Aircraft Maintenance Engineering Licence Categories – Guide
What are the Aircraft Maintenance Engineering licence categories?
Aircraft Maintenance Engineering licence categories define the scope of maintenance work and certification authority granted to an AME. Under DGCA CAR-66, the main licence categories are A, B1, B2, B2L, B3, L, and C, each with specific privileges related to line or base maintenance.
Before understanding the different Aircraft Maintenance Engineering Licence categories and their sub-categories in depth, it is important to first understand who a licensed Aircraft Maintenance Engineer is, what an AME licence is and what it offers from a career point of view. An AME licence is not just a qualification; it is a legal power and authorisation that defines the scope of work, responsibility, and career growth of an aircraft maintenance engineer.
In this blog, we have covered all the important aspects related to the AME licence, including why it is required, whether it is mandatory or not, and whether it is valid worldwide. It also explains who issues the AME licence, the different types of licences, their main categories and sub-categories, and the powers and privileges associated with each licence. Additionally, in this guide, we have explained the required modules, experience requirements, educational qualifications, essential skills, licence validity, licensing fees, application process, and the salary prospects after obtaining an AME licence.
Overall, this blog is designed to give students, parents, and aviation aspirants a complete and clear understanding of the Aircraft Maintenance Engineering licence and its importance in the aviation industry worldwide.
What Is an Aircraft Maintenance Engineering Licence
An Aircraft Maintenance Engineering (AME) Licence is a legal power and authorisation that grants an Aircraft Maintenance Engineer to sign the Certificate of Release to Service (CRS) for an aircraft before take-off and after maintenance, inspection, or repair on it. In simple terms, no civil aircraft is allowed to take off unless it has been signed and certified by a licensed Aircraft Maintenance Engineer, which confirms that the aircraft is in airworthy condition, meaning fit to fly condition.
This AME licensing power is part of a globally standardised framework introduced by the International Civil Aviation Organisation (ICAO) under its ICAO Annexure 1 – Personnel Licensing. Just as the World Health Organisation (WHO) regulates global health standards, ICAO, a specialised agency of the United Nations, is responsible for regulating international civil aviation activities, including personnel licensing, training standards, and aviation safety requirements worldwide. In simple words, without ICAO's compliance, no civil registered aircraft can fly nationally and internationally.
Why an AME Licence Is Mandatory in India
Further, to implement and harmonise the above and other related ICAO’s global aviation standards, every ICAO member state is required to adopt national civil aviation rules and regulations for aircraft registered under its jurisdiction.
Accordingly, civil aviation authorities worldwide—such as EASA for European nations, FAA for the United States, TCCA for Canada, and DGCA for India—have established strict regulatory frameworks within their own legal systems to ensure compliance with these international safety standards.
In India, this global framework is implemented as national law. Once an aircraft is registered as a civil aircraft, irrespective of its owner or operator, it is legally mandated under the Aircraft Act, 1934, and the Aircraft Rules, 1937, that no aircraft is permitted to take off unless it is certified and signed by a licensed Aircraft Maintenance Engineer.
Therefore, to comply with both ICAO standards and the rules of India’s civil aviation regulatory authority, the Directorate General of Civil Aviation (DGCA), an AME licence is mandatory. Without this licence, no engineer is authorised to certify an aircraft, and without certification, no aircraft can operate.
In simple terms, even if you own an aircraft, you cannot fly or operate it unless it has been released to service by a licensed AME. The importance of an AME licence in aviation is similar to that of a pilot licence—just as no one can fly an aircraft without a valid pilot licence, no one can certify an aircraft for flight without a valid AME licence, regardless of their technical knowledge or engineering background.
In short, the AME licence is the key enabler of aviation operations, making Aircraft Maintenance Engineers the backbone of the aviation industry.
Applicability of EASA Part-66 AME Licence vs DGCA CAR-66 AME Licence
The type of AME licence required to certify an aircraft depends entirely on where the aircraft is registered, not on where it is flying or operating. For example, the EASA Part-66 licence applies to all civil-registered aircraft that fall under the jurisdiction of the European Union Aviation Safety Agency (EASA). Similarly, in India, the DGCA CAR-66 licence applies to all civil-registered aircraft regulated by the Directorate General of Civil Aviation (DGCA), Government of India. This requirement remains the same regardless of where the aircraft is flying, landing, or taking off.
In simple words, if an aircraft is registered under EASA, it cannot take off unless it is certified and signed by an EASA-licensed Aircraft Maintenance Engineer or an AME approved by EASA. And, if an aircraft is registered under DGCA, it cannot take off unless it is certified and signed by a DGCA-licensed Aircraft Maintenance Engineer or an AME approved by DGCA.
In short, the registration country of the aircraft determines which AME licence is legally valid, irrespective of the aircraft’s operating country or route.
Who Issues the AME Licence?
When students take admission to an Aircraft Maintenance Engineering Course (AME Course), many of them and even their parents believe that after completing the course, the college or AICTE will issue the AME licence. This is completely incorrect. Neither the college, nor AICTE, nor any other educational body has the legal authority to issue an Aircraft Maintenance Engineering Licence.
Who Actually Issues AME Licences Worldwide:
Globally, AME licences are issued only by the civil aviation regulatory authority of the country under which the aircraft is registered. These authorities are responsible for regulating aviation safety, airworthiness, and personnel licensing.
Some examples of competent civil aviation authorities across the world are:
- FAA – Federal Aviation Administration (United States)
- EASA – European Union Aviation Safety Agency (Europe)
- TCCA – Transport Canada Civil Aviation (Canada)
- DGCA – Directorate General of Civil Aviation (India)
Each authority issues AME licences that are valid only for aircraft registered under its jurisdiction.
