Contents

- 1 What does VX and VY stand for?
- 2 How is VX determined?
- 3 What is VX for a Cessna 172?
- 4 Why does VX and VY change with altitude?
- 5 Does VX change with weight?
- 6 What is VX poison?
- 7 Why does VX increase with altitude?
- 8 What is best climb rate?
- 9 How fast does a Cessna 172 need to go to take off?
- 10 What is the landing speed of a Cessna 172?
- 11 What is VX and VY relationship?
- 12 What is best angle of climb?
- 13 Why does true airspeed increase with altitude?

## What does VX and VY stand for?

Vx is the speed where you have the most excess force (thrust), and Vy is the speed where you have the most excess power (horsepower).

## How is VX determined?

Vx is located where you have the most space between the thrust required and thrust available lines. So, if you plot it for several altitudes, you can see it move to the right slightly as you climb. Vx’s true airspeed increases as you climb. But, that’s true airspeed, not indicated.

## What is VX for a Cessna 172?

When you get airborne you will pitch for the best angle of climb speed, also known as VX. This is the speed that will get you the most altitude in the shortest distance. In training, we typically imagine that a 50-foot-tall obstacle is right off the end of the runway.

## Why does VX and VY change with altitude?

The top of the power curve represents Vy and the tangent’s contact with the power curve represents Vx. The speeds at the bottom of this curve are true airspeeds which makes it easier to represent performance at all altitudes. Notice that Vy and Vx both increase with an increase in altitude as true airspeeds.

## Does VX change with weight?

Vx and Vy change as DA goes up and change with weight. For every 1000′ increase in altitude Vx increases approximately 0.5 mph and Vy decreases 0.66 mph. Also remember Vx & Vy speeds decrease as weight decreases. Vx and Vy can be reduced ½ of the percent of weight reduction.

## What is VX poison?

VX is an extremely toxic synthetic chemical compound in the organophosphorus class, specifically, a thiophosphonate. In the class of nerve agents, it was developed for military use in chemical warfare after translation of earlier discoveries of organophosphate toxicity in pesticide research.

## Why does VX increase with altitude?

Therefore, dropping straight down from the tangent point (point A) to point B, we find that the best angle of climb speed has increased to 75 knots. And this is the basic reason why Vx increases with altitude.

## What is best climb rate?

Best Rate-of-Climb:

- Best rate of climb, or Vy, maximizes velocity to obtain the greatest gain in altitude over a given period of time.
- Vy is normally used during climb, after all obstacles have been cleared.
- It is the point where the largest power is available.
- Occurs above L/Dmax for a jet.
- Occurs at L/Dmax for a prop.

## How fast does a Cessna 172 need to go to take off?

60 knots is considered to be the optimum takeoff speed. This speed will allow enough lift under the wings to give a smooth, stall-free takeoff. What is the landing speed of a Cessna 172?

## What is the landing speed of a Cessna 172?

The 172S POH recommends 61 knots for a final approach speed for a short field landing, which is 9 knots faster than 1.3 X Vso. As for the Cirrus SR22T, they recommend 80-85 knots on final, and 79 knots crossing the threshold.

## What is VX and VY relationship?

Vx is the slowest (IAS), and is the Maximum ANGLE of climb. It allows one to climb to altitude within the shortest horizontal distance. Vy is slightly faster, and is the Maximum RATE of climb. It allows one to climb to altitude in the shortest time.

## What is best angle of climb?

Best Angle of Climb speed (V_{x}) gets you the greatest altitude per unit of ground distance (feet per mile). When you’ve got a FAA-Standard 50-foot-tree at the departure end of the runway you’ll aim for the best angle of climb to ensure you don’t wind up in the tree.

## Why does true airspeed increase with altitude?

For a given power setting, True Airspeed increases with altitude because there is less drag due to the air being less dense. Aircraft are more efficient at high altitude because of this simple fact.