What is an Aircraft? Definition, Type, Classification & Grouping
What is an Aircraft? Definition, Types, Classification and Grouping of Aircraft Explained
In aviation terminology, “aircraft” is the legally recognised term used by regulatory authorities such as DGCA, ICAO, and EASA for all flying machines capable of deriving support in the atmosphere. This term includes aeroplanes, helicopters, gliders, balloons, airships, and other aerial vehicles, regardless of their design or complexity.
In India, the definition and classification of aircraft are governed by the Directorate General of Civil Aviation (DGCA) through various Civil Aviation Requirements (CARs). These regulations establish clear criteria for aircraft classification based on weight, complexity, propulsion, and operational capability, ensuring uniform safety, airworthiness, and licensing standards across the aviation sector.
Understanding what constitutes an aircraft—and how different aircraft are classified—is essential for Aircraft Maintenance Engineers (AMEs), aviation students, pilots, operators, and industry professionals. It directly impacts maintenance standards, certification authority, type-rating requirements, and operational limitations.
This article provides a comprehensive and regulatory-accurate explanation of aircraft, covering:
The official DGCA definition of an aircraft
The difference between an aircraft and an aeroplane
Classification of aircraft based on the Method of Lift Generation
Classification of aircraft based on weight
Classification of aircraft based on complexity
Classification of aircraft based on aircraft grouping for CAR-66 AME licensing
Whether you are preparing for DGCA examinations, exploring an aviation career, or seeking technically correct aviation knowledge, this guide delivers a complete and reliable understanding of aircraft from an Indian regulatory perspective.
What Is an Aircraft?
“Aircraft” means any machine which can derive support in the atmosphere from reactions of the air other than reactions of the air against the earth's surface and includes balloons, whether fixed or free, airships, kites, gliders and flying machines.”
Further, within the scope of the CAR:
“Aircraft means any machine that can derive support in the atmosphere from the reactions of the air other than reactions of the air against the earth's surface.”
This definition establishes the legal scope of aircraft under Indian aviation law, covering all categories of atmospheric flight.
Difference Between Aircraft and Aeroplane
The terms aircraft and aeroplane are often used interchangeably in everyday language, but technically and legally, they do not mean the same thing. Understanding this distinction is essential for aviation studies, DGCA exams, and regulatory documentation.
Aircraft
An aircraft is a broad and generic term used to describe any machine capable of flight that derives support from the atmosphere.
It includes:
Aeroplanes (airplanes)
Helicopters
Gliders and sailplanes
Balloons and airships
Drones (UAVs)
Tilt-rotor and experimental flying machines
In DGCA, ICAO, and CAR documentation, “aircraft” is the legally recognised umbrella term.
Aeroplane
An aeroplane (also called airplane) is a specific type of aircraft.
An aeroplane is:
A fixed-wing aircraft
Heavier-than-air
Powered by an engine (piston, turboprop, or jet)
Generates lift through aerodynamic airflow over its wings
Examples include commercial jets, trainer aircraft, and private fixed-wing aeroplanes.
Key Difference at a Glance
Important Concept to Remember
✔ All aeroplanes are aircraft
✘ Not all aircraft are aeroplanes. For example:
A helicopter is an aircraft, but not an aeroplane.
A balloon is an aircraft, but not an aeroplane.
Classification Based on Lift Generation
Aircraft are systematically classified based on how they derive lift and whether they use a power source. This fundamental classification is recognised internationally and adopted by the Directorate General of Civil Aviation (DGCA) under Civil Aviation Requirements (CAR).
At the highest level, aircraft are divided into Lighter-than-Air Aircraft and Heavier-than-Air Aircraft.
Lighter-than-Air Aircraft
Lighter-than-air aircraft derive lift primarily from buoyancy, meaning they float in the atmosphere because the gas inside them is lighter than the surrounding air. These aircraft do not rely on aerodynamic lift generated by wings or rotors.
A) Non-Power-Driven Lighter-than-Air Aircraft
Balloon
Spherical Balloon
Non-Spherical Balloon
Balloons rise and descend by controlling the temperature or quantity of the lifting gas and are commonly used for meteorological observations, training, and recreational flying.
