Questions tagged [airspeed]

The speed of an aircraft relative to the air. Among the common conventions for qualifying airspeed are: indicated airspeed ("IAS"), calibrated airspeed ("CAS"), true airspeed ("TAS"), equivalent airspeed ("EAS") and density airspeed.

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35 views

Is there any free online source where I could look at and/or study the V-G charts for different kinds of airplanes? [closed]

Charts for any kind and number (the more the better) of airplanes would do. I have never flown, nor do I think I will. I am just an aviation enthusiast, and like studying the mechanics of flight. If ...
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What is the relation between velocity and rate of pitch?

I saw the answer to airspeed and rate of turn but this I think isn't what I want. I've seen it many times that aircraft will pitch up much slower when at higher speeds particularly fighter aircraft. ...
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60 views

Is it possible to determine if winds were high without groundspeed, wind speed, AoA or AoS?

I have a data set that includes TAS, IAS, GPS Lat/Lon, Inertial Lat/Lon, ENU speed, inertial speeds, attitude, and accelerations. I don't need to know the exact wind speed, and I don't think that's ...
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What's the relation between TAS and Mach in tropopause?

I understand that TAS decreases with altitude with constant Mach number in troposphere, however I'm not sure what happens in tropospause, as the temperature is constant, however the density is still ...
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232 views

How close is the air resistance or drag force to being proportional to the airspeed squared?

How is the total air resistance force exerted upon a body (aircraft or car) related to its speed relative to air at far away? A simple Newton's force momentum analysis suggests that the force $F \...
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Why do gusts change the airspeed during landing, but turning (which changes where the wind is coming from) does not?

As we know it, aircraft are extremely sensitive to gust during its final landing stage. They can lose airspeed if the wind changes to tail, ad thus loose lift or need to adjust their thrust in order o ...
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Why would 2 aircraft fitted with the P&W PT6 Engine have different top speed?

Why can the Quest Kodiac and Cessna Caravan not exceed 200 knots? PT6 from Pratt and Whitney in other implementations like Epic E1000 and Pilatus PC12 can cruise at over 300 knots. The Kodiac and ...
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What is the commercial passenger aircraft top speed record?

Aircraft manufacturers claims commercial passenger aircrafts cruise at the speed of 400-500 knots. But is the top speed of a commercial passenger aircraft recorded (while in air)? If so, what is the ...
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112 views

What is the power curve [closed]

Someone help me understand this thing in a simple way. I understand it helps determine Vx.
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93 views

What plane has the widest range in speed in which it can operate? [duplicate]

What propellor plane, other than planes with vertical takeoff capability, has the largest gap in speed between its slowest stall speed and its maximum airspeed? I am looking for a plane with a short ...
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59 views

Constant turn radius with Δ airspeed and bank

Can someone explain how speed impacts rate of turn and and degree of bank required? I'm trying to understand this practice problem but can't get the concept: Say you have 2 vehicles travelling at ...
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Does “trimmed for current speed” mean that the plane will do whatever to maintain the current airspeed?

If I understand right, when you are trimmed for current speed, let’s say 290 KTAS, does that mean if airspeed increases to 295, the plane will pitch up to slow it back down? And vice versa for the ...
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Linking equivalent airspeed with waypoints, altitude, time and speed

Say I want to find out EAS and I'm given a time that a pilot will reach a waypoint that is "X" Nautical Miles away, an altitude & I'm also given a ground speed that is increased by a tailwind. Is ...
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118 views

What are the equation linking static air temperature with true airspeed & altitude?

If I want to calculate static air temperature (OAT), but I'm only given an altitude and a true airspeed. Is there such an equation that relates these principles together. I've had a look at wikipedia ...
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Why is a 737 Original speed-restricted below 10 kft with inoperative windscreen heating?

According to this page on the 737's operational limitations, the Original 737s (737-100/-200) are limited to 250 KIAS below 10 kilofeet if the windscreen-heating system is inoperative: Anti-Ice &...
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Is any device installed on airplane to measure wind speed relative to the ground, and its direction?

