Questions tagged [pitot-static]

A pressure-based system for measuring airspeed and altitude.

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Please describe ram pressure in simple terms [duplicate]

Please someone describe the following sentence in simple words: The Airspeed Indicator is calibrated for 'standard' sea level density, so it will only read TAS if the density of the air through which ...
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On the A330 why does switching off the ADRs require alternate LG extension and inhibit nose wheel steering?

In the incident examined in this video the pilots experienced an unreliable airspeed indication due to pitot tube blockage in an A330. They followed the abnormal checklist for unreliable airspeed ...
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Does static pressure(p - p∞) at wing surface change exponentially, with square of the velocity?

Integration of static pressure over wing we get lift. and Formula for lift is L= 1/2 x Cl x A x V2 x ro; that implies that static pressure (p - p∞) change exponentially(as square of velocity), becuase ...
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Do pitot tubes account for reduced pressure at altitude?

Do pitot tubes account for reduced pressure at altitude? Does indicated airspeed reduce with altitude? If so, how much? Is it different for small planes vs big commercial airliners?
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Why might flight schools prohibit you from testing pitot heat during pre-flight?

Why might flight schools prohibit you from testing pitot heat during pre-flight? I know of a school in Texas that has this policy but don’t understand why. Here is a snippet of the C172 AFM which ...
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How long does a pitot tube last?

Aircraft components need periodic maintenance, this should be the same for the pitot tube that is an essential instrument for pilots. So do you know when should a pitot tube go into maintenance? I can'...
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3 votes
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How long should a pitot tube extend from the wing?

It seems that most of the pitot tubes are "L" shaped. However, there are some pitot tubes that shapes like a straight pipe. I am wondering that, for a straight pitot tube installed on the ...
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Can pitot tube measure boundary layer? Why? [closed]

Can pitot tube measure boundary layer? Why? Why not?
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Is the use of 1/8 NPT ports on pitot/static instruments derived from an FAA standard?

On almost every pitot-static instrument used in general aviation aircraft, a 1/8 female NPT port is provided to connect the instrument to the pitot-static system. I was told that is is a requirement ...
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-3 votes
1 answer
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If the altitude of the aircraft is given by the pitot tube, in icing condition with heat on, how is real altitude /speed interpretation done? [duplicate]

If the altitude of the aircraft is given by the pitot tube, in icing condition with pitot heat on how is real altitude /speed interpretation done? Because the air density and temperature is not ...
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Is air velocity at aircraft static port always same as freestream velocity?

Is air velocity at plane static port always same as freestream velocity? If I find at aircraft place where air velocity is same as freestream,can I use it as my correct static port or that can not ...
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What are the relations between Angle of attack and Calibrated Airspeed?

I would like to estimate Angle of Attack using trigonometric relations i.e AoA = arctan (w/u) airspeed components (i.e u, v, w). When I am considering body 'x' velocity ('u' component), is it ...
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Does the airspeed indicator measure speed inaccurately at different angles of attack?

A point of confusion for me has been this: Does the pitot tube measure the airspeed of the plane in the direction of its flight path, or does it measure the speed of the air parallel to the pitot tube ...
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4 votes
1 answer
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If an airplane has a Vertical Speed Indicator is there a requirement that it be periodically checked for accuracy?

I believe I understand that there is no specific US FAA requirement for aircraft to carry a Vertical Speed Indicator (VSI). I believe I understand the basic operation of a VSI. It measures the rate ...
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How can static pressure be obtained over a range of airspeeds? [duplicate]

Multiple instruments rely on static air pressure, i.e. pressure unaffected by airspeed. To my understanding, no such air should exist around an aircraft. Air in motion exhibits a lower pressure ...
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1 answer
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Are pitot systems protected from ice?

Aircraft use pitot tubes or pitot-static tubes. Do these have some kind of anti-ice system? If so, how? And if not, why not? I'll just point out that it doesn't seem trivial to de-ice such a thing. A ...
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How is airspeed measured on supersonic aircraft? [duplicate]

Behind the shock wave air is subsonic, would that not cause an issue with the pitot tubes or any other sensor?
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Why is the pitot tube located near the nose?

