AC 121-1A

Change 4Historical

Advisory circular · Standard Operations Specifications - Aircraft Maintenance Handbook

Approved
July 7, 1978
Last reviewed
October 25, 2024
Cancels
AC121-1A CHG 3AC120-21AC120-24A
Family
AC 121-1 · 1 version
Revision
A, change 4
14 CFR parts
1

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed November 22, 2025.

Show pages 214–225
Page 226Open in PDF

Gage - Remote Pressure 6,000 A B C S Mask, Oxygen OC A B C Oxygen Cylinder - Portable * A B C S Regulator, Oxygen 6,000 A B C S * Hydrostatic and life limits shall be entered here and shall not exceed those set forth in Part 173, Chapter I, Subtitle "B" of CFR Title 49.

Pneumatic System, Chapter 36 OC A B C 2C Indicator-Pressure, Bleed Air Manifold 12,000 A B C 2C Transmitter-Pressure, Bleed Air Manifold 12,000 C 2C Valve - Shut-Off, Bleed Air 6,000 C 2C Auxiliary Power, Chapter 49 OC A B C S Auxiliary Power Plant ** E.T.I. 1250 A B C S or Note 1 5,000 Starts Tank, Oil, APU OC A B C ** Note 1: Whichever occurs first.

Doors, Chapter 52 OC A B C 2C 6C S ST Actuator, Cargo Ramp 12,000 A B C Actuator, Pedal Door and Ramp Lock 12,000 A B C Actuator, Pressure Door 12,000 A B C Actuator, Pressure Door Down Lock 12,000 A B C Actuator, Pressure Door Up Lock 12,000 A B C Central Gear Box Assy., Pedal Door Actuator 12,000 A B C Jack Screw Assembly, Pedal Door Actuator 12,000 A B C Valve, Flow Regulation 12,000 B C Valve, Pressure Door, Selector 12,000 B C Valve, Pressure Reducing, Cargo Ramp 12,000 B C Valve, Selector, Door Locks 12,000 B C Valve, Shuttle, Ramp Lock & Pressure Door 12,000 B C Fuselage, Chapter 53 Structural inspection Nacelles, Chapter 54 requirements are as specified Stabilizers, Chapter 55 in Parts I, III, and IV of Windows, Chapter 56 Lockheed Service Publication Wings, Chapter 57 SMP No. 231 dated June 1, 1967.

Power Plant, Chapter 71 OC A B C EC S Mount, Engine EC B C EC S

Page 227Open in PDF

Cowling OC A B C EC Firewall OC B C EC Effective date ____________________ Page 11 of 12

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE LOCKHEED MODEL 300 (C-141A) Overhaul Inspection and Period Check Period Engine - Turbine, Chapter 72 OC A B C EO S Engine, Turbo Fan P&W TF-33-P7/ JT3D-5A 4,000 A B C EO S Note I Note I: Major Inspection at 2,000 hours.

Engine Fuel and Control, Chapter 73 A B C EO Actuator, Fuel Shut-Off EO B C Control, Fuel EO B C Filter Assembly, Fuel De-Icing OC B C EO Heater, Fuel De-Icing EO B C Indicator, Engine Fuel Inlet Temperature 12,000 A B C Indicator, Fuel Flow 2,000 A B C Pump, Fuel EO B C Switch, Differential Pressure OC B C EO/FC Switch, Inlet Pressure OC B C EO/FC Transmitter, Rate of Flow, Fuel 2 EO B C Valve Assembly, Fuel Pressurization and Dump EO B C Ignition, Chapter 74 A B C EO Cable, Exciter, Electrical Power EO B C Cable, Special Purpose EO B C Exciter, Ignition EO B C Plug, Igniter OC C EO Engine Air, Chapter 75 A B C EO Actuator, Compressor Bleed EO B C Regulator, Anti-Icing Air EO B C Regulator, Duct Seal Pressure OC B C EO/FC Regulator, Pressure, CSD Oil Tank OC B C EO/FC Valve and Actuator Assembly, Anti-Icing Air EO B C Valve Assembly, Breather Pressurizing EO B C

Page 228Open in PDF

Valve, Bleed Air Shut-Off EO B C Valve, Check, Duct Seal Pressure OC B C EO/FC Valve, Compressor Bleed EO B C Valve and Control Assembly, Compressor Bleed EO B C Valve, Nacelle Preheat OC B C EO/FC Valve, Nose Cowl Anti-Ice OC B C EO/FC Valve, Shut-Off, Compartment Cooling (Zone I) OC B C EO/FC Valve, Shut-Off, Compartment Cooling (Zone II) OC B C EO/FC Engine Controls, Chapter 76 A B C EC ST Power Lever System, Cables, Pulley, Rods and Linkages OC B C EC ST Tension Regulator, Throttle OC EC Effective date ____________________ Page 12 of 12

