Which statement regarding IFR flights within ICAO controlled airspace is true?

The statement that clearance for a VOR or ILS approach does not waive FM immunity requirements is correct because it reflects the established standards regarding radio communications and safety regulations within ICAO controlled airspace.

Under ICAO regulations, FM (Frequency Modulation) immunity requirements are in place to ensure that aircraft systems are protected from interference from other radio sources, which is critical for the safe operation of IFR (Instrument Flight Rules) flights. Clearance for any specific approach, including VOR (VHF Omnidirectional Range) or ILS (Instrument Landing System), does not exempt the aircraft from compliance with FM immunity regulations. This requirement remains in effect to maintain the integrity and safety of navigation and communication systems throughout all phases of flight, regardless of the specific approach being utilized.

Therefore, understanding these requirements helps pilots and operators ensure that their equipment meets the necessary standards, enhancing safety and reliability while operating in controlled airspace.