Vx and Vy
VY Canis Majoris
VY Canis Majoris is an extreme oxygen-rich red hypergiant or red supergiant and pulsating variable star located at 1.2 kiloparsecs away from Earth in the constellation of Canis Major. It is one of the largest known stars by radius, and is also one of the most luminous and massive red supergiants, as well as one of the most luminous stars in the Milky Way.
Full Answer
Do VX and Vy converge with altitude?
It’s clear than Vx and Vy converge with altitude when measured as indicated airspeeds. Clearly Vy increases as a TAS with altitude (Figure 43) but it does so relatively slowly compared to Vx as a TAS.
How does altitude affect TAS and Vy?
TAS relating to any given IAS increases with altitude, causing power required at any given IAS to increase. This causes the Vy to decrease with increasing altitude, until they are equal at the absolute ceiling.
Does VX (IAS) increase with altitude?
This causes the Vy to decrease with increasing altitude, until they are equal at the absolute ceiling. As far as I know Vx (IAS) increases with altitude and Vy (IAS) decreases ( e.g. Vx at SL 70 Kias at FL210 76 Kias-- Vy 94kias at SL and 76 kias at FL 210. Beech Bonanza).
Does VX and Vy change with weight?
Answer: Vx remains constant and Vy decreases. Additionally, does VX and VY change with weight? Yes, both will vary. They both depend on minimizing drag and having lots of thrust or power. Obviously, thrust or power will not vary with weight, but they * do * vary with airspeed, and so does the drag on the airplane.
How does altitude affect VX and VY?
If Vy is measured as a true airspeed, it increases approximately 1% for every thousand feet increase in altitude. That's right! If you measure Vy in terms of TAS it will increase, not decrease with altitude. Therefore, if Vy is 82 knots (TAS) at sea level, it must be approximately 90 knots (TAS) at 10,000 feet.
Why does VY increase with altitude?
3:324:52Why Vx & Vy Change With Altitude - YouTubeYouTubeStart of suggested clipEnd of suggested clipWith altitude as a true airspeed it just doesn't increase that quickly therefore the indicatedMoreWith altitude as a true airspeed it just doesn't increase that quickly therefore the indicated airspeed value needed to produce any given true airspeed value decreases at a slower.
Does VX increase or decrease with altitude?
3:415:19Does Vy Decrease with Altitude? | Vx and Vy | Climb PerformanceYouTubeStart of suggested clipEnd of suggested clipThis is the maximum rate of climb table in the performance section of the poh. It's showing the bestMoreThis is the maximum rate of climb table in the performance section of the poh. It's showing the best rate of climb speed at different altitudes. But it's showing them not in true airspeed. But in the
How does altitude affect lift drag ratio?
In summary, the Reynolds-Number decreases with an increasing altitude, which means that drag increases with an increasing altitude - assuming velocity and reference length are constant.
What is the difference between VY and VX?
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 and VY calculated?
Projectile motion equationsHorizontal velocity component: Vx = V * cos(α)Vertical velocity component: Vy = V * sin(α)Time of flight: t = 2 * Vy / g.Range of the projectile: R = 2 * Vx * Vy / g.Maximum height: hmax = Vy² / (2 * g)
What is the effect of flap extension on VX and VY?
Both are related to Lift and DRAG, with the higher flap settings having the lower Vx/Vy, with Vx/Vy increasing as flap setting decreases. The actual Angle / Rate of Climb will be decreased in all cases when any flap is used.
How does wind affect VX and VY?
Vy is altitude gained over time and Vx is altitude gained over distance. This is where it gets confusing; A headwind will affect the climb angle relative to the earth. Extreme example is climbing into a headwind which is equal to your speed.
Why does true airspeed increase with altitude?
With EAS constant, true airspeed increases as aircraft altitude increases. This is because air density decreases with higher altitude. The measurement and indication of airspeed is ordinarily accomplished on board an aircraft by an airspeed indicator ("ASI") connected to a pitot-static system.
Which is faster, VX or VY?
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.
Why do you need to fly at higher altitudes?
At higher altitudes, because of the less dense air, you need to fly at a higher angle of attack for a given true airspeed. And, if you're flying at a higher angle of attack, you're generating more induced drag. So, as you climb, your angle of attack for level flight increases and you generate more induced drag.
What is VFE in a thunderstorm?
The control surfaces actually stall first. This is also known as thunderstorm penetration speed. VFE is known as Maximum Flap Extended Speed. This is the speed in which we can fly with flaps extended (VFE is located on Airspeed Indicator – Top of White ARC) VLE Known as the 'Maximum Landing Gear Extended Speed'.
What is V speed?
In aviation, V-speeds are standard terms used to define airspeeds important or useful to the operation of all aircraft. In general aviation aircraft, the most commonly used and most safety-critical airspeeds are displayed as color-coded arcs and lines located on the face of an aircraft's airspeed indicator.
How does air density affect lift?
Halving the density halves the lift, halving the density halves the drag. In the atmosphere, air density decreases as altitude increases. This explains why airplanes have a flight ceiling, an altitude above which it cannot fly.
What is the absolute ceiling?
Along with service ceiling and combat ceiling, absolute ceiling is a term used to describe the maximum density altitude that a particular aircraft can operate under Standard Air conditions. This term refers to the altitude at which an airplane is only able to maintain a maximum climb of only 100 feet per minute.
How much does airspeed increase?
On average, true airspeed increases about 2% per 1,000' of increase in altitude, but the actual change depends on temperature and pressure.
Why does an aircraft climb?
An aircraft climbs because of excess thrust or excess power. Vx is your best angle of climb speed, and Vy is your best rate of climb speed. POP QUIZ number two - Vx is the speed where you have the most: Awesome! Excess Force. Excess Force. Excess Power.
Why does a propeller generate the most thrust at a slow speed?
Why? Because it's at a high angle of attack. As your airspeed increases, the propellor's angle of attack decreases, and it can generate less thrust.
What is the speed where you have the biggest difference between power required and power available?
Vy is the speed where you have the biggest difference between power required and power available.
Do you have more parasite drag at high speeds?
So, at slow speeds, you have more induced drag. (You fly at a higher angle of attack, right?) At high speeds, you have more parasite drag. (You're at a lower angle of attack.) If you add the two drag amounts together, you get total drag.
What is VX in physics?
Vx is the speed at which excess thrust is maximum and excess thrust is thrust available minus drag. Thrust available decreases with increasing altitude but the relationship between thrust and IAS does not. Because Vx is an IAS, Vx is the same at all altitudes. Vy is the speed at which excess power is maximum.
Is constant VX a good assumption for a piston engine?
The way Vx and Vy vary with altitude depend on the way that thrust and power available vary with speed and altitude.#N#Constant Vx might be a good assumption for a constant thrust jet engine, but it's not appropriate for a piston engine with prop.
