Calculating landing distance for Flight

In summary, the conversation discusses the calculation of the total landing distance of an aircraft over a 15m high obstacle. It involves using the equations for approach distance, flare distance, and ground roll, as well as considering factors such as approach speed, descent angle, load factor, and deceleration. The individual has found values for approach and flare distance but is unsure about the calculation of ground roll, specifically the inclusion of mass. The conversation concludes with the suggestion to use the work-energy equation or the kinematic equations and the clarification that mass does not play a significant role in the calculation of ground roll.
  • #1
praveenpandiyan
28
1

Homework Statement


An a/c has an approach speed of45 m/s with descent angle of 7.1 deg. if the a/c load factor is 1.2 and constant deceleration at touch down is .25g (g=9.81).its total landing distance approx over a 15m high obstacle is

Homework Equations



R=v/g(n-1)
Sa=(h-hf)/tan( teta)
Sf=Rsin(teta)
hf=R(1-cos(teta)
Sg=v2m/(2*F)
R-radius,hf-flare height,Sa-approach dist,Sf-flare distance,Sg-ground roll
S=Sa+Sf+Sg

The Attempt at a Solution


well i have found value for approach and flare distance.but for ground roll I am lacking mass to consider for calculation or do i miss smeting?.. any suggestion wld be helpfull.[/B]
 
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  • #2
praveenpandiyan said:

Homework Statement


An a/c has an approach speed of45 m/s with descent angle of 7.1 deg. if the a/c load factor is 1.2 and constant deceleration at touch down is .25g (g=9.81).its total landing distance approx over a 15m high obstacle is

Homework Equations



R=v/g(n-1)
Sa=(h-hf)/tan( teta)
Sf=Rsin(teta)
hf=R(1-cos(teta)
Sg=v2m/(2*F)
R-radius,hf-flare height,Sa-approach dist,Sf-flare distance,Sg-ground roll
S=Sa+Sf+Sg

The Attempt at a Solution


well i have found value for approach and flare distance.but for ground roll I am lacking mass to consider for calculation or do i miss smeting?.. any suggestion wld be helpfull.[/B]
in your work-energy equation for Sg, m/F per Newton 2 is given! Or use the kinematic equations instead.
 
  • #3
You have an initial horizontal velocity at touchdown and the deceleration. That's enough. For ground roll, and leaving aside air resistance, mass doesn't matter.
 
  • #4
yeah.i see it now,its a simple force eqn. thanks all
 
  • #5


Hello, thank you for your question. Based on the given information, it seems like you have all the necessary equations to calculate the total landing distance. However, you are correct in pointing out that you are missing the aircraft's mass. This is an important factor in determining the ground roll distance, as it affects the deceleration of the aircraft.

To calculate the ground roll distance, you will need to use the equation Sg=v^2m/(2*F), where v is the approach speed, m is the mass of the aircraft, and F is the deceleration force. Since you are given the approach speed and deceleration force, you will need to find the mass of the aircraft in order to calculate the ground roll distance.

If the mass of the aircraft is not given, you may need to make some assumptions or estimates based on the type of aircraft and its typical weight. It may also be helpful to consult with a pilot or aviation expert for more accurate estimates. Once you have the mass of the aircraft, you can plug it into the equation and calculate the ground roll distance.

I hope this helps. Good luck with your calculations!
 

What is the importance of calculating landing distance for a flight?

The landing distance for a flight is crucial for ensuring the safety of both the passengers and the aircraft. It determines the amount of runway needed for the aircraft to come to a complete stop, taking into account factors such as weight, speed, and weather conditions. This calculation helps pilots make informed decisions and ensures that the aircraft can safely land and come to a stop within the available runway length.

How is the landing distance calculated?

The landing distance is calculated using a formula that takes into account the aircraft's weight, speed, and other factors such as wind and runway conditions. This formula is typically provided by the aircraft manufacturer and is based on extensive testing and data analysis. Pilots can also use performance charts provided by the manufacturer to determine the landing distance for a specific flight.

What factors can affect the landing distance for a flight?

Several factors can affect the landing distance for a flight, including the weight of the aircraft, air temperature, wind speed and direction, runway condition, and altitude. The aircraft's speed, flaps configuration, and braking effectiveness also play a significant role in the calculation. Pilots must take all of these factors into account when determining the landing distance for a particular flight.

Why is it important to have a margin of safety when calculating landing distance?

A margin of safety is crucial when calculating landing distance as it accounts for unexpected factors that may affect the aircraft's ability to stop. This can include a sudden change in weather conditions, equipment malfunction, or human error. A margin of safety allows for a buffer, ensuring that the aircraft can still come to a stop safely even if something unexpected occurs.

What are some challenges in accurately calculating landing distance for a flight?

One of the main challenges in calculating landing distance is the constantly changing nature of flight conditions. Factors such as wind, temperature, and weight can vary throughout a flight, making it difficult to accurately predict the landing distance. Pilots must also take into account human factors, such as fatigue or distractions, which can affect their ability to accurately calculate and execute the landing distance. Additionally, the use of incorrect data or failure to account for all relevant factors can also lead to inaccurate calculations.

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