A device or tool which can measure actual wind speed to the ground rather than to the airplane. Also a device which detect the wind direction to the plane. The device I meant is something like this ...
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Is it right to extend flaps only in the white arc?

If the cruise speed is >80kts on the downwind leg but I can only extend flaps in the white arc, am I right in saying I need to get to the white arc, even if I'm on - for example - 100kts? For ...
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310 views

Why use Mach number for describing the speed of aircraft?

What does Mach speed mean for describing aircraft speed if the speed of sound changes with temperature?
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256 views

Why does the F16 HUD give you one number for your speed and the analogue gauge another?

Why does the F16 HUD give you one number for your speed and the analogue gauge another different number?
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How does speed affect lift?

I understand the lift coefficient shown above. But does lift increase with speed, and how? I understand I can't apply this to the graph as it is a coefficient, but if I had an angle of attack of 10 ...
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2answers
221 views

What is a jet engine's fuel flow at constant IAS?

Here is my assumption: In straight and level flight of a jet turbine engine: One IAS = One drag = One thrust = One fuel flow Therefore, the fuel flow will be approximately the same for a ...
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1answer
85 views

Airspeed Calibration alternate static source, what is this for?

I found a 'Airspeed Calibration Alternate Static Source' Figure in C172R POH. There are three kinds of Figure, 1. Heater off, Vents and Windows Closed 2. Heater On, Vents Open and Windows Closed 3. ...
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What is the highest indicated airspeed ever achieved in a traditional aircraft?

It is fairly well known that the SR-71 holds the record for highest speed for a traditional aircraft (not a rocket/able to land and takeoff under its own power). However since the SR-71 flies much ...
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What is the difference between TAS and GS? [duplicate]

I'm looking for an explanation of true airspeed and ground speed.
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200 views

Are there locations/altitudes with minimum speed requirements?

For example, a slower aircraft operating on the North Atlantic Track System would have an operational impact on surrounding/overtaking aircraft as well as potentially increasing ATC workload to ensure ...
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How can I calculate the speed gain from using multiple STC modifications together?

Looking at a parts manufacturer website, they list various STC'd modifications for Mooneys with estimated (cruise?) speed gains for each. However, I've heard that those gains are not additive. For ...
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456 views

What is the fastest unpressurized aircraft?

What is the fastest unpressurized aircraft with oxygen masks that can carry people?
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How do I calculate TAS from IAS in this question?

How can I calculate the answer to this EASA PPL ECQB question? An aircraft cruises at altitude 5000 ft on a heading of 180° with an indicated airspeed of 100 kt. The wind vector is 180° with 30 ...
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What is the regular stall speed of an F-16 flying in a straight-and-level path?

I want to know what is the minimum speed that an F-16 can fly at without stalling. I have searched the web, but found no exact information answering my question. Most of them say that it depends on ...
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297 views

Does the MU-2 have a crossover airspeed?

Airplanes generally have a crossover airspeed (a minimum airspeed below which directional control of the airplane cannot be maintained in the event of a rudder hardover). This is because, as airspeed ...
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339 views

How does an airspeed indicator look from the inside?

How does a typical GA airspeed indicator look from the inside and how does it work?
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189 views

What will be the performance penalties of increasing the wing area of a delta winged aircraft to obtain a lower approach speed?

Delta winged aircraft such as the Dassault Mirage III have an approach speed of 170 knots as specified by the manufacturer. The Mirage F1 was designed to have a lower take off and landing speed than ...
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336 views

How to find TAS for given CAS, FL and OAT?

Here is another question for my PPL Exam. If anyone can illuminate me with explaining every step to achieve TAS with given parameters, it would be great. Given: Calibrated airspeed (CAS): 155 kt. ...
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1k views

How to calculate Equivalent Airspeed immediate from Calibrated Airspeed?

