383:
302:
141:
749:
1006:
435:"Red" airways; this was sometimes a "fan" marker, whose radiated pattern was elongated at right angles across the airway course so an aircraft slightly off course would still receive it. A "Z" marker was sometimes located at low- or medium-frequency range sites to accurately denote station passage. As airway beacons used the same 3,000 Hz audio frequency as the inner marker, the "A" indicator on older receivers can be used to detect the inner marker.
1016:
39:
31:
451:) normally indicates the ILS back-course final-approach fix where approach descent is commenced. It is identified by pairs of Morse-code "dots" at 3000 Hz (95 pairs per minute), which will trigger the white light on a marker beacon indicator, but with a different audio rhythm from an inner marker or en-route marker.
434:
On some older marker beacon receivers, instead of the "O", "M" and "I" indicators (outer, middle, inner), the indicators are labeled "A" (or FM/Z), "O" and "M" (airway or Fan and Z marker, outer, middle). The airway marker was used to indicate reporting points along the centerline of now obsolete
108:
to provide an indication of an aircraft's specific position along the route, but from the 1960s they have become increasingly limited to ILS approach installations. They are now very gradually being phased out of service, especially in more developed parts of the world, as
350:
middle marker light starts blinking, and a repeating pattern of audible morse code-like dot-dashes at a frequency of 1,300 Hz in the headset. This alerts the pilots that they are descending through the CAT I decision altitude (typically 200 feet (60 m)
463:
refers to the older type of beacons used mostly for en-route navigation. Fan-type marker beacons were sometimes part of a non-precision approach and are identified by a flashing white light and a repeating dot-dash-dot signal. Recent editions of the
321:
402:
161:
160:
638:
can refer to almost any type of marker beacons used in aviation (including inner/middle/outer markers), since most of them transmit signal in the fan-shaped pattern (i.e. in a shape of a hand-held fan held up perpendicular to the flight
430:
of less than 200 feet (60 m) AGL. Triggers a flashing white light on the same marker beacon receiver used for the outer and middle markers; also a series of audio tone 'dots' at a frequency of 3,000 Hz in the headset.
216:
is highly directional, and is pointed straight up. The valid signal area is a 2,400 ft (730 m) × 4,200 ft (1,280 m) ellipse (as measured 1,000 ft (300 m) above the antenna.) When the
716:
345:
works on the same principle as an outer marker. It is normally positioned 0.5 to 0.8 nautical miles (1 km) before the runway threshold. When the aircraft is above the middle marker, the receiver's
320:
401:
158:
291:
372:
130:
685:
318:
399:
157:
746:
662:
Note: They are only used on a few instrument approaches anymore, to mark positions along the inbound course, when there is only one marker present: for an example, see the
905:
275:
In the U.S., LOMs are identified by two-letter Morse code modulated at 1020 Hz. LOMs use the first two letters of the parent ILS's identification. For example, at
282:
runway 31R the ILS identifier is I-RTH and the LOM ident is RT. If this facility were a locator middle marker (LMM) its identifier would be the last two letters, TH.
319:
400:
159:
261:(ILS) instrument approach for aircraft. Aircraft can navigate directly to the location using the NDB as well as be alerted when they fly over it by the beacon.
597:
901:
686:
https://enasr.faa.gov/eNASR/nasr/Current/NavAid/?%E2%80%A0Navaid_ID=&%E2%80%A0Navaid_Name=&Type=FAN_MARKER&%E2%80%A0City=&State_Code=
472:
publication no longer mention fan markers. In August 2024 nineteen fan markers remain in the FAA database with seven listed as "DECOMMISSIONED".
748:
738:
909:
552:
34:
Locator Outer Marker (LOM), a High
Frequency (HF) Non-Directional Beacon, co-located with an "outer marker" (OM) 75-MHz Marker Beacon.
121:
There are three types of marker beacons that may be installed as part of their most common application—an instrument landing system.
1050:
1040:
279:
81:
953:
93:
17:
648:
949:
272:, have abandoned marker beacons completely, replacing the outer marker with a NDB; and, more recently, with GPS fixes.
