C/P vs P/S method

Jaybird180

Jaybird180

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Jaybird180
I'm reading the Instrument Flying Handbook and an area that I do not have comprehension about involve the 2 methods of Basic Instrument Flying, Control/Performance and Primary/Supporting.

How would you explain what the difference is between the two? I got from the IFH that the difference is in the importance placed on the Attitude Indicator, but that is all I get.

Is it appropriate to favor one over the other or are there times when you will switch, depending upon the maneuver or phase of flight? Or is it strictly pilot preference?

I am honestly looking for an answer that is useful to me. I asked the question of 2 CFII's and neither even knew what I was talking about when I used the terminology. Should I make any judgements about the CFII's or is it simply one of the topics that only matters in groundschool?
 
Jaybird180 said:
I asked the question of 2 CFII's and neither even knew what I was talking about when I used the terminology. Should I make any judgements about the CFII's or is it simply one of the topics that only matters in groundschool?
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Run. Far far away. They should know. It's also part of Area VI in the CFII PTS.
 
Bullshlt. It's just gobbledygook that is of little value. That's the reason instructors don't know or care.
HPNPilot1200 said:
Run. Far far away. They should know. It's also part of Area VI in the CFII PTS.
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Wayne, I can't tell if you're being sarcastic or not.
 
I call bull**** on Wayne. It may be gobbledygook but a CFII should know the differences. Like a lot of the FOI stuff, this can be useful if applied as intended.

Jay, I'm not an expert, but I tend to like the control/performance method of setting up the instrument scan, where one adjusts the airplane attitude using the AI <control> and looks at the other instruments (Altimeter, heading indicator, VSI, airspeed) to see that you're getting the intended result <performance>. In this method the AI gets most attention with other instruments getting less.

The Primary/Supporting method has you put more emphasis on the instrument that is primary for your goal. If it's a climb, that instrument may be the altimeter and/or the VSI if it's a constant rate climb, or the altimeter and airspeed if it's a constant speed climb. If it's a turn, the heading indicator may be primary, with the TC supporting. The nice thing about P/S is that you DON'T focus a lot on the attitude indicator so you can easily adjust to a gyro failure.

But the differences between methods only really matters early on in the instrument training, where it's best to pick one and be consistent with it. It's sort of like the "elevator controls airspeed and power controls altitude" vs "power controls speed and elevator controls altitude" argument. By the time you're a proficient instrument pilot, you realize that everything is interrelated, and you'll have worked out a scan pattern of your own that ensures you are getting all the info from all the instruments, and doing the necessary cross-checking. This becomes a gestalt and is not a "look here, then look there, then look there" sort of thing. Even when you end up going partial panel, as long as you cover up the "bad" instruments your scan still remains on automatic. This is probably why Wayne says it doesn't matter - because by the time you take your ride it just doesn't matter any more. It DOES, however, matter on your written test, because there are questions on the methods.
 
Tim, after reading the article and then your post I think its clear enough...and helps make Wayne seem a little less like a cranky old man (smile).
 
I've been flying instruments a long time, and I've never been able to fully wrap my mind around primary/supporting. I memorized the terms enough to pass my IR written and oral back in 1971, but pretty much ram/dumped it thereafter and during that training actually used what I learned from the Air Force Manual on instrument flying I found in the U of M library -- control and performance. It just made sense to me, which P/S did not. C&P is what I learned in Navy flight training, too. I had to relearn P/S long enough to pass my CFI-I ride, but forgot it again as soon as the ride was over. A few years back, the FAA finally relented and allowed C&P to be used in place of P/S on IR and CFI-I rides, and since then, I haven't made the least effort to learn, remember, or teach anything about P/S.

That said, a CFI-I should be able to explain and teach at least one of those two methods even if they can't explain the other, because I don't know of any third way to fly instruments effectively.
 
Ron Levy said:
I've been flying instruments a long time, and I've never been able to fully wrap my mind around primary/supporting. I memorized the terms enough to pass my IR written and oral back in 1971, but pretty much ram/dumped it thereafter
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Same here. Control/performance always made much more sense.
 
The problem with primary/supporting is the fact that they change based on particular flight manuever.:goofy:
 
In which case why not just tell the IR student that he already figured out most of what he needs to know about the method with the cross-checking he learned while working on steep turns for his PPL ride, and the only difference is that somebody snuck in and shrunk the windshield down to 3.25"? Do a quick demo where he does a steep turn using visual references, then show him one just like it only using the atttitude instrument rather than the windshield. Then memorize three more BS questions on the written (to go with the other three about different kinds of fog) and keep on moving.

TMetzinger said:
But the differences between methods only really matters early on in the instrument training, where it's best to pick one and be consistent with it. It's sort of like the "elevator controls airspeed and power controls altitude" vs "power controls speed and elevator controls altitude" argument. By the time you're a proficient instrument pilot, you realize that everything is interrelated, and you'll have worked out a scan pattern of your own that ensures you are getting all the info from all the instruments, and doing the necessary cross-checking. This becomes a gestalt and is not a "look here, then look there, then look there" sort of thing. Even when you end up going partial panel, as long as you cover up the "bad" instruments your scan still remains on automatic. This is probably why Wayne says it doesn't matter - because by the time you take your ride it just doesn't matter any more. It DOES, however, matter on your written test, because there are questions on the methods.
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wabower said:
In which case why not just tell the IR student that he already figured out most of what he needs to know about the method with the cross-checking he learned while working on steep turns for his PPL ride,
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Problem is, as I've learned doing steep turns as part of IR training per the PIC syllabus, most of them never learned how to do steep turns right in the first place. Yes, it's no longer in the PTS, but it's still in our syllabus simply because it's a useful IR training tool.
 
Jay, Its really scary to hear that an instrument instructor has no clue what you are talking about.

As far as the P/S method, I was kind of taught that, your primary instrument is whatever you are trying to hold constant in that maneuver, and supporting is anything else that can provide valuable information. That seems to work well with what books say is "primary" for various flight conditions.
 
ajstoner21 said:
As far as the P/S method, I was kind of taught that, your primary instrument is whatever you are trying to hold constant in that maneuver, and supporting is anything else that can provide valuable information. That seems to work well with what books say is "primary" for various flight conditions.
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So, in a climbing turn, which is the "primary" instrument? Or do you have two "primary" instruments in that situation (one for the climb and one for the turn)? That's the sort of thing which makes my head hurt when trying to understand P/S.
 
I learned C/P which instantly made way more sense when the PIC instructor pitched it to me than the FAA P/S tripe. As Ron alluded, I just chalked it up to one of those inane things I had to regurgitate for the written along withe the FAA's definition of coordinated flight and principles of educational theory.

If you want to self study it, pick up the Dogan Instrument Flight Training Manual.
 
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