Service Letter Index
AIR TRACTOR AT-402B · Service Bulletins
Overview
This document is a service bulletin for the Air Tractor AT-402B, detailing various inspections, modifications, and maintenance requirements applicable to the aircraft. It includes a comprehensive list of subjects and components that require attention across different serial numbers.
- Applicable to all Air Tractor models listed.
- Includes inspection and maintenance guidelines for various aircraft components.
- Addresses issues such as cracks, corrosion, and component failures.
- Provides specific serial number ranges for certain modifications.
- Highlights the importance of regular maintenance checks.
- Includes revisions and updates to previous service letters.
- Covers both structural and operational components.
- Emphasizes safety and compliance with maintenance protocols.
Summary written by AI from the source document. Check the original before relying on it. See which parts of Sprinkle are written by AI.
Reference only, not for flight. Use the current approved manual for your aircraft. See terms, section 5.
Document
Source
Copy found at airtractor.com. Sprinkle hosts a reference copy with an added summary, specifications and searchable full text.
Document details
- Type ·
- Service Bulletins
- Year ·
- 2017
- File size ·
- 179 KB
- Copy found at ·
- airtractor.com
- Language ·
- en
What is the Service Letter Index?
The Service Letter Index is a service bulletins for the AIR TRACTOR AT-402B, dated 2017.
What year was the Service Letter Index published?
The Service Letter Index — the AIR TRACTOR AT-402B service bulletins on file — is dated 2017.
Common. More common than 91% of the aircraft models we track.
Most owners only have the POH. Here's the essential set for the AIR TRACTOR AT-402B.
- Pilot's Operating Handbook / AFM
- Checklist
- Maintenance Manual
- Parts Catalog (IPC)
- Systems & Wiring
- Service Bulletins on file
- Type Certificate (TCDS)
AIR TRACTOR AT-402B for sale now
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In this document
Applicability
The bulletin applies to multiple Air Tractor models including 300, 302, 400, 401, 402, 501, 502, 602, and 802.
Inspection Requirements
Details various components that require inspection, including rudder pedal support tubes, battery cables, and main landing gear.
Modification Guidelines
Outlines necessary modifications for specific serial numbers to ensure compliance and safety.
Component Failures
Addresses potential failures in components such as the vertical fin, wing attach angles, and flap actuators.
Corrosion and Cracks
Highlights the need to check for corrosion and cracks in critical structural components.
Revisions
Indicates revisions to previous service letters and updates on maintenance practices.
Summary written by AI from the source document. Check the original before relying on it. See which parts of Sprinkle are written by AI.
Safety notes
- Inspect for cracks in lower longerons and wing attach tubes.
- Check for corrosion on structural components.
- Ensure compliance with all inspection and maintenance protocols.
- Address any identified component failures immediately.
- Follow serial number guidelines for specific modifications.
- Regularly review updates to service letters for new safety information.
Summary written by AI from the source document. Check the original before relying on it. See which parts of Sprinkle are written by AI.
