Tail Moment Arm For Given Tail Moment Coefficient Calculator

Formula Used:

\[ \text{Horizontal Tail Moment Arm} = -\frac{\text{Tail Pitching Moment Coefficient} \times \text{Reference Area} \times \text{Mean Aerodynamic Chord}}{\text{Tail Efficiency} \times \text{Horizontal Tail Area} \times \text{Tail Lift Coefficient}} \]

Tail Pitching Moment Coefficient (C_mt):

Reference Area (S):

m²

Mean Aerodynamic Chord (c_ma):

Tail Efficiency (η):

Horizontal Tail Area (S_t):

m²

Tail Lift Coefficient (C_Tlift):

Horizontal Tail Moment Arm:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Tail Moment Arm?

The Horizontal Tail Moment Arm is the distance between the lift center of the horizontal tail and the center of gravity of the aircraft. It is a critical parameter in aircraft stability and control analysis.

2. How Does the Calculator Work?

The calculator uses the following formula:

\[ \text{Horizontal Tail Moment Arm} = -\frac{C_{mt} \times S \times c_{ma}}{\eta \times S_t \times C_{Tlift}} \]

Where:

\( C_{mt} \) — Tail Pitching Moment Coefficient
\( S \) — Reference Area (m²)
\( c_{ma} \) — Mean Aerodynamic Chord (m)
\( \eta \) — Tail Efficiency
\( S_t \) — Horizontal Tail Area (m²)
\( C_{Tlift} \) — Tail Lift Coefficient

Explanation: This formula calculates the moment arm required for the horizontal tail to provide the necessary pitching moment for aircraft stability.

3. Importance of Tail Moment Arm Calculation

Details: Accurate calculation of the tail moment arm is crucial for aircraft design, stability analysis, and ensuring proper control response. It affects the aircraft's longitudinal stability and handling characteristics.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. Ensure all values are positive except for the Tail Pitching Moment Coefficient, which can be negative. Reference Area, Mean Aerodynamic Chord, Tail Efficiency, and Horizontal Tail Area must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What is the significance of the negative sign in the formula?
A: The negative sign indicates that the tail moment arm is measured in the opposite direction from the reference point, typically the aircraft's center of gravity.

Q2: How does tail efficiency affect the moment arm?
A: Higher tail efficiency reduces the required moment arm, as the tail can generate more effective lift with the same surface area.

Q3: What are typical values for tail moment arm?
A: Tail moment arm values vary significantly depending on aircraft size and design, but typically range from a few meters for small aircraft to over 10 meters for large commercial jets.

Q4: How does tail area affect the required moment arm?
A: Larger tail areas generally allow for shorter moment arms, as they can generate more lift force for the same angle of attack.

Q5: Why is the tail pitching moment coefficient important?
A: The tail pitching moment coefficient represents the effectiveness of the tail in generating pitching moments, which directly influences the required moment arm for stability.