AIR TRACTOR AT-502A Instructions for use

AIR TRACTOR, INC.
Olney, Texas
AT-502A/502B/504
TABLE OF CONTENTS
MAINTENANCE SECTION
Page No.
ENGINE MAINTENANCE................................................................................................................. 01
Introduction .......................................................................................................................... 01
Maintenance......................................................................................................................... 01
Cleaning Your Engine Exterior............................................................................................. 01
Fuel ................................................................................................................................ 02
Figure 101 Fuel Nozzles...................................................................................................... 03
Oil ................................................................................................................................ 03
Figure 102 Location of Oil Drain Plugs................................................................................ 04
Air Filters.............................................................................................................................. 05
Miscellaneous ...................................................................................................................... 06
Compressor Washes............................................................................................................ 07
Figure 103 Gas Generator Case.......................................................................................... 07
Troubleshooting ................................................................................................................... 08
Starting Procedures ............................................................................................................. 08
Ground Run Procedures...................................................................................................... 09
Routine Maintenance Inspection........................................................................................ 010
INTRODUCTION................................................................................................................................. 1
FUEL REQUIREMENTS..................................................................................................................... 1
OIL REQUIREMENTS ........................................................................................................................ 1

AIR TRACTOR, INC.
Olney, Texas
AT502A/502B/504
TABLE OF CONTENTS (Continued)
MAINTENANCE SECTION
Page No.
TIRE INFLATION................................................................................................................................ 1
LIFTING AND JACKING..................................................................................................................... 1
MAIN WHEELS................................................................................................................................... 2
Main Wheel Alignment .......................................................................................................... 2
BRAKES.............................................................................................................................................. 3
Brake Master Cylinders.......................................................................................................... 3
Brake Bleeding....................................................................................................................... 4
Parking Brake......................................................................................................................... 4
TAIL WHEEL....................................................................................................................................... 4
Tail Wheel Fork...................................................................................................................... 5
Tail Wheel Fork Housing........................................................................................................ 5
Tail Wheel Lock Pin and Housing.......................................................................................... 6
MAIN AND TAIL GEAR ATTACH BOLTS .......................................................................................... 6
TAIL GEAR SPRING........................................................................................................................... 7
MAIN GEAR SPRING......................................................................................................................... 8
WINGS ............................................................................................................................................. 10
Wing Attachment to Fuselage.............................................................................................. 10
Wing Center Splice Connection........................................................................................... 11
Wing Walk............................................................................................................................ 11

AIR TRACTOR, INC.
Olney, Texas
AT-502A/502B/504
TABLE OF CONTENTS (Continued)
MAINTENANCE SECTION
Page No.
FUEL TANKS.................................................................................................................................... 12
Fuel Tank Senders............................................................................................................... 13
Fuel Tank Receiver.............................................................................................................. 13
FUEL SYSTEM DRAINS .................................................................................................................. 14
FUEL SYSTEM SCREENS AND FILTERS...................................................................................... 14
AILERONS........................................................................................................................................ 14
FLAPS ............................................................................................................................................. 15
AILERON AND FLAP RIGGING....................................................................................................... 16
AILERON AND FLAP BELLCRANKS AND SUPPORTS ................................................................. 16
FLAP ACTUATOR ............................................................................................................................ 17
Flap Actuator Troubleshooting............................................................................................. 18
Flap Actuator Removal Instructions..................................................................................... 19
Flap Actuator Installation Instructions.................................................................................. 19
Flap Motor Troubleshooting................................................................................................. 20
HORIZONTAL STABILIZERS........................................................................................................... 20
Stabilizer Struts.................................................................................................................... 21
Stabilizer Rigging................................................................................................................. 21
VERTICAL FIN.................................................................................................................................. 21
RUDDER........................................................................................................................................... 22
RUDDER CONTROLS...................................................................................................................... 22
ELEVATORS..................................................................................................................................... 23

AIR TRACTOR, INC.
Olney, Texas
AT-502A/502B/504
TABLE OF CONTENTS (Continued)
MAINTENANCE SECTION
Page No.
ELEVATOR CONTROL .................................................................................................................... 24
COCKPIT CONTROLS..................................................................................................................... 25
ELEVATOR TRIM TABS................................................................................................................... 26
TRIM TAB CONTROLS .................................................................................................................... 26
TRIM LEVER..................................................................................................................................... 27
FUSELAGE REMOVABLE SKINS.................................................................................................... 27
FUSELAGE FIXED SKINS................................................................................................................ 27
FUSELAGE COCKPIT SKINS.......................................................................................................... 28
FUSELAGE FRAME ......................................................................................................................... 28
WINDSHIELD.................................................................................................................................... 28
CANOPY DOORS............................................................................................................................. 28
SEAT ............................................................................................................................................. 28
ENGINE DRIVEN AIR CONDITIONER ............................................................................................ 29
Cautionary Information......................................................................................................... 30
R134a Information................................................................................................................ 30
Application Specifications .................................................................................................... 32
Diagnosis Confirmation of Compressor Failure................................................................... 32
Compressor Repair.............................................................................................................. 36
Compressor Replacement ................................................................................................... 40

AIR TRACTOR, INC.
Olney, Texas
AT-502A/502B/504
TABLE OF CONTENTS (Continued)
MAINTENANCE SECTION
Page No.
Service Procedures.............................................................................................................. 41
Common Causes of Compressor Failure ............................................................................ 46
HOPPER........................................................................................................................................... 47
HOPPER GATE BOX........................................................................................................................ 47
HOPPER LID .................................................................................................................................... 48
GATE BOX CONTROLS................................................................................................................... 48
SPRAY LEVER CONTROLS............................................................................................................ 48
SPRAY PUMP................................................................................................................................... 48
SPRAY PLUMBING .......................................................................................................................... 49
BOTTOM LOAD PLUMBING............................................................................................................ 49
SPRAY NOZZLES ............................................................................................................................ 49
STRIPPING AND RE-PAINTING PARTS......................................................................................... 50
Stripping and Repainting Aluminum Parts........................................................................... 50
Priming Aluminum Parts with Chromated Alkyd Primer....................................................... 51
Stripping & Repainting Steel Parts....................................................................................... 51
Materials Used for Stripping, Painting, & Preservation........................................................ 52
TORQUE VALUES FOR SHOP USE ............................................................................................... 53
ELECTRICAL SYSTEM.................................................................................................................... 54
General ................................................................................................................................ 54
Starter/Generator................................................................................................................. 54