Applicants should be familiar with the information in this FAA Safety Briefing. One of the scenarios for the oral portion of the checkride might be a night visual approach to a runway that has the PAPI NOTAMed out of service. When I ask how they would mitigate that threat, most applicants don’t really know. One effective way is with the 3:1 rule, which says that for each 1 NM from the threshold, the airplane will be about 300 feet above the runway when on a 3 degree glidepath. This does not guarantee obstacle clearance, but it’s a great tool to start with. It can also be said that when an airplane is on a 3 degree glidepath, 3 miles from the runway, it is about 1,000 feet above the runway.
The FAA has outlined seven criteria for a stabilized approach on page 9-6 of the Airplane Flying Handbook. The seven items listed by the FAA can be condensed into the C-FLAPS acronym:
C - Checklists, complete.
F - Flight path (horizontal and vertical), proper.
L - Landing configuration, set.
A - Airspeed, within normal approach criteria.
P - Power setting, adjusted and constant.
S - Sink rate, as planned/expected.
If one or more of the above items is not achieved by a certain point, the airplane is not stabilized and a go-around should be initiated. The Airplane Flying Handbook states, “For a typical GA piston aircraft in a traffic pattern, an immediate go-around should be initiated if the approach becomes unstabilized below 300 ft AGL.” 300 feet AGL may or may not be the appropriate altitude based on the specific airplane, runway, and current conditions, but it is still important for pilots to select a minimum height at which they will decide to go-around if not stabilized. This selected height can be different for each landing, but the pilot should always know how far they will take an unstabilized approach before choosing to go-around. Think of it as a “Personal Decision Height.”
Forward slips should only be used when previously briefed and/or when simulating an abnormal/emergency scenario that makes a go-around less desirable. A forward slip should not be used to fix a poorly planned/executed approach. With rare exceptions, the best thing to do when unstabilized is promptly execute a go-around.