B) Power-Driven Lighter-than-Air Aircraft
Airship
Airships are equipped with engines and control surfaces, allowing them to be navigated and propelled in a desired direction, unlike free balloons.
Heavier-than-Air Aircraft
Heavier-than-air aircraft are those that weigh more than the air they displace and therefore require aerodynamic lift to remain airborne. Lift is generated due to airflow over wings or rotors.
A) Non-Power-Driven Heavier-than-Air Aircraft
Glider (Sailplane)
Gliders do not have an engine and remain airborne using natural air currents such as thermal lift and ridge lift. They are widely used for training and sports aviation.
B) Power-Driven Heavier-than-Air Aircraft
These aircraft use engines to generate thrust, enabling sustained and controlled flight.
1) Aeroplane
Aeroplanes generate lift using fixed wings and are further classified based on their operating surface:
Landplane – Operates from land runways
Seaplane – Operates from water surfaces
Amphibian – Capable of operating from both land and water
2) Helicopter
Helicopters generate lift using rotating wings (rotors) and have the unique capability of vertical take-off and landing (VTOL), hovering, and low-speed manoeuvring.
Classification of Aircraft Based on Weight
The Directorate General of Civil Aviation (DGCA) classifies aircraft based on maximum take-off mass (MTOM) to determine maintenance standards, licensing requirements, and operational limitations.
This classification plays a critical role in airworthiness certification, AME licensing, and regulatory compliance.
Large Aircraft
As per DGCA Civil Aviation Requirements (CAR): “Large aircraft” means an aircraft, classified as an aeroplane with a maximum take-off mass of more than 5700 kg, or a multi-engined helicopter.”
Aircraft falling under this category are subject to:
Higher airworthiness and maintenance standards
Type-rated AME certification requirements
Enhanced operational and safety oversight
Examples include large commercial passenger aircraft and multi-engine helicopters used for transport or offshore operations.
Small Aircraft
Small aircraft are generally aeroplanes with a maximum take-off mass of 5700 kg or less and single-engine helicopters.
which are further classified under Light Aircraft categories, non-complex motor-powered aircraft, or specific aircraft groups, depending on their design and operational characteristics.
These aircraft typically:
Have simpler maintenance and certification requirements
Do not require type-rated licensing in many cases
Are commonly used for training, general aviation, and private operations
Classification of Aircraft Based on Complexity
DGCA classifies aircraft based on design complexity, propulsion type, operational capability, and certification requirements.
This classification directly affects maintenance standards, AME licensing scope, type-rating requirements, and regulatory oversight.
Complex Motor-Powered Aircraft
As per DGCA Civil Aviation Requirements (CAR), an aircraft is classified as complex motor-powered if it meets any one of the following conditions.
A) Complex Aeroplane
An aeroplane is considered a complex motor-powered vehicle if it is:
Above 5700 kg Maximum Take-Off Mass (MTOM), or
Certificated for more than 19 seated passengers, or
Certificated for operation with a minimum crew of at least two pilots, or
Equipped with turbojet engine(s) or more than one turboprop engine
These aircraft typically require:
Type-rated AME certification
Higher maintenance organisation approvals
Enhanced operational oversight by DGCA
B) Complex Helicopter
A helicopter is classified as complex motor-powered if it is:
Above 3175 kg Maximum Take-Off Mass (MTOM), or
Certificated for more than 9 seated passengers, or
Certificated for operation with a minimum crew of at least two pilots, or
A tilt-rotor aircraft
Complex helicopters are subject to:
Advanced maintenance programmes
Type-specific training and certification
Higher safety and compliance standards
Non-Complex / Light Aircraft Categories
Aircraft not classified as complex motor-powered are further categorised by DGCA as Light Aircraft, divided into Category 1 and Category 2, based on weight, design simplicity, and operational characteristics.
