ATC IssuesA place where pilots may enter the 'lions den' that is Air Traffic Control in complete safety and find out the answers to all those obscure topics which you always wanted to know the answer to but were afraid to ask.
I've been trying to work out the rationale behind the naming, numbering and lettering for our (UK) SIDs and STARs. Naming the SID after the terminating point seems pretty sensible (asking the upcoming questions on another forum one chap pointed out that the UK's naming of the STAR after the terminating point seemed silly to him, and I am starting to see why, but I'm sure I've just stimulated another topic for discussion!)
My main pondering points are the number and letter at the end of the designator. As I understand it the number is the revision, that makes sense. On SIDs the letter (if there is one) identifies the departing runway (with all SIDs off a given runway at a given airport having the same letter) and as far as I can gather on a STAR the letter identifies the start point on the STAR. (UK ones at least.)
With regards to SIDs, if you look at say all the Compton SIDs, those letters are unique -- so B and C departures are Luton, D and E are Birmingham and so on. Is that a happy coincidence or was it engineered that way?
Is there any scheme behind the letters on STARs, or was it simply 'oh, we need a STAR to start here and end there, it's the first one to that point so we'll call it FOO 1A?'
How much of any such schemes is UK or Europe-specific?
I had a flick through PANS-OPS and PANS-ATM, they go into copious detail on how the procedures are designed (horrible memories of learning that stuff for the ATPLs) but don't talk much about the naming.
If you named all the SIDs after the place you depart from and all the STARs after the place you are going to, then all the EGLL inbound and outbound routes would be a 'Heathrow One something or other'.
In taxonomy, things are given names so that no doubt exists as to their identity.
The names chosen give an indication of the waypoint you eventually are flying TO.
The number is the revision or 'edition' of that route, and the letter identifies the start point of your route to the destination fix, whether it be a specific runway, (in the case of a SID), or a specific en-route waypoint, (as in a STAR).
Historically the SIDs extended further from the destination. EGCC had SIDs which terminated in 4 different 'countries'. The Mid !990s saw significant changes in SID/STAR nomenclature, driven by ICAO.
Oz STARs are named after the arrival fix, with various routes (transitions) to that fix. The numbering starts at 1, every time the STAR is amended in any way the number goes up 1 until you reach 10, which is numbered as 1 and start again. We've recently added letters which indicate the type of approach the STAR terminates in A=ILS, B=VOR/DME, V=Visual Approach. U & P are used for RNP approaches. I believe the adding of the letters was to comply with PANS-OPS. All of the above may be completely useless to you in the UK. If so, please accept my humble apologies.
Thanks Zooker -- and topdrop. As Zooker said, whatever 'it' is you have to give it a name so you can identify it. The question really was with regards to the SID letters -- and the fact that for 'B' and 'C' departures for any SIDs out of Luton, the B or C identifies it as being a Luton departure, D and E identify it as being Birmingham and so on -- whether being able to identify like that was deliberate or just a coincidence.
To put it another way, if Brum had a CPT 1A departure, could Luton have a CPT 1A as well? (I can't help feeling I'm starting to answer my own question, because I wouldn't have thought you'd do that.)
I'm sure it doesn't work for the entire UK, after all there are more than 13 runways with SIDs (that's assuming we used all 26 letters which I guess we don't anyway). So you'd have to work out groups of airfields that shared common SID endpoints and assign letters to runways within that group. I guess.
I've no idea what names are used now, but waaaay back the SID names for Heathrow were decided on-station and some of the guys and gals involved had wacky senses of humour. E.g. It was absolutely no coincidence that a route often used by Iberia aircraft was given a "Drake" SID.
The reporting points DRAKE BENBO and HARDY are in use today, all famous historical (Royal) Naval names and DRAKE is on the route often used by Iberia flights... probably where the wag in the tower got the name from as it was on the published route (the exit point from UK airspace)
2. Composition of designators 2.1 Plain language designator 2.1.1 The plain language designator of a standard departure or arrival route shall consist of: a) a basic indicator; followed by b) a validity indicator; followed by c) a route indicator, where required; followed by d) the word “departure” or “arrival”; followed by e) the word “visual”, if the route has been established for use by aircraft operating in accordance with the visual flight rules (VFR). 2.1.2 The basic indicator shall be the name or name-code of the significant point where a standard departure route terminates or a standard arrival route begins. 2.1.3 The validity indicator shall be a number from 1 to 9. 2.1.4 The route indicator shall be one letter of the alphabet. The letters “I” and “O” shall not be used.
... 3. Assignment of designators 3.1 Each route shall be assigned a separate designator. 3.2 To distinguish between two or more routes which relate to the same significant point (and therefore are assigned the same basic indicator), a separate route indicator as described in 2.1.4 shall be assigned to each route. 4. Assignment of validity indicators 4.1 A validity indicator shall be assigned to each route to identify the route which is currently in effect. 4.2 The first validity indicator to be assigned shall be the number “1”. 4.3 Whenever a route is amended, a new validity indicator, consisting of the next higher number, shall be assigned. The number “9” shall be followed by the number “1”.
My bold. The UK uses the point at which the STAR ends. I thought we were alone, but interesting to learn that Oz is similarly determined to confuse.
UK STAR's are named after where they end because that is the clearance limit, and its quite a useful indicator (and also worrying) that when an inbound is given direct to the hold and they say "where?", you wonder if they have actually done an arrival brief... The rest of the time the name is just a nice reminder that its as far as you go.
So, you fly the STAR to the hold (initial approach fix), then the procedure approach to the final approach fix, then down the final approach to the destination. It makes sense to know where you are going. Just like on departures, the SID is named for where you end up - because hopefully we all know where you have taken off from !!
And another thing.. The stars are sometimes common to more than one destination. eg BIG arrivals for LL and WU, and Alkin ones for KB and LC. The stars and designators are the same. Only the transitions after BIG or ALKIN are different.
As for airport codes I like the US way of doing this. ie, JFK (IATA) & KJFK (ICAO), SFO & KSFO and EYW & KEYW (Key West). Who would have guessed EGGW was LTN instead of Gatwick. Don't guess is the answer I suppose. I know our system is geographically based but it is not easy to use.
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