WRITTEN BY MANOJ KUMAR P, ASST. DIRECTOR AIRWORTHINESS, DGCA

“In Aviation Each Step has a Footprint. And it is called Signature.”

During a friendly conversation with one of my friends regarding maintenance on a ship and aircraft, he stated, ‘If a ship has a technical problem at least it can float, whereas an aircraft having the similar problem, it can’t float in air.’ What my friend stated in passing always strikes me and encourages me to do my assigned task with due focus and diligence whenever I perform aircraft maintenance, documentation, auditing, handling stores, etc.

Ensuring an aircraft fly safely requires various types of maintenance (preventive, snags, scheduled, unscheduled, etc.) to be performed on the aircraft at various periodicities based on days, flying hours, aircraft engine starts, aircraft landings, aircraft cycles, etc.

In aviation, maintenance documentation (referring and recording) ensures that the scheduled maintenance is performed as per the maintenance manuals and in a correct sequence of steps. If any step in any of the maintenance tasks is skipped / missed or done in the incorrect order, it could result in a catastrophe. In aviation history many aircraft accidents have been caused due to such small missteps or missing of small steps.

FOR EXAMPLE:
a) Small screw which was erroneously left in the maintenance area after maintenance, in due course of time it can get stuck and obstruct the movement of the control columns, or make a hole in any of the hoses or pipelines of the hydraulic, fuel, pneumatic, Oxygen etc.
b) Using a wrong size screw or bolt or nut or any other expendable can cause improper securing of the component or equipment or hose etc. This can cause the components falling out of their designated place due to vibrations and malfunction of the component and aircraft systems.

So, it is evident that, maintenances on aircraft must be performed step by step as per applicable Manuals and Regulations. In order to ensure that no step of a maintenance task is skipped, Civil Aviation Regulators have mandated the operators to adhere to the maintenance documentation method of signing off and the use of task card / worksheets.

A Proper Documentation Gives Us The Following Information:
a) Step by step maintenance undertaken.
b) Who did the job?
c) When was the job done?
d) Which special tools were used?
e) What were the values of the checks done?
f) How much work was finished?
g) Which documents were referred?

THE REGULATIONS
Based on the history of aircraft accidents and incidents, various aviation regulators have stipulated various regulations for maintenance organisations to imbibe and adhere to. Some of the regulations which are applicable to this article are as follows:
I) Para 1.4.13 of FAA Advisory Circular No. 145-9A defines Maintenance Function as a step or series of steps in the process of performing maintenance, preventive maintenance, or alterations.
II) CAR GM 145.A.48 Performance of maintenance states that, A ‘sign-off’ is a statement issued by the ‘authorised person’ which indicates that the task or group of tasks has been correctly performed. A ‘sign-off’ relates to one step in the maintenance process and is, therefore, different to a certificate of release to service.
III) Para (1) of AMC 145.A.48(c) Performance of maintenance states the procedures should be aimed at minimising multiple errors and preventing omissions. The procedures should specify that every maintenance task is signed off only after completion.
IV) ‘Critical Maintenance Task’ means a maintenance task that involves the assembly or any disturbance of a system or any part on an aircraft, engine or propeller that, if an error occurred during its performance, could directly endanger the flight safety. GM M.A.402(h) Performance of maintenance and appendix VII of CAR-M/Part M — Complex Maintenance Tasks has stipulated list of complex tasks
V) AMC M.A.305(h) Aircraft continuing airworthiness record system states that keeping continuing airworthiness records in a form acceptable to the competent authority normally means in paper form or on a computer database or a combination of both methods.
VI) Para 3 of AMC M.A.401(c) Maintenance data states Maintenance tasks should be transcribed onto the work cards or worksheets and subdivided into clear stages to ensure a record of the accomplishment of the maintenance task. Of particular importance is the need to differentiate and specify, when relevant, disassembly, accomplishment of task, reassembly and testing.
VII) Para b of M.A.401 Maintenance data states that the applicable maintenance data is:
a) any applicable requirement, procedure, standard or information issued by the competent authority or the Agency,
b) any applicable airworthiness directive,
c) applicable instructions for continuing airworthiness, issued by type certificate holders, supplementary type certificate holders and any other organisation that publishes such data in accordance with CAR 21.
d) any applicable data which is accepted by the regulator.