DGCA’s Role in Issuing AME Licences in India:
In India, as per Rule 61 of the Aircraft Rules, 1937, and the Aircraft Act, 1934, the Directorate General of Civil Aviation (DGCA) is the legally empowered and competent authority to issue the Aircraft Maintenance Engineering Licence to eligible candidates.
To harmonise India’s AME licensing requirements with international ICAO standards & EASA standards, DGCA introduced the CAR-66 regulations. These regulations define all eligibility criteria, including modules, experience, examinations, and privileges, required for the issuance of an AME licence in India.
Types of Aircraft Maintenance Engineering Licence Categories
Before understanding the different Aircraft Maintenance Engineering (AME) licence categories, it is important to first understand what the term 'aircraft' actually means. An aircraft is not limited to only aeroplanes; it also includes helicopters, gliders, sailplanes, hot-air balloons, airships, and other flying machines. Since every aircraft type differs in design, systems, engines, and complexity, its maintenance requirements are also different.
Because of these technical differences, the Aircraft Maintenance Engineering licence is divided into multiple categories and sub-categories. This structured licensing system ensures that an AME is trained, qualified, and legally authorised to maintain only those aircraft and systems for which they are competent. This categorisation plays a critical role in maintaining aviation safety standards worldwide.
Main AME Licence Categories:
There are mainly seven Aircraft Maintenance Engineering licence categories, namely Category A, B1, B2, B2L, L, B3, and C. Each licence category defines the level of maintenance work an engineer is permitted to perform and the certification privileges they hold.
However, understanding licence categories alone is not enough. It is equally important to understand the type of maintenance performed on aircraft.
Types of Aircraft Maintenance:
Aircraft maintenance is broadly divided into two main types:
Line Maintenance – Routine inspections, defect rectification, component replacement, and minor maintenance tasks are performed on operational aircraft.
Base Maintenance – Heavy maintenance checks, structural inspections, and major overhauls are carried out inside hangars over an extended period.
Line Maintenance vs Base Maintenance-wise licence categories:
All AME licence categories, such as A, B1, B2, B2L, L, and B3, allow engineers to perform line maintenance tasks only. These licences do not permit base maintenance certification.
To certify base maintenance, an engineer must hold a Category C licence. Category C authorises base maintenance certification, but only for the aircraft type for which the engineer already holds a relevant B-category licence, such as B1, B2, or B3.
In simple terms, the Category C licence works like a master-level qualification. It cannot be obtained directly and cannot be issued based on a Category A licence. To become eligible for Category C, an engineer must first hold and gain experience under a B-category licence.
Important Difference Between Category A and Category B1:
One crucial point that students, parents, and aviation aspirants must clearly understand is the difference between Category A and Category B1, even though their sub-category names appear similar.
Category A licence includes the following sub-categories:
A1 – Aeroplane Turbine
A2 – Aeroplane Piston
A3 – Helicopter Turbine
A4 – Helicopter Piston
Category B1 licence includes the following sub-categories:
B1.1 – Aeroplane Turbine
B1.2 – Aeroplane Piston
B1.3 – Helicopter Turbine
B1.4 – Helicopter Piston
Although the aircraft types look the same, the scope of authority to sign the maintenance tasks is completely different. Category A licence holders are trained for specific and limited line maintenance tasks only. They are often referred to as task-trained engineers, authorised to certify only particular maintenance activities.
On the other hand, category B1 licence holders are trained and authorised to perform complete line maintenance tasks and activities obviously related to mechanical systems. Because of this, all the privileges of a Category A licence are automatically included in a Category B1 licence, but not vice versa.
Mechanical and Avionics Branch-wise Licence Categories Explained
As we know, aircraft are extremely complex machines with many interconnected systems. When an aircraft lands at an airport, the maintenance team has very limited time before the next scheduled take-off. Operators want to keep aircraft flying as much as possible because of the huge investment in aircraft (crores of rupees) and the ever-increasing demand for air travel.
It is not practical for a single engineer to check every system of an aircraft before take-off because:
The aircraft systems are very complex.
The time between flights is extremely limited.
To manage this efficiently, aircraft maintenance responsibilities are divided into two main branches: Mechanical and Avionics.
The Mechanical Branch of Aircraft Maintenance Engineering deals with the physical and mechanical systems of the aircraft. Engineers licensed in this branch are responsible for certifying these systems as safe and operational. Examples include:
Aircraft structure (fuselage, wings, etc.)
Landing gear systems
Powerplant, including engines and APUs (Auxiliary Power Units)
Hydraulic and pneumatic systems
Essentially, the mechanical branch licensed Aircraft Maintenance Engineers ensure that all mechanical and structural components of the aircraft are working properly.
Accordingly, licence holders in Category A1, A2, A3, A4, B1.1, B1.2, B1.3, B1.4, B3, and Category C coming from these licences are authorised to certify the respective mechanical components of the aircraft, as per the scope of their licence category.
2. Avionics Branch of Aircraft Maintenance Engineering:
The Avionics Branch of Aircraft Maintenance Engineering focuses on the electrical and electronic systems of the aircraft. Engineers licensed in this branch certify:
Aircraft electrical systems
Instrumentation systems
Radio and navigation systems
Other electronic control systems
In short, the avionics branch licensed aircraft maintenance engineers take care of all electrical and electronic components of the aircraft.
Accordingly, licence holders in Category B2, B2L, L, and Category C coming from these licences are authorised to certify the respective avionics components of the aircraft, as per the scope of their licence category.
Why Branch-wise Licensing Is Necessary:
Dividing maintenance work into these branches allows multiple engineers to work simultaneously on different systems of the aircraft. This approach:
Speeds up maintenance in the limited turnaround time between flights.
Ensures thorough and safe inspection of all systems.
Helps airlines maximise aircraft utilisation without compromising safety.
Without this division, one engineer would need too much time to inspect the entire aircraft, delaying flights and increasing operational risks.
Category A Aircraft Maintenance Engineering Licence (A1, A2, A3, and A4)
A Category A Aircraft Maintenance Engineering (AME) Licence authorises an engineer to certify and release an aircraft for limited line maintenance tasks only, for which the engineer has been specifically trained and approved. This licence does not permit certification of complete line maintenance activities. Category A licence holders are commonly referred to as task-trained line maintenance engineers, as their privileges are restricted to basic, routine, and repetitive maintenance tasks, primarily on the mechanical side of the aircraft, in accordance with approved maintenance data and regulatory limitations.
The Category A licence is further divided into four sub-categories—A1, A2, A3, and A4—based on the type of aircraft and engine configuration. Each sub-category defines the exact aircraft type on which the engineer is authorised to perform limited maintenance tasks.
Category A1 licence (Aeroplane Turbine):
It applies to aeroplanes fitted with turbine engines, which typically include large commercial transport aircraft such as passenger jets and cargo aeroplanes. A Category A1 licence holder is authorised to perform and certify only specific line maintenance tasks on turbine-powered aeroplanes for which they are trained and approved. They can release the aircraft to service only for those approved tasks and are not permitted to certify complete line maintenance or complex system rectifications.
Category A2 licence (Aeroplane Piston):
It applies to aeroplanes fitted with piston engines, generally used in training, private operations, and general aviation. With this licence, an engineer can certify limited mechanical line maintenance tasks on piston-engine aeroplanes within their task authorisation. The scope remains restricted to basic maintenance activities, and full line maintenance certification is not allowed.
Category A3 licence (Helicopter Turbine):
It applies to helicopters fitted with turbine engines, commonly used in commercial, offshore, emergency medical, and utility operations. A Category A3 licence holder is authorised to perform and certify limited line maintenance tasks on turbine-powered helicopters. Their certification privileges are confined strictly to the tasks they are trained for and do not extend to complete line maintenance activities.
A Category A4 licence (Helicopter Piston):
It applies to helicopters fitted with piston engines, typically used for training and light utility operations. Engineers holding this licence can carry out and certify specific routine line maintenance tasks on piston-engine helicopters, limited to their approved scope and task training.
In summary, all Category A sub-categories (A1, A2, A3, and A4) permit only limited line maintenance certification and do not allow base maintenance or complete line maintenance activities. Category A licences are considered the entry-level licensing category in the Aircraft Maintenance Engineering hierarchy. Engineers seeking broader maintenance authority and higher responsibility must progress to Category B1 or B2 licences, where full line maintenance certification privileges are granted.
Category B1 Aircraft Maintenance Engineering Licence (B1.1, B1.2, B1.3 & B1.4)
A Category B1 Aircraft Maintenance Engineering Licence authorises an engineer to certify and issue the Certificate of Release to Service for complete line maintenance activities performed on an aircraft. As per DGCA CAR-66 regulations, a Category B1 licence holder is responsible for maintenance and certification related to aircraft structure, powerplant, mechanical systems, and associated electrical systems. In addition to mechanical responsibilities, a B1 licence holder is also permitted to perform limited work on avionics systems, provided that such work involves only simple functional tests to prove serviceability and does not require complex fault diagnosis or troubleshooting.
It is important to understand that a Category B1 licence automatically includes the privileges of the corresponding Category A sub-category. This means that all the maintenance tasks and certification privileges available to a Category A licence holder are inherently included within the Category B1 licence. Because of this wider scope and authority, Category B1 engineers form the backbone of airline and helicopter line maintenance operations across the world.
Category B1.1 Licence (Aeroplane Turbine)
The Category B1.1 licence applies to aeroplanes fitted with turbine engines, which primarily include large commercial passenger and cargo aircraft. A B1.1 licence holder is authorised to certify complete line maintenance activities performed on turbine-powered aeroplanes and issue the Certificate of Release to Service after ensuring the aircraft meets all airworthiness requirements. This licence allows the engineer to maintain and certify aircraft structures, turbine powerplants, mechanical systems, and associated electrical systems. In addition, the licence permits limited avionics-related tasks involving simple functional checks to confirm serviceability, without engaging in complex troubleshooting. A Category B1.1 licence inherently includes all the privileges of a Category A1 licence.
Category B1.2 Licence (Aeroplane Piston):
The Category B1.2 licence applies to aeroplanes fitted with piston engines, which are commonly used in general aviation, flight training, and private operations. A B1.2 licence holder is authorised to certify complete line maintenance on piston-engine aeroplanes and issue the Certificate of Release to Service upon completion of maintenance. The scope of this licence covers aircraft structure, piston powerplants, mechanical systems, and associated electrical systems. Similar to other B1 categories, the engineer may perform simple avionics functional checks to prove serviceability, provided no troubleshooting is involved. The privileges of a Category A2 licence are automatically included within a Category B1.2 licence.
Category B1.3 Licence (Helicopter Turbine):
The Category B1.3 licence applies to helicopters fitted with turbine engines, which are widely used in offshore operations, emergency medical services, law enforcement, and commercial helicopter services. A B1.3 licence holder is authorised to certify complete line maintenance activities on turbine-powered helicopters and issue the Certificate of Release to Service. This licence allows maintenance and certification of helicopter structure, turbine engines, mechanical transmission systems, and associated electrical systems. Limited avionics work involving simple functional checks is also permitted, as long as no fault diagnosis is required. A Category B1.3 licence includes all the privileges of a Category A3 licence.
