Part-66 Module 4: Electronics Fundamentals

The table starts with the simplest thing a circuit can be built from and works its way up. Semiconductors take the top of it: diodes at 4.1.1, transistors at 4.1.2, then integrated circuits at 4.1.3, where a whole circuit arrives inside one part. From there, 4.2 turns to the board all three get soldered to, and 4.3 leaves hardware behind altogether for servomechanisms, which are an arrangement rather than a thing. The deepest requirement anywhere in the module is the diode row at 4.1.1(a), where EASA’s title asks for its “description and characteristics” and the UK’s for its “symbols, characteristics and properties”, and even that row sits only at level 2, where understanding the theory and reading a schematic are part of the requirement rather than describing the subject.

A diode passes current one way and blocks it the other, and that single property carries more of an aircraft than its size suggests. It’s how the alternating current a generator produces becomes the direct current a bus can live with, inside a transformer rectifier unit, and it’s also the small diode across a relay coil, absorbing the spike a collapsing magnetic field throws out, which would otherwise pit the contacts that switched it. Level 2 sits on this row and nowhere else in the module.

Transistors and integrated circuits follow, both at level 1. A transistor uses a small current to control a much larger one, which makes it a switch with nothing inside to wear out and, biased between its extremes, an amplifier, while an integrated circuit is that trick repeated until a whole circuit fits on a chip you could lose in the carpet. The UK’s title for 4.1.3(a) draws the distinction the level wants: logic circuits deal in ones and zeros, linear circuits in signals that vary continuously. Behind the blank rows sits the physics: the PN junction, how a transistor is built, and, in the UK’s wording of 4.1.3(b), the operational amplifier and its feedback network.

Printed circuit boards get a topic to themselves at 4.2. A board is what replaced wiring one component to the next by hand: copper tracks etched onto an insulating laminate, components soldered to pads or mounted straight onto the surface, and a conformal coating against moisture and salt. What matters to a B1.1 engineer is handling rather than manufacture: the damage you can personally do is electrostatic discharge, where a charge far too small to feel can destroy a device outright or wound it so it fails weeks later on somebody else’s shift.

Servomechanisms close the module at 4.3, and their place in an electronics paper rather than a systems one tells you what they are: an idea rather than a box. The requirement here is the principle, at level 1, and the UK’s title for that row names synchro components, the transmitter and receiver pairs that carry a shaft angle down three wires so a flap on the wing can tell an indicator on the flight deck where it has got to. Construction and operation sit on the row below, where the UK’s wording adds defects and hunting, and that row carries a dash.

20 multiple choice questions inside 25 minutes, and no paper in the whole of category B1.1 is shorter. Under the UK CAA, Module 8 and Module 9A both match it on the multiple choice part, and 9A then adds a written answer this one never has. Short doesn’t mean quick to read, though: the subjects sit very close together in Module 4, and a stem about a diode and a stem about a transistor can look alike until their last line, so the time is best spent reading each question to its full stop before looking at anything underneath it.

The 75% pass mark puts the target at 15 correct answers and leaves 5 in reserve, and a short paper spends a reserve like that in a particular way, because there’s no back half to make anything up in. On a long paper, a poor opening is a poor opening and most of the sitting is still ahead of you. Here, what’s still ahead of you is a handful of questions, and a margin gone in the first few minutes is simply gone, so everything after it has to be right, and that’s a harder way to sit an exam than the size of the paper suggests.

Every row but one is marked below, and what’s marked is wording: printed circuit boards at 4.2 is the only title both authorities put the same words to. The levels behave quite differently, because on the UK text as we read it they match EASA’s the whole way down, dashes included. So the depth this syllabus asks for doesn’t turn on which licence you’re working towards, however far apart the two headings over a row may look.

By a single letter, in the module’s own name: the EASA text calls it Electronics Fundamentals and the UK text calls it Electronic Fundamentals. That’s what the two regulations print rather than a slip in our table, and it matters only when you’re searching, because a provider quoting one spelling and a provider quoting the other are describing the same paper.

Underneath the spelling it’s one exam. Both set 20 questions in 25 minutes, both number it Module 4, both run to nine topics carrying the same numbers, and our reading of the UK table has both asking the same knowledge level of every one of them. That’s worth having if your route changes partway: someone who prepared under one authority and ends up sitting under the other loses nothing at all on this module, because the reading already done still fits the paper, and the row you were on is the row you’re still on. Module 4 belongs among the nine on that basis rather than on the question count alone.

The rows themselves are titled differently almost throughout: on the deeper diode row, EASA asks for “operation and function” where the UK asks for “materials, PN junction, detailed operation”. On servomechanisms, EASA’s first title stops at “principles” while the UK’s spells out “open and closed loop systems, synchro components”. Where EASA asks for a transistor’s “description and characteristics”, the UK asks for its “symbols, description and characteristics”, and it names symbols on the diode row as well. Fair enough, too: reading a schematic is written into the level 2 description that governs that row.

None of that adds an examinable subject to either side: every row this category isn’t required to read is among the reworded ones, so most of the UK’s extra detail describes ground neither paper asks a B1.1 candidate to cover. What’s left is a difference in how much of a row its heading chooses to say out loud.

The wider split between the two authorities is on the EASA versus UK CAA page: mutual recognition, which licence to go for, and what happened to the conversion route.

This page covers one of the 13 papers. The rest of the guide covers the route they sit inside: what the exam is, what else you must have done besides passing it, and how the two authorities differ.

Both authorities require the same thirteen subjects. Only the numbering and some of the titles differ, and the UK still uses the A suffix on four of them where EASA has dropped it. Each has a page of its own.