Primary/Supporting Instrument Flying

[Steve Job]

I'm studying for the "test", and other than rote memorization, I can't seem to find a way to get this method through my thick noggin. The control/performance method seems so much more elegant. Any hints out there on how to make sense of this "official" method?
Thanks!

 

[matthammer]

http://www.flightinstructortheresa.com/primary___supporting_instruments.pdf

I used to think that the primary/supporting method didn't make much sense. But now that I have a little more time under my belt, I've found it's actually how I fly naturally. It's a simple matter of realizing what instrument will give you the most precise and pertinent information for each maneuver, and what instruments most naturally back up the information presented by those "primary" instruments. Memorizing the different primary/supporting pairings is obviously important for passing the knowledge and oral exams; but when you're actually flying, what's important is that you have the wherewithal and understanding to accurately determine where to get the information you need and how to verify it.

 

[Steve Job]

Thanks Matt. I have found that my IQ drops about 20 points while under the hood, so I don't have much brain power to spare analyzing which instruments to look at during each specific flight maneuver based on that chart. Maybe one day it will become natural, but for now I guess I need to buckle down and memorize! I was hoping that if I understood the underlying concepts better, I could simply derive the answers, which (for me) makes it much easier to learn.

 

[Ghery]

Thanks Matt. I have found that my IQ drops about 20 points while under the hood, so I don't have much brain power to spare analyzing which instruments to look at during each specific flight maneuver based on that chart. Maybe one day it will become natural, but for now I guess I need to buckle down and memorize! I was hoping that if I understood the underlying concepts better, I could simply derive the answers, which (for me) makes it much easier to learn.

Only 20 points? You're doing well.

 

[midlifeflyer]

Matt gave a really good explanation. One important thing to realize (that some people don't) is that C/P and P/S are not scanning techniques; they are methodologies of instrument interpretation (part of the problem is that C/P "looks" like a scan technique).

The goal of interpretation is typified by those questions on the knowledge test that ask you to look at an instrument cluster and decide which is the failed instrument. Since, for example, a real gyro failure in a round-gauge airplane is not announced by a big, hairy hand covering some instruments with sticky notes, the cross-referencing (scan) and knowledge of which instruments are giving the pertinent information (C/P or P/S) is the skill that can save one's bacon.

 

[Steve Job]

I think I have been mixing up scan techniques with these two methods of interpretation. That's an important distinction. It's just much easier to reason out the C/P than the P/S method.

I think I'm going to patent a new in-op flag that resembles a big, hairy hand holding a sticky note!

 

[nosehair]

Conceptually.

Primary: The instrument that tells you the exact precise information that you want at that moment.

Supporting: Other instruments that back-up the info provided by The Primary Instrument for that bit of information.

Example: Straight & Level

Primary Straight: Heading Indicator (gyro or compass)
Supporting: AI (wings level) Turn Needle or Coordinator (no turning)
airspeed steady.

Primary Level: Altimeter
Supporting: VSI, AI, ASI

Primary Turning: While entering the turn, turn coordinator and /or AI become Primary during control application to establish bank and rate of turn. Heading Indicator becomes Supporting to back up the primary indicators of turn. Primary level remains the same, until..

you change pitch. Then the Altimeter becomes Supporting to the Primary pitch indicator which is, depending on your technique or the aircraft's performance, VSI or ASI, with the AI supporting that.

Basically, it means focusing on the Primary Instrument for that activity.

I boil it down to 3 things: We have to fly a Heading, an Altitude, and an Airspeed. That's what we told ATC we would do.

Power takes care of the a/s, as long as you take care of the heading and altitude promptly and smoothly. Fly a constant heading and a constant altitude and the airspeed stays steady, so you just have to focus on those two Primary Instruments. Check the EveryThing Else Supporting Instruments to just make sure these two aren't lying, but they are supporting.

When you're not holding a Heading, or an Altitude, then these two Primary Instruments are no longer Primary, so what is replacing them? What are you doing? Making a Power change? Then, in that moment, the power guage is Primary. Slowing Down? Airspeed becomes Primary.

Get the concept?

 

[poadeleted20]

I'm studying for the "test", and other than rote memorization, I can't seem to find a way to get this method through my thick noggin. The control/performance method seems so much more elegant. Any hints out there on how to make sense of this "official" method?

If you're speaking to the written test, all I can suggest is rote memorization followed by a memory core dump after the test. The FAA some years ago changed its "primary/supporting only" stance for practical tests, and now accepts knowledge of either method on the IR practical test for both pilots and instructors. Unfortunately, the written tests have not caught up with that, and still ask primary/supporting questions -- one can only hope they'll come up with a "dual track" system like they did for the ATP written with 121 and 135 options.

FWIW, since I agree with Steve's characterization of the two methods, I teach C&P exclusively, and have been using it myself for many decades since learning it in Navy flight training in 1973.

 

[coflyer]

Rod Machado's Instrument Pilot's Handbook has a very clear presentation about P/S method. Rod also developed an easy way to remember those combinations.

 

[Steve Job]

Nosehair, that's exactly what I was looking for! Ron, it's good to know either way will work during the oral. And Coflyer, I will have to add Rod's book to my ever growing inventory. Matt and Mark, thanks for taking the time to respond with your thoughtful answers.

You folks are incredible with your well thought out answers to my silly questions. Now if I can just find a way to bring my IQ back up!

 

[dtuuri]

For those IFR students interested in an overview of attitude instrument flying, specically the difference between Control/Performance and Primary/Supporting, I've produced a tutorial that attempts to cut to the chase here: "It's not your flying, it's your attitude".

It also covers Howard Stark's original method of blind flying. Other tutorials are available free if you click on the link in my signature line.

dtuuri