Category B1.4 Licence (Helicopter Piston):
The Category B1.4 licence applies to helicopters fitted with piston engines, which are typically used for training, light utility, and private helicopter operations. A B1.4 licence holder is authorised to certify complete line maintenance on piston-engine helicopters and issue the Certificate of Release to Service after maintenance. The scope of this licence includes helicopter structure, piston engines, mechanical systems, and associated electrical systems. As per CAR-66 provisions, the engineer may also perform simple avionics serviceability checks without troubleshooting. The privileges of a Category A4 licence are automatically included within a Category B1.4 licence.
All Category B1 licence holders are authorised for complete line maintenance certification but are not permitted to certify base maintenance activities. Base maintenance certification requires a Category C licence, which can only be obtained after holding an appropriate B1 or B2 licence. Among all AME licence categories, the Category B1 licence is considered one of the most in-demand and globally recognised mechanical licences in the aviation industry.
Category B2 AME Licence (Avionics Stream)
A Category B2 Aircraft Maintenance Engineering licence authorises an engineer to certify maintenance work related to avionic and electrical systems of an aircraft. This licence is specifically designed for engineers who specialise in aircraft electronics rather than mechanical systems.
A B2 licence holder is legally permitted to issue a Certificate of Release to Service (CRS) after carrying out maintenance on the avionics and electrical systems of an aircraft type endorsed on their licence. These systems include communication, navigation, flight instruments, automatic flight control systems, and other related electronic and electrical components.
In addition to pure avionic systems, a Category B2 licence holder may also certify avionic and electrical systems that are installed within engine or mechanical systems, provided that only simple tests are required to prove their serviceability. This means a B2 engineer can certify the electrical or electronic part of a system, but not the mechanical portion that falls under B1 authority.
Line Maintenance Privileges of Category B2:
A Category B2 licence allows the holder to certify minor scheduled line maintenance and simple defect rectification related to avionic and electrical systems. However, these privileges are strictly limited to the specific tasks that are endorsed in the certification authorisation issued by a DGCA-approved maintenance organisation.
Another important restriction is that a B2 licence holder can certify only the work that they have personally performed within the maintenance organisation that issued their certification authorisation. The certification privilege is also limited to the aircraft type rating already endorsed on the licence.
Category B2 Does Not Include A Sub-Category:
One very important point that aviation students must clearly understand is that a Category B2 licence does not include any Category A sub-category. Unlike Category B1 licence holders, who automatically inherit the privileges of Category A, a Category B2 licence holder does not get any A-category certification privileges.
This means a B2 engineer cannot certify mechanical line maintenance tasks unless they separately hold a Category A or B1 licence for that aircraft type.
In simple terms, a Category B2 AME licence is meant exclusively for avionics engineers. It authorises certification of electrical and electronic systems only, while mechanical systems remain outside its scope. This clear separation between mechanical (B1) and avionic (B2) licensing ensures higher safety, accountability, and system-specific expertise in aircraft maintenance.
Category B2L AME Licence (Light Aircraft – Avionics & Electrical)
A Category B2L Aircraft Maintenance Engineering licence is a specialised licence introduced under CAR-66 for engineers working on light aircraft. This licence focuses on electrical and avionics systems of light aeroplanes and helicopters, where system complexity and maintenance scope are lower compared to large transport category aircraft.
A Category B2L licence holder is authorised to issue a Certificate of Release to Service (CRS) and also to act as B2L support staff for maintenance activities carried out on aircraft types endorsed on their licence. This makes the B2L licence both a certifying and supporting licence within its defined limits.
Scope of Maintenance Under Category B2L:
A B2L licence holder may certify maintenance performed on the electrical systems of light aircraft. This includes power supply systems, lighting systems, electrical distribution, and related components installed on the aircraft.
In addition, a B2L engineer is authorised to certify maintenance performed on avionics systems, such as communication, navigation, and basic flight instrumentation, but only within the system ratings specifically endorsed on the licence. This ensures that the engineer is certified only for systems they are formally trained and approved to work on.
Airframe System Rating Privilege:
An important additional privilege under Category B2L is available when the licence holder also holds an “airframe system” rating. In such cases, the B2L engineer is permitted to perform electrical and avionics tasks within the powerplant and mechanical systems, provided that only simple tests are required to prove serviceability.
This means that while B2L engineers are not mechanical specialists, they may certify the electrical or avionic portion of an engine or mechanical system, as long as the work does not involve complex mechanical testing or adjustments.
Difference Between B2 and B2L:
In simple terms, Category B2 is meant for large commercial aircraft, whereas Category B2L is designed for light aircraft operations. The scope of systems, depth of complexity, and certification privileges under B2L are intentionally limited to ensure safe and efficient maintenance of light aircraft used in general aviation, training, and private operations.
Why the Category B2L Licence Is Important:
The B2L licence plays a crucial role in general aviation by ensuring that electrical and avionics maintenance on light aircraft is carried out by properly licensed engineers. This aligns with ICAO safety principles while also reducing unnecessary licensing barriers for engineers working outside large airline environments.
Category L Aircraft Maintenance Engineering Licence (Light & Special Aircraft)
The Category L Aircraft Maintenance Engineering Licence is a specialised licence category designed for engineers working on light aircraft and special aircraft types, such as sailplanes, gliders, balloons, airships, and light helicopters. These aircraft have simpler structures, propulsion systems, and avionics, and therefore require a separate licensing framework under CAR-66.
A Category L licence holder is authorised to issue a Certificate of Release to Service (CRS) and also to act as Category L support staff for aircraft types and systems endorsed on the licence.
General Scope of Category L Licence
A Category L licence holder may certify maintenance performed on:
Aircraft structure
Power plant (engine)
Mechanical systems
Electrical systems
In addition, the licence allows certification of work carried out on:
Radio systems
Emergency Locator Transmitters (ELT)
Transponder systems
Other basic avionics systems are provided, provided that only simple tests are required to prove serviceability.
