15.
Direction Finding Instrument Approach Procedure
15.1 Direction finding (DF) equipment has long been used to locate lost aircraft and to guide aircraft to areas of good weather or to airports; and now at most DF equipped airports, DF instrument ap-proaches may be given to aircraft in emergency.
15.2 Experience has shown that a majority of actual emergencies requiring DF assistance involve pilots with a minimum of flight experience. With this in mind, DF approach procedures provide maximum flight stability in the approach by utilizing small turns, and descents in a wings level attitude. The DF specialist will give the pilot headings to fly and tell the pilot when to begin descent.
15.3 DF instrument approach procedures are for emergency use only and will not be given to IFR weather conditions unless the pilot has declared an emergency.
15.4 To become familiar with the procedures and other benefits of DF, pilots are urged to request practice guidance and approaches in VFR weather conditions. DF specialists welcome the practice and, workload permitting, will honor such requests.
16. Intercept and Escort
16.1 The concept of airborne intercept and escort is based on the SAR aircraft establishing visual and/or electronic contact with an aircraft in difficulty, providing inflight assistance, and escorting it to a safe landing. If bailout, crash landing or ditching becomes necessary, SAR operations can be conducted without delay. For most incidents, particularly those occurring at night and/or during instrument flight conditions, the availability of intercept and escort services will depend on the proximity of SAR units with suitable aircraft on alert for immediate dispatch. In limited circumstances, other aircraft flying in the vicinity of an aircraft in difficulty can provide these services.
16.2 If specifically requested by a pilot in difficulty or if a distress condition is declared, SAR coordinators will take steps to intercept and escort an aircraft. Steps may be initiated for intercept and escort if an urgency condition is declared and unusual circumstances make such action advisable.
16.3
It is the pilot’s prerogative to refuse intercept and escort services. Escort services will normally be provided to the nearest adequate airport. Should the pilot receiving escort services continue on to another location after reaching a safe airport, or decide not to divert to the nearest safe airport, the escort aircraft is not obligated to continue and further escort is discretionary. The decision will depend on the circumstances of the individual incident.
17.
Visual Emergency Signals
NOTE.
See FIG GEN 3.6.1 through FIG GEN 3.6.17.
18. Ditching Procedures
18.1 In order to select a proper ditching course for an aircraft, a basic knowledge of sea evaluation and other factors involved is required. Selection of the ditching heading may well determine the difference between survival and disaster. (See FIG GEN 3.6.18, FIG GEN 3.6.19, FIG GEN 3.6.20, and FIG GEN 3.6.21).
18.2 Common Oceanographic Terminology:
18.2.1 Sea. The condition of the surface that is the result of both waves and swells.
18.2.2 Wave (or Chop). The condition of the surface caused by local winds.
18.2.3 Swell. The condition of the surface which has been caused by a distant disturbance.
18.2.4 Swell Face. The side of the swell toward the observer. The backside is the side away from the observer. These definitions apply regardless of the direction of swell movement.
18.2.5 Primary Swell. The swell system having the greatest height from trough to crest.
18.2.6 Secondary Swells. Those swell systems of less height than the primary swell.
18.2.7 Fetch. The distance the waves have been driven by a wind blowing in a constant direction, without obstruction.
18.2.8 Swell Period. The time interval between the passage of two successive crests at the same spot in the water, measured in seconds.
18.2.9 Swell Velocity. The velocity with which the swell advances with relation to a fixed reference point, measured in knots. There is little movement of water in the horizontal direction. Swells move primarily in a vertical motion, similar to the motion observed when shaking out a carpet.
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