Threshold Speed Given Distance For Deceleration In Normal Braking Mode Calculator

Formula Used:

\[ V_t = \sqrt{8 \times S_3 \times d + V_{ex}^2} + 15 \]

Distance for Deceleration in Normal Breaking Mode (S3):

Deceleration (d):

m/s²

Nominal Turn-off Speed (Vex):

m/s

Threshold Speed for Transition (Vt):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Threshold Speed for Transition?

The Threshold Speed for Transition is calculated based on 1.5 times the stall speed and represents the speed at which an aircraft transitions between different braking modes during landing.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ V_t = \sqrt{8 \times S_3 \times d + V_{ex}^2} + 15 \]

Where:

\( V_t \) — Threshold Speed for Transition (m/s)
\( S_3 \) — Distance for Deceleration in Normal Breaking Mode (m)
\( d \) — Deceleration (m/s²)
\( V_{ex} \) — Nominal Turn-off Speed (m/s)

Explanation: This formula calculates the threshold speed based on deceleration distance, deceleration rate, and nominal turn-off speed, with an additional safety margin of 15 m/s.

3. Importance of Threshold Speed Calculation

Details: Accurate threshold speed calculation is crucial for aircraft landing safety, ensuring proper transition between braking modes and optimal deceleration performance.

4. Using the Calculator

Tips: Enter the distance for deceleration in normal braking mode in meters, deceleration in m/s², and nominal turn-off speed in m/s. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is there a +15 m/s added to the calculation?
A: The +15 m/s provides a safety margin to ensure the threshold speed is adequately above the minimum required transition speed.

Q2: What is the significance of the 8 multiplier in the formula?
A: The 8 multiplier accounts for the relationship between distance, deceleration, and speed change during the braking process.

Q3: How does nominal turn-off speed affect the threshold speed?
A: Higher nominal turn-off speeds result in higher threshold speeds, as the aircraft needs more distance to decelerate to the turn-off speed.

Q4: When is this calculation typically used?
A: This calculation is used in aircraft landing performance analysis and runway design to ensure safe braking transitions.

Q5: Are there limitations to this formula?
A: This formula provides an estimation and should be validated with specific aircraft performance data and operational conditions.