The pitot tube located near the nose could be affected by the boundary layer and could increase the error. Then why is the pitot tube located near the nose?
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What would cause a non-zero indicated airspeed reading on the ground?

What kind of failure would cause an indicated airspeed of say 200 knots on the ground (stationary)?
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Why are pitot-static measurements preferred over other velocimetry techniques?

I believe hot wire anemometers (HWA, frequently used in wind tunnels to measure flow velocity) or other sensitive techniques could be used to determine the airspeed. Are there specific reasons for why ...
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5 votes
1 answer
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What is the reason for the fence aft of the static ports on some airplanes and helicopters?

Airbus AS350 helicopters and Bell 206 helicopters have a 1/2" long fence behind the static port. CRJ 200/700 have a .060" step on the aft side of the static port. What would be the reason ...
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How to use a set of Pressure Transducer to mimic pitot static tube for VTOL vertical airspeed indicator?

May i know if i have 3 pressure transducer, 1 facing upwards and the other downwards to measure the vertical velocity of a VTOL (Vertical Takeoff and Landing aircraft) and another 1 on the nose of the ...
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3 votes
1 answer
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Why are some A350s missing SSA probes on their nose?

I recently just noticed that some A350s are missing their iconic set of 3 main SSAs (Side Slip Angle Probes) on their nose. I'm not sure if its an issue of newer variants or varied airline options, ...
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Why do larger aircraft need two or more static ports?

Some background information: "Static pressure is the measurement of the ambient barometric pressure at the aircraft’s CURRENT location AND CURRENT Altitude. The Static Port is located in a position on ...
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3 answers
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Why does the faster-moving air over the static port not result in a lower static pressure?

I understand the concept that the static port is measuring "static" pressure, meaning the pressure the air is exerting on its surroundings. However, there is also Bernoulli's principle, which, put ...
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Where is pure outside static air pressure indication on A320?

I'm looking for the indication of the outside static air pressure in the cockpit. Where is it located? One of the ECAM pages? Thanks!
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3 votes
2 answers
7k views

Where is the pitot static drain located on a Piper PA-28?

Some PA-28 airplanes have pitot static drain where the pilot pushes 2 buttons to open the system. But where does the water drip out from the airplane? Is there a hole underneath the airplane? Where? ...
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Altimeter shows 100 foot drop when power is added. Is this a leak in the static system or broken altimeter and how long will the fix take?

My instructor and I were preparing for my Private Pilot Check ride today when we noticed that the analog altimeter would suddenly lose 100 feet when we added power. The only way I can think to ...
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How does static port measures the static pressure?

I have always thought that there is a probe or sensor kind of thing inside the static port so that it "measures" the static pressure and compare to other pressure sources for airspeed, altitude, and ...
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1 vote
1 answer
550 views

How does a G1000 equipped with a GDC 74 calculate IAS from dynamic pressure?

How exactly does a G1000 system equipped with a GDC 74 air data computer calculate the indicated airspeed that is displayed on the PFD from difference between the total and static pressure (i.e. ...
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Pitot tube model

EDIT: Background on my application I am making a few measurement models for an extended Kalman filter (EKF). The EKF is meshing an INS and a GPS currently, but the GPS update rate does not update ...
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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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3 votes
2 answers
251 views

Do any aircraft automatically test that the pitot-static system is functioning properly before liftoff?

Given that a properly-functioning pitot-static system is absolutely essential for flight (a plane cannot be flown without valid airspeed data, or at least not for long), are there aircraft that ...
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3 votes
2 answers
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Static port and Bernoulli [duplicate]

Static ports open directly to the outside of fuselage. When aircraft is flying, there will be air flowing outside of static port. How does this not cause a vacuum effect inside the static port. Due to ...
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What does the Airspeed indicator show when your pitot tube is blocked?

