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SAFIR 5L
OPERATION AND ATTENDANCE MANUAL
PG 01-31
Instructions for Replacement of APU In-Operation
Dismantling of APU from aircraft
- Perform cold start of APU (preservation)
-
Empty the oil tank
- Dismount connector cable of APU devices, connectors and thermocouple compensation cables of exhaust gas
temperature transmitters on exhaust pipe
- Dismount inlet and outlet fuel piping from APU
- Blind all disconnected APU inlets and airframe installation
- Blind the APU entry into the compressor (intake), the output of the compressor (air output of APU) and
exhaust pipe
-
Pack APU to
original
transport package
- Make a record of APU dismounting into APU engine log book
When mounting new APU on an airplane, the following works must be performed:
Unpack APU and, if applicable, accessory devices. Verify its identity according to the assembly document.
Wash the external surfaces by petrol, if they are preserved – protect the conductors and electric installation
components from petrol penetration. Dry up the washed surfaces. Drain off the preservative solution from the
internal spaces of the Fuel-Oil System device.
The time between unpacking and dewaxing and between activating APU in an airplane must not be longer
than 3 months.
Mount the ignition plug on the APU (if it is not already mounted directly by the Manufacturer). Perform the
mounting of the ignition plug in accordance with Article 4.8.8.
Install APU and other devices on the airplane according to the reference manual. Detach the blinding plugs
gradually during mounting, so that the apertures would not stay exposed in vain.
Perform other work related to activation according to Article 4.4.1.
Activation
4.4.1.
First Actuation
The following work must be performed before the First Actuation:
-
Remove the cloth tape, which protects the APU compressor suction inlet. Assure that the compressor wheel
rotates freely.
-
Check the connection of Oil, Fuel, Air, Actuating and Control System according to the relevant schemes and
assembly documentation approved by the manufacturer APU
-
Try out the Control System function by the LUN 5265 Testing Case – see Article 4.8.2.
-
Fill the oil tank with oil up to the ”MAX” mark.
-
Inspect the engine compartment,
remove extraneous objects
.
-
Perform cold start lasting 13 sec. with ignition circuit breaker switched off .
(after APU switch off must flow fuel from drain)
-
Check the leak-tightness of the fuel and oil installation.
-
Perform APU start to idling. Watch closely the progress of actuation and operation. Shut down the APU from
Idling Mode operation after 2 minutes of operation.
-
Check the leak-tightness of the Fuel and Oil Systems, fill up the oil in the tank to the ”MAX” mark.
-
Perform the work requisite before engine actuation. Start APU to (100%) speed and then perform cold turn and
engine start-up. Check the lag time after APU switch off:
