power cables. Figure 7-5 shows typical deck-edge
electrical installations.
The dc service cable is oval-shaped and contains
three female pins that mate to male pins on the aircraft.
The ac service cable is rectangular-shaped and contains
six female pins that mate to male pins on the aircraft.
Use the following safety precautions when you
work with deck-edge electrical power systems:
! Use care when you are connecting the heavy
cables to the aircraft. Damage to the aircraft
power receptacles may result if too little slack
is left in the cables.
! Be sure that the remote switches are turned off
prior to connecting or disconnecting service
cables to the aircraft.
! The flush deck outlets often get water in them
because of rain or heavy seas. Do not use these
outlets if water is present. You will get
shocked.
PITOT-STATIC SYSTEM
The Aviation Electrician's Mate (AE) rating
maintains the pitot-static system and most aircraft
instruments. The pitot-static system in an aircraft
includes some of the instruments that operate on the
principle of the barometer. It consists of a pitot-static
tube and three indicators, all connected with tubing that
carries air. The three indicators are the altimeter, the
airspeed and Mach number indicator, and the
rate-of-climb indicator. The airspeed indicator displays
the speed of the aircraft. The altimeter displays the
altitude of the aircraft. The rate-of-climb indicator
shows how fast the aircraft is climbing or descending.
Each instrument operates on air taken from outside the
aircraft during flight. The relationship between the
pitot-static tube, the airspeed indicator, the altimeter,
and the rate-of-climb indicator is shown in figure 7-6.
The pitot tube is mounted on the outside of the
aircraft at a point where the air is least likely to be
turbulent. It points in a forward direction parallel to the
aircraft's line of flight. One general type of airspeed tube
mounts on a mast extending below the nose of the
fuselage. Another is on a boom extending forward of the
leading edge of the wing. Although there is a slight
difference in their construction, their operation is the
same.
Static means stationary or not changing. The static
port introduces outside air, at its normal outside
atmospheric pressure, as though the aircraft were
standing still in the air. The static line applies this
outside air to the airspeed indicator, the altimeter, and
the rate-of-climb indicator.
7-6
A
B
C
ANF0705
Figure 7-5.—Typical deck-edge electrical installations. (A)
Hangar deck; (B) catwalk; (C) flush deck.