UNDERSTANDING THE REGULATIONS
Based on the above said regulations it is expected that the AMOs adhere to the regulations and devise an appropriate procedure for maintenance documentation as follows:
a) Point I and Point VI mandate operators to identify the complex maintenance tasks of their fleet and prepare the work cards or worksheets with the following provisions:
i. Step or series of steps in the process of performing maintenance
ii. Maintenance task is subdivided into clear stages.
iii. Record of accomplishment of each stage / Provision for signing by the engineer and technician who performed the task with date and time.
b) Point II and Point III mandate that an AME needs to sign-off task or group of tasks has been correctly performed by him/her and to be signed only after task completes.
c) In Point V, the regulator provides a provision to the operator to maintain the continuing airworthiness records either in paper form or in electronic form or both which are in a form acceptable to the regulator.
d) Point VII lists the documents that fall under maintenance data and same needs to be considered for task cards / work sheets and for maintenance too.

ACTION TO BE TAKEN
Hence, CAMO must prepare and plan the maintenance tasks based on the following:
1) Maintenance data:
a) Any applicable requirement, procedure, standard or information issued by the competent authority or the Agency
b) Any applicable airworthiness directive
c) Applicable instructions for continuing airworthiness, issued by type certificate holders, supplementary type certificate holders and any other organisation which is approved by the concerned regulator
d) Maintenance Manuals for e.g., AMM, EMM, APUMM, SRM, CMM, TSM, AFM etc.,
e) Safety precautions, cautions
f) Any checks need to be done post maintenance
g) Ensure that an error capturing method is implemented after any critical maintenance task is performed.
h) Ensure that the risk of multiple errors during maintenance and the risk of errors being repeated in identical maintenance tasks are minimized.

2) Current status of aircraft:
a) Applicability of that maintenance for the specific aircraft either based on MSN
b) Aircraft configuration, including modification status, (AD, SB, STC etc.)
c) Components installed (maintenance may vary based on the component OEM of the applicable aircraft system)
d) Past history of defects on the system
e) Pre-requisite aircraft and ambient conditions

3) Required items:
a) Consumables
b) Rotables
c) Expendables
d) Lubricants
e) General and special tools
f) Equipments
g) Ground Support Equipment

4) Facility preparation:
a) Hangar requirements
b) Expected ambient conditions
c) Manpower requirements

The prepared task card should also emphasize on the following:
a) Step by Step procedure
b) Provision for recording the tested values wherever applicable
c) Details of the AMEs and Technicians involved in the maintenance
d) Provision for AMEs and Technicians signature with date and time
e) Serial numbers and calibration validity details of the special tools / equipment used
f) Documents referred (If any)
g) Status of the stages of maintenance task completed.

In current scenario / trend of go green, save trees, save environment concepts due to global warming, it’s recommended to reduce the usage of paper and upgrade other possible methods to reduce usage of paper. In this regard, aviation regulators encourage the operators to reduce the usage of paper and recommend use of an acceptable technology / gadget for continuing airworthiness records without compromising the regulations.

Due to above said provision for usage of technology / gadget for maintaining the continuing airworthiness records, it is possible that the operator / AMO may practice as follows:
a) AME may perform the task on the aircraft and may record the performed maintenance task in the appropriate gadget later
b) May refer the manual once for the complete planned maintenance task and perform the task without referring to the manual while accomplishing the complete maintenance task
c) AME may just refer the manual in the gadget and simply sign in the work order.
Hence, It is recommended that the operator may add the following additional features to their software / gadget which is being used for, with the provision for recording the following:
a) Marking / selecting in the gadget for the step of the maintenance task completed
b) Personnel accessing
c) Time and date for the chapters referred in the gadget
d) Details of the special tools and test equipment used for the maintenance
e) Testing values (wherever applicable)
f) Status of the stages of maintenance task completed

So, it is evident that every maintenance being performed on aircraft must be as per step by step procedure in OEM Manuals and supporting documents. In order to ensure that no step is skipped, a documentation method of signing off is introduced by the Civil Aviation Regulators.

SUMMARY
In aviation, it is very important to perform every maintenance diligently with proper documentation of the maintenance tasks performed, personnel involved, equipment used, etc.Due to go green concept, to reduce the paper usage and to promote the usage of latest technology, the operators are recommended to use computerised documentation methods without compromising on the regulatory requirements.

During the changeover to technology, it is possible for the operators to misinterpret the regulations and not comply with the requirements of the regulations. The important points which need to be considered in the computerised method of maintaining continuing airworthiness records are as follows:
a) Marking / selecting in the gadget for the step of the maintenance task completed
b) Recording of the Personnel Accessing
c) Recording of the ATA chapters and tasks accessed on the gadget
d) Details of the special tools and test equipment used for the maintenance
e) Testing values (wherever applicable)
f) Status of the accomplishment of maintenance task.

(Published in Aviation World July-August 2020 edition. Views expressed are personal)