Touchdown velocity Calculator

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✖Weight Newton is a vector quantity and defined as the product of mass and acceleration acting on that mass.ⓘ Weight Newton [W]			+10% -10%
✖Freestream density is the mass per unit volume of air far upstream of an aerodynamic body at a given altitude.ⓘ Freestream density [ρ_∞]			+10% -10%
✖The Reference Area is arbitrarily an area that is characteristic of the object being considered. For an aircraft wing, the wing's planform area is called the reference wing area or simply wing area.ⓘ Reference Area [S]			+10% -10%
✖Maximum Lift Coefficient is defined as the lift coefficient of the airfoil at stalling angle of attack.ⓘ Maximum Lift Coefficient [C_L,max]			+10% -10%

✖Touchdown Velocity is the instantaneous velocity of an aircraft when it touches the ground during landing.ⓘ Touchdown velocity [V_T]

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Formula

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Touchdown velocity

Formula

`"V"_{"T"} = 1.3*(sqrt(2*"W"/("ρ"_{"∞"}*"S"*"C"_{"L,max"})))`

Example

`"4.456759m/s"=1.3*(sqrt(2*"60.34N"/("1.225kg/m³"*"5.08m²"*"1.65")))`

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Touchdown velocity Solution

STEP 0: Pre-Calculation Summary

Formula Used

Touchdown Velocity = 1.3*(sqrt(2*Weight Newton/(Freestream density*Reference Area*Maximum Lift Coefficient)))
V_T = 1.3*(sqrt(2*W/(ρ_∞*S*C_L,max)))
This formula uses 1 Functions, 5 Variables

Functions Used

sqrt - A square root function is a function that takes a non-negative number as an input and returns the square root of the given input number., sqrt(Number)

Variables Used

Touchdown Velocity - (Measured in Meter per Second) - Touchdown Velocity is the instantaneous velocity of an aircraft when it touches the ground during landing.
Weight Newton - (Measured in Newton) - Weight Newton is a vector quantity and defined as the product of mass and acceleration acting on that mass.
Freestream density - (Measured in Kilogram per Cubic Meter) - Freestream density is the mass per unit volume of air far upstream of an aerodynamic body at a given altitude.
Reference Area - (Measured in Square Meter) - The Reference Area is arbitrarily an area that is characteristic of the object being considered. For an aircraft wing, the wing's planform area is called the reference wing area or simply wing area.
Maximum Lift Coefficient - Maximum Lift Coefficient is defined as the lift coefficient of the airfoil at stalling angle of attack.

STEP 1: Convert Input(s) to Base Unit

Weight Newton: 60.34 Newton --> 60.34 Newton No Conversion Required
Freestream density: 1.225 Kilogram per Cubic Meter --> 1.225 Kilogram per Cubic Meter No Conversion Required
Reference Area: 5.08 Square Meter --> 5.08 Square Meter No Conversion Required
Maximum Lift Coefficient: 1.65 --> No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

V_T = 1.3*(sqrt(2*W/(ρ_∞*S*C_L,max))) --> 1.3*(sqrt(2*60.34/(1.225*5.08*1.65)))

Evaluating ... ...

V_T = 4.45675879769247

STEP 3: Convert Result to Output's Unit

4.45675879769247 Meter per Second --> No Conversion Required

FINAL ANSWER

4.45675879769247 ≈ 4.456759 Meter per Second <-- Touchdown Velocity

(Calculation completed in 00.004 seconds)

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Credits

Created by Vinay Mishra

Indian Institute for Aeronautical Engineering and Information Technology (IIAEIT), Pune

Vinay Mishra has created this Calculator and 300+ more calculators!

Verified by Maiarutselvan V

PSG College of Technology (PSGCT), Coimbatore

Maiarutselvan V has verified this Calculator and 300+ more calculators!

< 5 Landing Calculators

Landing ground roll distance

Go Landing Roll = 1.69*(Weight Newton^2)*(1/([g]*Freestream density*Reference Area*Maximum Lift Coefficient))*(1/((0.5*Freestream density*((0.7*Touchdown Velocity)^2)*Reference Area*(Zero-lift drag coefficient+(Ground effect factor*(Lift Coefficient^2)/(pi*Oswald efficiency factor*Aspect Ratio of a wing))))+(Coefficient of Rolling Friction*(Weight Newton-(0.5*Freestream density*((0.7*Touchdown Velocity)^2)*Reference Area*Lift Coefficient)))))

Landing Ground Run

Go Landing Ground Run = (Normal Force*Velocity at Touchdown Point)+(Weight Of Aircraft/(2*[g]))*int((2*Velocity of Aircraft)/(Reverse Thrust+Drag Force+Reference Of Rolling Resistance Coefficient*(Weight Of Aircraft-Lift Force)),x,0,Velocity at Touchdown Point)

Touchdown velocity

Go Touchdown Velocity = 1.3*(sqrt(2*Weight Newton/(Freestream density*Reference Area*Maximum Lift Coefficient)))

Touchdown velocity for given stall velocity

Go Touchdown Velocity = 1.3*Stall Velocity

Stall velocity for given touchdown velocity

Go Stall Velocity = Touchdown Velocity/1.3

Touchdown velocity Formula

Touchdown Velocity = 1.3*(sqrt(2*Weight Newton/(Freestream density*Reference Area*Maximum Lift Coefficient)))
V_T = 1.3*(sqrt(2*W/(ρ_∞*S*C_L,max)))

What speed does a Boeing 747 land at?

A 747 'Jumbo Jet' would typically land at a speed of about 145kts-150kts (166mph-172mph), depending on the landing flap setting selected.

How to Calculate Touchdown velocity?

Touchdown velocity calculator uses Touchdown Velocity = 1.3*(sqrt(2*Weight Newton/(Freestream density*Reference Area*Maximum Lift Coefficient))) to calculate the Touchdown Velocity, The Touchdown velocity is a function of instantaneous weight, freestream pressure, and maximum lift coefficient of the aircraft. Touchdown Velocity is denoted by V_T symbol.

How to calculate Touchdown velocity using this online calculator? To use this online calculator for Touchdown velocity, enter Weight Newton (W), Freestream density (ρ_∞), Reference Area (S) & Maximum Lift Coefficient (C_L,max) and hit the calculate button. Here is how the Touchdown velocity calculation can be explained with given input values -> 4.456759 = 1.3*(sqrt(2*60.34/(1.225*5.08*1.65))).

FAQ

What is Touchdown velocity?

The Touchdown velocity is a function of instantaneous weight, freestream pressure, and maximum lift coefficient of the aircraft and is represented as V_T = 1.3*(sqrt(2*W/(ρ_∞*S*C_L,max))) or Touchdown Velocity = 1.3*(sqrt(2*Weight Newton/(Freestream density*Reference Area*Maximum Lift Coefficient))). Weight Newton is a vector quantity and defined as the product of mass and acceleration acting on that mass, Freestream density is the mass per unit volume of air far upstream of an aerodynamic body at a given altitude, The Reference Area is arbitrarily an area that is characteristic of the object being considered. For an aircraft wing, the wing's planform area is called the reference wing area or simply wing area & Maximum Lift Coefficient is defined as the lift coefficient of the airfoil at stalling angle of attack.

How to calculate Touchdown velocity?

The Touchdown velocity is a function of instantaneous weight, freestream pressure, and maximum lift coefficient of the aircraft is calculated using Touchdown Velocity = 1.3*(sqrt(2*Weight Newton/(Freestream density*Reference Area*Maximum Lift Coefficient))). To calculate Touchdown velocity, you need Weight Newton (W), Freestream density (ρ_∞), Reference Area (S) & Maximum Lift Coefficient (C_L,max). With our tool, you need to enter the respective value for Weight Newton, Freestream density, Reference Area & Maximum Lift Coefficient and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

How many ways are there to calculate Touchdown Velocity?

In this formula, Touchdown Velocity uses Weight Newton, Freestream density, Reference Area & Maximum Lift Coefficient. We can use 1 other way(s) to calculate the same, which is/are as follows -

Touchdown Velocity = 1.3*Stall Velocity

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