MART Vol. II MO/MP - NESA - Civil Air Patrol

Figure 5-6In a crosswind, the pilot estimates the airplane’s drift, and computes a driftcorrection factor to be added to or subtracted from the aircraft heading. If heestimates 5º of drift to the right, his drift correction will be to subtract 5º from theairplane’s heading, and turn the aircraft 5º to the left. The aircraft would thus havea heading of 025, its course over the ground would remain 030, and the ADFwould show a relative bearing of 005, or 5º to the right. In the rowboat-crossingthe-riveranalogy, the boat's bow points upstream, but due to the current, it travelsin a straight line across the river. The aim point is slightly to the right of the bowas the boat proceeds across.All ADF stations transmit an audible identifier that you must identify beforeusing the signal for navigation. All ADFs are highly susceptible to interferencewhen thunderstorms are in the general vicinity, and their transmissions arerestricted to line-of-sight only. Signals can also be blocked by terrain or otherobstructions, especially when the aircraft is operating at low altitudes.5.5.2 Very High Frequency Omnidirectional Range (VOR)The very high frequency omnidirectional range (VOR) radio navigation systemoperates on a specific frequency in the VHF range of 109.0 to 117.9 megahertzand transmits 360 directional radio beams or radials that, if visible, wouldresemble the spokes radiating from the hub of a bicycle wheel. Each station isaligned to magnetic north so that the 000 radial points from the station tomagnetic north. Every other radial is identified by the magnetic direction to whichit points from the station, allowing the pilot to navigate directly to or from thestation by tracking along the proper radial. The VOR is an accurate and reliablenavigational system, and is the current basis for all instrument flight in the U.S.77