'Pilot' Magazine had an article on avionics this month which unequivocally stated:
If you fly with non FM Immune equipment in class A, B, or C airspace, or under IFR/IMC conditions, you are breaking the law.
This had me worried, as I was doing just that last week (IFR in IMC under the edge of the Birmingham TMA, for example), so I looked it up.
Unless I've read it wrong, only the equipment
required by the ANO (Section 1 Schedule 5) has to be FM Immune, and any other equipment you may carry or choose to use is up to you? As I understand it therefore:
IFR in CAS: must have radio, transponder, ADF, DME and VOR*
VFR in CAS: must have radio
Landing in CAS: must have ILS* if airspace notified as requiring it
i.e. the ones marked * must be FM immune and only under those circumstances. And I remember a training flight where we flew through the Lyneham CTA IFR tracking CPT on a non-immune set: yes, we were in VMC, but we definitely got an IFR clearance...
Am I missing something, or was the article in 'Pilot' misleading?
Tim