A plane’s angle of attack is the angle between its airfoil’s chords and airflow.
Lift and drag both increase with an increasing angle of attack until the critical angle of attack is reached.
The critical angle of attack is when an aircraft experiences maximum lift.
A plane stops generating lift and stalls if its angle of attack increases above its critical angle of attack.
Other important angles in aviation include pitch angle and angle of flight.
The pitch angle is the angle between the plane’s airfoils and the flat ground. The angle of flight is the angle between a plane’s velocity vector and either the horizon or flat ground.
What Does Angle of Attack Mean in Aviation?
In aviation, the angle of attack is the angle at which airflow connects with an aerofoil’s chord.
So, the angle of attack is the difference between where a wing is pointing and where the wind is going.
The angle of attack tells a pilot how much drag and lift a plane is experiencing.
Why is the Angle of Attack So Important?
The Angle of Attack is important in aviation because it informs pilots how much lift their aircraft experiences.
Both lift and drag increase with an increasing angle of attack until a certain limit called the critical angle of attack is reached.
A plane stalls if its angle of attack exceeds its critical angle of attack.
So, pilots need to monitor their angle of attack to ensure they don’t cross their critical angle of attack.
If a pilot crosses their aircraft’s critical angle of attack, the aircraft won’t experience any more lift and will begin to descend.
In What Ways Does the Angle of Attack Affect Flight?
The angle of attack affects flight in several ways.
- The angle of attack informs a pilot of what lift and drag their aircraft is experiencing.
- The higher the angle of attack, the higher the lift and drag forces on the aircraft.
- Conversely, lift and drag are lower when the angle of attack is lower.
- A plane maximizes lift at its critical angle of attack, but experiences stalling if it crosses the critical angle of attack.
- A plane loses all lift when it stalls and begins to descend.
So, simply put, the angle of attack is so important to understand because if the critical angle of attack is reached and then exceeded, it will cause an aircraft to lose lift and fall from the sky.
Inevitably, pilots need to avoid exceeding their critical angle of attack.
How is Angle of Attack Measured?
Angle of attack is usually measured with a free movement vane that’s attached to either the aircraft’s fuselage or on a wing-mounted boom.
The vane is aligned with airflow, and the sensor inside it calculates the angle of attack, which is relayed to the pilot.
An alternative approach is using pressure-based probes that have multiple ports.
The port pressure difference is then used to calculate the aircraft’s angle of attack.
What is the Formula to Calculate the Angle of Attack?
The formula for calculating angle of attack is as follows:
CL = CLα (α-αL=0)
- CL is the Lift Coefficient
- CLα is the Lift curve Slope.
- α is the Angle of Attack
- αL=0 is the Zero lift angle
What Does Critical Angle of Attack Mean?
Lift and drag both increase with an increasing angle of attack until a certain point known as the critical angle of attack is reached.
A plane’s lift is maximized at its critical angle of attack.
If a plane increases its angle of attack beyond its critical angle of attack, it will reduce its lift and stall.
When a plane stalls, it can no longer maintain forward flight and descends from the sky.
So, a critical angle of attack is the maximum safe angle of attack for an aircraft.
Increasing an aircraft’s angle of attack beyond its critical angle of attack is unsafe since it causes the plane to stall.
What is the Difference Between Angle of Attack and Pitch Angle?
The Pitch Angle is the angle between an airfoil’s chord and the flat surface, while the angle of attack is the angle between the airfoil’s chord and airflow.
So, the pitch angle helps define the aircraft’s position relative to the Earth’s surface.
In contrast, the angle of attack indicates an aircraft’s direction relative to wind flow.
Both angles are only equal on an aircraft if the air approaches the aircraft horizontally to the Earth’s surface.
What is the Difference Between Angle of Attack and Flight Path Angle?
Flight path angle is the angle between a plane’s velocity vector for a flight and a fixed flat surface, usually either the flat ground or the horizon.
In contrast, the angle of attack is the angle between a plane’s airfoil chords and airflow.
An aircraft’s flight path angle is positive when the plane tilts upwards or ascends from the horizon, and it’s negative when the plane tilts downwards or descends from the horizon.
The flight path angle helps identify the plane’s direction of movement relative to the horizon or flat ground.
Meanwhile, the plane’s angle of attack informs the pilot how much lift and drag the aircraft experiences and the direction of its wings relative to the airflow.
In conclusion:
- A plane’s angle of attack is the angle between its airfoil chords and outside airflow.
- A plane’s angle of attack matters because it indicates how much lift and drag the plane experiences.
- Lift and drag both increase with an increasing angle of attack.
- A critical angle of attack is the angle of attack at which a plane experiences maximum lift and would begin to stall if the angle of attack increases beyond this point.
- In contrast, an aircraft’s pitch angle is the angle between its airfoil’s chords and the flat surface, while a flight path angle is the angle between a plane’s velocity vector and flat ground.
John is a highly skilled and dedicated Certified Flight Instructor with a passion for teaching students of all ages how to fly, and takes enormous pride and satisfaction seeing his students become licensed pilots.
After holding various roles in the aviation industry as a pilot, John decided to become a flight instructor, and for the past decade has worked at several flight schools that offer pilot training programs of all levels, due to the rewarding nature of the job.
John has been quoted or mentioned in major publications, including Chron, Flying Mag, and National Review.
