An airfoil is a key part of an aircraft that generates lift. It has a leading edge and trailing edge, with the chord connecting the two. The shape and thickness of the airfoil, including its camber, determine whether it is best suited for commercial or fighter aircraft. Commercial aircraft typically use thicker, cambered airfoils for low speeds and high lift, while fighter jets use thinner, symmetric airfoils for high speeds and low lift. The National Advisory Committee for Aeronautics (NACA) developed a numbering system to classify different standard airfoil profiles.

1. AIRFOIL

2. Lift
• A force which moves aircraft in upward direction is called lift.
• This force can be generated by (Airfoil).
• Many parts of aircraft produce lift such as fuselage, Tail surface etc.

3. Airfoil
• Airfoil is a part of the aircraft which is used to generate lift.
Without airfoil aircraft can never fly because no lift is generated thus
aircraft never moves in upward direction. The parts such as wing and tail
surface are known as airfoil. It has leading edge and trailing edge.

4. Leading Edge
• Leading edge is the front of the airfoil. Leading edge can present
the airfoil function. If leading edge is thick or a cambered then it
is used in commercial aircrafts because commercial aircraft
operate at low speed and high lift but if its leading edge is sharp
or non cambered then this type of airfoils are used in fighter
aircrafts because fighter aircraft operate at high speed and low
lift.

5. Trailing Edge
• Trailing edge is back of the airfoil or wing. Trailing edge consist of
ailerons and flaps which are used to operate aircraft in air. The
airflow separated by leading edge rejoins at trailing edge. The
trailing edge may be sharp, flat or rounded.

6. Chord
• Chord is an imaginary straight line which joins leading edge and trailing
edge. Chord determine the width of the wing. Most wings are not
rectangular, so they have different chords at different positions.

7. Camber
• Camber determine thickness of airfoil. It is characteristic curve of
upper or lower surface
• If airfoil is thick then it is cambered and non symmetrical or
Asymmetrical. This airfoil is used for commercial aircraft.
• If airfoil is sharp then it has low cambered and it is symmetrical.
This airfoil is used in fighter aircraft.

8. Mean Camber
• An imaginary line which divides airfoil in tow equal parts is called
Mean Aerodynamic camber.
• Line is from leading edge to trailing edge.
• It may or may not straight line.

9. Naca Airfoil Numbering System
• Naca consist following types of airfoil
• 4-Digit airfoil
• 5-Digit airfoil

10. Naca 4-Digit Airfoils
• There are many types of 4 digit airfoils in Naca.
• 4412
• 3314
• 2412

11. Naca 5-Digit airfoils
• These are 5-Digit airfoils in Naca.
• 22020
• 12112
• 44144
If middle digit is (zero) then camber is (simple) and if middle digit is
(one) then camber in naca 5-digit is (reflex).