PPRuNe Forums - RT phraseology for let downs

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Quote:

Originally Posted by dagowly (Post 9255812)

No one cares if you call it RT phraseology or RTF :rolleyes: everyone knows what you mean.

OP - You want to ask for a cloud break decent -

"<station> request cloud break descent"

"<callsign> descend to altitude xxxx, QNH/RPS xxxx (xxxhpa)"

"xxxx (xxxhpa) set, descend to altitude xxxx <callsign>"

They will get you to the TSL (terrain safe level) that will be on their radar screen which will depend on the area (1000' above the surface level or to 2000' over mountainous terrain, rounded up to the nearest 100'). At that point if you require further (which you will need to ask for) they will automatically put you on a TS, remind you of your own terrain clearance and then approve your descent. They will not give you levels below the TSL. Any further questions, please ask. I deal with this request by civil and mil aircraft on a daily basis :ok:

Totally wrong! In class G, the controller would reply something like 'no known (or observed if using radar and you are identified) traffic to affect descent to altitude xxxx'

I'm a bit confused here. Isn't it illegal to descend below MSA in IMC?

Quote:

Originally Posted by chevvron (Post 9256031)

Totally wrong! In class G, the controller would reply something like 'no known (or observed if using radar and you are identified) traffic to affect descent to altitude xxxx'

'Something like'? They either follow the procedure correctly, or not. It isn't a clearance either. If you are IMC and therefore DS under UK FIS rules in class G, you will be descended and given standard separation against other traffic/contacts to the ASA/TSL. Once at the ASA/TSL it is the pilot's decision if they want to descend further. If they do chose to, then they will automatically be given a TS as no controller is allowed to give a DS below a safe altitude/level.

I don't know how to make this all any clearer.

One caveat I would put is that ATC will always cover their backs so that in event of an accident they are not involved in blame.

I can remember donkeys years ago being in a position where we had to land a twin and land quickly.

The military base were colour code red with an 80 foot cloud base. On hearing the problem we were vectored for a PAR and had the usual chatter all the way down to the point that if not visual at the minima on the PAR we should miss.

Obviously we were not visual and they knew it too so having passed that information intensified the talk down till the high intensity lights became visual at 80 feet :E but great bunch of intuitive people

Pace

Chevron

Don't know when you last did a descent to get VMC below but Dagowly is pretty much spot on, the only minor errors if you can call it that, is if when a DS ac arrives at the TSL, you should request the aircrafts intentions and only apply TS (& approve further descent) if the pilot request TS, not automatically impose TS. He would then be given "taking your own terrain clearance descent approved".
Also the 1000 feet above would not use the surface as datum but the highest obstacle.
So not totally wrong but a pretty clear way of explaining I thought.

Moli

Quote:

Originally Posted by Moli (Post 9258240)

I was looking at it from a Farnborough point of view after 7 years of retirement. In class G airspace, the pilots 'normally' asked for traffic service (or RIS as it was) to descend through cloud and hence I would not 'clear' them to a specified altitude but simply pass information as required. Bearing in mind Farnborough LARS sectors have/had a blanket of 1,500ft below which radar service is not provided except within the area covered by the Farnborough SMAC chart you would terminate radar service on passing 1500 and advise the pilot that further descent is at his/her discretion.