25
SAFIR 5L
OPERATION AND ATTENDANCE MANUAL
PG 01-31
4.
SERVICE INSTRUCTIONS
General Survey
These instructions can be used for routine work related to APU operation. Their aim is to ensure trouble-free
operation from activation to complete overhaul.
Trouble-free operation of APU depends predominantly on the regular and correct performance of periodic work.
All the work related to operation and troubleshooting must be entered into the APU Engine log book and device
certifications.
In case of occurrence of a failure, the claim must be filed within 1 month at the latest. The claim will be
acknowledged only when all due data are recorded in the Engine log book.
Assembly and Operation Instructions
4.2.1.
А
. Assembly Instructions
APU is installed with its horizontal rotor turbine axis perpendicular to the longitudinal airplane axis.
It is suspended on the airframe by means of three flanges.
Control box and ignition device, filter and servo block and fuel pump are located on the airframe separately.
Return fuel filter and anti-stall bleed valve is installed in the piping of the system.
For correct function of APU, the following must be ensured:
range of fuel pressure on input to APU Fuel System: see article 3.10
pressure on fuel output from the APU Fuel System (behind the Filter and Servo Block) see article 3.10
respect the requirement of minimum gas pressure condition behind turbine (in the exhaust pipe): see article
3.10
for sufficient supply of air to enter the compressor APU and the minimum size of opening into the installation
space APU see Article 3.10
maximum under-pressure in the compressor suction area against ambient air: see article 3.10
suction of exhaust gases of APU or other engine, as well as warm air from pneumatic starter or blow-off
air, is not permissible!
cleanliness of the APU compressor suction area must be maintained, penetration of foreign matter into
APU compressor is not permissible!
fuel drainage from APU is ensured by the airplane system.
respect the maximum under pressure in area of compressor suction pressure condition
behind turbine (in the outlet pipe)
