What types of inspections are required for IFR operations?

For IFR (Instrument Flight Rules) operations, certain inspections are specifically mandated to ensure the aircraft's navigational equipment is functioning correctly and safely. The requirement for VOR (VHF Omnidirectional Range) inspections, as well as static system, altimeter, and encoder system checks, is crucial because these systems are essential for maintaining accurate altitude information and navigation during instrument flight.

VOR inspections ensure that the navigational signals are accurate, which is vital for guidance during flights that rely on likely low visibility conditions. Static/altimeter/encoder system checks are necessary to ensure that altitude readings are correct, which is a critical factor in maintaining safety in a controlled airspace and during approaches and landings where precision is essential.

While weight and balance inspections and engine performance assessments are important for overall aircraft safety and performance, they are not specifically required inspections that pertain to IFR operations. Similarly, Visual Flight Rules (VFR) checks are mainly applicable when flying under visual flight rules, where weather conditions and visibility allow pilots to fly using visual references. Thus, the inspections outlined in the correct choice directly relate to the requirements established for safe IFR operations.