A) Category 1 – Light Aircraft
Category 1 Light Aircraft includes:
Aeroplanes with MTOM less than 1200 kg that are not complex motor-powered
Sailplanes and powered sailplanes with MTOM 1200 kg or less
Balloons within CAR-specified volume limits
Airships designed for not more than two occupants, within CAR-specified lifting gas or hot air volume limits
These aircraft generally have:
Simplified systems
Lower maintenance complexity
Limited operational scope
B) Category 2 – Light Aircraft
Category 2 Light Aircraft includes:
Aeroplanes with MTOM up to 2000 kg that are not complex motor-powered
Sailplanes and powered sailplanes with MTOM up to 2000 kg
Balloons and hot air airships
Gas airships with:
Maximum static heaviness of 3%
Non-vectored thrust (except reverse thrust)
Simple structural and control system design
Non-power-assisted flight controls
Very Light Rotorcraft
Category 2 aircraft may operate under broader conditions than Category 1 but still fall below complex aircraft regulatory thresholds.
Classification of Aircraft Based on Aircraft Grouping (CAR-66 Licensing Context)
Under DGCA CAR-66, aircraft are grouped to define the scope of Aircraft Maintenance Engineer (AME) licensing, certification privileges, and type-rating requirements.
This classification is not based on weight alone; instead, it focuses on aircraft complexity, installed systems, performance, and operational characteristics.
Aircraft grouping under CAR-66 is a licensing-oriented framework, essential for determining what category of aircraft an AME is authorised to certify.
Group 1 Aircraft
Group 1 includes aircraft with high technical complexity and advanced systems, which require DGCA-approved type-rated AME certification.
This group includes:
Complex motor-powered aircraft
Multi-engine helicopters
Aeroplanes with a maximum certificated operating altitude exceeding FL290
Aircraft equipped with fly-by-wire (FBW) flight control systems
Any aircraft for which a DGCA type rating is mandated
Operational and regulatory characteristics:
Typically used in commercial air transport
Require specialised maintenance procedures
Subject to strict regulatory oversight and continuous airworthiness management
Group 2 Aircraft
Group 2 includes aircraft not classified under Group 1 that are powered by turbine engines or advanced propulsion systems.
Group 2 is further subdivided as follows:
Group 2a – Single-turboprop aeroplanes
Group 2b – Single-turbine engine helicopters
Group 2c – Single-piston engine helicopters
General characteristics:
Do not fall under the complex motor-powered aircraft criteria
Have moderate system complexity
Commonly used for regional transport, utility, surveillance, and training operations
Group 3 Aircraft
Group 3 consists of:
Piston-engine aeroplanes that are not classified as complex motor-powered aircraft
Typical features:
Relatively simple mechanical and avionics systems
Widely used in flight training, general aviation, and private operations
Often maintained under non-type-rated AME privileges, depending on the license category
Group 4 Aircraft
Group 4 includes aircraft with non-conventional propulsion or non-powered flight characteristics, excluding any aircraft already classified under Group 1.
This group includes:
Sailplanes
Powered sailplanes
Balloons
Airships
Operational characteristics:
Operate at lower speeds and altitudes
Have specialised but simpler maintenance requirements
Governed by specific DGCA operational and airworthiness provisions
Conclusion
Aircraft form the backbone of modern aviation, encompassing a wide range of flying machines—from simple gliders and balloons to highly complex commercial jets and advanced helicopters. Understanding what an aircraft is, along with its technical classifications, regulatory definitions, and operational groupings, is fundamental for anyone pursuing a career in aviation or seeking accurate knowledge of the industry.
DGCA’s structured classification system—based on weight, complexity, and CAR-66 aircraft grouping ensures safe operation, standardised maintenance practices, and clear licensing pathways for Aircraft Maintenance Engineers (AMEs). Distinguishing between terms such as aircraft and aeroplane, and recognising categories such as complex motor-powered aircraft, light aircraft, and aircraft groups, helps eliminate common misconceptions and promotes regulatory compliance.
For AME aspirants, aviation professionals, and students, this knowledge is not just academic—it directly impacts licensing eligibility, certification privileges, maintenance responsibility, and career progression. A clear understanding of aircraft classifications aligns technical expertise with regulatory requirements, reinforcing safety and professionalism across the aviation ecosystem.
As aviation technology continues to evolve, the principles defining aircraft remain rooted in aerodynamics, engineering discipline, and regulatory oversight. Mastering these fundamentals lays a strong foundation for success in the ever-advancing world of aviation.
Author: SkyInsight Aviation Editorial Team
Last Updated: January 2026
