Gengis refers to the type certification, an interesting source! For the use of the pilots, this should be reflected in the POH, anf for the
Icarus it is on page 15 / section 5. No idea if this a typical microlight POH structure. What happens if it is in the type certification data but not in the POH I have no idea - I don't believe the pilot is expected to see/know the TCDS/TADS data.
frontlefthamster, I didn't mean to say that it always is in section 2, but it has to be in the POH (ok, AFM) for aircraft certified under FAR 23, and this is where it typically ends up. Just in case you want the reference that it has to be in the POH:
Originally Posted by FAR 23.1583 / EU CS23.1583
"The Aeroplane Flight Manual must contain operating limitations determined under this part 23, including the following:"
....
(h) ....a list of installed equipment that affects any operating limitation and identification as to the equipment 's required operation for which approval has been given"
I corrected my post above to say typically.
The heart of what I wrote is that, for private operations of non-complex aircraft, the source for minumum equipment is the POH (whichever section) and the law, of which I quoted parts (there is more, and it might not be all in one place, either), and it is very little indeed. Broken stuff might have to be labeled INOP (no idea where that rule is).
mad_jock has the sensible answer - if what you have installed is broken, do you really want to fly with the aircraft? Persistently broken instruments can indicate shoddy maintenance. A few days ago, I took of in an Arrow with broken autopilot, and electric trim disabled due to a sticky trim switch (= risk of runaway). None of which are mandatory.
During the flight, the HSI failed, and the G/S indicator did not work. Both of which were more essential. Half of the purpose of the flight (ILS practice) was wasted.