What type of approaches require the APPR mode to be turned off?

The correct answer is VOR approaches because the Autopilot's Approach (APPR) mode is designed primarily for approaches that involve lateral and vertical guidance, such as Instrument Landing System (ILS) approaches, which provide precise localizer and glide slope information.

VOR approaches, on the other hand, typically do not have vertical guidance, which means that the aircraft's autopilot cannot effectively use APPR mode for these types of approaches. Pilots need to manually control the aircraft's descent and lateral positioning when flying a VOR approach. This manual control is necessary to ensure the aircraft remains on the correct descent path and course, as VOR approaches rely solely on the navigation signal provided by the VOR station without additional vertical guidance.

Other types of approaches, such as ILS and RNAV, are designed to make use of autopilot modes that guide the aircraft vertically and laterally, hence the specific requirement to turn off APPR mode for VOR approaches to maintain safe and effective aircraft control.