasks such as Special Checks, modifications and non-airworthiness items will be added. Each check in the hierarchy includes the appropriate tasks from the previous check. For example the Ramp Check 2 contains all the tasks of the Ramp 1 plus some additional ones.
The planned length of each check varies, depending on the size and age of the aircraft, but typically for a large transport aircraft a Transit check will take less than an hour, Ramp checks 2 or 3 hours, Service checks 1 or 2 days, Inter checks about a week and Major checks 4 to 6 weeks. Of course, the actual time taken will depend on factors including faults and defects found during the check, availability of spares and materials and availability of manpower.
For small aircraft and components in workshops, it is possible to use Job Cards or Work Sheets and manually arrange them into the correct order, however, for a Major Check on a large aircraft this would be a daunting task! In most organisations, computer systems are used to plan and sequence the check tasks. These provide a degree of automation and may use Gant Charts to display the targets or ‘milestones’
to be achieved during the check.
Once the content and sequence of the check have been confirmed, the check documentation must be produced. Again, this may be done manually but most organisations will use a computer database of referenced tasks to produce the relevant Job Cards or Work Sheets.
In some organisations computers systems are used to display tasks and permit ‘on-line’
certification upon completion.
The items in the task or job database are often referenced using the Aircraft Maintenance Task Oriented Support System (AMTOSS). This is a coding system, based on ATA100, which the major manufacturers now use to identify specific tasks in the Maintenance Manual.
It may also be a function of the Planning Department to ensure the facilities required to complete each check are available. This includes hangar space, servicing parts and materials, lifed parts and components scheduled for replacement, parts to repair known defects (ADDs) and perform modifications, the tools and equipment to carry out the tasks and the technical information the engineers will need.
In small organisations the Planning Department may also be responsible for ensuring sufficient manpower is available and also that the aircraft is released from service for maintenance. In large organisations, separate departments will have these responsibilities and the Planners must liase with them.
It is the job of the Maintenance Planning organisation or department to ensure that the requirements of the Maintenance Programme are satisfied and thus ensure that both airworthiness and operational requirements are met.
The planned work, including AMS tasks, Special Checks, Modifications, Deferred Defects, configuration changes and non-airworthiness tasks (e.g. ‘cosmetic’ changes etc.) are prioritised and scheduled into a logical order to prevent repetition and conflict. For instance, there is no point opening and closing the engine cowlings for each separate task on the engine, or programming cleaning and rectification tasks in the same area at the same time.
The planners will assess the time that will be required to perform the planned maintenance and add a contingency factor for the repair of faults and defects found during the check. This is done using previous experience but to assist in the planning, the manufacturer may produce a Maintenance Planning Data (MPD) document which sets standard man hour times for scheduled tasks
Consideration must also be given to AMS work which is due to be performed close to a planned check. It may be expedient to carryout some tasks early to avoid a special maintenance input which would disrupt the airline schedule.
Similarly, it may be possible to get a ‘variation’
(extension of time limit) form the CAA or Approved Organisation and defer some maintenance to a more convenient check. However, the guidelines for granting such concessions are stringent and must be strictly applied to ensure continued safety.
For aircraft of foreign origin, mandatory modifications promulgated under the authority of the National Aviation Authority of the country of origin are, unless notified otherwise by the CAA, mandatory for aircraft registered in the United Kingdom. Such modifications prescribed by the CAA are summarised in the CAA publication entitled ‘Foreign Airworthiness Directives’.
CAA appropriately approved design organisations must keep a Civil Modifications Record giving details of each modification approved.
All work undertaken in the incorporation of a modification must be supervised either by an Organisation approved by the CAA to make certifications in respect of such incorporation, or by an appropriately licensed aircraft maintenance engineer. Whoever supervises the work must be satisfied that it has been carried out, inspected and tested where necessary, in conformity with the specifications, drawings and instructions relating to the approved design before a Certificate of Compliance is issued. The modification should be entered in the aircraft records including, for aircraft of MTWA exceeding 2730 kg, the Modification Record Book.
In some cases the work of incorporation of a modification may be supervised by an Organisation in foreign country in which the airworthiness standards are acceptable to the CAA.
Modifications are changes made to the aircraft after issue of the Certificate of Airworthiness.
These changes may be required due to deficiencies found in service or changes in operating requirements. Some may be carried out on the production line but most are incorporated during the service life of the aircraft.
At an early stage in the design of a modification of United Kingdom origin, particulars must be given to the CAA so that the modification may be classified as a Minor or Major modification according to the nature and extent of the investigation in connection with approval.
Modifications must be such that the design of the aircraft, when modified, complies, at least, with the requirements which were applicable at the time the aircraft type was originally certified.
If the CAA considers that a modification is necessary to ensure continued airworthiness of a particular type of aircraft, it may require such a modification to be incorporated as a condition of the validity of the Certificate of Airworthiness.
Such modifications are classified as Mandatory Modifications and are summarised in the CAA publication entitled ‘Mandatory Aircraft Modifications and Inspections Summary’.
Major Modifications
Application for the approval of a Major modification must be made to the CAA on CAA Form AD 282 which should be sent to the Aircraft Projects Department of the CAA. The total fee for approval of Major modification is based on the cost of the investigations and the applicant will be notified in writing of any additional costs which are payable during the course, or on completion, of the CAA investigations.
The CAA, may require a Certificate of Design from an approved Organisation before approving a Major modification.
