Use of the IND-350

CHAPTER SIX

T-34C INSTRUMENTS

Common Errors

i..

Failure to set up NAVAIDS and transponder prior to takeoff.

ii.

Failure to set up NAVAIDS properly.

(a)

Failure to twist correct departure course in IND350.

(b)

Failure to check VOR/TACAN switch in the proper position.

(c)

Failure to select T/R position on TACAN.

iii.

Failure to identify each NAVAID.

604.

USE OF THE IND350

General Almost without exception, military aircraft make use of a radio compass system

as the primary navigation instrument. In the T34C, this system's cockpit display is the radio

magnetic indicator (RMI). In its role as a compass, you have used this instrument since the

Contact Stage. In the Instrument Stage, you will combine this usage with the interpretation of

aircraft position as depicted on the RMI's VOR and TACAN needles.

The RMI's principal shortcoming is its small size. Just as it is difficult to resolve small heading

differences on the face of this instrument, it is also difficult to recognize small deviations from

your desired course as depicted on the VOR and TACAN needles, hence the IND350.

The course deviation indicator (CDI) is the major component of the IND350; its other

components are the Omni Bearing Selector (OBS) and TO/FROM indicator.

It is important to reemphasize here that, in the event of a discrepancy between RMI and CDI, rely

upon the RMI for course information.

To properly use the IND350, you must first twist the desired course with the OBS. Then, set the

VOR/TACAN switch to the appropriate position. The TO/FROM indicator will then show

whether the course selected will take you TO or FROM the NAVAID tuned. If you are within

10 of the course selected, the course deviation indicator will provide a picture of relative

position.

With a VOR frequency or TACAN channel selected, each "mark" on the CDI represents 2 of

deviation (full scale deflection of 10). With a localizer frequency selected and the VOR/TACAN

switch toggled to "VOR," each mark on the CDI represents of deviation (full scale deflection

of 2).

Figure 65 presents a typical situation. The selected course inbound to the station is 360 and the

aircraft is 5 left of course (imagine your aircraft on the tail of the VOR needle and at the center of

the CDI). You must, therefore, turn right (into the CDI) to establish the aircraft on the desired

6-12 RADIO INSTRUMENT FLIGHT PROCEDURES