View Full Version : VOR Selection

18th Aug 2009, 16:00
A recent article in CAA GASIL stated 'many instructors use STIR (Select,Tune, Identfy, Radial) when selecting a VOR.

I was under the impression most instructors in the UK use SITS (Select Indentify Test Sensible Information) or TITS. Since the article was about miselection or VORs, SITS to me seems more logical, since the (S)sensible information element can catch errors, and works equally with NDBs and to some extent GPS.

I would be interested what other instructors are using, and where STIR originates from?

Cows getting bigger
18th Aug 2009, 19:00
I use SID (select, identify, display).

18th Aug 2009, 19:03
I've never used any of them, and have never taught any of them.

Pick the VOR, dial the frequency, listen to it, use it...not exactly rocket science.

18th Aug 2009, 22:23
I agree... no rocket science... BUT... students find it so easy when given something concrete to work with. At my school, TITS = Tune Ident Twist Stand-by

Call it whatever you want....

18th Aug 2009, 22:31
How about SIU Select, Ident, Use!

19th Aug 2009, 00:07
I think some instructors go overboard pushing mnemonics such as this. This is why we have checklists. Basic actions such as tuning a radio don't really need memory aids any more than we need a checklist to open the door.

19th Aug 2009, 02:26
My previous school used "Tune-Identify-Test" but you can't test a VOR like swinging an ADF needle and so it is modified to "Check no flags" and by then the student forgets to twist the OBS knob for the intended radial - so much for mnemonics.:(

19th Aug 2009, 02:42
You can't test a VOR? Really?

So if it idents it's working - by definition?

19th Aug 2009, 08:26
Not sure I agree with instructors going overboard with mnemonics, they have there place.

and lets not forget red, blue, green

Checklists have there place, especially when you have a copilot to read out the checks, but during pre aerobatics checks, I don't want to be reading a checklist. As for restart and shutdown on singles mnemonics and checklists are not much use.

19th Aug 2009, 15:21
Hi Keygrip, never had a Mod asking me a question before, but there's always a first time, right ?

The confusion stems from the view taken by some instructors that monitoring an audible ident is necessary throughout an ADF letdown but because the VOR has the flags, the audio is turned off after the "Identify" stage and the rest of the letdown is spent keeping an eye out for any flag popping up. Why shouldn't we monitor the ident in the entire VOR procedure ? I have no idea because that was the way I was taught.

19th Aug 2009, 16:05

Monitoring of the NDB is necessary during use as there may be no indication of a loss of signal, otherwise; the needle may simply die where it is, and one could follow a dead needle.

With a VOR signal, loss of signal will cause the instrument to flag. The purpose of identifying the station isn't to verify a constant signal, but to make sure one is tuned to the correct station. This is no different than the ADF procedure, in that any use of a ground based nav transmitter must include verification that one has selected the correct transmitter facility.

Once a VOR has been selected and identified, however, continuing to ride the audio isn't necessary. Fluctuations of the ambiguity meter (to/from flag) and flashing or presence of the off indicator flag suggest signal instability or loss, as does variation of the CDI needle. (If it were an ADF, one might see no changes in the needle position...suggesting a strong signal, and thus might follow a dead needle during a signal loss, transmitter failure, or instrument problem).

The VOR equipment on board, of course, requires regular tests for accuracy on an operational basis using either a VOR or VOT test signal.

19th Aug 2009, 17:13

I think you miss Keygrips point (and his irony as well, me thinks!)

He knows full well that you can test a VOR and certainly in the environment that he works it is as much a part of flying as it is in the rest of the world. Indeed, the VOR test in FAA land is more common and more rigourous that it is elsewhere.

His second comment also demonstrates a degree of irony....even though the VOR is emitting a morse ident does that automatically mean that it is emitting the correct signal and that the machine is reliable. It may be that the VOR is sending out TST to mean the signal is unusable - but your flag will still be 'away' on the instrument. It may also be that the CDI can be centered using the OBS and the singal is blatantly out of tolerance. How many people actually do decode the morse properly each time?

Cows getting bigger
19th Aug 2009, 17:45
My Garmin 530 does it for me. :)

19th Aug 2009, 18:26
Actually, the Garmin 530 really doesn't.

19th Aug 2009, 19:39
The RAF Jetstream mafia used to teach 'TIMTS'. Presumably because they couldn't really teach 'TITS'?

Anyway, this utterly stupid acronym stood for:

Tune - OK, how the heck else are you going to select a VOR or NDB? By thought??
Identify - fair enough.
Markers - WTF have 'markers' got to do with anything? Or maybe they still thought lovingly about 'airways fan markers'?
Tracks - Again, if you want to follow a radial on an HSI, how else are you going to do it?
Selections - Huh? That covered a whole host of potential switch pigs and was a completely useless check.

I'd go with Whopity - select it, check it, use it!

Another METS nonsense was the 'Four asymmetric considerations' when flying an asymmetric approach. These were:

Clearance obtained
Runway clear
Gear down
Stable approach

WTF has any of this got to do with asymmetric flying? Did they accept symmetric approaches without clearance, to blocked runways with the gear up from unstable approaches? And why no mention of VCH or MAAS?