So the question in the topic. I want to clarify whether the speed indications is maintained or go to 0.
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1 answer
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Which company manufactures the air data system on the Boeing 787-9 'Dreamliner'

I'm asking specifically about the manufacturer and model of the Pitot probes/tubes that provide the pilots with current air speed readings. Pretty sure it's either UTC or Honeywell but can't find ...
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3 answers
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Does the pressure at the static ports drop as the aircraft's speed increases?

This answer by Tyler Durden explains what static ports are and how they work: The "static ports" allow air into the instrument to provide the input for the air pressure on the side of the aircraft. ...
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Is it possible to totally override the flight computer on the Airbus A320-family (in simple non-technical terms)?

As I know, in the autopilot oriented airplanes like an A321 the plane doesn't let the pilots pitch down when the plane gets an over-speed warning. So what if the pitot-static system isn't working ...
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2 votes
2 answers
886 views

Where exactly are the pitot tubes positioned on the A330/340?

While going through a document for analysis I came across a statement saying the positions 1 and 2 of the pitot probes are symmetrical on long-range Airbus aircraft but not on their single-aisle ...
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5 votes
1 answer
906 views

How is the static pressure in the pitot static system reconciled when there are two outside static pressure ports?

On airplanes where there are two static pressure sources (ports) on each side of the fuselage what is the result of the static pressure as compared to aircraft with a single port. (I'm not talking ...
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What additional functionality is provided by the F-14 nose pitot, absent in early models?

Early model F-14A had no nose pitot: ... but they seem to have quickly acquired them sometime in the late 1970s. The Iranian F-14s have them, and it's quite hard to find a picture of an F-14 without ...
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14 votes
2 answers
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Why does the Boeing 737 have a pitot tube on the tail?

From this link: Can anyone explain why the Boeing 737 has a pitot tube for the elevators? Wouldn't the airspeed be measured the same from the front of the airplane and the tail? Is the airspeed ...
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What is the meaning of "static pressure"?

I don't really know what static pressure is. Does the ASI (Airspeed Indicator) use cockpit pressure as static pressure, to find the dynamic or differential pressure? I just found this statement : ...
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4 votes
2 answers
534 views

How does the mechanical linkage of the airspeed indicator convert dynamic pressure to KIAS?

I understand the underlying principle of an airspeed indicator, ie. that it uses the Pitot-static system to measure the dynamic pressure as the difference between total pressure and static pressure. ...
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When was the pitot-based ASI first used on aircraft?

The pitot was first invented well before aircraft, yet early aircraft lacked an airspeed indicator (ASI). What aircraft first had a pitot-based ASI, and when?
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Why can the aircraft not turn on pitot heaters itself?

There have already been some posts about pitot heaters: when to turn them on/off, why not leave them on etc. I don't want to go over that. I am an engineer, so I'd like to ask: if the flight ...
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2 votes
1 answer
1k views

What would be the effects of installing pitot tubes on the engine covers?

What are the effects on airspeed measurements, if the pitot tubes were installed right on the engine covers of an aircraft instead of being on the nose. Would the reading be false? If so, would the ...
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8 votes
1 answer
577 views

How does an air-data computer convert ram air pressure from the pitot tube into airspeed?

I know how the analog airspeed indicator shows the airspeed from the ram air pressure from the pitot tube. But I'd like to know how an air-data computer converts the raw pressure data to airspeed that ...
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17 votes
7 answers
7k views

Is it possible to accurately measure airspeed without pitot tube?

This is a follow-up to my previous question: How does this IMU work and how to convert its output into meaningful information? for which many people asserted that I need a pitot tube and a static ...
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1 vote
1 answer
2k views

How to calculate the static pressure in a pitot tube?

In a pitot-static tube, we have two different pressure, the static pressure $p_s$ and the total pressure $p_0 = p_s + \frac{1}{2}\rho v^2$, which comes from the Beroulli equation for incompressible ...
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