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE LOCKHEED MODEL 300 (C-141A) Overhaul Inspection and Period Check Period Engine Indicating, Chapter 77 A B C 2C S Converter, Engine Instrument 3,000 B C Generator, Tachometer EO B C Indicator, Engine Pressure Ratio 2,000 A B C 2C Indicator, Engine Vibration 6,000 A B C Indicator, Exhaust Gas Temperature 2,000 A B C 2C Indicator, Tachometer 2,000 A B C Pick-Up, Engine Vibration EO C Transmitter, Pressure Ratio EO C 2C Exhaust, Chapter 78 A B C EO S Actuator, Thrust Reverser 2EO A B C EO Control, Thrust Reverser 2EO B C EO Door, Thrust Reverser OC A B C EO Filter, Thrust Reverser OC B C EO Nozzle Assembly, Primary Exhaust EO A B C Pump, Thrust Reverser 2EO B C EO Telescopic Unit, Thrust Reverser OC A B C EO Valve, Flow Regulator, Thrust Reverser OC B C EO Valve, Relief OC B C EO/FC Engine Oil, Chapter 79 A B C EO S

Page 229Open in PDF

Bulb, Temperature OC C EO Cooler Assembly, Fuel Oil Coolant EO B C Heat Exchanger, Air-Oil EO B C Indicator, Engine Oil Temperature 6,000 A B C Indicator, Oil Pressure 6,000 A B C Pump Assembly, Oil EO C Strainer Assembly, Oil, Main OC C EO Switch, Low Oil Quantity OC C EO Switch, Oil Pressure OC C EO Tank Assy., Lubricating Oil EO B C Transmitter, Oil Pressure EO B C Valve, Oil Pressure Relief EO C Starting, Chapter 80 OC A B C EO Starter, Engine EO B C Valve, Pressure Regulating EO B C Effective date ____________________ ---------------------------------------------------------------- ---------------------------------------------------------------- FIGURE 31. OPERATIONS SPECIFICATIONS AIRCRAFT MAINTENANCE

- LOCKHEED JETSTAR - MODEL 1329 Form Approved.

UNITED STATES OF AMERICA Budget Bureau FEDERAL AVIATION AGENCY No. 04-R075.

WASHINGTON Page 1 of 11

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE - GENERAL LOCKHEED JETSTAR - MODEL 1329 Aircraft shall not be utilized in air carrier or commercial operations unless:

a. The aircraft and its component parts, accessories and appliances are maintained in an airworthy condition in accordance with the operator's maintenance manual. Such manual shall at least include the methods, procedures and limitations contained in the Lockheed JetStar Handbook of Operating and Maintenance Instructions.

b. The aircraft and its component parts, accessories, and appliances are maintained in an airworthy condition in accordance with the maximum time limits hereinafter set forth for the accomplishment of the overhaul, periodic inspection, and routine checks of the aircraft and its component parts, accessories, and appliances.

Page 230Open in PDF

c. OC "On Condition" items will be maintained in continuous airworthy condition by periodic and progressive inspections and checks, services, repair and/or preventive maintenance and are appropriately described in the operator's maintenance manual.

d. Parts or sub-components not listed herein will be checked, inspected and/or overhauled at the same time limits specified for the component or accessory to which they are related.

Abbreviations used in the JetStar Model 1329 maintenance specifications are defined as follows:

PF - Indicates "Preflight Inspection" FC - Indicates "Functional Check" BC - Indicates "Bench Check" EO - Indicates "Engine Overhaul" EC - Indicates "Engine Change" OC - Indicates "On Condition" R&R - Indicates "Remove and Replace" HYD - Indicates "Hydrostatic Test" C - Indicates "Calibration" ST - Indicates "Scrap Time" DI - Indicates "Detailed Inspection" in accordance with manufacturer's methods and procedures ETI - Elapsed Time Indicated Effective date ____________________ Page 2 Of 11

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE LOCKHEED JETSTAR - MODEL 1329 Preflight Inspection/Check To be accomplished each service calendar day.

"A" Inspection/Check To be accomplished at intervals not to exceed 80 hours time in service after the preceding "B" or "C" Inspection/Check period.

"B" Inspection/Check To be accomplished at intervals not to exceed 160 hours time in service after preceding "B" or "C" Inspection/Check period.

"C" Inspection/Check

Page 231Open in PDF

To be accomplished at intervals not to exceed 640 hours time in service after preceding "C" Inspection/Check period.

Special Inspections The frequency and procedure for performing special inspections will be accomplished as specified in the operator's maintenance manual.

Overhaul and inspection/check period time limitations specified in hours and calendar time are maximum limits of whichever occurs first.

