ADF

#1. The phenomenon of coastal refraction which affects the accuracy of ADF bearings:

• Ais most marked at night.
• Bcan be minimised by using beacons situated well inland.
• Ccan be minimised by taking bearings where the signal crosses the coastline at right angles.
• Dis most marked one hour before to one hour after sunrise and sunset.

#2. An aircraft is intending to track from NDB ‘ A' to NDB ‘B' on a track of 050° (T), heading 060° (T). If the RBI shows the relative bearing of ‘ A' to be 180° and the relative bearing of ‘B' to be 330° then the aircraft is:

• APort of track and nearer ‘ A'.
• BPort of track and nearer ‘B'.
• CStarboard of track and nearer ‘ A'
• DStarboard of track and nearer ‘B'.

#3. ADF Quadrantal Error is caused by:

• Astatic build up on the airframe and St. Elmo's Fire.
• Bthe aircraft's major electrical axis, the fuselage, reflecting and re-radiating the incoming NDB transmissions.
• Cstation interference and/or night effect.
• DNDB signals speeding up and bending as they cross from a land to water propagation path