Mahindra GIPPSAERO GA8-TC 320 - Page 51

CASA Approved
C01-01-08 5 Feb 2009 Page 3-15
Section 3
Model GA8-TC 320 Emergency Procedures
3.4.10. Pitot Static Malfunction
If erroneous readings of the pitot-static instruments (airspeed indicator, altimeter or vertical
speed indicator) are suspected, the most likely cause is icing of the wing mounted pitot-static
probe. The initial action is to select the pitot heat to ON. If the problem persists one minute after
switching on the pitot heat, the alternate static source should be selected.
The corrections presented in Table 3-1 for speed and Table 3-2 for attitude should be used
when operating with aps up and the alternate static source selected. With 14° and 38° ap
the change in airspeed does not exceed 5 knots and the change in altitude does not exceed
60 ft with the alternate static source selected. If the system continues to operate incorrectly, use
known pitch and power settings to maintain sufcient airspeed.
For aircraft that are not tted with either pitot heat or alternate static systems, follow the steps in
paragraph 3.3.6 Inadvertent Icing Encounter.
KIAS
Alternate
Source
Correction to be
added
(knots)
70 0
80 -1
90 -2
100 -3
110 -4
120 -4
130 -5
Table 3-1 Alternate Static - Airspeed Calibration (Flaps Up)
NOTE:
Indicated airspeed assumes zero instrument error
Altitude
Alternate Source
(ft)
Correction to be added (ft)
KIAS
70 80 90 100 110 120 127
1000 0 0 -20 -20 -40 -40 -60
5000 0 0 -20 -20 -40 -60 -60
10,000 0 0 -20 -20 -40 -60 -60
Table 3-2 Alternate Static - Altimeter Calibration (Flaps Up)
01 Aug 2011