Full document text
SNOW ENGINEERING CO. ENGINEERING NUMBER 01 Wichita Falls, Texas REPORT ORDER MODEL All TITLE BY CHK'D SERVICE LETTER INDEX Leland Snow SERIAL All DATE *2/8/17 PAGE 1 OF 11* APPLICABILITY 300 302 400 401 402 501 502 602 802 S/L 301 302A 400A 401B 402A 502A 802A No. SUBJECT 402B 502B 503A 1-18 Incorporated in all aircraft. 19 Wire Deflector Cable (Thru 0060) X 20 Rudder Pedal Support Tube (Thru 0067) X 21 Battery Cable thru Firewall (Thru 0040) X 22 Park brake Valve (0061 thru 0112) X X 23 Battery Cable thru Firewall (Thru 0100) X 24 Not Applicable. 25 Back-fire door hinge (Thru 0037) X 26 Bolts thru fin front spar attach X X X 27 Bolts thru wing rear spar/fuselage X X X 28 Main and tail gear bolts X X 29 Eye bolt top of master cylinder (Thru 0112) X X 30 Wire deflector cable (Thru 0107) X 31 Cover plate under wing spar X X X 32 Alternator housing (Thru 0161) X 33 Induction hose on carburetor X 34 Tail gear spring X 35 Flap actuator Micro-Switches (Thru 0160) X X 35A Not Applicable. X 36 Wing attach angle Install. (Thru 0217) X X 37 Cracks in lower longerons (Thru 0240) X X 38 Wing rear-spar attach to fuselage (Thru 0224) X X 39 Brake master cylinders (Thru 0216) X X 40 Hopper removal and inspection X X X 41 Park brake valve (0061 thru 0358) X X X 42 Elevator counterweights (Thru 0300) X X X 43 Ring cowl attach lugs X 44 Emergency Egress (Thru 0433) X X X 45 Main Landing Gears X X X 45A Fuselage Bushings-stab. (Thru 0434) X X X 46 Baggage Door Placard (Thru 0460) X X X 47 Fuselage Fitting-Fin Attach (Thru 0240) X X 48 Rudder Hinges (Thru 0260) X X 49 Brake hose attach at wheel (Thru 0241) X X 50 Engine mount ring and bolts X 51 Flap Microswitches (Thru 0369) X X X 52 Hopper lid seal material (Thru 0475) X X X 53 Alternate Induction Elbow (Thru 0470) X SNOW ENGINEERING CO. ENGINEERING NUMBER 01 Wichita Falls, Texas REPORT ORDER MODEL All TITLE BY CHK'D SERVICE LETTER INDEX Leland Snow SERIAL All DATE * 1/20/04 PAGE 2 OF * APPLICABILITY 300 302 400 401 402 501 502 602 802 S/L 301 302A 400A 401B 402A 502A 802A No. SUBJECT 402B 502B 503A 54 Ring Cowl Attach Lugs X 55 Wing Lower Spar Cap Splice Rework X * 55A Engine Forward Fireshield (Thru 0516) X 55B Battery Drain Sump (Thru 0613) X 56 Main Landing gear spring X X 57 Main Landing gear clamp block X X X X X X X 58 Main Landing gear axle bolts X X X X X X X 59 Fuselage Frame Cracks Upr. Engine Mount X 60 Vertical Fin Rib Cracks (0261-0640) X X 61 Primer Line Cracks X 62 Horizontal Stabilizer Eyebolts (Thru 0634) X X X 63 Aft Fuselage Diagonal Tube X X X X 64 Shoulder Harness (Thru 0630) X X X 65 Rudder-Aileron Interconnect (0634) X X X 66 Installation of 40007-3 Gears X X X 67 Industrial Battery Replacement X 68 Precision Aero Ring Cam for R1340 X 69 Cracks in Wing Attach Tube (Thru 0666) X X X X 70 Wing Lower Spar Cap Splice Rework X * 70A Prop Tip Separation X 71 Nuts on Main Gear Axle Bolts (Thru 0679) X X X X 72 Vertical Fin Attach Plate (Thru 0240) X X 72A All Metal Elevator Installation (0001 thru 0673) X X X 73 Propeller Tip Separations X X 73A VR1528-11 Voltage Control (400-0609 thru X X 0699 502-0001 thru 0030) 74 Speed Ring Flexible Mounting (301/401 thru X X X 