Complex avionics troubleshooting or advanced system diagnostics are not permitted under Category L.
Category L Sub-Categories Explained
Because light and special aircraft vary significantly in design and operation, Category L is further divided into multiple sub-categories, each aligned with a specific aircraft type.
L1 – Sailplanes and Powered Sailplanes
The L1 licence applies to sailplanes and powered sailplanes. It allows certification of structural, mechanical, electrical, and basic avionics maintenance required for glider operations.
L1C – Composite Sailplanes
The L1C licence is a specialised version of L1, applicable to composite sailplanes. Due to the use of advanced composite materials, this sub-category requires additional structural knowledge related to composite construction and repairs.
L2 – Balloons
The L2 licence applies to hot-air balloons and gas balloons. It covers maintenance of balloon envelopes, burners, fuel systems, baskets, and associated mechanical and electrical systems.
Important Note:
- Sub-category L2 includes L1.
- Any limitation applied to L2 automatically applies to L1 as well, in accordance with CAR-66 provisions.
L2C – Composite Balloons
The L2C licence applies to balloons constructed using composite materials.
Important Note:
- Sub-category L2C includes L1C, meaning any limitation on L2C also affects L1C.
L3H – Light Helicopters (Non-Complex)
The L3H licence applies to light helicopters with simpler mechanical and electrical systems. It allows certification of airframe, engine, mechanical, electrical, and limited avionics work using simple functional tests.
L3G – Gyroplanes
The L3G licence applies to gyroplanes. It authorises certification of maintenance tasks related to structure, propulsion, mechanical systems, and basic avionics used in gyroplane operations.
L4H – Light Helicopters (Special or Restricted Types)
The L4H licence covers specific light helicopter types that fall outside standard L3H applicability. It is generally used for restricted or specialised helicopter operations.
L4G – Powered Aircraft (Special Light Categories)
The L4G licence applies to special light-powered aircraft, including certain experimental or limited-certification aircraft categories approved under CAR-66.
L5 – Airships
The L5 licence applies to airships. It allows certification of structure, propulsion, mechanical systems, electrical systems, and basic avionics necessary for airship operations.
Why the Category L Licence Is Important
Category L licences ensure that non-commercial and special aircraft are maintained by engineers who are specifically trained for their unique designs and operating characteristics. This maintains safety while avoiding unnecessary licensing complexity meant for large commercial aircraft.
In short, Category L is the backbone of general aviation, recreational aviation, and special aircraft maintenance, playing a vital role in flight safety beyond airlines.
Category C Aircraft Maintenance Engineering Licence (Base Maintenance Certification)
The Category C Aircraft Maintenance Engineering Licence is the highest level of AME licence under CAR-66. This licence authorises the holder to issue the Certificate of Release to Service (CRS) following base maintenance of an aircraft type endorsed on the licence.
Unlike other licence categories that certify individual systems or tasks, Category C certification applies to the aircraft as a complete unit, including all systems, structures, and components. Without Category C certification, an aircraft cannot return to service after base maintenance.
Scope of Certification Under Category C:
A Category C licence holder is permitted to certify scheduled base maintenance by issuing a single CRS for the entire aircraft after all required maintenance activities have been completed.
This certification is not based on the Category C engineer personally performing every maintenance task. Instead, it is based on the fact that:
Maintenance has been carried out by competent mechanics, and
All relevant maintenance tasks have been individually certified and signed off by appropriate Category B1, B2, B2L, B3, and L support staff, according to their respective specialisations.
Primary Responsibility of a Category C Engineer:
The principal function of Category C certifying staff is to ensure that:
All required base maintenance tasks have been properly called up.
Every task has been completed in accordance with approved maintenance data, and
All tasks have been correctly certified by authorised B-category and L-category support staff before issuing the final CRS.
In simple words, the Category C engineer acts as the final authority who confirms that the aircraft is fully airworthy and safe to return to service after base maintenance.
Relationship Between Category C and Other AME Licences:
Category C does not replace Category B or L licences. Instead, it depends on them.
Only those Category C personnel who also hold a valid Category B1, B2, B2L, B3, or L licence may perform both roles—that is, act as support staff and certifying staff during base maintenance. Without holding one of these licences, a Category C holder can perform only the certification role, not hands-on maintenance certification.
This is why Category C is often compared to a master-level qualification in aircraft maintenance.
Why the Category C Licence Is So Important:
Category C engineers are responsible for the final airworthiness decision of an aircraft after heavy maintenance checks, such as C-checks or major base maintenance inspections. Their certification directly affects:
Flight safety
Regulatory compliance
Airline operational approval
In short, Category C licence holders carry the highest level of responsibility in aircraft maintenance engineering, making them the final gatekeepers of aviation safety.
Experience & Module Requirements for AME Licence (CAR-66)
Note: “Operating aircraft experience” means maintenance on live, in-service aircraft operated by airlines, air taxi operators, aero clubs, flying clubs, owners, etc.
Table 1: Category-wise Modules & Experience Requirement
Experience Requirement for AME Licence under CAR-66:
Passing the required CAR-66 modules alone is not sufficient to obtain an Aircraft Maintenance Engineering (AME) licence. Along with module qualification, candidates must also complete a specified period of practical maintenance experience on operating aircraft. Operating aircraft means aircraft that are actively in service with airlines, charter operators, flying clubs, or approved maintenance organisations, not static or training-only aircraft.
The amount of experience required depends on the licence category applied for and the candidate’s educational background. This practical experience ensures that the applicant has real-world exposure to aircraft systems, maintenance procedures, safety practices, and regulatory compliance before being granted certification privileges.
