IFR Scan Technique

[White and Fluffy]

Hi,

I have recently started my MECIR and have received varying information on the method of conducting an IFR scan. During my NVFR rating and CPL I was taught a basic 'T' scan of the main instruments with cross reference to other instruments after each cycle. This was used in all phases of flight, climbing, descending, S&L, turning, etc. Now I have another instructor and they are teaching to use different scan patterns for different phases of flight with primary and secondary scans to differenet instruments. This means trying to remember about 6 different patterns and is really hard to do when you are trying to remember everything else.

My question is, what do other people do and in the long run what is the industry standard for both single pilot GA ops and the airlines? What would be expected in a sim check for an airline? If I can stay with the 'T' scan I will, if this is not adequate for more advanced aircraft and situations then I would prefer to start using the varied patterns now so it becomes second nature.

Any help and view points are greatly appreciated.

W & F.

[Justin.C]

Hi W&F it seems you and I are in the exact same position as i`m about 1/4 way into my mecir too. The reason for these new scan techniques is because IFR training is all based on IMC conditions and a high level of accuracy.... in various stages/configurations of flight, particular instruments will be of primary importance to maintain accurate control. where i`m at i`ve been taught various scan patterns with the A/H generally always being the most important. They told me everyone finds the new scans very hard to adapt to and maintain as you will get tired quickly from intense concetration, but once mastered you will be very accurate and consistent with your flying... I suggest you try your hardest to learn your schools scan methods as they will make you disciplined and and accurate with your flying!!!

Cheers, Justin.C :)

[Arm out the window]

Don't stress on it too much, guys - it's true that some instruments take on greater or lesser importance depending on the phase of flight, but once you've been flying on instruments for a while you'll develop a feel for where you should be looking most at what time.

If flying schools were to teach a single basic scan for everything, they'd be oversimplifying how most people really do things, and doing their students a disservice. For example, in a turn through a decent amount of heading change, the compass is less important than the AI, VSI and altimeter. Similarly, in a climb or descent, the altimeter's not so critical (as long as you're monitoring it regularly enough to keep tabs on how far you've got to go) until approaching the desired altitude - all common sense stuff.

If you're confused, I think the main thing to remember above all else is to spend the vast majority of the time on the AI, and control your attitude in small, positive increments. Set attitude and power, balance, then scan.
If you feel like it's getting on top of you, have you specifically set an attitude, or are you kind of waving it around somewhere in the general vicinity of where it's supposed to be?

Also, use your peripheral vision. While looking at the AI, you can see all sorts of things such as the VSI trend, etc, so think about that.

Finally, there's also a mini-scan to be done on the AI itself - pitch dot, gull wings and bank pointer. Spend most of the time on that and you'll be OK.

[Howard Hughes]

I have always used the 'hub and spokes' scan technique, I don't think it really matters what you use, so long as you get it up to speed!

SCAN, SCAN, SCAN!

Thats what its all about and as Arm out the window says, you wll eventually learn where to focus at varying stages.:ok:

[aussie027]

In my day guys we were taught basic "T scan" when doing an instrument take off and climbout.
The basic scan was the" radial scan" with the AI at the centre (hub and spoke basically) and then a "selective radial scan "for specific manoeuvres where you use the AI as the hub and scan other instruments such as say the altimeter and HSI during a level turn more than the airspeed, VSI and Turn coord.

I assume White and Fluffy that is what that second instructor you spoke about is teaching???

AS arm out the window says dont stress too much, use what they teach in the beginning and you will feel more comfortable as your experience grows and can then use a combination of methods if you find it works best for you.
I have had a CIR for over 20yrs and now I just "Use the Force", it works for me but then again I went to "the Dark Side" years ago. :E:E:E

Remember that single pilot IFR esp in a light twin that may not be too well equipped and like most of them have marginal performance esp on 1 engine is one of the most difficult and demanding flying tasks esp when you are low IFR AND low Twin time.
So fly cautiously and well within your limits (and the aircrafts) and learn something every trip and you should be just fine.

Remember ANC,...Aviate , Navigate, Communicate. in that priority order ALWAYS!!!:ok:
It CAN AND WILL DEFINITELY SAVE YOUR A** esp when you are alone, tired and it all seems to be going pear shaped.
During VFR ops it is very important, during IFR ops in IMC it is VITAL!!!
It has saved mine.
Best of luck with your training. :ok:

[Mr. Hat]

T scan will help you for a good part of your career. Later on things change a little. For ILS one of the biggest helpers is the half groundspeed on the VSI with more or less if above or below slope....

[Roller Merlin]

Flying on instruments is really is the same thing as flying Visual...that is to replace the big world outside with the little one inside (AI) and the same rules apply, but are smaller and harder to notice. When the attitude is stable and trimmed, you should look away from the AI to other instruments or do other checks for only just enough time to see what you need to observe, then back to the AI, again for just long enough to observe what you need. Make power changes by feel and sound, then when trimmed on the AI, scan to check power and fine tune it. I also recommend:

Move HDG bug or CSE before rolling
All changes on the AI, slowly, set, lock, trim and look.
Trim all the time even at low angles of bank.
When looking away from AI, think: 'priority', and 'next event' that will occur (eg: arrival at HDG, ALT, IAS target etc). Prompts like this assist if you are having trouble missing items when busy.

Often slow scanrate is quoted as being a trainees problem in a busy IF exercise. My view is that technique is of much more importance - if you do not trim and balance well in IF the fastest scan will not help you much. ALso scaning very rapidly is of no use if you cannot see the trends occuring. So make changes on the IA slowly and trim carefully is the key. Think "priority' (HDG, IAS, or whatever) then prepare for next event.

THe old hands will often say they 'just look around' rather than scan - they are really recognizing patterns and until the newbies have this expertise they need to work on techniques. Remember, you only need to look away from the AI at what you are trying to maintain or achieve at the time.

ILS: Closing C/L think: HDG change (Bank-ON, OFF, wait.) Avoid just rolling toward the CDI, otherwise you will ocillate down final.
VSI: ROD=5%x G/S, constant pitch on AI when settled, tiny changes.
Next event - check ready
Arm's advice is spot on. Relax, trim, prioritize and prepare for events ahead.
RM

[hoggsnortrupert]

You will develope what works for you;
Instructors that say you must use this, stay away from?
Instructors that explain Instrument scan priorities, is something else completely!
Also learn to everynow and then, include the instruments over on the right hand side in your scan, and as you become comfortable, learn to scan these and use these from the Left seat.
It is an ART, one that you develope, it is a personal thing:
But develope it all the same.
H/Snort.:ok:

[Eaglehawk]

For what it is worth from an old IFR Instructor, you have been taught T scan which is normal for the basic IF sequences and the more advanced scans for advanced IF.These are correct for the stage you were at then.

Be aware that you can get so much information elswhere (good though it may be) that you become slower to teach because you lose your faith in the teaching you are getting. In other words you are overloading an already 100% IFR workload with unnessary doubts.

[Shouldhe]

The 'T-scan' is not really describing the scan, but rather the layout of the instruments ALT AI ASI
HSI

That is what is referred to as a T scan. The rest is really only ONE scan - that is the selective radial scan. This ONE scan changes (becomes selective) due to the priorities at the time. For example, if you are conducting a level, rate one turn, it will take you 2 mins to complete the orbit, so when we roll in (always on the AI) we don't need to scan the HSI for almost two minutes; (we will include it in our scan, but not AS A PRIORITY until almost on our heading). Nothing is going to change that we aren't expecting (we know it will take two mins to reach our heading). What we focus MORE on during this time is the ATT, our VSI and ALT and make ATT changes to correct any deviations in level or AoB.

This works for climbing/descending as well. If we are climbing for a long time, the ALT is not important until the later part of the climb, so we only scan it occasionally, until we are approaching the height, and then include it in our scan more often.

The trick (not really a trick at all) is to understand what is the important instrument (secondary to the AI that is) and scan it as and when required.

Remember, there is only one true scan, the SELECTIVE radial scan.

Good luck with your IF flying

[Chimbu chuckles]

Hopefully you're being taught a situation specific radial scan...remember the importance of the (I)VSI...S&L and descending incorporate it in your scan at least twice as often as the Altimeter...a much ignored instrument in my view.:ok: