Figure 5 - P-8010012

INSTRUMENT NAVIGATION

Figure 5

6. UHF/NDB navigational information is limited to line-of-sight range.

Curvature of the earth and/or geographic obstacles, such as mountains, limit UHF range.

However, as altitude increases UHF range of reception increases.

VHF OMNIDRECTIONAL RANGE (VOR)

VOR is a major improvement over the ADF. It has become the mainstay of civil aviation

because of its simplicity and reliability. Military aircraft (especially the larger types) are

sometimes equipped with VOR, although it is rare to find a VOR in a tactical Navy jet. In

VT-10, the T-34 and T-39 aircraft have VOR.

The characteristics of VOR are:

1. VOR operates in the lower half of the VHF band. VOR frequencies are between 108.0

and 117.9 MHZ and are relatively free from atmospheric disturbances.

2. VOR presents magnetic bearing information. The produced signal is aligned to

magnetic north. Because your aircraft uses a compass system that is also aligned to magnetic

north, there are no inconsistencies in the presentation.

3. VOR is limited to line of sight range. VHF radio waves travel only in straight lines and

do not have the ability to bounce off the atmosphere. Your VOR reception will depend on the

absence of obstacles between your aircraft and the VOR station. 1QODQ'

1-6

RADIO AIDS TO NAVIGATION