0699), (501 thru 0030) 75 Hour Meter Recording Rate X X X 76 Parking Brake Valve X X X X X X X 77 Rudder Cable Inspection X X X X X X X X X 78 Brake Master Cylinder Installation X X X X X X 79 Fuel Hose Deterioration X X X 80 Oil Cooler Ejector (Thru 0030) X 81 No longer applicable * 82 Brake Master Cylinder Eyebolt X X X X X * Indicates Revision SNOW ENGINEERING CO. ENGINEERING NUMBER 01 Wichita Falls, Texas REPORT ORDER MODEL All TITLE BY CHK'D SERVICE LETTER INDEX Leland Snow SERIAL All DATE *1 /28 /14 PAGE 3 OF APPLICABILITY 300 302 400 401 402 501 502 602 802 S/L 301 302A 400A 401B 402A 502A 802A No. SUBJECT 402B 502B 503A 83 Vertical Fin Spar Attach Bolts X X X X 84 Spray Pump Fan Blade Failure X X X 85 Carbon Pile Electrical System X X 86 Flexibile Speed Ring Attach Straps X X X 87 Vertical Fin Rear Spar X X X X X X X 88 Vertical Fin Rib Cracks (Thru 0380) X X X 89 Wing Attach Angles X X X X X X X 89A Wing Attach Angles X X X X X X 90 Extreme Corrosion on Spar Caps X X X 91 Airspeed Limits on Turbine Models X X X X 92 Cracks at Wing Attach Tube Bushing X X 93 Corrosion In Horizontal Stabilizer Brace Rivets X X X X 94 Cleveland 40-133 Wheel Bolts X X X X 95 Wing Skin Rivets Main Spar Flange X X 96 Emergency Cockpit Door Release X X X X X X X 97 Cockpit Overturn Skid Plate X X X X X X X X X * 98 Corrosion on Stabilizer Internal Brace X X X X X X X X X 99 Corrosion on Wing Rear Spar Caps X X X 100 Rudder-Aileron Interconnect Cables X X X X 101 FCU Manual Override Kit Availability X X 102 Cockpit Heater X X X 103 Control Stick Yoke Bolt X X X X X X X 104 Main Landing Gear Service Life X X X X X X X 104A Landing Gear Failure, p/n 40091-2 X 105 Fiberglass Elbow in Engine Induction System X X X 106 Start Lever Control Lock Spring X X 107 Parking Brake Valve X X X X X X X 108 Battery Restraint X X X 109 Spray Plumbing X X X X X X X 110 Main Wheel Bearings X X X X 110A Pratt & Whitney PT6A-45R Engine Accessory X Gearbox Coupling Shaft Decoupling (Thru 0192) 111 Fuel Filter Warning Light X X X X 112 Step Cracks X X X X X X X 113 Flexible Speed Ring Attach Straps X X X 114 Spray Plumbing X X X X X X X 115 Collins Air Conditioner Installation X X X X X X X 115A Engine Forward Fireshield Ring Attach Brackets X 116 Extreme Spar Cap Corrosion X X X
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* Indicates Revision SNOW ENGINEERING CO. ENGINEERING NUMBER 01 Wichita Falls, Texas REPORT ORDER MODEL All TITLE BY CHK'D SERVICE LETTER INDEX Leland Snow SERIAL All DATE 12/21/07 PAGE 4 OF * APPLICABILITY 300 302 400 401 402 501 502 602 802 S/L 301 302A 400A 401B 402A 502A 802A No. SUBJECT 402B 502B 503A 117 Landing Gear Bolt Replacement X X X X X X X 118 Hopper Removal & Inspection X X X X X 119 Tail Spring Replacement X X X X X X X 120 Oil Cooler Blower Availability X 121 Prop Cable Lock Washers X X X X 122 Ignition Switch X X X 123 Ignition Switch X X X 123A Cracked Py Air Line on PT6A-45R Engines X X 123B APU Receptacle X 124 Metal in Oil Contamination X X X X X X X X X 125 Low Oil Pressure Warning Light X X 126 PT6A Engine Oil Scavenge Tubes X X X X X 126A PT6A-45R Engine Vibration X X 126B APU Receptacle X 126C Not Applicable 127 Vertical