1055:
520:
426:
located at the beginning (threshold) of the runway on some ILS approach systems (usually
Category II and III) having
592:
925:
893:
731:
469:
465:
877:
845:
793:
201:
before the runway threshold. It is typically located about 1 NM (1.85 km) inside the point where the
705:
205:
intercepts the intermediate altitude and transmits a 400 Hz tone signal on a low-powered (3 watts), 75
937:
885:
881:
577:
1009:
671:
921:
889:
873:
857:
785:
724:
699:
492:
486:
1045:
945:
825:
573:
258:
110:
62:
1019:
993:
917:
96:
which radiates vertically a distinctive pattern for providing position information to aircraft".
973:
865:
311:
246:
913:
757:
392:
150:
85:
985:
897:
869:
853:
801:
797:
547:
535:
ITU Radio
Regulations, Section IV. Radio Stations and Systems – Article 1.107, definition:
8:
833:
829:
821:
781:
969:
841:
817:
809:
569:
352:
186:
1015:
977:
516:
105:
702:
This FRS publication has detailed description of ILS and other navigational systems.
69:
a means to determine position along an established route to a destination such as a
1060:
861:
268:
navigation is well established in the aviation community. Some countries, such as
222:
961:
663:
601:
556:
427:
360:
213:
981:
777:
773:
209:
1034:
933:
789:
753:
706:
Operational Notes on Visual-Aural Radio Range & Associated Marker
Beacons
617:
347:
276:
242:
198:
941:
849:
837:
813:
805:
54:
290:
989:
371:
129:
89:
113:
and other technologies have made marker beacons increasingly redundant.
965:
568:
Note:Some ILS approaches have no navigation aid at all situated at the
414:
356:
333:
230:
202:
173:
190:
104:
From the 1930s until the 1950s, markers were used extensively along
38:
481:
218:
58:
225:
detects the signal. The system gives the pilot a visual (blinking
66:
642:
269:
229:
outer marker light) and aural (continuous series of audio tone
194:
70:
929:
206:
30:
906:
Satellite emergency position-indicating radiobeacon station
226:
605:
265:
51:
221:
passes over the outer marker antenna, its marker beacon
711:
670:, effective 5 Sep 2024 - here GRIGG is a fan marker.
580:(DME), GPS, or radar fixes, to identify the position.
363:
if one of several visual cues has not been spotted.
189:(FAF), is situated on the same course/track as the
257:). An LOM is a navigation aid used as part of an
245:, the outer marker has often been combined with a
902:Emergency position-indicating radiobeacon station
1032:
732:
264:The LOM is becoming less important now that
712:International Telecommunication Union (ITU)
676:–from an old edition of AIM, section 1-1-9.
588:
586:
422:Similar to the outer and middle markers, a
910:Standard frequency and time signal station
739:
725:
27:Type of VHF radio beacon used in aviation
583:
370:
359:) and should have already initiated the
289:
128:
37:
29:
515:(first ed.). Osprey. p. 186.
236:
82:International Telecommunication Union's
14:
1033:
88:(RR) a marker beacon is defined as "a
720:
510:
438:
94:aeronautical radionavigation service
752:
624:McGraw-Hill Dictionary of Aviation.
24:
664:LOC-D document for Gillespie Field
381:
300:
139:
25:
1072:
700:2008 Federal Radionavigation Plan
693:
650:Instrument Flight Training Manual
61:, usually in conjunction with an
1014:
1005:
1004:
747:
413:Problems playing this file? See
397:
332:Problems playing this file? See
316:
285:
185:, which normally identifies the
172:Problems playing this file? See
155:
1051:Aeronautical navigation systems
946:Instrument landing system (ILS)
894:Radio direction-finding station
756:and systems in accordance with
679:
572:, but use other means, such as
366:
124:
1041:Radio stations and systems ITU
878:Radionavigation mobile station
846:On-board communication station
794:High altitude platform station
673:Quote regarding marker beacons
656:
628:
611:
562:
541:
529:
504:
13:
1:
622:; Answers.com: attributed to
498:
454:
42:Middle marker antenna at KONT
926:Ship's emergency transmitter
886:Radiolocation mobile station
882:Radionavigation land station
578:distance measuring equipment
576:(VOR) radial intersections,
233:-like 'dashes') indication.