I want to calculate each step like IAS -> CAS -> EAS -> TAS as a chain. Each chain step should depend on the previous chain step. IAS is clear. This is function of pressures. With Bernoulli equation, ...
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Does diving after a take-off help gaining altitude?

I have often read fictions about aircraft, where a pilot does an action that I cannot explain: During a takeoff with an heavy aircraft (four motors for example), the pilot rolls to the end of the ...
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1answer
139 views

Airliner speed when descending through 10,000 feet

How do airliners get to 250 kts when descending through 10,000 feet as required by the FAA? Do you level off at 10,500 feet until speed is less than 250 and then descend further? Must pilots ask ATC ...
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383 views

Why does an increase of airspeed result in a decrease of angle of attack?

In Chapter 02: Aerodynamics of Flight of Helicopter Flying Handbook, on page 10, it says: Induced flow velocity is increased, resulting in a decrease in AOA. I don't understand how airspeed can ...
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1answer
237 views

How do changes in flight affect L/D max and the speed at which I must travel to maintain it?

I have an plane flying at L/D max and I want to maintain L/D max. Firstly, if this plane burns through a portion of fuel and becomes lighter, how would I have to change the speed to maintain it? My ...
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2answers
181 views

What’s the speed for lowest sink rate on a DA20?

In the DA20, the POH lists for glide speed (flaps up) only one speed giving the best glide angle / furthest distance (73 KIAS). But what about, if I don’t need that much distance to glide (e.g. ...
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282 views

Why is airspeed different in climbs and descents although the AoA doesn't change?

Here are the background facts: This excercise has the objective to familiarise the student with the slow flight characteristics. The steps are: 1)Establish straight and level, 90% RPM, 15 units ...
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What is the effect of altitude on true airspeed?

I know that wind is taken into account when we compute the TAS(true airspeed) and GS(ground speed). However what is the relationship between the TAS and altitude? For example: What is the true ...
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1answer
261 views

How is altitude correlated with true airspeed?

I am trying to understand the BADA 3.0 dataset (specifically I am looking at Performance Summary Tables): E.g. What is not obvious to me is why those tables mention only single TAS for specific FL. ...
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1answer
122 views

Is there an increased concern for stall safety in a 1G steep turn?

Most people know the standard, "At a 60 degree bank, an aircraft experiences 2G's" checkpoint for load-factor on an airplane. I assume that this statement has an underlying, unspoken assumption that ...
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Why is indicated airspeed rather than ground speed used during the takeoff roll?

My instructor asked me this question during my lesson and I couldn't come up with any answers. He asked why do I need to look at the indicated airspeed rather than ground speed when in takeoff roll or ...
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Pitot tube pressure question

I have this question is the pressure measured in the entry of the pitot tube the same when the plane is flying headwind or turning a 360 degree turn while maintaining the same indicated airspeed?
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Why is trim for take off affected to Vmc(Speed maintain control)?

I am studying in Vmc part, but I have hard time to understand that trim for take off is affected to Vmc. How and why does it make Vmc speed increase?
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What is a jet (unit) shown in Windows 10 calculator? [closed]

From Windows 10's calculator: What is a "jet" (physical unit)? And why does it equal 480 knots or 888,88 km/h, if a jetliner's cruising speed is around 950 km/s? Or why does it equal 0.73 M, if a ...
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144 views

Temperature sensor are needed to compute True Airspeed for low speed aircrafts?

I know standard air data computer can produce true air speed with total air pressure, static air pressure, and total air temperature. But for a low speed aircraft <100 knots, do I need to install a ...
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276 views

Why were the space shuttle’s flight controls only certified for low airspeeds?

Somewhat ironically for a vehicle designed to reach orbital speed, the space shuttle’s flight control system was only certified for airspeeds up to 333 KIAS, and exceeding 470 KIAS (the maximum ...
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133 views

How should I answer this question about measuring airspeed using dynamic pressure?

I have come across a question in the PPL Principle of Flight material which I can't understand how to answer: Give your opinion on the statement "Measuring dynamic pressure is the way to ...