Instrument Rating Checkride Practice Test

Which factor is essential for the calculation of a flight's Outer Marker during IFR?

1. Expected time of arrival

2. Altitude change of more than 500 fpm

3. Type of holding fix

4. Weather not forecasted

The correct answer is: Altitude change of more than 500 fpm

The correct choice highlights the importance of altitude changes during instrument flight rules (IFR) operations, particularly in the context of determining the Outer Marker (OM). During an approach, the OM is a specific point that signifies the beginning of the final approach segment. An altitude change of more than 500 feet per minute (fpm) is critical because it can impact how a pilot manages the descent profile, stabilizes the aircraft, and ultimately the timing at which the aircraft reaches the OM. In IFR operations, maintaining a specific rate of descent ensures that the pilot is on track to intercept the glide slope or another descent path correctly, thereby increasing the precision of the approach. Excessive altitude changes can lead to unstable approaches or deviations from the intended flight path, particularly as the pilot may not be able to react as quickly as needed to maintain control of the aircraft. Other factors provided in the choices may influence flight operations but are not essential for calculating the OM. For instance, the expected time of arrival is useful for overall management of flight schedules, while the type of holding fix relates to holding pattern procedures. Weather not forecasted may affect flight safety and decision-making but does not play a role in the specific calculation of the Outer Marker during an approach. Hence,