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 382–393
Page 394Open in PDF

Valve, brake shuttle O.C. X X X Wheels O.C. X X X Anti skid control box O.C. X F/C @ sched.

Anti skid generator 4,000 X retract check Lights - Chapter 33 24,000 X X X X Emergency light system O.C. X X X Rotating beacon 2,000 X X X Navigation System - Chapter 34 24,000 X X X X The maintenance program (overhaul and inspection) for this chapter is to be established in coordination with the assigned inspector except for the following:

Ammeter, pitot heat O.C. X X X Compass, magnetic O.C. X X Swing @ 2 years Detector, overspeed warning O.C. X X F/C @ BIP Pitot static system O.C. X X Annual leak ck.

Probe, pitot tube O.C. X X X Selector, instrument static O.C. X X Annual leak ck.

Effective date ____________________ Page 7 of 16

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE (SNIAS) NORD-262A AND 262 A/M-298

O/H L PF P BIP OTHER Oxygen System - Chapter 35 24,000 X X X X Cylinder O2** O.C. X Regulator/indicator O.C. X F/C @ time of cyl.

retest

Page 395Open in PDF

Masks O.C. X X Water/Waste System - Chapter 38 24,000 X X X X System plumbing O.C. X X Structure - Chapters 52 thru 57 Chapters 52 thru 57 - covered in the following pages, are structural items and therefore do not have specific overhaul times. These items, generally speaking, cannot be removed from the aircraft; and even if they could, nothing could be done from a maintenance standpoint to restore their original condition.

Therefore, the airworthiness of these items will be determined by inspection/examinations in extensive detail. If specific times are not cited, the items are to be considered "On Condition". if the carrier elects to list structural inspection items in some manner other than FAA-approved specifications, the document must be referenced in the carrier's specifications and revision handled in a similar manner to specifications revisions. X-ray or other approved NDT methods may be substituted in lieu of visual inspections where applicable.

Effective date ____________________ Page 8 of 16

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE (SNIAS) NORD-262A Detail Insp. L PF P BIP OTHER Doors - Chapter 52 24,000 X X X X Rear passenger door 12,000 External inspection

- check of safety cables, hinges, lock hooks X X X X Internal inspection of door structure, locking mechanism & hooks X Magnetic particle inspection of hooks 12,000 Forward cargo door 12,000 External inspection, lock, hooks and hinges X X X X

Page 396Open in PDF

Internal inspection of door structure, lock mechanisms and hooks X Magnetic particle inspection of hooks 12,000 Nose area and landing gear doors 4,000 X X X X Hinges and operating mechanism X X Emergency exits, overhead, or when window and floor level 24,000 cabin lining replaced External inspection X X X Detailed external inspection (door removal) of door structure & latch mechanism X Internal inspection, door structure, latch mechanism & latch rigging X Fuselage - Chapter 53 24,000 X X X X Radome 4,000 X Detail & External inspection X X X External/ Fuselage skin O.C. internal inspection External inspection, skin, joints & cutouts X X X Internal inspection of support structure, joints & cutouts X Station D pressure bulkhead 12,000 Forward face X X Aft face & attach structure 12,000 Flight deck area, window frames and exposed structure 4,000 X X Instrument panel & supports, control pedestal, seat tracks, control attach structure 4,000 X Cockpit window frames, internal structure, panel supports, cockpit structure & system components 12,000

Page 397Open in PDF

Effective date ____________________ Page 9 of 16

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE (SNIAS) NORD-262A Detail Insp. L PF P BIP OTHER Fuselage - Chapter 53 (Cont'd) Flight deck area below floor line visual inspection of nose gear support units, structure and system components in area X X Structure inspection with all cockpit flooring removed 12,000 Nose gear area structure 4,000 X X X Inspect for looseness or misalignment of gear units or supporting structure X Detailed inspection, penetrant or other special type inspection of all nose gear fixed components and attachments to fuselage fittings. Dimensional checks of pins and bores 12,000 Inspection of fuselage hull cutout framing and reinforcements, main passenger door, emerg.

exits, cargo door, windows, outflow valves, etc. 12,000 X X X External inspection of framing and reinforcements X X Internal inspection of hull cutouts & reinforcements with upholstery and trim removed 12,000 Galley and lavatory areas Visual inspection of areas below galley & lavatory for corrosion 8,000 Area above cabin & cargo floor seat rails, general

Page 398Open in PDF

support for seats & cargo restraints X X X Inspection of seat rails, attach structure, interior of fuselage skin, stringers, splices, and belt frames 12,000 Area below cabin & cargo floor, fuselage skin interior, floor support structure, belt frames X X Area below cabin & cargo floors, detailed inspection of all system equipment, floor support structure, fuselage formers & stringers 12,000 Effective date ____________________ Page 10 of 16

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE (SNIAS) NORD-262A AND 262A/M-298 Detail Insp. L PF P BIP OTHER Fuselage - Chapter 53 (Cont'd) Fuselage center section, detailed inspection of fuselage formers and stringers in area of Sta 9 & 11 4,000 Wing attach fittings and bolts. Magnetic particle inspection of bolts and detailed inspection of immediate fuselage skin and structure around fittings 16,000 Main wheel pod area 4,000 X X X X Detail inspection of main gear support arm, tie rods, brace strut, shock

Page 399Open in PDF

absorber, gear mountings, air conditioning equipment, waer methanol equipment, hydraulic reservoir & equipment. 12,000 Rear pressure bulkhead Detailed inspection of rear face X X Detailed inspection of fwd. face 12,000 Tail section, detailed inspection of splice joint, systems equipment, formers, stringers, empennage attach fittings and support rods and tail cone. 4,000 X X Nacelles - Chapter 54 24,000 X X X X Inspection of firewall and engine mount attach points E.C. X X Inspect interior and exterior of nacelles with tail pipe removed 4,000 X Inspect all flight control cables, bellcranks & associated equipment in nacelles 12,000 X X Detailed visual inspection of nacelle structure, center section attach angles, forward side of front spar, spar rails and brackets 4,000 Engine QEC structure E.O. X X X Magnetic particle inspection 4,000 Engine of engine mount and mount to firewall attach bolts. engine attach bolts

- magnetic particle insp. @ E.O.

Effective date ____________________ Page 11 of 16

Page 400Open in PDF

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE (SNIAS) NORD-262A Detail Insp. L PF P BIP OTHER Stabilizers - Chapter 55 24,000 X X X X Vertical stabilizer, rudder, tabs & dorsal fin X X X X Detailed visual inspection of dorsal fin, vertical fin, vertical fin attach points, rudder & hinge points, vertical fin tip cap area 4,000 Detailed inspection of rudder internal During structure O.C. cover replacement Detailed inspection of internal structure of dorsal fin 12,000 Penetrant inspection of vertical stabilizer attach fittings, fin attach bolts & rudder hinge fittings 12,000 Inspect visible structure at rudder hinge points and vertical stabilizer attach points 12,000 Horizontal stabilizer, elevator and elevator tabs X X X X Detailed visual inspection of horizontal stabilizer, hinge points, attach points, elevator structure, elevator covering and tip caps 4,000 Detailed inspection of internal structure of horizontal and vertical stabilizers 12,000 Penetrant inspection of horizontal stabilizer attach points, attach bolts, attachment bars, support frames, brace strut, vee fitting and elevator hinge fittings 16,000

Page 401Open in PDF

Detailed inspection of During elevator internal cover structure O.C. replacement Wings - Chapter 57 24,000 X X X X Forward fuselage to wing fairing area, condition of forward spar and fairing attach fasteners 4,000 Wing leading edge ribs 7-13 noting condition of spar and general structure 4,000 Effective date ____________________ Page 12 of 16

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE (SNIAS) NORD-262A Detail Insp. L PF P BIP OTHER Wings - Chapter 57 (Cont'd) Aft fuselage to wing fairing area, noting mounting of flap position transmitter, hydro valves, aft spar and flap torque tube 4,000 Lower fuselage to wing fairing area, noting condition of wing attach fittings and system installations 4,000 External inspection of center wing structure (ribs 1-21) noting skin condition, areas adjacent to attachment fittings to fuselage, areas adjacent to nacelle, flap hinge attach points and outer wing attach points 4,000 Center wing structure As (internal structure) required radiographic inspection in by accordance with airframe

Page 402Open in PDF

manufacturer's flight recommendations O.C. cycles Center to outer wing attach fittings, perform detailed inspection of fittings and bolts as installed 4,000 Outer wing structure (ribs 22-49) noting attachment fittings at rib 22, hinge attach points at ribs 25, 30, 35, 43, & 49 4,000 Aft section of wings (ribs 7-49) detailed inspection of engine nacelle longeron to rear spar in area of ribs 15 thru 17, flap hinge, arms, and cylinder attach brackets at ribs 7, 17, 25, 30 & 35, aileron hinge brackets and mounting areas at ribs 35, 41, 42, 43 & 49. Check on condition of aileron balance curtain 4,000 Wing leading edge area (ribs 22-49) detailed inspection of skin, interior structure, wing deicer equipment by removing leading edge or use of radiographic procedure 8,000 Detailed inspection of tip cap and surrounding area with cap removed 8,000 Magnetic particle, penetrant or similar special inspection of outer/center wing attach fittings and bolts 24,000 Effective date ____________________ Page 13 of 16

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE

Page 403Open in PDF

SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE (SNIAS) NORD-262A Detail Insp. L PF P BIP OTHER Wings - Chapter 57 (Cont'd) Outer wing structure ribs 30-49 detailed interior inspection with all access panels opened 8,000 Detailed inspection of internal area of forward wing to fuselage fairing.

Remove all inspection panels. 12,000 Detailed inspection of leading edge (ribs 7-13 areas) noting condition of all equipment internally housed in the area 12,000 Aft wing section (rib 7-35) flap support fittings, magnetic particle or penetrant inspection of removable parts 12,000 Aft wing/fuselage fairing area. Detailed inspection of entire area including flap torque tube, mount brackets & bearings Penetrant inspection of aileron quadrants, mount brackets & bolts 24,000 Magnetic particle, penetrant or similar special inspection of center wing to fuselage attach fittings, links & bolts 24,000 Outer wing structure (rib 22-30) radiographic inspection of forward lower spar rail between 22 & 23, 23 & 24. Lower skin forward of rear spar between ribs 22 & 23, 23 &

24. Lower skin doublers between ribs 25 & 26, 28 &

Page 404Open in PDF

29. (Drain fuel prior to inspection) 24,000 Detailed visual inspection of flaps. Note condition of areas adjacent to hinge arms 4,000 Magnetic particle or penetrant inspection of flap, hinge arms, actuator attach fittings & bolts 12,000 Detailed visual inspection of ailerons visible structure hinge brackets & adjacent structure 4,000 Magnetic particle or penetrant inspection of aileron hinge brackets, aileron pushrods, and attach bolts 12,000 Effective date _____________________ Page 14 of 16

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE (SNIAS) NORD-262A

O/H L PF P BIP OTHER Propeller System - Chapter 61 X X X X Propeller Ratier Figeac FH-146 2,000 X X X Auto feather capsule O.C. X X F/C @ 1,000 hrs.

Auto feather pitot masts O.C. X X X X Contactor, feather pump 8,000 X X Feather pump 2,000 X X Governor, prop control E.O. X X Relay unit, prop control 8,000 X X Switch, prop feather O.C. X X X Powerplant - Chapter 71 X X X X Cowling O.C. X X X Engine - Chapter 72

Page 405Open in PDF

Engine Turbomeca Bartau VI C 2,000 X X X Hot (Refer to manufacturer's section specification for life inspection limited parts) @ 1/2 E.O.

Engine Fuel System - Chapter 73 X X X Fuel control unit E.O. X X Indicator fuel flow 5,000 X X Indicator fuel used O.C. X X Transmitter fuel flow 5,000 X X Transmitter fuel pressure diff. E.O. X X Valve, electrical fuel shutoff 2 E.O. X X F/C @ E.O.

Valve, safety shutoff O.C. X X F/C @ E.O.

Ignition System - Chapter 74 X Coil E.O. X Torch ignitors E.O. X Engine Air System - Chapter 75 Engine anti-ice electro valve O.C. X F/C @ E.O.

Engine Controls System

- Chapter 76 Engine control linkage (forward of firewall) O.C. X Inspect E.C.

Effective date ____________________ Page 15 of 16

OPERATIONS SPECIFICATIONS

AIRCRAFT MAINTENANCE SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE (SNIAS) NORD-262A

O/H L PF P BIP OTHER Engine Indicating - Chapter 77 X X X X Indicator Tachometer 5,000 X X