If there is a blockage in PITOT TUBE......Read on?

Question

Will there be any effectitons to Vertical Speed Indicator(VSI) and Altimeter Indicator(AI)?I know Airspeed Indicator will not work properly,but What about Vertical Speed Indicator and Altimeter Indicator?As u may know,Airspeed Indicator is linked to VSI and AI with Static Port pipe.

Any suggestion would be appreciated

Answer 1

Of the three bits of info required to land an A/C the most important is airspeed. If the pitot is blocked you will not have that info in the cockpit. Skilled pilots may get away without this info but even thay admit that the seat of the pants is nowhere as reliable as a functioning ASI. Don't fly until you know the pitot is functioning.

Answer 2

Pitot Tube Blockage

Answer 3

tony, get a copy of faa's hand book of aeronautical knowledge!
http://www.faa.gov/pilots/training/handbook/

Chapter 6—Flight Instruments
Pitot-Static Flight Instruments.......................

There are two major parts of the pitot-static system: the
impact pressure chamber and lines, and the static
pressure chamber and lines. They provide the source of
ambient air pressure for the operation of the
altimeter, vertical speed indicator (vertical velocity
indicator), and the airspeed indicator.
The openings of both the pitot tube and the static vent
must be checked during the preflight inspection to
assure that they are free from obstructions. Blocked
or partially blocked openings should be cleaned by
a certificated mechanic. Blowing into these openings is
not recommended because this could damage the
instruments.
Page 6-8
BLOCKAGE OF THE PITOT-STATIC SYSTEM
Errors almost always indicate blockage of the pitot tube,
the static port(s), or both. Blockage may be caused by
moisture (including ice), dirt, or even insects. During preflight,
make sure the pitot tube cover is removed. Then,
check the pitot and static port openings. A blocked pitot
tube affects the accuracy of only the airspeed indicator.
However, a blockage of the static system not only affects
the airspeed indicator, but can also cause errors in the
altimeter and vertical speed indicator.
BLOCKED PITOT SYSTEM
The pitot system can become blocked completely or
only partially if the pitot tube drain hole remains open.
If the pitot tube becomes blocked and its associated
drain hole remains clear, ram air no longer is able to
enter the pitot system. Air already in the system will
vent through the drain hole, and the remaining pressure
will drop to ambient (outside) air pressure. Under these
circumstances, the airspeed indicator reading decreases
to zero, because the airspeed indicator senses no
difference between ram and static air pressure. The
airspeed indicator acts as if the airplane were stationary
on the ramp. The apparent loss of airspeed is not
usually instantaneous. Instead, the airspeed will drop
toward zero.
If the pitot tube, drain hole, and static system all
become blocked in flight, changes in airspeed will not
be indicated, due to the trapped pressures. However, if
the static system remains clear, the airspeed indicator
acts as an altimeter. An apparent increase in the ram air
pressure relative to static pressure occurs as altitude
increases above the level where the pitot tube and drain
hole became blocked. This pressure differential causes
the airspeed indicator to show an increase in speed. A
decrease in indicated airspeed occurs as the airplane
descends below the altitude at which the pitot system
became blocked.
The pitot tube may become blocked during flight
through visible moisture. Some airplanes may be
equipped with pitot heat for flight in visible moisture.
Consult the AFM or POH for specific procedures
regarding the use of pitot heat.


BLOCKED STATIC SYSTEM
If the static system becomes blocked but the pitot tube
remains clear, the airspeed indicator continues to
operate; however, it is inaccurate. Airspeed indications
are slower than the actual speed when the airplane is
operated above the altitude where the static ports
became blocked, because the trapped static pressure is
higher than normal for that altitude. When operating at
a lower altitude, a faster than actual airspeed is
displayed due to the relatively low static pressure
trapped in the system.
A blockage of the static system also affects the altimeter
and VSI. Trapped static pressure causes the altimeter to
freeze at the altitude where the blockage occurred. In
the case of the VSI, a blocked static system produces a
continuous zero indication.

Answer 4

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RE:
If there is a blockage in PITOT TUBE......Read on?
Will there be any effectitons to Vertical Speed Indicator(VSI) and Altimeter Indicator(AI)?I know Airspeed Indicator will not work properly,but What about Vertical Speed Indicator and Altimeter Indicator?As u may know,Airspeed Indicator is linked to VSI and AI with Static Port pipe.

Any...

Answer 5

To work properly, the altimeter and vertical speed indicator (VSI) must be properly connected to the static port.

The airspeed indicator, on the other hand, compares the static pressure to the ram pressure (pressure of air coming into the pitot tube), so it needs to be connected to both.

If you taped over the pitot tube at the place where the oncoming air enters, the airspeed indicator would malfunction, but the VSI and altimeter should still work.

Note however that some aircraft (mine included) have a combination mast that houses the pitot tube and the static port, so if you covered the mast completely, it would mess up all three instruments.

Answer 6

The VSI and the Altimeter would function normally as they do not require data from the Pitot tube. The ASI, VSI and the Altimeter might share the same static port, but they are designed to function independently. And any instrument sharing common data will be designed such that it will not pollute the common data.

However blockage of the static port will affect all the three instruments.

Answer 7

I think VSI and AI will work with a blocked pitot tube. They are both operated by a type of modified barometer which has to do with the pressure of an airtight chamber.

Answer 8

VSI and the altimeter should continue to work fine even with the pitot tube blocked. If the static port or as on larger aircraft, static ports become blocked then you might have VSI(or VVI) and altimeter problems.

Answer 9

i believe the only error ull get if the pitot tube ram air hole is blocked would be speed, altimeter is totally static and im not sure about VSI an instructor i think told me only speed but i want to think it would also matter... but altimeter for sure wouldnt matter

Answer 10

It sounds, from your question, as though you are on a course, and haven't been paying attention. Ask someone else on the same course, and see if they have been listening to the instructor.
It should tell you in your course book anyway.