down has drained. + + + + + Fuel Flow zero 20 drops/minute Measure after 5 minutes Divider operation when residual
fuel from previous fuel manifold purge on shut-down has drained.
+ + + + + IGV Actuator zero 20 drops/minute At seal drain drain port. + + + + + Oil Consumption zero 6.5 ccm/hour APU coming from shop is (new APU) considered as new. + + + + + Oil Consumption 6.5 ccm/hour 65 ccm/hour Oil consumption in (used APU) relation to APU operating
hours and condition. -------------------------------------------------------------------------------
(a)
The leakage rates shown in table are acceptable for normal engine operation. Leakage more than the limits or a sudden leakage increase, must be monitored frequently and/or necessary maintenance scheduled.
(b)
In case there are more than 20 drops/minute at the drain mast, do the necessary trouble shooting to isolate the source of the leakage.
C. Engine Starter Motor-Duty Cycle Three consecutive start attempts are permitted without cooldown. After the third start attempt the starter motor must cool down for at least 60 minutes.
D. Lubrication System
(1)
Oil specification - approved lubricants of vendor.
(2)
Oil reservoir capacity 5.7 l (6 US qt) approx.
(3)
Oil consumption - should not exceed 65 cc per operating hour.
E. Electrical System:
(1)
Power supply (aircraft bus) or,
(2)
Battery 28.6 +/- 2 V DC.
F. Bleed-Air Control System
(1)
Inlet Guide-Vane Actuator - Nonoperating - Closed.
(2)
Surge Control Valve - Nonoperating - Open.
(3)
Bleed Load Valve - Normal position - Closed.
ENGINE - DESCRIPTION AND OPERATION
__________________________________
1. General
_______
The APU supplies:
-
pneumatic power for 'Main Engine Start (MES)',
-
pneumatic power for the Environmental Control System (ECS),
-mechanical shaft power to drive an AC generator and a fan. The fan cools the lubrication system and supplies the cool air to cool the APU compartment.
2. System Description
__________________
(Ref. Fig. 001)
The APU consists of two basic units:
A. Power/Load Compressor Section (Ref. 49-21-00)
The power section is essentially a single-shaft assembly with the
following major components:
-single-stage centrifugal compressor with a 7,5 : 1 pressure ratio.
-reverse-flow annular combustion-chamber,
-two-stage axial-flow turbine. The load compressor is a direct-drive modular assembly, installed between the power section and the accessory gearbox. It is a single-stage centrifugal compressor with a compressor ratio of 4:1. Inlet guide vanes (IGVs) are installed at the entrance of the compressor housing to control the compressor output to the aircraft pneumatic system.
B. Accessory Gearbox (Ref. 49-26-00) The accessory gearbox is installed on the end face of the load compressor casing and is driven by the power section. It has drive pads for:
-an AC generator,
-
a starter motor,
-
a fuel-control unit and lube module,
-
a cooling fan.
R EFF : 001-049, 101-105, 107-107, 151-199, 49-20-00Page 1 201-210, Config-2 Aug 01/05
CES
Auxiliary Power Unit Figure 001
R EFF : 001-049, 101-105, 107-107, 151-199, 201-210, Page 249-20-00Config-2 Aug 01/05
CES
3. Operation/Control and Operation
_______________________________
The following components control APU start:
-master switch 14KD (MASTER SW) and
-
APU start switch 2KA (APU START)
A.
APU Start
(1)
When the MASTER SW 14KD is set to ON, the ECB is energized.
-energize the APU fuel-feed pump 4QC.
(2)
This causes the ECB to transmit the following commands:
- open the APU air-intake flap;
- open the FUEL LP VALVE 3QF;
(3)
After setting the APU START pushbutton to the 'ON'-position:
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