En Route Comms Failure Question

[Dengue_Dude]

Hi, we've just had an interesting discussion on the flight deck concerning the ICAO Comms failure procedures.

Given that the aircraft comms are at fault, an IFR flight and there is no EAT received or acknowledged.

When do you descend to make good your ETA? We are not quite sure if you are supposed to go overhead your destination navaid at cruise altitude or descend according to your current flight plan to make good your original ETA.

What's confusing me is the 'make ETA +30', is the 30 minutes time to descend from overhead at cruise altitude or just a time 'window' in case you're late - you know like a bit of flex before overdue action is taken?

Sorry if this is a bit basic or been asked time and time again, but as the only native English speaker on the flight deck I said I'd try to find an answer as there are so many ifs, buts and ors in the Jeppesen Supplement I'm now quite confused. Also the section we read doesn't actually mention the 7600 squawk (it was mentioned in the Hong Kong PRC national section on Emergencies).

Can anyone give me some guidance or point me to something that unravels the legalese writings I'm struggling with? Is there a Guru?

Thanks

[ratarsedagain]

My reading of the ICAO basic Comms fail procedure, is that you would maintain Cruise Altitude until commencement of descent over the designated nav aid serving the aerodrome of intended landing, the time of which would be either your EAT given and acknowledged, or ETA according to the filed flight plan if no EAT given.
I would read the '30 minutes' as the time to descend, and make the approach, as your ETA for the approach aid is "revised according to current flight plan".
The thing to be aware of is regional differences from the basic.
e.g. Procedures for the European region (general) have you descending from cruise alt over the designated nav aid as per ICAO basic, however in the UK, you would arrange to be over the designated landing aid according to the published descent profile, or the highest notified MSA if no profile published.
Hope this helps :ok:

[Dengue_Dude]

Yes, thanks for the reply.

We wondered whether the 30 mins was the time given to descend from overhead the beacon associated with your destination.

What we weren't clear about was whether you were supposed to descend to make good your ETA or EAT (if given) or arrive overhead at cruise altitude, then descend to arrive at up to ETA plus 30 mins.

It's still not absolutely clear but your reading is much the same as ONE of our options.

There MUST be a defintive answer out there but looking in the Jepps the 'black and white' isn't fully clear to me - who is English and so is the text but someone moved the interface out of sync!!!

Am I just thick?? Or was it written by lawyers?

[Dengue_Dude]

Please don't regard this comment as provocative but:

Is the lack of response here due to disinterest

or,

are the ICAO Comms Failure basic rules as obscure to others as they are to me?


I remember doing English Comprehension at Grammar School 30 + years ago, I was quite good at it then. . .

OH how times have changed.

[RUDAS]

as far as I understand it,one is required to arrive at cruise level overhead the navaid serving the destination,then start a spiralling descent into the aerodrome.:cool:

[411A]

Likewise, would agree with RUDAS.

Oddly enough, had to do this (more or less) one time only, arriving at LHR.
ATC asked us to remain at FL370 while holding at LOGAN, due to an ATC radio problem with another aircraft.
Now the hold at that time at LOGAN was depicted at 'max 210KIAS'.
As this was clearly not possible at out altitude, so informed the controller.
He asked 'why not?'

Maybe if fam flights could be done on a more regular basis...or indeed done at all, the ATC folks would have a better understanding of aircraft performance.

After this ATC 'problem' with another aircraft was solved, descent was begun in the holding pattern at LOGAN.
Then...onwards to LAM and more holding.
The ATIS was reporting 4km...but I began to wonder.
Asked the F/E to monitor LHR ground, and sure enough, they were in the process of switching to LVP procedures, all the while the ATIS still indicated 4km.

Made a beeline for LGW...and was the first in the very long line that followed.

That particular day...LHR ATC was not as sharp as desired...or usually expected.

[Dengue_Dude]

I can't thank you enough for the replies. The trouble IS (or is it just me) that you COULD read it two ways.

I am glad the consensus is that you arrive overhead at cruise level THEN descend because that makes sense.

They'll (in all but the outback) have you on primary and secondary radar. They won't be able to talk TO you and get a response.

They will have established by then (failed vectoring etc) that you can't hear THEM. So following the latest flightplan to destination makes every kind of sense.

Presumably then this IS where the 'extra' 30 minutes comes in ie for the descent.

If they've been tracking you progress throughout your flight from failure to destination, there'd be NO NEED for the 30 minutes would there?

They'd know EXACTLY where you were and would have arranged for other aircraft to be vectored away from you iaw ICAO Procs.

I believe you guys have cracked it and given me the confidence to go back, reread and then translate in 'everymans' English for the guys I work with - remember for them, English is a second language.

I don't even do ONE that well, so I admire them for it.

Thanks again.

411A - yes surprising that, LHR are usually right on the button.

edited for clarity (one day I'll get it right first time :-) )

[the grim repa]

rataresedagain is bang on the money.