METS - undoubtedly the worst training I ever suffered in the RAF. Fortunately I only had to endure 15 hours of their bull$hit on the horrible Jetstream T Mk 1. I hope the things were eventually bulldozed into a scrap pile.

Together with their aeroplanes.

19th Aug 2009, 21:09
Thanks for all your input, but I'm still looking for anyone who has heard of STIR , according to the UK CAA 'used by many instructors' so far not one pprune!

20th Aug 2009, 07:23
Quite frankly I had never heard of anyone using a Mnemonic to operate a VOR till I read this thread. STIR is obviously concocted by DC for editorial purposes.

20th Aug 2009, 08:04
This obsession with Mnemonics is what I call the "MacDonald's" approach to aviation - ie for 15 year old - put the fries here for 5 mins, then add the burger etc. Great system until the fat fryer fails!. It doesn't teach the understanding behind what you are doing and inhibits trainees from "thinking"!

Even some quite big airlines are using these systems so you constantly having to think now which mnemonic do I use this time and what does it stand for!

Am not totally against mnemonics but we do seem to have gone overboard on them.

Mind you the one I remember from my Hamble days was "Port Published, Right Reciprocal". This was designed for the VOR CDI needle to swing from left to right when used as a cut for a waypoint - if the VOR was on your Port set the Published Radial, if on the right set the reciprocal (of the published radial). This was a handy system because when the workload was high if you saw the needle was on the left you had yet to reach the waypoint and vice versa.

Of thats all TTFN!

20th Aug 2009, 09:41
I hear the wisdom of a certain late FIC instructor in those words! I couldn't agree more. Ho for another cup of tea and slice of apple.


20th Aug 2009, 20:33
I am still seeking the 'many instructors' who according to DC of use STIR, perhaps it's an editorial error. Perhaps I should offer a reward.

21st Aug 2009, 06:03
I'd never heard of 'STIR' before reading about in the latest GASIL. Nor have I ever heard of anyone who didn't understand that, to use a radio you first have to tune it....

Far too many mnemonics have been invented over the years. Some are really only for FIs to identify the actual requirement, others are plain daft.

Such as that DRIBBL or DABBL thing which I've heard is taught by one particular outfit?

Cows getting bigger
21st Aug 2009, 06:25
I think it' DABLE. :)

Personally, I just use FREDA & BUMPFFCHH (noting the various versions of the latter :\ )

21st Aug 2009, 09:23
What is DRIBBL or DABBL ?

21st Aug 2009, 12:14
Never heard of STIR. Wouldn't select and tune mean the same thing ? Some people just like to make up stuff to be different. Doesn't matter how it is remembered as long as it is. Using a mnemoninc is no different to using a checklist, memory is all about association.
What I have an issue with is instructors who change a students perfectly well executed method or action to their own for no reason other than ego. I have seen this a lot

22nd Aug 2009, 07:56
At the Flying School where I taught, DABEL was used in the climb; if I remember correctly, it went as follows:

D - Direction
A - Airspeed
B - Balance
E - Engine
L - Lookout

I personally found it useful to use such mnemoics, particularly when introducing a new element of the syllabus, as they provided a simple way to cover the various elements involved. However, I do have a very vivid memory of teaching one chap the climb using this method. We briefed it thoroughly (or so I thought), then, having demonstrated, when it came to his turn, we kept getting to the 'B' - and he couldn't remember what it stood for! I find myself sitting here now, several years on, chuckling away as I recall how the lesson descended into farce as we repeatedly tried to get this sorted. In the end, I just said 'forget DABEL', do what you think is right!'. And guess what? He did - and was fine. Simon, if you're out there - well done, mate!

So, I learnt about teaching from that. However, I did continue to use DABEL and can remember no other cases of students having problems. Like many things in life, there is more than one way to skin a cat. In my humble view, mnemonics have their place but are just one of the tools that can be employed to teach a technique or method.

22nd Aug 2009, 11:40
What a daft sequence 'DABEL' is then..... Why no mention of Attitude? That is the key to visual flying.

Maintaining anything (in this case the climb) should be simply, L00kout, Attitude, Instruments.

Instruments in this situation, as well as ASI, altimeter, DI and ball includes a good Ts & Ps check every 1000 ft or so and L00kout should include a positive check that there's nothing hiding behind the nose, so a gentle turn into a clear area, followed by a reverse to clear the previously hidden area. NOT shoving the control column forward to peer over the cowling - that's lazy and a very poor habit to develop.

I used to suggest the positive check every time the altimeter needle passed 000 and the engine instruments every time the altimeter neddle passed 500. Needle up, l00kout behind the nose, needle down look at the engine Ts and Ps - easy to remember and no additional mnemonic.

22nd Aug 2009, 12:08
Beagle agree 100% - KISS = Keep It Simple Stupid!

Why make it so complicated with these ridiculous mnemonics? The student has enough to think about.

Flying is quite simple but there seem to be plenty around who want to make it complicated.