Nesis
— User’s Manual
7.3
Altitude Indicator
The
slip-skid indicator
, also known as the ball or inclinometer, indicates the coor-
dination of aileron and rudder.
Remember: Nesis can be used in VFR
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conditions only. Hence attitude indicator should be
treated as an insignificant help to the pilot and nothing more.
7.3
Altitude Indicator
An altitude indicator, also known as altimeter, is used to measure the atmospheric pressure
from a static port outside the aircraft. This measurement is then converted into an altitude
above mean sea level, in accordance with a mathematical model defined by the ISA. The alti-
tude is always calculated according to some reference pressure (QNH value – baro-correction).
This pressure must be set by a pilot and can be changed during flight. The QNH value is
typically obtained from air traffic control. Please, refer to section 4.1 on page 22 for more
details about how to set the QNH reference pressure.
Figure 51:
The altitude indicator with the scale given in meters.
The indicator shown on figure 51 is used to display calculated altitude and reference QNH
pressure (baro-correction). The altitude is shown by two needles, where the short needle
points to 1000 feet (or meters) and the long needle points to 100 feet (meters).
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The pressure based altimeter is more precise then the GPS obtained altitude. The absolute
pressure sensor used in Nesis has absolute error of less than one hectopascal, which is about
8 m at the sea-level. This precision is maintained over wide temperature range.
7.4
Vertical Speed Indicator and Accelerometer
A vertical speed indicator (VSI), also known as a variometer, a rate-of-climb indicator, or
a vertical velocity indicator (VVI), is an instrument in an aircraft used to inform a pilot of
the instantaneous rate of descent or climb. In powered flight the pilot makes frequent use of
the VSI to maintain level flight, especially during turning manoeuvres. Figure 52 shows VSI
used in Nesis.
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VFR – visual flight rules. These rules are a set of aviation regulations under which a pilot may operate an
aircraft in weather conditions sufficient to allow the pilot, by visual reference to the environment outside
the cockpit, to control the airplane attitude, navigate, and maintain safe separation from obstacles such
as terrain, buildings, and other aircraft.
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The feet version of altimeter can be configured to show the third – 10000 feet – needle as well.
Version 2.0
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©
Kanardia
2011