Fin Front Spar X X X X X X X 128 FCU Air Purge in PT6 Engines X X X X 129 Horizontal Stab. Attach Eyebolts X X X X X X 129A Horizontal Stab. Attach Eyebolts X X * 129B Horizontal Stab. Attach Eyebolts X X X X 130 Automatic Flagman Installation X X X X X X X X X 131 PFT Generator Control Unit X X X X X 132 Stewart Warner Hobbs Pressure Switches X X X X X X X X 133 Extend C.G. Limits on AT's Retrofitted with all - X X X metal Elevators and Rudder 134 R1340 Crankshaft Counterweight Cracking X X 135 R1340 Crankshaft Counterweight Cracking X X 136 R1340 Crankshaft Counterweight Cracking X X 137 Turbine Fuel Filters X X X X X X 137A Gate Stop Position Indicator X X 138 Vertical Fin Front and Rear Spar Failure X X X X 139 Not Applicable. 140 Flap System Travel Overrun X X X X X X X 141 Left Side Oil Cooler Platform Step X X X X X 142 Hopper Rinse System Check Valve X X X X X X X 143 Turbine Oil Cooler X X 144 Vertical Fin Rib Cracking X X X 145 Main Wing Spar Replacement (Not Applicable) 146 Aft Fuselage Failures (Apply to 802, 802A only) X 147 Equipment Mounted Under the Seat X X X X X X X X X * Indicates Revision SNOW ENGINEERING CO. ENGINEERING NUMBER 01 Wichita Falls, Texas REPORT ORDER MODEL All TITLE BY CHK'D SERVICE LETTER INDEX Leland Snow SERIAL All DATE *12/30/19 PAGE 5 OF APPLICABILITY 300 302 400 401 402 501 502 602 802 S/L 301 302A 400A 401B 402A 502A 802A No. SUBJECT 402B 502B 503A 148 Fuel Contamination X X X X X X X X X * 149 Engine Driven Air Conditioner Compressor X X X 150 Aileron Rudder Interconnect System X 151 Main Landing Gear Installation X 152 Shoulder Harness X X X X X X X X X 153 Emergency Cockpit Door Release X X X X X X X X 154 Hallett Fuel Valve X X X X X X 155 Vertical Fin Front Spar Fitting X X X X X X X 156 Rudder Pedals X X X X X X X X 157 PT6 Engine Oil Fill Tube X X X 158 A/C Compressor Drive Pad Spline Lubrication X X X X 159 Retrofit of Air Conditioner to R134a Refrigerant X X X X 160 Main Landing Gear Axle Failure X X X X 161 Service Life On Aluminum Lower Spar Caps X X X 162 Curtis Quick Drain Valves/Wings & Header Tank X X X X X X X X X 163 L.E. Skin Cracks at Attachment to Nose Ribs X X X X 164 High Rate Filling of Hopper X X X X X X X X X 165 Flap Actuator Jack Screw Failure X X X X X X X 166 Brake Master Cylinder Eyebolt X X X X X X X X X 167 PT6A P3 Air Filter Maintenance X X X X X 168 Air Conditioner Compressor Clutch X X X X 169 Tail Spring Clamp Block Bolts X X X X X X X X X 170 Air Conditioner Drive Pad X X X X 171 Tail Wheel Lock Bushing Repair X X X X X X X X X 172 Beta Valve Plunger Sticking X X X X X 173 PT6A FCU To Fuel Nozzle Manifold Fuel Line Chafing X X X 174 Turbine Fuel Filter X X X 175 Rudder-Aileron Interconnect Cables X X X X X X X 175A Rudder Horn Cracking (0001-0042) X 176 Vertical Fin Rib Cracking X X X 177 A/C Drive Pad to AGB Housing Interference X X 178 Imbalance of Fuel in Fuel Tanks X X X X X X X X X 178A Recommendations to Prevent Fuel Imbalance... X X X X X X X X X 179 Air-Conditioner Evaporator-Blower Motor X X X X 180 Horizontal Stabilizer Attaching Pedestal X X X X X X X X X 180A Horizontal Stabilizer Attaching Pedestal X X X X X X X X X 181 R-12 Air-Cond.