descend and "descend and mantain"

[L'Argonauta]

Hey there,
listening to Live ATC at Boston Logan I heard controllers using "descend and mantain" very often, what is the difference between "descend 4000" and " descend and mantain 4000"?

[PSR]

Nothing, some people just like to use more words...

[The Beerhunter]

can also pre-empt cockpit badgering for lower.

[HEATHROW DIRECTOR]

<<"descend 4000">>

Bit ambiguous, IMHO. Does it mean descend by 4000ft, e.g. from 12000ft to 8000ft or TO altitude 4000ft?

[Catwalk Dweller]

"Nothing, some people just like to use more words..."

Not true - this is prescribed phraseology in the States:
http://www.faa.gov/air_traffic/publications/atpubs/ATC/atc0405.html#atc0405.html.1

Search for "CLIMB/DESCEND AND MAINTAIN""

[southoftheborder]

Although, the standard ICAO phraseology should be 'descend to altitude 4,000 feet' occasionally, some controllers may say this in order to prevent pilots from badgering them. Also, on occasion, i myself may say, 'climb to maintain FL...' when there is traffic above/ below, and quite often to non-British pilots, who for the reasons Catwalk Dweller mentions above, will start to reach a clearance limit and will ask for further climb/ descent. I guess really though, things like this are just done at the discretion of a controller.

[2 sheds]

Although, the standard ICAO phraseology should be 'descend to altitude 4,000 feet'...
Actually, what you are quoting is the UK variation which inserts the word "altitude" for clarity. ICAO specifies...
FASTAIR 345 DESCEND TO 4 000 FEET... which is potentially inviting misunderstanding.

2 s

[BrATCO]

I would use "Descend 4000' QNH 1018".

If I don't want the pilot to bother me with further request, I would add "I call you back (in X minutes) for lower.

If there's a traffic below, I would say in an other message "I confirm, maintain 4000' reaching, traffic...", followed by the traffic information.

I also do it with flight levels, either for climb or descent.

Few months ago, there was an incident with a United States' aircraft.
After a callsign confusion, the controller said "XXX654, maintain FL310", the US pilot read-back "Maintain FL 310, XXY654"... and started a descent from 390 to 310 with no mention of a descent.:bored:

[Knackers]

Our MATS states that if an aircraft is expected to maintain a level, you should say "descend to and maintain ....."

[055166k]

In the UK we are aware of the "Maintain" effect on US carriers....following incidents back over many years. On first check-in we say "Maintain" with NO mention of a level value if the current level is to be maintained.....it also shortens the R/T.

[BrATCO]

055166k,
We (in France) are aware of that particularity too, the incident I mention was mostly due to the callsign confusion, the fact that the pilot didn't mention the descent removed a slice of cheese.

When I want the pilot to stay at his cleared and steady level, I don't mention the level at all, not even "maintain".

Most of my welcome messages are "Bonjour, identified".
I suspect that "Bonjour" is not really phraseo-correct (not recommanded by ICAO, even though useful for HF, I reckon) and that "identified" doesn't mean anything... :confused:
My aim is that the pilot "proceeds as cleared by previous controller, until further notice" and "identfied" seems to work...

[Sonnendec]

I use mainly "climb/descend FLxxx", but when i need the pilot to maintain the level (i.e. traffic higher/lower or being the final level i am going to clear him) i sometimes use the "climb/descend and maintain" phrase. It might not make any difference, because i´m aware that both clearances mean the same, but i get less requests for higher/lower when using the "maintain" at the end.

Maybe it´s just a personal perception, who knows :rolleyes:

Best regards.

[radarman]

When vectoring, the phraseology is (and always has been) 'C/s turn right/left heading XXX'. No mention of maintaining or continuing the heading. The pilot is expected to carry out the instruction and then wait for further. So why has the 'm' word crept into climb and descent instructions, causing all this confusion?