Experience Relaxation Based on Educational Background:
DGCA provides experience relaxation under CAR-66 (66.A.30) for candidates with relevant technical education or approved training. There are three recognised routes to fulfil experience requirements.
Candidates without any technical qualification must complete the full experience duration, which typically ranges from 3 to 5 years, depending on the licence category. This experience must be gained entirely through operating aircraft.
Candidates holding a recognised engineering or AME-related degree are eligible for reduced experience requirements, generally 2 to 3 years, provided the degree is awarded by a recognised university, and the experience is relevant to aircraft maintenance.
The fastest and most structured route is through a DGCA CAR-147-approved AME training organisation. Candidates completing CAR-147 training require only 1 to 2 years of practical experience, making this the most preferred pathway for aviation aspirants aiming for early licence issuance.
Importance of Recent and Valid Experience:
DGCA places strong emphasis on the recency and continuity of maintenance experience. At least one year of experience must be recent, meaning it should be close to the date of the licence application. For licence additions or extensions, a minimum of three months of recent experience is required.
Experience used for licence issuance must generally fall within the last 10 years. However, for candidates with defence aviation backgrounds, experience up to 15 years old may be considered, subject to DGCA evaluation.
Category C Licence Experience Requirement Explained Clearly:
The Category C AME licence is specifically meant for base maintenance certification and carries the highest level of responsibility. A Category C licence holder certifies the aircraft as a whole after base maintenance, rather than individual systems.
For large aircraft, a candidate must have a minimum of three years of experience as a Category B1.1, B1.3, or B2 licence holder on large aircraft. Alternatively, candidates holding B1.2 or B1.4 licences require five years of experience on large aircraft to qualify for Category C.
For aircraft other than large aircraft, at least three years of experience as a B1 or B2 licence holder or as approved base maintenance support staff is required.
It is important to understand that a Category C engineer does not independently perform all maintenance tasks. Certification is based on confirmation that all required work has been completed and signed off by appropriately licensed B1, B2, B2L, B3, and L category support staff.
Automatic Experience Credits for Certain Licence Holders:
DGCA provides automatic experience credit in certain cases. Holders of B1.2 or B3 licences are automatically considered to meet the experience requirements for Category L subcategories, including L1, L1C, L2, and L2C, without additional experience validation.
Acceptance of Defence and Non-Civil Aviation Experience:
Experience gained in military aviation or aircraft manufacturing organisations can also be considered. A candidate with 12 years of defence or manufacturing experience, combined with at least one year of civil aviation maintenance experience, may be treated as meeting CAR-66 experience requirements, subject to DGCA assessment.
In simple terms, modules make you technically eligible, but practical experience makes you legally eligible for an AME licence. Even if all CAR-66 modules are cleared, DGCA will not issue a licence unless the required maintenance experience is properly completed and documented. DGCA-approved training significantly reduces the experience timeline and provides the most reliable pathway toward becoming a licensed Aircraft Maintenance Engineer.
Aircraft Maintenance Engineering Salary
The salary of an Aircraft Maintenance Engineer (AME) depends on several factors, such as licence category (A, B1, B2, B2L, B3 or C), aircraft type rating, experience level, and the organisation they work for. In the initial stage, before obtaining a full DGCA licence, trainees and technicians earn a modest salary. However, after acquiring a valid AME licence and an aircraft type rating, salary growth becomes significant. Licensed AMEs working with airlines, MROs, or charter operators earn higher compensation due to the high responsibility of certifying aircraft airworthiness. With experience, specialised type ratings, and base maintenance authorisation, AMEs can progress to senior technical roles with attractive pay and long-term career stability in the aviation industry.
To know further details about salary with average figures, visit our dedicated blog by clicking the following link:
https://www.aircraftmaintenanceengineering.co.in/2025/12/aircraft-maintenance-engineering-salary.htmlHow to Get an Aircraft Maintenance Engineering Licence in India (Step-By-Step Guide)
Obtaining an Aircraft Maintenance Engineering (AME) Licence in India is a regulated licensing process under DGCA CAR-66. The licence is issued only after fulfilling training, examination, experience, skill assessment, and regulatory approval requirements. Importantly, freshers cannot directly apply for a Category C licence. Category C is a progression licence, not an entry-level licence. Below is the correct and legally accurate process.
Step 1 – Complete DGCA-Approved AME Training (CAR-147) or Equivalent Qualification:
The journey toward an AME licence usually starts with completing a DGCA-approved Aircraft Maintenance Engineering course conducted under CAR-147. This training provides structured theoretical knowledge, practical exposure, safety culture, human factors, and aviation legislation as per ICAO standards.
Although CAR-147 training is not the only route, it is the most preferred and fastest pathway, as it provides maximum relaxation in experience requirements and prepares candidates directly for DGCA module examinations and real aircraft maintenance environments.
Step 2 – Clear DGCA CAR-66 Module Examinations:
After or during training, candidates must pass the DGCA CAR-66 module examinations relevant to the licence category they wish to apply for (A, B1, B2, B2L, B3, or L).
Each licence category has a defined set of mandatory modules by DGCA, covering aircraft systems, maintenance practices, electrical, avionics, human factors, and aviation legislation. Clearing all required modules as per aircraft maintenance engineering syllabus is essential, but passing exams alone does not grant any licence or certification authority.
Step 3 – Gain Required Practical Aircraft Maintenance Experience:
Once the required modules are cleared, the candidate must acquire practical maintenance experience on operating (live) aircraft maintained by an approved maintenance organisation.
The duration of experience depends on the candidate’s educational background:
DGCA-approved AME course holders require a minimum of experience.
Engineering degree holders require moderate experience.
Candidates without approved training require longer experience.