Effective date ____________________ Page 3 of 11

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE LOCKHEED JETSTAR - MODEL 1329

OVERHAUL INSPECTION & HOURS OR YRS. CHECK PERIOD OTHER Air-Conditioning, Chapter 21 10,000 PF A B C Actuator Emerg.

Press. 2,600/5 yrs. B C Controller Cabin Press. 2,600/5 yrs. B C Control Temperature OC B C Exchanger Heat 2,000 B C Fan Turbine Assy. 1,200 B C Indicator Cabin Air Temp. 5,000 PF A B C Indicator Cabin Rate of Climb 2,600 PF A B C Indicator Duel Altimeter/Diff.

Press. 4,000 PF A B C Oil Change, Cooling Turbine 640 B C Relay Cabin Press. 2,600/5 yrs. B C Regulator Cooling Fan Assy. 2,600/5 yrs. B C Refrigeration Assy. 3,000 B C Valve Bleed-Air Flow Control 2,600 B C Valve Shut-Off

Page 232Open in PDF

Flt. Station 2,600/5 yrs. B C Valve Shut-Off Emerg. Press. 2,600/5 yrs. B C Valve Shut-Off Engine Bleed 2,600/5 yrs. B C Valve Out-Flow Cabin Press. 1,200 B C Valve Needle Cabin Press. 2,600/5 yrs. B C Valve Check 5,000 B C Auto-Pilot, Chapter 22 10,000 PF A B C Accelerometer OC C Bracket Assy.

Servo Drive 2,000/2 yrs. B C Coupler Engage OC A B C Computer OC B C (B C at "C") Control Altitude 2,000/2 yrs. B C Controller 2,000/2 yrs. B C Drive Aileron Servo 2,000/2 yrs. B C Drive Elevator and Rudder Servo 2,000/2 yrs. B C Gyro Rate 2,000/2 yrs. B C Gyro Vertical 2,000/2 yrs. B C Communications, Chapter 23 10,000 PF A B C To be determined by assigned inspector.

Effective date ____________________ PAGE 4 of 11 PAGES

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE LOCKHEED JETSTAR - MODEL 1329

OVERHAUL INSPECTION & HOURS OR YRS. CHECK PERIOD OTHER Electrical Power, Chapter 24 10,000 PF A B C Battery OC PF A B C Contactor, Generator Line 4,000 B C Control Panel, Generator 2,000 PF A B C

Page 233Open in PDF

Generator, Starter 1,200 B C (Inspect brushes every 400 hrs.)

Inverter, Rotary 800 PF A B C Loadmeter 4,000 B C Meter Frequency 4,000 PF A B C Relay, Battery, Series OC PF A B C Relay, Inverter Input OC PF A B C Relay, Inverter Output OC PF A B C Voltmeter 4,000 PF A B C Equipment/Furnishings, Chapter 25 10,000 PF A B C Axe Fire OC PF A B C Belts, Seat OC PF A B C Galley OC PF A B C Harness, Shoulder OC PF A B C Kit, First Aid OC PF A B C Lavatory OC PF A B C Mask, Smoke OC PF A B C Raft, Life 6 mo. PF A B C Seats OC PF A B C Vest, Life 6 mo. PF A B C Fire protection, Chapter 26 10,000 PF A B C (Functional check every 2 1/2 years) Actuator Explosive OC B C (Replace every 2 years) Controller, Fire detection OC PF A B C Element Sensing OC PF A B C Extinguisher, Portable * PF B C Sphere, Fire Extinguishing * B C * Hydrostatic and life limits shall be entered here and shall not exceed those set forth in Part 173, Chapter I, Subtitle "B" of CFR Title 49.

Effective date ____________________ PAGE 5 of 11 PAGES

Page 234Open in PDF

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE LOCKHEED JETSTAR - MODEL 1329

OVERHAUL INSPECTION & HOURS OR YRS. CHECK PERIOD Flight Controls, Chapter 27 10,000 PF A B C Actuator Flap 6 yrs. B C Actuator Flap Screwjack 6 yrs. B C Actuator Pitch Trim 2,000 B C Booster Assy. Aileron 3,000 B C Booster Assy. Elevator 3,000 B C Compensator Mach Trim 2,000/2 yrs. B C Contactor Stabilizer Trim Normal 1,000 B C Contactor Stabilizer Trim Emerg. 2,000 B C Coupling Flapdrive, L.E. 5 yrs. B C Gear Box Flapdrive, 120 degree 6 yrs. B C Gear Box Flap 5,000 B C Motor Hydraulic Flap 5,000 B C Motor Pitch Trim Primary 1,000 B C Stop Hydraulic Flap 5,000 B C Fuel, Chapter 28 10,000 PF A B C Indicator, Fuel Quantity 2,600 PF A B C Hose, Fuel Jettison 1 yr. B C Pump, Fuel Boost Main.

