Monitoring IDENTS

[HEALY]

Hi guys

Currently preparing for a sim assesment where a twin locator appch needs to flown (Oz pilots may know who im talking about!!!). It is conducted in a 767

My question is in 2 parts. Firstly, do you need to monitor the idents of both locators during the approach (like an ordinary NDB appch)...and secondly does such acft like the 767 have automatic identifying of aids and provide failures of such aids as NDB/Locators


Help much appreciated

[Capt Fathom]

No auto ident.
You will have to identify both navaids before the approach.
If the aircraft or ground equipment fails, a flag will appear next to the appropriate needle on the RMI. (Make sure the RMI switches are in the ADF position, not VOR)
So there is no need to monitor the ident during the approach ... which would be difficult given two aids to listen to!

[BlueEagle]

I was told to monitor the ident of the NDB you are using as your Primary tracking aid at the time.

[Old Smokey]

Identify both locators (individually of course) immediately prior to the approach. If you have EFIS provided digital ident, DON'T believe it until aurally identified (I've seen too many corrupted idents, particularly with NDBs), and then -

If you have mechanical indicators -

Constantly monitor the ident of the nearest locator, switching to the other when it becomes the nearest. Working properly, a failed system should park at 90°/270°, but don't trust this.

If you have electronic (EFIS) indicators -

There should be no need to constantly monitor the ident. In the event of NDB or aircraft system failure, the offending pointer will simply vanish.

Regards,

Old Smokey

[john_tullamarine]

As we monitor the NDB aural as a failure check, the question really becomes one of "if we don't listen, do we have an alternative of at least the same reliability as a failure check ?"

As those of us who were weaned onto NDBs can attest, monitoring the aid is not an Herculean task ...

[LYKA]

Monitor the ident throughout the approach due to no failure flags on most ADF's etc.

[fireflybob]

On many occasions in the simulator I would fail the audio for the ADF and very rarely did the crew notice as they were busy flying the approach.

Capt Fathom - the RMIs which I am familiar with only show an OFF flag when using a VOR and there is no signal. If its switched to ADF and the beacon in use fails the needle will point to the next best signal!

I think the main factor is that when flying an ADF approach always try and back it up with other approach facilities - FMC/GPS/adjacent VOR/DME etc. It is rare that the NDB is the ONLY source of information available.

Perhaps we also have to ask ourselves whether we should be letting down in public transport a/c using such antiquated aids such as NDB although I am aware that it is the only approach facility in certain parts of the world.

[Capt Fathom]

Amazing the different procedures adopted by airlines. Obvious not all 767's are the same.
Good luck HEALY, just do what you do in your current operation.