Most compliance conversations about EASA EWIS training start from a false premise: that EASA has mandated electrical wiring interconnection system training for everyone who touches an aircraft. It has not. What exists is AMC 20-22, “Aeroplane Electrical Wiring Interconnection System Training Programme”, published in AMC-20 Amendment 23 (Annex to ED Decision 2022/001/R) — and it is far more precise, and far more useful, than the blanket-mandate version of the story.

This guide sets out what AMC 20-22 says, where the obligation actually sits in the regulations, which of the eight target groups carry a direct requirement and which do not, and how the syllabus is structured across those groups.

1. What AMC 20-22 is — and the thing most people get wrong

AMC 20-22 is an Acceptable Means of Compliance. In its own words, it “describes acceptable means, but not the only means, of compliance with the appropriate certification, maintenance and operating regulations.” It is not a standalone rule creating a new training duty. It is EASA’s worked answer to a duty that already exists elsewhere.

Its stated purpose is a philosophy rather than a checklist: AMC 20-22 “promotes a philosophy of training for all personnel who come into contact with aeroplane EWIS as part of their job and tailors the training for each workgroup to their particular needs.” Following it, EASA says, “will improve the awareness and skill level of the aviation personnel in EWIS production, modification, maintenance, inspection, alterations and repair.” The AMC also notes that it “can be applied to any aeroplane training programme.”

The scope split that changes everything

Here is the sentence that most summaries skip. AMC 20-22 places the syllabus for personnel directly involved in the maintenance and inspection of EWIS — Target Groups 1 and 2 — in Appendices A and C. For everyone else, Groups 3 through 8, it says plainly:

“Although there is no direct regulatory requirement for EWIS training of these personnel, operators may choose to provide EWIS training.”

That is the myth dismantled in one line. Groups 3 to 8 sit in Appendices B and C as guidance. EASA is explicit about why it still recommends training them: “Although these groups are not directly involved in the maintenance of EWIS, they have the potential to have an adverse impact on EWIS. This can occur through inadvertent contact with EWIS during aeroplane cleaning or when individuals perform unrelated maintenance that could impact the integrity of EWIS. Mechanics leaving drill shavings on wire bundles is one example of how this could occur.” It makes the same case for the people writing the paperwork: “Some people prepare paperwork that guides mechanics, training this target group in EWIS should help to ensure that proper attention is paid to EWIS issues.”

Recommended, reasoned, and evidenced — but not mandated. If you want the longer treatment of that distinction, see Is EWIS training mandatory?

2. Where the obligation actually lives

Because AMC 20-22 is a means of compliance, the enforceable duty sits in the implementing rules it points at. Section 2 names them directly: the AMC “has been published in order to provide the approved organisations with acceptable means of compliance to comply with their training obligations as required in paragraphs 21.A.145 and 21.A.245 of Part-21, 145.A.30 and 145.A.35 of Part-145 and M.A.706 of Part-M with respect to EWIS.”

• 145.A.30 and 145.A.35 (Part-145) — personnel requirements and certifying staff. This is the hook for a maintenance organisation.
• M.A.706 (Part-M) — personnel requirements on the continuing airworthiness management side.
• 21.A.145 and 21.A.245 (Part-21) — production organisation approval and design organisation approval respectively.

That last distinction matters when you are scoping an internal training needs analysis. 21.A.145 and 21.A.245 concern POA and DOA holders — they are not the hook for a line maintenance organisation. Part-145 and Part-M sit in Regulation (EU) No 1321/2014; Part-21 sits in Regulation (EU) No 748/2012.

One housekeeping note for anyone reading the AMC’s own reference list: it cites Regulations (EC) No 216/2008, 1702/2003 and 2042/2003. All three are superseded. The current continuing airworthiness regulation is Regulation (EU) No 1321/2014.

AMC 20-22 also sits alongside two companion AMCs worth knowing: AMC 20-21, “Programme to Enhance Aeroplane Electrical Wiring Interconnection System Maintenance”, and AMC 20-23, “Development of Electrical Standard Wiring Practices Documentation”.

3. The eight target groups

AMC 20-22 was “developed for eight different target groups and may be used for the minimum requirements for initial and recurrent training (see training matrix).”

Before the table, the rule that catches organisations out most often. Target grouping follows duties, not licence category:

“Depending on the duties, some may fall into more than one target group and, therefore, must fulfil all objectives of the associated target groups.”

A B2 who inspects as well as maintains is not “Group 1 or Group 2”. They are both, and they must meet the objectives of both. In our experience this is the single most common gap found when an EWIS training matrix is audited against actual job cards — the matrix was built from licence categories rather than from what people are authorised to do.

Not sure where a given role lands? Work through Which EWIS Target Group Am I?

4. What EASA EWIS training actually covers

Appendix A (Groups 1 and 2) and Appendix B (Groups 3 to 8) share the same seven lettered module blocks across syllabus items 1 to 41:

• A — General EWIS Practices (items 1–7)
• B — Wiring Practices Documentation (8–12)
• C — Inspection (13–16)
• D — Housekeeping (17–22)
• E — Wire (23–31)
• F — Connective Devices (32–36)
• G — Connective Device Repair (37–41)

Groups 1 and 2: the full stack, with differences

Both receive the complete syllabus, but the matrix splits certain items. Marked Group 1 only: items 3–6 (tools; verifying calibration and certification; required wiring checks using troubleshooting procedures and charts; measurement and troubleshooting using meters), items 20–22 (contamination protection planning; protection during aeroplane maintenance and repair; cleaning processes), and the whole of block G — 37 circular connectors, 38 rectangular connectors, 39 terminal blocks modular, 40 terminal blocks non-modular, 41 grounding modules.

Marked Group 2 only: item 14 (human factors in inspection), item 15 (zonal areas of inspection) and item 25 (inspection criteria and standards for wire and wire bundles).

Groups 3 to 8: targeted subsets

• Group 3 — the documentation block (8–12), most of the Wire block (23–31) and Connective Devices.
• Group 4 — items 1, 2, 7, 13, 16, 17–19, 20–22, 27 and 31.
• Group 5 — items 13, 14, 15, 16, 17–19, 20–22, 27 and 31.
• Groups 6, 7 and 8 — item 1 safety practices, items 17–19 contamination sources, and items 16 (wiring system damage) and 27 (typical damage and areas found), all at “Low level” — the exact phrase used in the source table.

“Low level” is doing real work in that table. Cabin crew and cleaners are not being taught to inspect a wire bundle to a standard. They are being taught to recognise that a bundle is not a shelf, a handhold, or somewhere waste liquid should end up.

5. Initial and refresher training

Initial

AMC 20-22 states that initial training “should be conducted for each designated work group” and that “the most important criteria are to meet the objectives of the Lesson Plans – Appendix C (using classroom discussion, computer-based training or hands-on practical training).” Assessment method is left open: it “should be at the discretion of the training organisation (such as written test, oral test or demonstration of skills).”

That is a deliberately outcome-led framing. The delivery medium is not the compliance question — the Appendix C objectives are.

Refresher

Refresher training “should be conducted in a period not exceeding two years.” It “could consist of a review of previously covered material plus any new material or revisions to publications”, and it “will follow the EWIS Minimum Initial Training Programme – Appendix A or B for that particular target group.” In other words, refresher content is anchored to the same target-group syllabus, not to a generic awareness session. More on the interval in EWIS refresher training and the two-year period.

6. Why EASA cares: the evidence behind the AMC

Section 7 of the AMC is short and pointed. “Over the years there have been a number of in-flight smoke and fire events where contamination sustained and caused the fire to spread. Regulators and Accident Investigators have conducted aircraft inspections and found wiring contaminated with items such as dust, dirt, metal shavings, lavatory waste water, coffee, soft drinks, and napkins. In some cases, dust has been found completely covering wire bundles and the surrounding area.”

It goes further on the training point specifically: “Aviation Accident Investigators have specifically cited the need for improved training of personnel to ensure adequate recognition and repair of potentially unsafe wiring conditions.” And on collateral damage: “a person performing an inspection of an electrical power centre or avionics compartment may inadvertently cause damage to wiring in an adjacent area.”

Two definitions from Section 6 explain the mechanism better than any commentary. Arc tracking: “A phenomenon in which a conductive carbon path is formed across an insulating surface. This carbon path provides a short circuit path through which current can flow. Normally, a result of electrical arcing.” Swarf: “A term used to describe the metal particles, generated from drilling and machining operations. Such particles may accumulate on and between wires within a wire bundle.” For EWIS itself, the AMC defers to the certification specification: “Electrical Wiring Interconnection System (EWIS): See CS 25.1701.” The rest of the vocabulary is collected in our EWIS glossary.

7. Which Raven course maps to which group

Our EWIS courses are built as a strict 1:1 mapping to the AMC. Each Waypoint corresponds to exactly one syllabus line item from AMC 20-22 (items 1–42), and Waypoints are grouped into Lessons A–G matching the AMC’s own module blocks. Target-group courses are then assembled from those Waypoints according to the “X” marks in the Appendix B matrix — so what a Group 4 technician sees is the Group 4 row, and nothing else. Groups 1 and 2 see the full stack, Modules A–G.

Remember the duties rule when you assign: someone whose authorisations span two groups needs the objectives of both. Separately, wiring in and around fuel tanks tends to surface in fuel tank safety work as well — our Fuel Tank Safety course is a common companion, though the two courses are distinct and neither credits against the other. The fuel tank side has its own pair of limitation types, set out in our guide to the difference between CDCCL and Airworthiness Limitation Items. If you are mapping training obligations across your organisation more broadly, the same structural logic applies to our EASA Part-IS guide.

Frequently asked questions