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bookworm
30th Jul 2006, 07:38
Yesterday, crusing at FL100, I was instructed to descend to FL70. After acknowledgement I was asked to maintain FL100 and then given a radar heading of 070. The correction was immediate and unambiguous, and presumably came from someone whose mouth didn't speak what their brain was thinking -- happens to us all from time to time.

But it made me recall that a while back there was talk of a convention of using assigned headings ending in 5 where possible to avoid confusion with assigned flight levels, which always end in 0. In yesterday's circumstances it might have sounded an alarm bell in my head if the assigned number had been 075.

What happened to the headings-end-in-5 convention? Not workable in practice?

Lookatthesky
30th Jul 2006, 07:54
It is certainly recommended as a 'Best Practice', though it is not mandatory.

2 sheds
30th Jul 2006, 08:22
"Best practice" is a ridiculous expression for something that is merely opinion! That aside, who says it is "best practice"?

What IS a requirement, in the UK, is that the word "degrees" is included with a heading value ending in a zero.

throw a dyce
30th Jul 2006, 09:09
I have yet to get an answer on this one.Up here in the Artic circle we are surrounded by Advisory routes and class G.We issue clearances that have Quadrantal levels and one is FL85.
Yet we are ''required'' to use the term degrees behind heading that have a zero.Well we can have fly heading 085,climb FL 85.No degrees needed.:confused:
This seemed to be a best practice designed by London for London.What about the rest of the country?:D

2 sheds
30th Jul 2006, 10:00
It's very simple...

"For all transmissions, with the exception of those used for surveillance or precision radar approaches, the word 'degrees' shall be appended to heading figures where the heading ends in zero, or in cases where confusion or ambiguity may result."

Dont tell um pike
30th Jul 2006, 11:58
Is anything in MATS1 ever that simple ? , the list of standard phrases for vectoring doesn't specify degrees like it does knots/miles etc so theres (another) grey area cop out (if your feeling belligerent).:rolleyes:

Can Open , Worms Out

DTUP

AirNoServicesAustralia
30th Jul 2006, 12:55
I would say that if the pilot gives a full readback of the instruction and the controller listens to the readback properly then there is no harm in using whatever heading you like. I don't find the need to use degrees as I will always say "Turn left heading 180, descend FL150." So surely the "Turn left heading" versus the "descend FL..." makes it clear which is which. I understand that pilots who may not be fully switched on at the time may get them swapped around and thats why it is our job as controllers to listen properly to make sure the instruction is understood. Just my opinion.

2 sheds
30th Jul 2006, 13:13
Is anything in MATS1 ever that simple ? , the list of standard phrases for vectoring doesn't specify degrees like it does knots/miles etc so theres (another) grey area cop out (if your feeling belligerent).:rolleyes:
Can Open , Worms Out
DTUP

Not really - my quote above is from MATS Part 1. Admittedly, the standard phrases ought also to indicate the potential inclusion of "degrees". Have you written to SRG to draw that minor anomaly to their attention?

Dont tell um pike
30th Jul 2006, 13:32
2sheds -Write to SRG ..... Hell no , head well below parapet but i do so enjoy the minefield that is MATS 1 :}

RAC/OPS
30th Jul 2006, 15:35
Headings ending in 5 is all very well, but what if you really wanted him on 270 deg. Could you say "turn left heading 275, then further left another 5"?

I propose using 271 or 276 to get around the Flight Levels +500ft problem mentioned by Throw a Dyce. Of course there will have to be situations where 269 or 274 will be used but these should be notified by the CAA and incorporated in MATS 2.

T9-ATCO
9th Aug 2006, 14:11
Well that rule is applicable only for cases where you are instructed to change heading for 5 deegres, for example if controller tells you to turn right 5 deegres, but it is not applicable if ATCO instucts you to fly heading 145!!! It can be very important in airspace where minimum radar vectoring altitudes are different and those 5 deegres can play very important roll in keeping you out of the MRVA which is above your flight altitude at the time!

Dr. Evil
9th Aug 2006, 15:12
2 sheds
That aside, who says it is "best practice"?
ICAO does...
AirNoServicesAustralia
I would say that if the pilot gives a full readback of the instruction and the controller listens to the readback properly then there is no harm in using whatever heading you like.
Can only agree to some extent. Biggest "problem" in ATC/Aviation is COMMUNICATION so therefore we should consider the Human Factor issue and prevent the "few" incorrect readback/hearbacks by using Hxx5 when misunderstanding could occur.

45 before POL
11th Aug 2006, 00:55
got to admit the 271/276 heading should work as would take away the confusion on Fl and Hdg. On a personal note i have found using "degrees" at all times has created less of a problem...in misintrepretation of a FL being passed.....but yes more R/T...only a little, but for some too much in todays enviroment. It works for me even though not mandatory.

AirNoServicesAustralia
11th Aug 2006, 09:44
Dr Evil I think you know how much we vector when sequencing into Dubai (and increasingly Abu Dhabi), too F*****G much, and I can safely say that I have never in 4 years controlling here had a pilot transpose heading for flight level, and I never use headings ending in 5's, 6's or anything else other than zeros. I clearly state "Turn left heading zero five zero", and I never give a turn instruction in the same transmission as a climb descent instruction. It really takes no more time to split the transmission into 2, and I think actually saves time since more than 6 words in a clearance to some airlines out here will always require a repeating of the clearance anyway. So personally I find the whole debate about ending headings in 5's to be a bit of a crock. But thats just my personal opinion, and I am sure ICAO knows best.

spekesoftly
11th Aug 2006, 10:16
Some 36 years ago, when I first started in ATC as a military controller, it was quite common to use one or two degree heading changes during a PAR or SRA. Eight years later, whilst under training for a civil licence, an instructor told me to only use five or ten degree heading changes, and like a good trainee, I didn't argue. Now we are told that headings ending in zero are bad news, and even those ending in five may cause confusion!

I'm a little concerned about where all this is leading - will we soon be left with just cardinal headings? ;)

throw a dyce
12th Aug 2006, 11:57
Use Metric levels.:ok: No confusion there.Fly Ten thousand six hundred degrees?:rolleyes:

spekesoftly
12th Aug 2006, 12:16
Have you not heard about pending HMG/EU legislation that will mandate the metric compass? :E

throw a dyce
12th Aug 2006, 18:15
Metrics are used in China and I believe Russia already.Why not.Everything else is going metric,and vis is already km's.You get used to them as all FL have their metric equivalent.
Metric headings?:uhoh: Just like heading 370 degrees:E

Hold West
14th Aug 2006, 07:54
I only use headings ending in "5" between 0 and 29 nautical minutes past the hour... the rest of the time I use radians east of north. Altitude should of course be expressed in Universal Coordinated Imperial Feet.

Dances with Boffins
14th Aug 2006, 08:14
My altimeter only does Imperial....:( .. and i can't see you lot managing "hectopascals" on a regular basis.

g m c
14th Aug 2006, 23:40
hope the last was for jest:ok:

same thing

Liklik balus
15th Aug 2006, 00:09
Let's do a 360 and get outta here!!!!!!!!!!!!!!!1:ugh: