Module 12 - questions not related to helicopters?

Thanks for raising this.

Module 12 is Helicopter Aerodynamics, Structures and Systems, so it covers the whole helicopter, not only the rotor-specific parts. Many of its systems topics are the same as on aeroplanes, and they are examined that way.

ILS is in scope. The avionic systems section of the Module 12 syllabus includes navigation systems, and helicopters certified for instrument flight fly ILS approaches just as aeroplanes do. You should expect ILS questions in the real exam.

Cargo compartment classes are a closer call. The Module 12 syllabus covers fire protection (detection and extinguishing) and cabin and cargo layout, including cargo retention, so cargo fire protection is fair game. The Class A, B, C classification itself comes from large aeroplane certification, though, so a question that rests entirely on those classes is more aeroplane than helicopter.

On contesting: if you think a question in your real exam is outside the syllabus, raise it with the organisation or authority that ran the exam, as soon as you can after sitting it while you still remember the wording. They will judge it on whether the topic is in the Module 12 syllabus, not on whether it feels helicopter-specific, so it is worth checking the syllabus first:
part66online.com/syllabus/view/12

If a question in our own Module 12 bank looks off-syllabus to you, please use the "Feedback on this question" box on the quiz page and choose "This question or answer is wrong". Those reports come straight to us and we review every one.