- Direction Finder (DF) equipment has long been used to locate lost aircraft and to guide aircraft to areas of good weather or to airports
- One of the most common systems that helps pilots, without being aware of its operation
- Now at most DF equipped airports, DF instrument approaches may be given to aircraft in a distress or urgency condition
- It is a ground-based radio receiver used by the operator of the ground station
- FAA facilities that provide VHF/DF services are identified in the Chart Supplement U.S.
- The equipment consists of a directional antenna system and a VHF radio receiver
- The VHF/DF receiver display indicates the magnetic direction of the aircraft from the ground station each time the aircraft transmits
- DF equipment is of particular value in locating lost aircraft and in helping to identify aircraft on radar
- DF IAPs are for emergency use only and will not be used in IFR weather conditions, unless the pilot has declared a distress or urgency condition
- Experience has shown that most emergencies requiring DF assistance involve pilots with little flight experience. With this in mind, DF approach procedures provide maximum flight stability in the approach by using small turns, and wings-level descents. The DF specialist will give the pilot headings to fly and tell the pilot when to begin descent
- DF IAPs are for emergency use only and will not be used in IFR weather conditions unless the pilot has declared a distress or urgency condition
- To become familiar with the procedures and other benefits of DF, pilots are urged to request practice DF guidance and approaches in VFR weather conditions
- DF specialists welcome the practice and will honor such requests, workload permitting
