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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.

Airspeed is the relative speed of an aircraft through an air mass.

The measurement and indication of airspeed is ordinarily accomplished on board an aircraft by an airspeed indicator ("ASI") connected to a pitot-static system. The pitot-static system comprises one or more pitot probes (or tubes) facing the on-coming air flow to measure pitot pressure (also called stagnation, total or ram pressure) and one or more static ports to measure the static pressure in the air flow. These two pressures are compared by the airspeed indicator to give an indicated airspeed reading.

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What is the reference used when measuring flight speed?

I'm a physicist who was amused by the argument in the comments of this question about gravity. The correct answer about the affect of the accelerating reference frame of the plane on the apparent gravity depends on how the airliner's speed is…
Paul T.
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What aircraft fly faster than 250 knots indicated airspeed under 10,000 feet for safety reasons?

14 CFR 91.117 limits aircraft to 250 knots indicated airspeed below 10,000 feet, but 91.117(d) allows aircraft to fly a higher speed if the minimum safe speed is higher. What aircraft and aircraft conditions might require an indicated airspeed…
ryan1618
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What are CAS and EAS used for?

What are calibrated airspeed (CAS) and equivalent airspeed (EAS) used for? When would a pilot need to know these?
TomMcW
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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 Caravan are advertised at only ~180 knots. Why is…
user46196
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Knots vs MPH, is there some standard for when to use which unit?

In looking at all the sources of aviation data, including POH's, instrument dials, instructional materials, FAA publications, METAR's, flying magazine stories, YouTube videos, etc., I see no standard usage of either knots (nautical miles per hour),…
PJNoes
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When a plane flies faster than the speed of sound, does the distance between plane and sound increase?

I had this discussion with my dad about a question he had asked. Basically he said: If a plane flies faster than the speed of sound, will he be able to overtake his own sound and hear itself? (let's leave behind the fact that he can run out of…
BRHSM
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What is the relation between airspeed and rate of turn?

I am reading about aircraft maneuvering and the end of section check contains this question: During a turn, if you reduce the airspeed and maintain the angle of bank, the result is a _____________ rate of turn. The correct answer is "higher"…
atlantis
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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 higher than other aircraft its indicated airspeed is…
pirocks
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How to calculate Equivalent Airspeed immediately 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 step. IAS is clear. This is a function of pressures. With the Bernoulli equation, IAS = f(p_total - p_static) CAS is not clear. But…
ptiza_v_nebe
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Why do pilots normally fly by CAS rather than TAS?

I think I know the answer to this question, but I want to confirm. Airline pilots normally fly a CAS/Mach profile, which means that above the CAS/Mach transition altitude they fly by Mach, and below it they fly by CAS (calibrated airspeed). Why do…
Russ
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Why does an airspeed indicator not simply read TAS?

If the airspeed indicator has inputs regarding air density (static port) and temperature. Why isn't Indicated airspeed from the indicator simply the same as True airspeed
John
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What is the relation between airspeed and altitude at fixed throttle setting in a private jet?

In the world of private jets, say a G-450, at a fixed throttle setting, does it simply go faster the higher it climbs/flies?
Johnny Mitch
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Ground Speed vs True Airspeed from Departure Point to Destination - time interval

Looking at navigation theory right now and I'm stuck in the understanding of TAS and GS. How does GS determine the time interval it takes for an aircraft to fly from the DP to the DEST, if TAS determines how the fast the aircraft is really going…
JandyPilot
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How can the cruise speed be larger than Vne?

I recently read the POH for a M20V, the advertising for this aircraft states that the top speed is 242 KIAS. The POH gives the Vne at 196/195 KCAL/KIAS. I have found a similar discrepancy, the Vl3 (light sport aircraft) mentions the aircraft has a…
Bob23 da newbie
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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?
Mike no smith
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