NOTE: Start from a value below the differential pressure
____
 tolerance.

 1)  Make sure the differential pressure is in tolerance.
 (c)  
Decrease the differential pressure until the clackers go off.

 1)  Make sure the differential pressure is less than the differential pressure tolerance.

 (d)  
Before you go to the next test altitude, do the step that follows: 1) Decrease the differential pressure to a value below the

 differential pressure tolerance of the next test altitude.
 F.  Put the Airplane Back to Its Usual Condition
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 S 865-024 WARNING: FAILURE TO REMOVE VINYL ADHESIVE TAPE FROM STATIC PORTS BEFORE
_______ FLIGHT MAY CAUSE LARGE ERRORS IN AIRSPEED SENSING AND ALTITUDE SENSING SIGNALS, WHICH MAY LEAD TO LOSS OF SAFE FLIGHT.
 (1)  
Put the mach airspeed warning and pitot static systems to their usual conditions.

 S 865-022

 (2)  
Remove electrical power if it is not necessary (AMM 24-22-00/201).

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 ALTITUDE ALERTING SYSTEM - DESCRIPTION AND OPERATION
____________________________________________________
 1.  General_______
 A.  AIRPLANES WITH EFIS; The altitude alert system is a part of the Digital Flight Control System (DFCS). Refer to 22-11-01 for altitude alert system coverage.
 B.  AIRPLANES WITHOUT EFIS; The altitude alert system is a part of the Digital Flight Control System (DFCS). Refer to 22-11-00 for altitude alert system coverage.
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 ELECTRONIC FLIGHT INSTRUMENT SYSTEM (EFIS) - DESCRIPTION AND OPERATION
______________________________________________________________________
 1.  General (Fig. 1)_______
 A.  The Electronic Flight Instrument System (EFIS) is one of five major subsystems of the Flight Management System (FMS). The other four major subsystems are: the Flight Management Computer System (FMCS), the Digital Flight Control System (DFCS), the autothrottle system (A/T), and the Inertial Reference System (IRS).
 B.  The EFIS provides displays for most of the airplane's navigational systems. The major displays provided by the EFIS are: color displays of pitch and roll; navigational maps; weather; radio altitude and decision height; and autopilot and flight path information. The EFIS also provides displays of: airspeed; ADF/VOR bearings; ILS data; and stall warning information.
 C.  The Electronic Flight Instrument system consists of the following components: two Symbol Generators (SGs), two Control Panels, two Electronic Attitude Director Indicators (EADIs), two Electronic Horizontal Situation Indicators (EHSIs), two Remote Light Sensors, an Electronic Flight Instrument (EFI) transfer switch, and two EFIS transfer relays (Fig. 1).
 (1)  
The symbol generators are located on the E2-3 rack in the main equipment center.

 (2)  
The control panels for the captain and first officer are located on the left and right side of the aft electronic panel.

 (3)  
The EADIs and EHSIs are located on captain's and first officer's instrument panels.

 (4)  
The remote light sensors are mounted on the glareshield.

 (5)  
The EFI transfer switch is located on the pilot's overhead panel.