Which of the following is NOT a part of the mandatory reports under IFR?

The correct answer identifies an item that is not included in the mandatory reports under Instrument Flight Rules (IFR). In IFR operations, pilots are required to submit specific reports that communicate important information related to air safety and navigation. Missed approach reports, for example, are essential because they inform air traffic control of a pilot's inability to land as planned and the actions taken in response. Similarly, reports of weather anomalies observed can significantly aid in maintaining safety by alerting others to potentially dangerous conditions.

Reports detailing VFR on top are significant as they inform air traffic control when a VFR (Visual Flight Rules) aircraft is operating at a higher altitude than the cloud layers, thus ensuring proper separation from IFR traffic.

In contrast, flight path deviations, while they may be a concern in terms of flight safety, are categorized more as operational notices rather than mandatory reporting requirements under IFR. This distinction is crucial because mandatory reporting typically focuses on issues directly impacting flight safety and air traffic management, whereas flight path deviations can be addressed in various operational contexts without necessitating a formal report unless they pose a significant risk.