This step ensures the applicant has real-world exposure to aircraft systems, maintenance tasks, safety procedures, and regulatory compliance before being entrusted with certification privileges.
Step 4 – Clear the DGCA Skill Test (Mandatory Before Licence Issuance):
Before licence issuance, DGCA conducts a Skill Test to assess the candidate’s practical knowledge, maintenance understanding, regulatory awareness, and human factor competence.
This skill test is mandatory and applies to all AME licence applicants. Even if a candidate has cleared modules and completed experience, failure in the skill test will stop licence issuance.
This step ensures that the engineer is not only theoretically qualified but also competent to maintain aircraft safely.
Step 5 – Apply for AME Licence Through eGCA (DGCA Licensing Portal):
After successfully completing modules, experience, and the skill test, the candidate can apply for the AME licence through eGCA (Electronic Governance of Civil Aviation), DGCA’s official online portal.
The application includes submission of:
Module pass certificates
Experience records and logbooks
Skill test clearance
Training certificates and identity documents
DGCA verifies all documents strictly as per CAR-66 regulations. Upon successful verification, DGCA issues the AME Licence for the applicable category and sub-category.
Step 6 – Obtain Aircraft Type Rating (Mandatory for Certification Privileges):
Holding an AME licence alone does not allow an engineer to certify aircraft. After licence issuance, the AME must undergo aircraft-specific Type Rating training (e.g., Airbus A320, Boeing 737, ATR, helicopters, etc.).
Only after successful completion of type training and organisational authorisation can an AME sign and certify maintenance tasks on that specific aircraft type.
Important Clarification About Category C Licence (Very Important):
A Category C AME Licence is NOT an entry-level licence.
Freshers cannot apply for Category C
A candidate must already hold a valid B1, B2, B2L, B3, or L licence
Category C is issued only to experienced licensed engineers
Category C authorises base maintenance certification, not line maintenance
In simple terms, Category C is a progression licence, similar to a master-level authority. Without holding and working under a line maintenance licence (B1/B2/B3/L), a candidate is not eligible for Category C.
To get an AME licence in India, a candidate must complete approved training, clear DGCA module exams, gain live aircraft maintenance experience, pass a mandatory DGCA skill test, apply through eGCA, and obtain aircraft type ratings. Category C licences are issued only to experienced licensed engineers and are not available to freshers.
DGCA AME Licence Exam Details (CAR-66 Modules)
The DGCA Aircraft Maintenance Engineering (AME) licence examinations are conducted in accordance with CAR-66 regulations and are designed to assess a candidate’s theoretical knowledge, regulatory understanding, and system-level competence required for aircraft maintenance certification. These examinations follow a standardised and transparent evaluation system to ensure safety and global compliance.
All CAR-66 basic module examinations are conducted in a multiple-choice question (MCQ) format. Each question provides more than two answer options, but only one option is correct. This format ensures objective evaluation and eliminates subjective bias during assessment.
The exam duration for each module is calculated based on an average of 75 seconds per question. This time allocation is carefully designed to test not only factual knowledge but also the candidate’s ability to analyse technical questions within realistic operational time constraints.
To successfully pass a CAR-66 module or sub-module examination, a candidate must score a minimum of 75% marks. There is no penalty for incorrect answers, meaning negative marking is not applied. Candidates are therefore encouraged to attempt all questions without the risk of marks deduction for wrong responses.
If a candidate fails a module examination, they are not permitted to retake the same module for at least 90 days from the date of the failed attempt. However, an important relaxation exists: if the candidate undergoes a tailored retraining course conducted by a DGCA-approved maintenance training organisation, the failed module may be reattempted after 30 days. Additionally, modules related specifically to limitation papers may also be retaken after a 30-day waiting period.
The validity period and time limits specified under CAR 66.A.25 apply individually to each module examination. An exception is granted when a module has already been passed as part of another licence category and the licence has been issued — in such cases, the module does not need to be revalidated.
DGCA places a strict limit on examination attempts to maintain competency standards. A candidate is allowed a maximum of three consecutive attempts per module. If all three attempts are unsuccessful, the candidate must wait one full year before starting a new set of three attempts for that module.
As part of regulatory transparency, every applicant must formally declare in writing to DGCA the number of attempts and examination dates taken during the previous year when applying for any CAR-66 examination. Providing incorrect or incomplete information can lead to rejection or regulatory action.
DGCA CAR-66 AME exams are MCQ-based with a 75% pass mark, no negative marking, defined waiting periods for reattempts, strict limits on exam attempts, and mandatory declaration of previous attempts. These rules ensure standardised, fair, and safety-focused licensing of aircraft maintenance engineers in India.
AME Licence Eligibility & Qualification Requirements
To apply for an Aircraft Maintenance Engineer (AME) Licence in India, a candidate must meet specific age, educational, examination, and documentation requirements laid down by the Directorate General of Civil Aviation (DGCA) under CAR-66. These requirements ensure that only suitably qualified and competent individuals are authorised to certify aircraft maintenance.
Minimum Age Requirement:
An applicant for the grant of an AME licence must be at least 18 years of age at the time of application. This is the minimum legal age prescribed by DGCA to ensure maturity, responsibility, and accountability in aviation safety-critical roles.
Educational Qualification Requirement:
The candidate must have passed the 10+2 examination with Physics, Chemistry, and Mathematics (PCM) from a recognised Board or University, or an equivalent qualification accepted by DGCA. These subjects are mandatory because AME training and licensing involve a strong foundation in physics-based systems, electrical and electronic principles, and applied mathematics.
Diploma Holders – Equivalent Qualification:
Candidates holding a Diploma in Engineering recognised by a State Technical Education Board, where Physics, Chemistry, and Mathematics were studied, are also considered educationally eligible. However, to establish equivalence with the 10+2 PCM requirement, the applicant must submit an official equivalence certificate issued by the concerned Board or University along with the licence application.