-Compressor Clutch Replacement X X X X 182 AT-502 Firewall-Forward Hopper-Rinse-Tank Support Brkt. X 182A AT-502 Firewall-Forward Hopper-Rinse-Tank Support Brkt. X * Indicates Revision SNOW ENGINEERING CO. ENGINEERING NUMBER 01 Wichita Falls, Texas REPORT ORDER MODEL All TITLE BY CHK'D SERVICE LETTER INDEX Leland Snow SERIAL All DATE *12/21/20 PAGE 6 OF APPLICABILITY 300 302 400 401 402 501 502 602 802 S/L 301 302A 400A 401B 402A 502A 802A No. SUBJECT 402B 502B 503A 183 Wing Main Spar Web Flange Cracks X X 184 Flap Actuator Relays X X X X X 185 AT-802 Wing Fatigue Life Increase (thru 0059) X 186 Aileron Stop Bracket Redesign (thru 0083) X 187 Vertical Fin Front Spar Fitting X X X 188 Wing Rear Spar Bushing Installation (thru 0091) X 189 Oil Cooler Thermostat X X X X 190 Rudder Cables X X X X 191 Emergency Door Release X X X X X X X X X * 192 Reduction in Wing Fatigue Life due to Winglet Install. X X X X X X X 193 Fuel Control Unit Purge Lines X X X 194 Upper Bolt through Wing Attach Angles... X 195 Upper Longeron Failures in Aft Fuselage Structure X X X X X X 195A Upper Longeron Failures in Aft Fuselage Structure X X 195B Upper Longeron Failures in Aft Fuselage Structure X X 196 Vertical Fin Front Spar Failure X X X 197 Cracks in Lower Spar Caps in AT-502A and X X Early AT-502 Aircraft 198 Inboard end of Stabilizer Strut X X X X X X X 199 Rudder Cables X 200 Rudder Cable to Rudder Control Horn Attach Hdwr. X X X X X X X X X 201 Hopper Fill Vent Ball Switch Shaft Coupler X X X X X X X X X 202 Wing Centersplice Rework for AT-400 Series... X X X 203 Wing Centersplice Rework for AT-802 Series... X 204 Wing Centersplice Rework for AT-602 Series... X 205 Wing Centersplice Rework for AT-500 Series... X X 206 Safe-Life for Wing Center Splice Connection… X X X X X X X 207 Brake Torque Plate Reinforcing Plate - 0337-0543 X 208 Water Immersion X X X X X X X X X 209 Proper Operation of Scott Model 4500A2 … X X X X X X X X X 210 Power Quadrant X X X X X X 211 Automatic Flagman Nose Support Modification X X 212 Electrostatic Discharge Damage of PT6A Engine... X X X X X 213 Superceded by 213A X 213A Upper Longeron Failures in Aft Fuselage Structure X 213B Upper Longeron Failures in Aft Fuselage Structure X 214 Tail Gear Springs X 215 Eddy Current Inspection Intervals… X X X X X X 216 Flap Inboard Hinge Cracking X X 217 Superceded by 217A X 217A Upper Longeron Failures in Aft Fuselage Structure X 217B Upper Longeron Failures in Aft Fuselage Structure X * Indicates Revision SNOW ENGINEERING CO. ENGINEERING NUMBER 01 Wichita Falls, Texas REPORT ORDER MODEL All TITLE BY CHK'D SERVICE LETTER INDEX Leland Snow SERIAL All DATE *12/21/17 PAGE 7 OF APPLICABILITY 300 302 400 401 402 501 502 602 802 S/L 301 302A 400A 401B 402A 502A 802A No. SUBJECT 402B 502B 503A 504 218 Superceded by 218A X X 218A Upper Longeron Failures in Aft Fuselage Structure X X 218B Upper Longeron Failures in Aft Fuselage Structure X X 219 Fuel Management/Ferry Fuel Proper Use X X X X X X X X X 220 Wing Centersplice Inspection X X X 221 Slow Engine Starts X X 222 Fairleads Installed in Tail Wheel Unlock Rod X X X X X X X X X 223 Wing Walk Material on Inboard Portion of Flaps X X 224 Main Landing Gear