According to 14 CFR Part 91, which additional instruments are required for IFR flight?

In accordance with 14 CFR Part 91, the regulations specify the required instruments for Instrument Flight Rules (IFR) operations. The inclusion of a gyroscopic pitch and bank indicator aligns with the requirements for six essential instruments mandated for IFR flight. These instruments comprise the altimeter, airspeed indicator, magnetic compass, turn coordinator, heading indicator, and vertical speed indicator, with the gyroscopic pitch and bank indicator serving a critical function in maintaining orientation and control in conditions where visibility is limited.

The gyroscopic pitch and bank indicator, often known as an artificial horizon or attitude indicator, provides pilots with vital information about the aircraft's orientation relative to the earth's horizon. This is crucial during IFR operations since pilots may not have visual references to ground features. Therefore, the presence of such a gyroscopic instrument enhances situational awareness and assists pilots in executing maneuvers safely and accurately under instrument conditions.

In the context of the other choices, while GPS receivers, radar altimeters, and airspeed indicators each serve important functions in flight operations, they do not meet the specific regulatory requirements designated by 14 CFR Part 91 as essential for IFR flight. In particular, airspeed indicators are typically acknowledged in VFR contexts, while radar altimeters are specialized instruments