The Airworthiness Approval Note (AAN) which is issued to the applicant, where the modification is approved, states that it is acceptable for incorporation in a particular aircraft or type of aircraft subject to compliance with the conditions of the AAN. Embodiment of the modification has to be in compliance with the Requirements. The AAN number must be entered on the Certificate of Release to Service (CRS).
Minor Modifications
A Design Organisation approved by the CAA to provide reports and make certifications in respect of such work, may approve and embody Minor modifications which must be recorded in the ‘Civil Modifications Record’. In cases where the design of the Minor modifications is not undertaken by an approved Design Organisation, the issue of CAA Form AD 261 to the applicant, when the modification is satisfactory, will signify CAA approval.
This form will give brief details of the modification, the registration marks and type of aircraft to which it applies and list the relevant drawing and specification numbers. It will also give details of the amendments, where applicable, to be made to the aircraft approved manuals, e.g.
Maintenance Manual, in consequence of the incorporation of the modification. The AD 261 number must be entered on the CRS.
'MAJOR' MODIFICATION
Commencing and Maintaining the Modification Record Book
New Aircraft Initially Registered in the United Kingdom:
a) Constructed in the United Kingdom. The constructor shall make available the information necessary to comply with the requirements, relevant to commencement for these aircraft, by stating the modifications embodied, additional to the basic design, at the time of certification.
b) Constructed outside the United Kingdom.
The applicant for issue of a United Kingdom Certificate of Airworthiness shall obtain from the aircraft constructor information similar to that required under (a), to comply with the Requirements.
A Modification Record Book must be kept for all aircraft with MTWA exceeding 2730 kg on the United Kingdom register. This Record Book is a statement of the modification history of the aircraft to which it relates in respect of modifications to those parts on which airworthiness depends and modifications made to the aircraft which affect modifications already listed; it also contains details of all those major repairs which have significantly altered the design. It does not apply to engines and propellers where suitable modification records are maintained in their own log books. The Modification Record Book is considered an addition to the aircraft log book.
The Modification Record Book contains a statement of the modifications embodied by the aircraft constructor which are additional to the basic design at the time of certification of the aircraft. Following the constructor’s modification record in the book, the owner or operator must record modifications or repairs which are embodied during the life of the aircraft. The Book must be up to date at the time of issue of the Certificate of Airworthiness, at the renewal of the C of A and when the aircraft is sold or leased.
Contents of the Modification Record Book The following shall be recorded in the Modification Record Book:
• Modifications made to those parts of the aircraft on which airworthiness depends.
• Modifications made to the aircraft which affect modifications already listed in the Record Book
• Major repairs, which have significantly altered the design affecting the airworthiness of the aircraft
The wording of documents (e.g. Modification Bulletins, Service Bulletins, Technical News Sheet) used to notify mandatory modifications and inspections shall be approved by the CAA or foreign airworthiness authority and the documents shall be certified and published and distributed by the appropriate constructor’s approved organisation.
Owners, operators and organisations undertaking overhaul/maintenance on aircraft, should ensure that the constructor of each type of aircraft is informed of their names and addresses to facilitate distribution of the documents which notify mandatory modifications and inspections.
When a change is made to a component which has already been the subject of a mandatory modification and this produces a new or modified component which achieves all the objectives of the previous mandatory modification, then the latter modification becomes an acceptable alternative to the previous one and shall be shown in the Company’s modification system and associated documentation.
Modifications and inspection, considered essential for airworthiness, will be classified as mandatory by the CAA in consultation, where appropriate, with the approved Organisation, and the compliance date limiting flying hours, cycles, or details of when the prescribed action must be taken, will be decided. In making this decision the degree of urgency and availability of modified parts will be taken into account.
Mandatory modifications and inspections are promulgated in manufacturers’ Service Bulletins or equivalent documents. The modification and inspections from UK manufacturers are summarised in the CAA publication, ‘Mandatory Aircraft Modifications and Inspections Summary’.
Mandatory modifications and inspections promulgated by foreign airworthiness authorities or manufacturers are, where appropriate, adopted by the CAA for application to the particular type of aircraft in the United Kingdom and these, together with ‘CAA Additional Directives’ are summarised in the CAA publication ‘Foreign Airworthiness Directives’.
Manuals and Records
Amendments to Manuals, i.e. the Flight Manual, Maintenance, Overhaul and Repair Manuals, the Crew Manual, or the Maintenance Schedule, arising from the incorporation of a Major or Minor modification in an aircraft shall be made in accordance with the requirements. In the case of Minor modifications approved under CAA Form AD 261 procedure the applicant shall submit details of the proposed amendments to the CAA for approval.
Where it is necessary to amend the particulars in the Certificate of Airworthiness or Flight Manual, the Certificate or Manual shall, unless agreed otherwise by the CAA, be forwarded to the local area office of the CAA.
Full particulars of the work done to incorporate the modifications, or details, results and work arising from the mandatory inspection, shall be entered in the appropriate log book, quoting the reference number of the appropriate document, e.g. Airworthiness Approval Note for a Major modification, Service Bulletin for a mandatory inspection. A CRS shall be completed, where appropriate and attached.
Work undertaken in incorporating a modification, or in carrying out a mandatory inspection, shall be supervised by an organisation approved by the CAA for the purpose, or by an appropriately licensed aircraft maintenance engineer. When the work is to be carried out on an aircraft
Work undertaken in incorporating a modification, or in carrying out a mandatory inspection, shall be supervised by an organisation approved by the CAA for the purpose, or by an appropriately licensed aircraft maintenance engineer. When the work is to be carried out on an aircraft