Hardware X 225 Cockpit Heater Tubes X X X X X X 226 Wing Lwr. Spar Cap Splice Rework & Rev. Safe Life X X X 227 Propeller Over-Speed Governor Control Switch X X X X 228 Reserved 229 Replacement Fuel Filter Element X X X X X X 229A Fuel Filter Element Inspection & Maintenance X X X X X X 230 Reserved 231 Drain Line From Airframe Fuel Pump X X X X X 232 Horizontal Stabilizer Auxiliary Fins X 233 Not for General Distribution-Cold Working X X 234 Not for General Distribution-Cold Working X X 235 Horizontal Stabilizer Brace Tube Assembly X 236 Main Landing Gear Attach Tube X 237 Plenum Firewall Seal Around Engine Mount Tube X 238 Not for General Distribution-Cold Working X X X X 239 Not for General Distribution-Cold Working X X X X 240 Not for General Distribution-Cold Working X X 241 Not for General Distribution-Cold Working X 242 Hand-held Fire Extinguisher In Cockpit X X X X X X X X X 243 Wing Rear Spar Connection X X X X X X X X X 244 Not for General Distribution-Cold Working X X X 245 Not for General Distribution-Cold Working X 246 Hartzell Propeller Overhaul Intervals X X X X X 247 Upper Rudder Hinge X X X X 248 Inspec. of Hopper Rinse Tank Shelf Attach Angles X 249 Recommended Service Life for Rubber Hose X X X X X X X X X * 250 Not for General Distribution-Cold Working X 251 Wing Fatigue Management Requirements X 252 Not for General Distribution-Eddy Current Insp X X * Indicates Revision SNOW ENGINEERING CO. ENGINEERING NUMBER 01 Wichita Falls, Texas REPORT ORDER MODEL All TITLE BY CHK'D SERVICE LETTER INDEX Leland Snow SERIAL All DATE *1/28/14 PAGE 8 OF APPLICABILITY 300 302 400 401 402 501 502 602 802 S/L 301 302A 400A 401B 402A 502A 802A No. SUBJECT 402B 502B 503A 504 253 Rev. C Engine Mount Cracking X X X X X 254 Not for Gen. Distrib.-Optional Ram Air Inlet Sys X 255 Not for Gen. Distrib.-Optional Ram Air Inlet Sys X 256 Procedures, Emergency & Normal X X X X X X X X X 257 Engine Inlet Air Filter Cleaning & Replacement X X X X X 258 Dents in Turbine Exhaust Pipes X X X X X X 259 Engine Fuel & Control-Fuel Control Unit(FCU) X X Change CDP Bellows & Py Orifice 260 Flap Actuator Coupling X X X X X X X X X 261 P3 Air Pressure Tube Fracture X 262 GPS Installations X X X 263 Not for Gen. Distrib.-Main Wing Spar Cap Rpl. X 264 Not for Gen. Distrib.-Main Wing Spar Cap Rpl. X 265 Spray Plumbing Safety Strap X X 266 Visual Inspection and Repair of Cracked X 11029-10 Aft Fuselage Tube 267 Main Landing Gear Attach Tube X 268 Reserved 269 Flap Torque Tube Plate Cracks X X X 270 Additional Header Tank Drain for Fireboss 802 X 271 Not for Gen. Distrib.-Retrofit Installation of X Optional Ram Air Inlet System 272 Not for Gen. Distrib.-Retrofit Installation of X Optional Ram Air Inlet System 273 Reserved 274 Rudder-Aileron Interconnect Cable Shields X 275 Inspection for Wing Leading Edge Rib Cracks X 276 Installation of Optional 3/8" Thick Windshield X X X X X * 277 AmSafe Airbag Installation Instructions X X X X X X X X X 278 Not for Gen.Distrib-Repairs & Treatment of X Corrosion on Croatian FireBoss 279 AmSafe Service Letter 23-008 X X X X X X X 280 Not for Gen-Distrib-Retrofit of 71112 Flap X Actuator on AT-802/802A Aircraft 281 Not for