PPRuNe Forums - Localiser back beam

PPRuNe Forums (https://www.pprune.org/)

- ATC Issues (https://www.pprune.org/atc-issues-18/)

- - Localiser back beam (https://www.pprune.org/atc-issues/608966-localiser-back-beam.html)

Mooncrest

17th May 2018 10:16

Localiser back beam

If, for whatever reason, an aircraft is making a visual approach to a runway and the ILS is radiating for the other end, are pilots permitted to use the back beam for azimuth guidance ? I know doing so would probably defeat the object of a visual approach but I'd be interested to know if any authorities or AOC holders have their own policies.

chevvron

17th May 2018 14:25

Officially in the UK no, but some countries do authorise back-course approaches.

topdrop

17th May 2018 22:57

There are many back beam localiser/DME (not ILS) approaches around the world - used to be plenty in the US - don't know if that is still true.
Selecting the BC switch, gives the normal left/right indications rather than reversed.

Packer27L

18th May 2018 09:32

Mmmmm sounds a bit dodgy.

Simtech

18th May 2018 13:28

From CAP 670:

ILS10.36 Facilities designed to radiate a back beam are not permitted.

I came across this when a foreign training captain snagged the sim for not letting him do a backcourse ILS at a British airport. He was quite surprised when this document was pointed out to him.

wiggy

18th May 2018 16:24

Quote:

Originally Posted by topdrop (Post 10149766)

There are many back beam localiser/DME (not ILS) approaches around the world - used to be plenty in the US - don't know if that is still true..

Looks like there are still some, just had a quick look at our documentation for the States and it reveals a Back course to Tucson 29R.....(also still a few in Canada, e.g. Goose).

wiggy

18th May 2018 16:25

Quote:

Originally Posted by topdrop (Post 10149766)

There are many back beam localiser/DME (not ILS) approaches around the world - used to be plenty in the US - don't know if that is still true..

Looks like there are still some, just had a quick look at our documentation for the States and it reveals a Back course to Tucson 29R.....(also still a few in Canada, e.g. Goose, RW 26.....Back course/NDB ).

Mooncrest

20th May 2018 12:35

Interesting replies to my question covering many possibilities. Allowed, not allowed, not designed for it, maybe. I suppose at many major airports there is at least a localiser on both ends of the runway nowadays so there is less likelihood of using a backbeam.

dook	20th May 2018 12:44

In my flying days back-beam approaches were not permitted because the signals were never calibrated.

I suspect that may still be the case, but I might be wrong.

wiggy

20th May 2018 14:19

So not approved in the U.K. but for the avoidance of doubt the back courses I referred to earlier at Tucson and Goose are published IFR procedures.

topdrop

21st May 2018 04:20

Quote:

there is at least a localiser on both ends of the runway nowadays so there is less likelihood of using a backbeam.

One place I worked has ILS one end and LOC the other. B737 cleared for the ILS - unfortunately both pilots had tuned the wrong frequency, the localiser at the other end and did not notice that glideslope was not active - . They were right of centreline, so followed the needle and turned right - quick vector to left avoided adjacent hills.
Note: this was back in the days when the pilot had to select the frequency.

oggers

21st May 2018 07:26

There is no prohibition anywhere on using the back course for advisory guidance when carrying out a visual approach. The difference between that and using the back course for an instrument approach where no such procedure is published should be obvious, I would have though before reading this thread.

I think Lookingforajob called it right.

All times are GMT. The time now is 01:11.