24
SAFIR 5L
OPERATION AND ATTENDANCE MANUAL
PG 01-31
APU Actuation in flight
- scope of airplane instrument speed for reliable APU actuation is depending on the APU
installation. This parameter should be verified by test.
The common maximum flight speed for successful APU start is
214 ÷ 321 KIAS
(400 ÷ 600 km/hour)
-
height
max. 26,500 ft (8000 m).
Other Limits
- Fuel pressure on input of the APU Fuel System
80 – 186 kP
а
- Fuel pressure on output from the APU Fuel System at the idle of APU
10÷25 kP
а
- Max. fuel viscosity
12 mm
2
/s
е
c.
- Pressure of gasses behind the turbine (in the spout)
max. 5 kP
а
- Negative air pressure in the APU suction area
max. 1,5 kP
а
-
Min. total input opening surface for the air flow into the APU installation
min. 300 cm
2
- Maximal permitted time of signaling light of high exhaust gas temperature
in the mode of APU start and engine
5 s
- Inside diameter of air pipes
min 48 mm
- Possibility of using different operational liquids must be agreed with original producer of
APU
- Maximal exhaust gas temperature
850 °C
- Nominal net voltage
28 VDC
- Precondition of successful APU start is that supply conductors of electric starter have the
adequate diameter = resistance (depending on the length), which must be choose that during
start the voltage on the battery terminals could not decrease under.
14 VDC
-total resistance of both lines between battery and electric starter must be in range
23±2 m
- Voltage on the electric starter terminals must not at the time the APU start and during his run
owing to the overall resistance of power cables and the internal resistance of the battery less
than
26 VDC
-
Minimum duration deceleration - time to stop the rotor APU from APU shutdown from idle
speed must be at least
45 sec
- After installing theAPU S5L unit on the aircraft and after grounding conductors connecting,
must be the resistance between grounding screw on the mounting flange of the control box
and the grounding screw on APU turbine casing flange.
max. 0.5
Ω
.
-
After the shutdown of APU from idle or 100 % speed and immediately after stopping the
rotor must go rotate by the rotor freely ! ! !