P/N RR 12040B and P/N RR 12040E 300 B C P/N RR 12040D and P/N RR 12040F 1,000 B C Pump, Fuel Boost Ext. Tanks 1,200 B C Probes, Fuel Quantity OC PF A B C Valve, Motor Shutoff 5,000 B C Hydraulic Power, Chapter 29 10,000 PF A B C Accumulator 2 yrs. PF A B C Bottle Air Emerg. Lndg. Gear Ext. * PF A B C Filter, Hydraulic Line, P/N AC-2768-10 OC PF **B C P/N AC-2768-101P and P/N AC-2768-101NBP **OC/2,500 PF B C Indicator, Hydraulic Press. 5,000 PF A B C Pump, Hydraulic Electric 3,000 PF A B C Pump, Hydraulic Engine 1,200 A B C Regulator, Air Pressure 18 mo. B C Reservoir, Hydraulic OC PF A B C Valve, Engine Shutoff 5,000 B C Valve, Wing Flap Selector Standby 3 yrs. B C

Page 235Open in PDF

Valve, Wing Flap Selector 3 yrs. B C * Hydrostatic and life limits shall be entered here and shall not exceed those set forth in Part 173, Chapter I, Subtitle "B" of CFR Title 49.

Effective date ____________________ Page 6 of 11

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE LOCKHEED JETSTAR - MODEL 1329 @ OVERHAUL INSPECTION & HOURS OR YRS. CHECK PERIOD OTHER Hydraulic Power, Chapter 29 Cont'd.

Valve, Dual Shuttle 1,800/3 yrs. B C Valve, Speed Brake Selector, P/N 263-0046 2 yrs. B C P/N 263-0067 3 yrs. B C Valve, Thrust Reserver Selector 3 yrs. B C Valve, Air Charging/Relief 1,200 B C Valve, Check Manual Control 5 yrs.

Valve, Main Gear Door Selector 3 yrs.

Ice and Rain Protection, Chapter 30 10,000 PF A B C Motor, Windshield Wiper OC B C Valve, De-Icer Distributor 5 yrs. B C Valve, Pressure Regulator 2,500 B C Instruments, Chapter 31 10,000 PF A B C

Page 236Open in PDF

Accelerometer, Vertical OC B C (BC & C every 4,000 hrs.)

Clock OC PF A B C Encoder Trip/Data 2,000 PF A B C Indicator Outside Air Temp. OC PF A B C Recorder Flight Data 2,000 PF A B C Landing Gear, Chapter 32 10,000 PF A B C Actuator, Nose Gear Steering 10,000 PF A B C Actuator, Nose Gear Retract 10,000 PF A B C Actuator, Main Gear Side Brace, P/N JL/1400-9 and FL1400-11 10,000 PF A B C P/N JL/1400-7 6,000 PF A B C Anti-Skid System OC PF A B C Strut, Main Landing Gear 10,000 PF A B C Strut, Nose Landing Gear 10,000 PF A B C Tires, Landing Gear OC PF A B C Valve, Brake Selector 3 yrs. PF A B C Valve, Landing Gear Control 4 yrs. B C Valve, Nose Wheel Steering 3 yrs. B C Valve, Steering Selector 3 yrs. PF B C Valve, Brake Shuttle 1,800/3 yrs. PF A B C Wheels, Landing Gear OC PF A B C * Lights, Chapter 33 10,000 PF A B C Battery, Emergency/ Charger OC PF A B C * Magnaflux wheel tie bolts every third tire change, and dye or zyglo inner and outer wheel halves every "C"

Page 237Open in PDF

check.

Effective date ____________________

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE LOCKHEED JETSTAR - MODEL 1329

OVERHAUL INSPECTION & Lights, Chapter HOURS OR YRS. CHECK PERIOD OTHER 33 Cont'd.

Light, Anti- Collision OC PF A B C Light, Landing OC PF A B C Light, Navigation OC PF A B C Light, Taxi OC PF A B C Navigation, Chapter 34 10,000 PF A B C To be determined by assigned inspector.

Oxygen, Chapter 35 10,000 PF A B C Cylinder Assy. * A B C Pressure Reducer 18 mo. A B C Cylinder, Portable * PF A B C Mask/Regulator Passenger 2 yrs. A B C (FC at B) Mask, Crew Oxygen 2 yrs. PF A B C Panel Control Pass. Oxygen 2 yrs. A B C Regulator Crew Oxygen 2 yrs. PF A B C Valve Pass. Mask Container Door Actuator 3 yrs. A B C Valve Pass. Mask Lanyard 3 yrs. A B C (FC at B) * Hydrostatic and life limits shall be entered here and shall not exceed those set forth in Part 172, Chapter I, Subtitle "B" of CFR Title 49.

Drag Chute, Chapter 39 10,000 PF A B C Parachute Assy.

Deceleration OC B C ** Airborne Auxiliary Power,