Gen-Distrib-9 Hole Attach Block X 282 Elevator Counterweight Bolt X X X X X X X X 283 Removal of Baggage Compartment X X X X X X X X X 284 Wing Inspection & Lower Spar Cap Replace. Times X 285 Stabilizer Rear Spar Mount Bracket X * Indicates Revision SNOW ENGINEERING CO. ENGINEERING NUMBER 01 Wichita Falls, Texas REPORT ORDER MODEL All TITLE BY CHK'D SERVICE LETTER INDEX Leland Snow SERIAL All DATE *12/21/17 PAGE 9 OF APPLICABILITY 300 302 400 401 402 501 502 602 802 S/L 301 302A 400A 401B 402A 502A 802A No. SUBJECT 402B 502B 503A 504 286 Fuel Filter Element Inspection and X X X X X X Maintenance 287 Rerouting Nose Light Wires X X X X 288 Retrofitting Brackett Foam Air Filter to X X Existing Ram Air Systems 289 Retrofitting Brackett Foam Air Filter to X X Existing Ram Air Systems 290 Reserved 291 Reserved 292 Reserved 293 Reserved 294 Reserved 295 Flap/Aileron Control Sys. Clearance Inspec. X X X X X X X 296 Fuselage Frame Wing Attach Tube Inspection X X X X X X X 297 Engine Mount Tube Inspections X X 298 Engine Mount Inspections X X X X X X X X X 299 Corrosion Inspection X X X X X X X X X 300 Elevator Trim Actuator Mounting Bracket X and Clamp Assembly 301 Proper Tiedown Procedures X X X X X X X X X 302 Recessed Grab Handle Inspection X X X X X X * 303 Py Line-Generator Interference X X 304 Special Purpose Operating Weight X X X X X X X 305 PT6A Accessory Drive Drain Line Oil Leaks X X X 306 Engine Plenum Drain Hole Clearance X X X X 307 Air Conditioner Drive Pad Assembly X 308 Boom Pressure Sensor Orifice X X X X 309 Rear Seat Air Conditioner Duct X 310 Engine Driven Low Pressure Fuel Pump X 311 PT6A-67F Data Plate Replacement X 312 Goodrich Starter Generator X X X X X 313 Aileron Torque Tube Bearings-802 X 314 Fuel Filter Clearance Hole X * 315 Fuel System Ice Inhibitors X X X X X X X X X * 316 Emergency Door Release Spring Bracket X X X X X 317 Rudder Controls Inspection & Maintenance X X X X X X X X X 318 Upgrades to FCU Override Control Handle X X X X X 319 Bird Strikes on Horizontal Tail X X X X X X X X 320 Environmental Limitations of Air Tractor Ram X X X X X Air Engine Induction * Indicates Revision SNOW ENGINEERING CO. ENGINEERING NUMBER 01 Wichita Falls, Texas REPORT ORDER MODEL All TITLE BY CHK'D SERVICE LETTER INDEX Leland Snow SERIAL All DATE *12/21/20 PAGE 10 OF APPLICABILITY 300 302 400 401 402 501 502 602 802 S/L 301 302A 400A 401B 402A 502A 802A No. SUBJECT 402B 502B 503A 504 321 Securing the Cover Plate on the Engine Filter X X X X X Pressure Switch 322 Cockpit Door Emergency Release Handle Stop X X X X X 323 Cockpit Door Emergency Release Alternate X X X X X Handle 324 United Instruments, Inc. 5934 Series X X X X X X X X X Altimeters & 7(1)00 Series (1)VSI Instruments 325 Hopper Markings X X X X X X 326 Slips & Falls While Entering, Exiting or Servicing X X X X X X X X X Planes* 327 Chafing of the Flexible Py Air Signal Line on the X X X Air Conditioner Compressor 328 Differential Torque Pressure X X X X X 329 Rudder Pedal Attach Assembly X X 330 RCA 2600-3 Digital Horizon Retrofit X X X X X X X X X 331 Upper Rudder Hinge X X X X 332 Brake Master Cylinder Eyebolt and Clevis X X X X X X X X X 333 Grab Handle Above