7:
475:
197:center-line, four to seven
10:
1077:
922:Experimental radio station
890:Radiolocation land station
874:Radiodetermination station
858:Aeronautical earth station
493:Index of aviation articles
487:Transponder Landing System
99:
1000:
826:Land mobile earth station
764:
574:VHF omnidirectional range
259:instrument landing system
63:instrument landing system
1056:Aircraft landing systems
994:Emergency locator beacon
653:; Amazon.com; accessed .
513:A Dictionary of Aviation
511:Wragg, David W. (1973).
116:
50:is a particular type of
918:Radio astronomy station
294:Middle-marker indicator
866:Aircraft earth station
786:Survival craft station
559:; ILS.com; retrieved .
386:
376:
375:Inner-marker indicator
353:above the ground level
305:
295:
247:non-directional beacon
144:
134:
133:Outer-marker indicator
43:
35:
758:ITU Radio Regulations
385:
374:
304:
293:
143:
132:
86:ITU Radio Regulations
41:
33:
986:Multi-satellite link
942:Radar beacon (racon)
898:Radio beacon station
870:Broadcasting station
854:Aeronautical station
802:Mobile earth station
549:ILS – Marker beacons
312:Middle marker signal
251:locator outer marker
237:Locator outer marker
18:Locator outer marker
834:Coast earth station
822:Land mobile station
774:Terrestrial station
708:a 1953 publication.
393:Inner marker signal
151:Outer marker signal
842:Ship earth station
818:Base earth station
810:Land earth station
600:2009-09-04 at the
570:final approach fix
555:2014-01-30 at the
445:back course marker
439:Back course marker
387:
377:
306:
296:
187:final approach fix
145:
135:
44:
36:
1028:
1027:
978:Satellite network
608:.com; retrieved .
403:
322:
162:
16:(Redirected from
1068:
1046:Radio navigation
1018:
1008:
1007:
974:Satellite system
862:Aircraft station
769:
751:
741:
734:
727:
718:
717:
688:
683:
677:
669:
660:
654:
646:
640:
632:
626:
615:
609:
590:
581:
566:
560:
545:
539:
533:
527:
526:
508:
428:decision heights
405:
404:
384:
324:
323:
303:
249:(NDB) to make a
164:
163:
142:
21:
1076:
1075:
1071:
1070:
1069:
1067:
1066:
1065:
1031:
1030:
1029:
1024:
996:
962:Radio altimeter
938:Secondary radar
914:Amateur station
767:
765:
760:
745:
696:
691:
684:
680:
667:
661:
657:
647:
643:
634:Note: The term
633:
629:
616:
612:
602:Wayback Machine
591:
584:
567:
563:
557:Wayback Machine
546:
542:
534:
530:
523:
509:
505:
501:
478:
457:
441:
420:
419:
411:
409:
408:
407:
406:
398:
395:
388:
382:
369:
361:missed approach
339:
338:
330:
328:
327:
326:
325:
317:
314:
307:
301:
288:
239:
179:
178:
170:
168:
167:
166:
165:
156:
153:
146:
140:
127:
119:
102:
65:(ILS), to give
28:
23:
22:
15:
12:
11:
5:
1074:
1064:
1063:
1058:
1053:
1048:
1043:
1026:
1025:
1023:
1022:
1012:
1001:
998:
997:
982:Satellite link
980: |
954:ILS glide path
884: |
798:Mobile station
772:
770:
762:
761:
754:Radio stations
744:
743:
736:
729:
721:
715:
714:
709:
703:
695:
694:External links
692:
690:
689:
678:
655:
641:
627:
610:
582:
561:
540:
528:
521:
502:
500:
497:
496:
495:
490:
484:
477:
474:
456:
453:
440:
437:
410:
396:
391:
390:
389:
380:
379:
378:
368:
365:
329:
315:
310:
309:
308:
299:
298:
297:
287:
284:
238:
235:
210:carrier signal
199:nautical miles
169:
154:
149:
148:
147:
138:
137:
136:
126:
123:
118:
115:
101:
98:
26:
9:
6:
4:
3:
2:
1073:
1062:
1059:
1057:
1054:
1052:
1049:
1047:
1044:
1042:
1039:
1038:
1036:
1021:
1017:
1013:
1011:
1003:
1002:
999:
995:
992: |
991:
988: |
987:
984: |
983:
979:
976: |
975:
972: |
971:
968: |
967:
964: |
963:
960: |
959:
958:Marker beacon
956: |
955:
952: |
951:
950:ILS localizer
948: |
947:
944: |
943:
940: |
939:
936: |
935:
934:Primary radar
932: |
931:
928: |
927:
924: |
923:
920: |
919:
916: |
915:
912: |
911:
908: |
907:
904: |
903:
900: |
899:
896: |
895:
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891:
888: |
887:
883:
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879:
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875:
872: |
871:
868: |
867:
864: |
863:
860: |
859:
856: |
855:
852: |
851:
848: |
847:
844: |
843:
840: |
839:
836: |
835:
832: |
831:
830:Coast station
828: |
827:
824: |
823:
820: |
819:
816: |
815:
812: |
811:
808: |
807:
804: |
803:
800: |
799:
796: |
795:
792: |
791:
790:Fixed station
788: |
787:
784: |
783:
782:Space station
780: |
779:
778:Earth station
776: |
775:
771:
763:
759:
755:
750:
742:
737:
735:
730:
728:
723:
722:
719:
713:
710:
707:
704:
701:
698:
697:
687:
682:
675:
674:
665:
659:
652:
651:
645:
637:
631:
625:
621:
620:
619:Marker beacon
614:
607:
603:
599:
596:
595:
594:FAA AIM 1-1-9
589:
587:
579:
575:
571:
565:
558:
554:
551:
550:
544:
538:
537:marker beacon
532:
524:
522:9780850451634
518:
514:
507:
503:
494:
491:
488:
485:
483:
480:
479:
473:
471:
467:
462:
452:
450:
446:
436:
432:
429:
425:
418:
416:
394:
373:
364:
362:
358:
354:
349:
344:
343:middle marker
337:
335:
313:
292:
286:Middle marker
283:
281:
278:
273:
271:
267:
262:
260:
256:
252:
248:
244:
243:United States
234:
232:
228:
224:
220:
215:
211:
208:
204:
200:
196:
192:
188:
184:
177:
175:
152:
131:
122:
114:
112:
107:
97:
95:
91:
87:
83:
79:
78:Article 1.107
76:According to
74:
72:
68:
64:
60:
56:
53:
49:
48:marker beacon
40:
32:
19:
970:Space system
957:
850:Port station
838:Ship station
814:Base station
806:Land station
681:
672:
658:
649:
644:
635:
630:
623:
618:
613:
593:
564:
548:
543:
536:
531:
512:
506:
460:
458:
448:
444:
442:
433:
424:inner marker
423:
421:
412:
367:Inner marker
342:
340:
331:
274:
263:
254:
250:
240:
183:outer marker
182:
180:
171:
125:Outer marker
120:
103:
77:
75:
55:radio beacon
47:
45:
990:Feeder link
604:; article;
90:transmitter
1035:Categories
966:Radiosonde
636:fan marker
499:References
461:fan marker
455:Fan marker
415:media help
357:glideslope
334:media help
277:New York's
231:morse code
203:glideslope
174:media help
459:The term
191:localizer
1010:Category
639:course).
598:Archived
553:Archived
482:AN/MRN-3
476:See also
223:receiver
219:aircraft
193:and the
59:aviation
57:used in
1061:Beacons
766:desig-
355:on the
241:In the
214:antenna
106:airways
100:History
92:in the
80:of the
1020:Portal
768:nation
666:
519:
270:Canada
212:. Its
195:runway
84:(ITU)
71:runway
67:pilots
930:Radar
668:(PDF)
489:(TLS)
348:amber
117:Types
517:ISBN
227:blue
181:The
606:FAA
470:AIM
468:'s
466:FAA
280:JFK
266:GPS
255:LOM
207:MHz
111:GPS
52:VHF
1037::
585:^
449:BC
443:A
341:A
73:.
46:A
740:e
733:t
726:v
525:.
447:(
417:.
336:.
253:(
176:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