DGCA Written Examination Requirement:
In addition to meeting the age and educational criteria, the applicant must have successfully passed the DGCA-prescribed written examinations, commonly known as the CAR-66 module examinations. These exams assess theoretical knowledge relevant to the licence category applied for and are a mandatory requirement before licence issuance.
Application Procedure Through eGCA:
The application for the grant of a new AME licence or any change/addition to an existing licence must be submitted using CA Form 19 through the eGCA (Electronic Governance for Civil Aviation) portal. The application must be accompanied by prescribed fees and all supporting documents as required by DGCA.
Each application must be supported by documentary evidence proving compliance with:
Applicable theoretical knowledge requirements
Practical training records
Aircraft maintenance experience, as relevant to the licence category
These documents must be valid and current at the time of application to ensure regulatory compliance.
Application for Change or Addition to Existing Licence
When applying for any change, endorsement, or addition to an existing AME licence, the applicant must submit their current original AME licence along with the application through eGCA. This allows DGCA to verify existing privileges before approving any modification.
In short, to be eligible for a DGCA AME licence, a candidate must be at least 18 years old, have passed 10+2 with Physics, Chemistry, and Mathematics (or an equivalent diploma), clear CAR-66 module exams, and apply through eGCA with complete documentation proving knowledge, training, and experience compliance.
DGCA Fees for AME Licence Issuance, Renewal, and Exams
The Directorate General of Civil Aviation (DGCA) prescribes specific fees for all activities related to Aircraft Maintenance Engineer (AME) licences, including examination, issuance, renewal, endorsements, and duplicate licences. These fees vary depending on the type of service and method of examination.
1. Examination Fees for Aircraft Maintenance Engineering Modules:
DGCA conducts examinations for AME licences under CAR-66, and the fees depend on whether the exam is conducted normally, online, or on demand:
Normal examination: ₹500 per paper
Online examination: ₹1,500 per paper
Online on-demand examination: ₹3,000 per paper
These fees ensure that candidates contribute to the operational costs of conducting written and online module exams.
2. AME Licence and Fees:
For licence issuance, validation, renewal, or duplicate certificates, DGCA charges as follows:
Issue or validation of licence, rating, authorisation, approval, or certificate of competency: ₹5,000
Renewal of licence, rating, authorisation, approval, or certificate of competency: ₹2,500
Issue of duplicate licence, rating, authorisation, approval, or certificate of competency: ₹500
These fees apply across all AME licence categories and ensure proper record management and regulatory compliance.
Frequently Asked Questions (FAQs) – Aircraft Maintenance Engineering Licence Categories
1. What are Aircraft Maintenance Engineering (AME) licence categories?
Aircraft Maintenance Engineering licence categories define the scope of maintenance work and certification authority granted to an AME. Under DGCA CAR-66, the main licence categories are A, B1, B2, B2L, B3, L, and C, each with specific privileges related to line or base maintenance.
2. Who issues the Aircraft Maintenance Engineering licence in India?
In India, the Directorate General of Civil Aviation (DGCA) is the only legal authority authorised to issue AME licences under the Aircraft Act, 1934 and Aircraft Rules, 1937. Colleges, AICTE, or universities do not issue AME licences.
3. Is an AME licence mandatory for aircraft operation in India?
Yes. An AME licence is legally mandatory. No civil aircraft registered in India can take off unless it has been certified and released to service by a DGCA-licensed Aircraft Maintenance Engineer, in compliance with ICAO standards.
4. Is the AME licence valid worldwide?
An AME licence is valid only for aircraft registered under the issuing authority.
For example:
DGCA CAR-66 licence → Valid for Indian-registered aircraft
EASA Part-66 licence → Valid for EASA-registered aircraft
Aircraft registration—not operating location—determines licence validity.
5. What is the difference between line maintenance and base maintenance?
Line Maintenance includes routine inspections, defect rectification, and component replacement performed on operational aircraft.
Base Maintenance includes heavy checks, structural inspections, and major overhauls performed inside hangars.
Line Maintenance includes routine inspections, defect rectification, and component replacement performed on operational aircraft.
Base Maintenance includes heavy checks, structural inspections, and major overhauls performed inside hangars.
Only Category C licence holders can certify base maintenance.
6. Which AME licence categories are allowed for line maintenance?
Licence categories A, B1, B2, B2L, B3, and L are authorised for line maintenance certification only, within the scope of their respective privileges.
7. What is the purpose of a Category C AME licence?
The Category C licence authorises an engineer to certify base maintenance by issuing a single Certificate of Release to Service (CRS) for the aircraft as a whole after heavy maintenance checks.
8. Can freshers apply directly for a Category C AME licence?
No. Category C is not an entry-level licence. A candidate must already hold and gain experience under a B1, B2, B2L, B3, or L licence before becoming eligible for Category C.
9. What is the difference between a Category A and Category B1 licence?
Category A allows certification of limited, task-specific line maintenance only.
Category B1 allows complete line maintenance certification for mechanical systems.
Category A allows certification of limited, task-specific line maintenance only.
Category B1 allows complete line maintenance certification for mechanical systems.
All Category A privileges are automatically included in Category B1, but not vice versa.
10. What is the difference between Category B1 and Category B2 licences?
Category B1 focuses on mechanical systems, including airframe, engines, and associated electrical systems.
Category B2 focuses on avionics and electrical systems, such as instruments, navigation, and communication systems.
Category B1 focuses on mechanical systems, including airframe, engines, and associated electrical systems.
Category B2 focuses on avionics and electrical systems, such as instruments, navigation, and communication systems.
B2 does not include Category A privileges.