Windshield X X 334 Landing Gear Service Life X X X X X X X X X 335 Engine Mount Inspections X 336 Install of New Balance Weight, Support Plates X Engine Ground Wire Support of BOV PX Line 337 Loose Items in Cockpit X X X X X X X X X 338 Flap Actuator Motors X X * 339 Retrofit of Engine Air Filter Element X X 340 Post Maint of Flight Control System Continuity X X X X X X X X X 341 Throttle Quadrant Friction Adjustment X X X X X X X X X 342 Replacement of A/C Compressor Drive Pad Assy X 343 Fuel Drain Valve Damage X X 344 Replacement of Nonconforming Diaphragm X X X X X X X X X Assemblies in Affected Altimeters 345 Rudder Pedal Attachment X X 346 FAA Airworthiness Directive (AD) 2016-05-13 X X X Repl. of Woodward FCU on Certain PT6A Eng. 347 Flap Torque Tube X X X X X X X X X * 348 Retrofit of Donaldson P609713 Pleated Filter X X X * Elem. To AC with Brack. BA-413EFoam Filter El 349 MVP-50T Disabling Master Caution & Master X X X Warning Lights Assc. w/Propeller RPM(NP) 350 Torque Gauge Filling With Engine Oil X X X X X * Indicates Revision SNOW ENGINEERING CO. ENGINEERING NUMBER 01 Wichita Falls, Texas REPORT ORDER MODEL All TITLE BY CHK'D SERVICE LETTER INDEX Leland Snow SERIAL All DATE *12/21/20 PAGE 11 OF APPLICABILITY 300 302 400 401 402 501 502 602 802 S/L 301 302A 400A 401B 402A 502A 802A No. SUBJECT 402B 502B 503A 504 351 Pneu. Emergency Dump Sys. Pres. Gauge With X Potential Erroneous Reading Correct. Action X X X 352 Installation of Power Quad. Anti-Reverse Fence X X X 353 AT-504 Airspeed Indicators X 354 MVP-50T G-Force Sensor Calibration X X X X X 355 Install. of Power Quad. Anti-Reverse Fence504 X 356 Install. of Power Quad. Anti-Reverse Fence402 X 357 Tail Wheel Axle Bolt X X 358 Seat Frame X X X X X X X X X 359 Vertical Fin Rear Spar Attach X X X X 360 Replacement of Woodward Overspeed Governor X 361 Fuel Filter Sealing Washers X X X X X 362 Owner's Manual Recommendations for PT6A- X X X X X Engine Maintenance 363 Pacific Propeller Intl. LLC P/N:6101A-12 Blade X X Assembly Taperbore Shotpeen 364 Dangers of Using Propeller Beta in Flight X X X X X 365 Installation of the 53404-1 Engine Air Filter X X 366 Aileron Bell Crank Support Inspection X 367 Flap Drive Actuator Arm Chafing on Fuel Hose X 368 AT-502A Chip Detector w/MVP-50T Engine X Monitor System 369 51198-1 Pulley Shaft X X X X 370 Brake Master Cylinder Upper Mounting Hole X X X X X X X X X 371 Reserved 372 Reserved 373 Installation of the Surelock Tail Wheel Lock X X X X * 374 Bleed Air Loss X X X X X X X X X 375 Flap Motor Mounting Studs X X 376 Flight Operations While Using Avgas Fuel X X X X X * 377 Modifications to Air Tractor Airplanes X X X X X X X X X 378 Change in Preferred Grease for Hartzell X X X X X X X X X Propellers 379 Cleaning Plastic Window Transparencies X X X X X X X X X * 380 Potsential for Magnetic Compass Interference X X X X X X X X X from Aircraft Electrical Systems 381 Fuel Placards Next to the Wing Fuel Ports X X X X X 382 Not for General Distribution 383 Horizontal Stabilizer Strut Cracks X 384 Installation of SCEET Flexible Ducting X X X X X X X X X 385 Operational Best Practices for Air Tractor Aircraft X X X X X X X X X * Indicates Revision