Skip to main content
23 votes
Accepted

Why is the pitot tube located near the nose?

There are several reasons to have the pressure sensors in the front section of the fuselage. The further aft the more turbulent the airflow is and the thicker the boundary layer caused by the ...
Jan's user avatar
  • 2,398
18 votes

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

who was responsible for ATC relaying false altitude information to the pilots Not an easy question mostly because it asks (even if not directly) to put the blame on someone. And although there is not ...
Stelios Adamantidis's user avatar
17 votes
Accepted

Is it possible to accurately measure airspeed without pitot tube?

Technically speaking, inertial measurements are not sufficient to derive airspeed. You need pressure measurement (or airspeed measurement, see LIDAR). Pitot-static probes are the most usual and ...
Gürkan Çetin's user avatar
17 votes
Accepted

Does the pressure at the static ports drop as the aircraft's speed increases?

The comment: In fact, the pressure at the static ports will drop as the aircraft's speed increases (Bernoulli principle) is not exactly accurate. The aircraft is a complex aerodynamic shape ...
Gerry's user avatar
  • 20k
16 votes
Accepted

Why not have Pitot Heat always on?

I can generally only speak for commercial aviation. The reasoning is probably the same or similar for General Aviation, but seeing as that is such a wide and varied field, with a tremendous number of ...
Frank's user avatar
  • 2,403
15 votes
Accepted

Why are pitot-static measurements preferred over other velocimetry techniques?

The linked article says that an HWA (hot-wire anenometer) is fragile and requires complex equations to relate the sensed value to the fluid speed as well as correct for inherent, unavoidable ...
Camille Goudeseune's user avatar
14 votes

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

A pitot probe strictly measure ram air pressure, commonly called "pitot pressure" or Pt pressure. A pitot tube measures pitot pressure and pitot pressure only. A separate static port is required to ...
Frank's user avatar
  • 2,403
14 votes
Accepted

Why does the Boeing 737 have a pitot tube on the tail?

There are five sets of pitot tubes on the 737, organized into two groups, the pitot tubes on the nose are used for airspeed measurements, independent for the pilot and copilot and one as a backup. ...
Ron Beyer's user avatar
  • 36.2k
12 votes
Accepted

Why might flight schools prohibit you from testing pitot heat during pre-flight?

I was taught to check it (on a C152/172) before every flight but I've also heard people say that you don't need to. Some reasons I've heard people give for not checking it are: Risk of draining the ...
Pondlife's user avatar
  • 71.8k
11 votes

Is it possible to accurately measure airspeed without pitot tube?

Airspeed - not reliably under all circumstances. You need to feel that wind somewhere in order to get a direct and accurate measure of the speed of it, and the pitot tube is an accurate and proven ...
Koyovis's user avatar
  • 61.8k
10 votes

Why can the aircraft not turn on pitot heaters itself?

There's much simpler and safer logic. Most modern Western transport aircraft automatically switch the pitot heaters on when in flight mode or at least one engine is running. Pilots can manually force ...
user71659's user avatar
  • 6,636
9 votes

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

What caused the ATC to pass incorrect information to the flight crew was that they had no reason to mistrust their own instruments. The altitude information displayed to the controller was transmitted ...
Jamiec's user avatar
  • 33.5k
9 votes

Why do experimental aircraft have such long tubes on the nose?

Yes- you can see an array of little doodads sprouting from the pitot probe in this photo, they are for accurately measuring the direction of airflow in 3 dimensions. They also are long to ensure that ...
niels nielsen's user avatar
8 votes
Accepted

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

No, there is no decrease or change with the use of pitot heat. The pitot system measures pressure. There is no airflow through the system in normal operation. Any airflow through the system would be ...
J W's user avatar
  • 16.6k
8 votes

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

Usually there is an intermediate module ADM (air data module) that makes the conversion from analog pressure into digital numerical value. One ADM will do this for the ram air pressure, another ADM ...
user40476's user avatar
  • 1,797
8 votes
Accepted

Why are some A350s missing SSA probes on their nose?

You are right: the three side slip angle probes are redundant because side slip can be calculated by the ADIRS without these probes. Airbus included them in earlier A350 models to crosscheck this ...
Bianfable's user avatar
  • 56.5k
8 votes

Why are pitot-static measurements preferred over other velocimetry techniques?

Hot wire anemometers are great for measuring turbulent fluctuations on a very fine timescale (say kHz). This is really not needed for aircraft speed. The very same wind tunnels that use HWA or LDA (...
Vladimir F Героям слава's user avatar
8 votes
Accepted

Are pitot systems protected from ice?

You can see an example sketch of a heated pitot tube in the FAA Handbook of Aeronautical Knowledge: As you can see, there are two heaters that heat the entire tube and (ideally) stop ice from forming ...
Bianfable's user avatar
  • 56.5k
8 votes

Please describe ram pressure in simple terms

Airspeed is basically measured by measuring the kinetic energy of the air molecules impacting dynamic pressure port (for example on a pitot tube). The higher the velocity, the more energy, hence more ...
Jpe61's user avatar
  • 29.1k
7 votes

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

A number of systems are under development- most are optical systems- determining airspeed using LiDAR. NLR, for example has developed an Optical Air Data System for this purpose: The developed ...
aeroalias's user avatar
  • 100k
7 votes
Accepted

What does the Airspeed indicator show when your pitot tube is blocked?

Depends on how much blockage. If fully blocked, as in air tight, the pitot side becomes like the sealed aneroid side of an altimeter and it only reacts to changes in static pressure, indicating the ...
John K's user avatar
  • 132k
7 votes

What does the Airspeed indicator show when your pitot tube is blocked?

If the pitot tube gets blocked in flight, such as by icing, the airspeed indication is maintained at first. Note that the indication is still subject to changes in static pressure as long as the ...
Rainer P.'s user avatar
  • 2,920
7 votes

Why is the pitot tube located near the nose?

The boundary layer grows in thickness as you move aft on a fuselage. It is thinnest near the nose. A pitot tube near the nose only has to protrude a small distance away from the fuselage skin in order ...
niels nielsen's user avatar
6 votes
Accepted

Why does indicated airspeed change with altitude?

As you state, IAS is simply based upon the difference between total pressure and static pressure. For low subsonic conditions: $$ p_t = p_s + p_q = p_s + \frac {1}{2} \cdot \rho \cdot V^2$$ $\rho$ ...
Koyovis's user avatar
  • 61.8k
6 votes

Why not have Pitot Heat always on?

Depends on the airframe and where it is operating. For light aircraft operating a low altitudes (<10,000 ft) pitot heat use is going to be dependent upon whether the pilot anticipates encountering ...
Romeo_4808N's user avatar
  • 74.1k
6 votes
Accepted

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

I believe that for point 1 that both ATC and pilot assumed the height information on the ATC radar display came from radar trigonometry and not the reply of the transponder. Neither was at fault here ...
ratchet freak's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible