Part-66 Module 6 study guide
Part-66 Module 6 · Work through your exam, one topic at a time.
Part-66 Module 6 - Materials and Hardware is one of the knowledge modules that make up the aircraft maintenance licence (AML) syllabus under the EU Part-66 framework. It is aimed at trainee and practising certifying staff - typically candidates working toward a B1 (mechanical) or B2 (avionics) licence, either through a Part-147 approved basic training course or through self-study followed by examinations at the competent authority. The Part-66 Module 6 study guide has 9 sections and about 3,162 words.
01Aircraft Materials - Ferrous
Ferrous airframe materials fall into three families: low-alloy steels such as 4130 chromium-molybdenum; corrosion-resistant steels, including the austenitic 300 series (302, 304, 321, 347), the martensitic 400 series (410, 440C) and precipitation-hardening grades such as 17-4PH; and maraging steels for highly stressed landing-gear parts. Learn the heat-treatment vocabulary precisely.
318 words, about 2 min02Aircraft Materials - Non-Ferrous
Aluminium alloys are the backbone of the airframe. 2024 (copper) has good strength and fatigue resistance but poor corrosion resistance, so sheet is usually Alclad - clad with a thin layer of pure aluminium that protects the core galvanically.
319 words, about 2 min03Aircraft Materials - Composite and Non-Metallic
A composite is reinforcement plus matrix. Reinforcements are glass (cheap, insulating, radar-transparent, moderate strength), aramid such as Kevlar (tough, good in tension, poor in compression, absorbs moisture) and carbon (stiffest and strongest, electrically conductive, brittle in impact).
325 words, about 2 min04Corrosion
Corrosion needs an anode, a cathode, an electrolyte and a metallic path. Remove any one and the cell stops.
339 words, about 2 min05Fasteners
Know the families: AN, MS and NAS bolts, machine screws, self-locking nuts (nylon insert and all-metal), castle nuts with cotter pins, shear nuts, and washers (AN960 flat, AN970 large area). Grip length must suit the joint; identification is by head marking and specification.
296 words, about 1 min06Pipes and Unions
Rigid fluid lines use aluminium alloy tubing (3003 or 5052-O for low pressure, 6061-T6 for higher pressure), corrosion-resistant steel (304, 321) or titanium where temperature or pressure demands it. End fittings are either flared or flareless.
336 words, about 2 min07Springs, Bearings and Transmissions
Spring types are helical compression, helical extension, torsion, leaf, Belleville (disc), wave and spiral. The controlling parameters are spring rate (load per unit deflection), preload or installed length, solid height for compression springs, and stress at the working deflection.
626 words, about 3 min08Control Cables
Aircraft control cables are preformed, stranded constructions - mainly 7x7 (stiffer, more abrasion resistant) and 7x19 (more flexible, used round small pulleys). Terminals are swaged (Nicopress type), spliced, ball-ended or threaded, and each has its own proof load and inspection criteria.
295 words, about 1 min09Electrical Cables and Connectors
Aircraft wire is selected by conductor size (AWG), strand count, insulation type and temperature rating, and by the current it must carry with acceptable voltage drop. Insulations include PVC, PTFE, ETFE/Tefzel, silicone and fibreglass; specifications such as MIL-W-22759 define the wire.
308 words, about 2 min