Radio Aids

Common radio aids available for navigational purposes include:

NDB's have a two or three character ident. The two serving Birmingham International Airport are:

"GM" and "GX"

They operate in the H.F spectrum "GM" on 338.0 KHz, and "GM" on 347.0 KHz. Their location is quoted in the following manner:

"GM" 331(M) 4.05nm to Thr 33 ; "GX" 151(M) 4.06nm to Thr 15

VOR (VHF Omnidirectional Ranging) is often combined with DME (Distance Measuring Equipment) to give a range and bearing display. By tuning in to two VOR/DME beacons on opposite sides of the track a pilot can obtain a 2-position fix.

Combined Attitude & VOR Display

VDF/Homer (VHF Direction Finder): With this system, useful if a pilot is flying in marginal conditions, the pilot, by arrangement with nearby Air Traffic Control, transmits for around 5 seconds, to allow the controller to fix a heading which the pilot should fly in order to reach the airfield. It can often be combined with range information to provide a fix. Information is usually given as a QDM (Magnetic heading for the aircraft to steer to reach the ground station with no wind), or as QUJ (True track from the aircraft to the ground station).

Radio bearings are classified according to their accuracy:

A (+/- 2deg); B (+/- 5deg); C (+/-10deg)

ILS/DME: Any aircraft landing using ILS homing is given the operational one to use. At Birmingham International Airport, pilots have 2 options, either RWY 33 or RWY 15. Information shows that RWY 33 has a magnetic heading of 331, therefore RWY 15 is 151M. The Ident for RWY 33 is I-BM, whilst RWY 15 has the Ident I-BIR. The Localiser frequency is 110.1 MHz in both cases. This is paired up automatically to 334.4 MHz for the Glide Path. The Frequency pairing tables are shown below:

TACAN & DME "X" Channels
MHz .00 .10 .20 .30 .40 .50 .60 .70 .80 .90
108 17 18 19 20 21 22 23 24 25 26
109 27 28 29 30 31 32 33 34 35 36
110 37 38 39 40 41 42 43 44 45 46
111 47 48 49 50 51 52 53 54 55 56
112 57 58 59 70 71 72 73 74 75 76
113 77 78 79 80 81 82 83 84 85 86
114 87 88 89 90 91 92 93 94 95 96
115 97 98 99 100 101 102 103 104 105 106
116 107 108 109 110 111 112 113 114 115 116
117 117 118 119 120 121 122 123 124 125 126

133  - - - 60 61 62 63 64 65 66
134 67 68 69  - 1 2 3 4 5 6
135 7 8 9 10 11 12 13 14 15 16

TACAN & DME ("Y" Channels)
MHz .05 .15 .25 .35 .45 .55 .65 .75 .85 .95
108 17 18 19 20 21 22 23 24 25 26
109 27 28 29 30 31 32 33 34 35 36
110 37 38 39 40 41 42 43 44 45 46
111 47 48 49 50 51 52 53 54 55 56
112 57 58 59 70 71 72 73 74 75 76
113 77 78 79 80 81 82 83 84 85 86
114 87 88 89 90 91 92 93 94 95 96
115 97 98 99 100 101 102 103 104 105 106
116 107 108 109 110 111 112 113 114 115 116
117 117 118 119 120 121 122 123 124 125 126

Frequency pairing of ILS Glide Path and Localiser
MHz .10 .30 .50 .70 .90
108 334.7

Chan.11

 334.1

Chan.12

 329.9

Chan.13

 330.5

Chan.14

 329.3

Chan.15
109 331.4

Chan.7

 332.0

Chan.6

 332.6

Chan.3

 333.2

Chan.5

 333.8

Chan.2
110 334.4

Chan.4

 335.0

Chan.1

 329.6

Chan.10

 330.2

Chan.9

 330.8

Chan.8
111 331.7

Chan.16

 332.3

Chan.17

 332.9

Chan.18

 333.5

Chan.19

 331.1

Chan.20

1