Questions tagged [pitot-static]

A pressure-based system for measuring airspeed and altitude.

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4
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1answer
108 views

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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2answers
289 views

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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1answer
256 views

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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0answers
86 views

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?
9
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2answers
2k views

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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4answers
199 views

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)?
5
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3answers
1k views

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 ...
5
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1answer
195 views

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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1answer
84 views

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 ...
3
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1answer
598 views

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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1answer
426 views

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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3answers
304 views

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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0answers
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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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2answers
4k 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? ...
6
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1answer
286 views

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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5answers
870 views

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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1answer
403 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. ...
2
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1answer
111 views

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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2answers
118 views

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?
3
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2answers
229 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 ...
3
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2answers
352 views

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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5answers
3k views

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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1answer
347 views

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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3answers
2k views

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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2answers
1k views

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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2answers
746 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 ...
5
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1answer
770 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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1answer
1k views

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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2answers
9k views

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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2answers
1k views

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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2answers
443 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. ...
10
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1answer
1k views

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?
9
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1answer
806 views

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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1answer
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 ...
7
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1answer
405 views

How does an ADIRU 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 ADIRU converts the raw pressure data to Airspeed that is ...
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7answers
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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1answer
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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3answers
3k views

What were the safety recommendations following the Aeroperú Flight 603 crash?

I just watched the Mayday Air Crash Investigation about Aeroperú Flight 603 and two questions that weren't answered are: Who was responsible What caused the ATC to relay false altitude information to ...
2
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1answer
337 views

Are there typical values of pitot-static and TAT probe measurement uncertainties?

I'm working on flight sensors for a project and I'm supposed to model noise in the Static Port, Pitot tube, and TAT probe measurements. I looked a lot for it online and could not get a convincing ...
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4answers
6k views

Why does indicated airspeed change with altitude?

I know that if you fly at a low altitude and at a high altitude at the same TAS, your IAS will be lower at the high altitude than at the low altitude. Why is this though? Wouldn't the static vent ...
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0answers
257 views

What may cause a pitot tube and Honeywell pressure sensor calibration inconsistency?

It is possible that my issue is specific to my setup, but I thought I'd try here if someone has experienced a similar issue. I will try to explain this clearly as possible, but it may be slightly ...
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3answers
5k views

What is the difference between a pitot tube and a pitot-static tube?

What is the difference between a Pitot tube and a Pitot-static tube? If an aircraft fitted with Pitot tube and static holes on the fuselage, is it necessary to consider the static pressure ...
7
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1answer
690 views

Why are some pitot tubes more prone to icing than others?

I understand that there were several cases pitot tube failure in a certain way. The pitot tubes were clogged by ice when the airplane was in cold and wet conditions. The remedy was to exchange the ...
7
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1answer
708 views

Why are static ports external on a non pressurized aircraft?

Seems like the intruments in a non pressurized aircraft have access to the static pressure right where they are. It seems like external ports would be subject to more error being exposed, and lines ...
4
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1answer
4k views

What temperature are Pitot Tubes heated to?

What temperature is a pitot tube usually heated to prevent ice? And are pitot tubes always heated to the same temperature, is there any difference between aircraft (say, a C172 and an A321)?
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3answers
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Why not have Pitot Heat always on?

Most (all?) aircraft have a Pitot Heat Switch which must be turned on in certain conditions. Seems Pitot Heat is one of those things you don't want to forget to switch on when it's needed, or worse, ...
7
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1answer
435 views

How does Pitot Heat influence airspeed indication (assuming no ice or moisture)?

Should Pitot Heat ON (in dry weather conditions) decrease airspeed indication because warmer (so less dense) air flows through the tube?
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2answers
2k views

What alternatives to pitot static systems are available or in development?

Air France 447 is a powerful example of what a serious situation unreliable air data indications can be if not handled properly by a crew. Still, whether crews are properly trained or use that ...
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0answers
130 views

Why does the Lockheed D-21B have three air data probes?

The Lockheed D-21 has three air data booms / pitot intake tubes: one on the nose and one on each wing. (Images here and here.) All three appear to be pitot-static tubes. Anyone know what purpose ...
8
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2answers
843 views

How does a Machmeter behave if the static port is blocked during a constant CAS climb?

Question: How will the machmeter behave in a constant CAS climb if the static source becomes blocked? Answer: The machmeter reading will decrease. Why? I couldn't find any logical reason for the ...