Instrument flying settings Cessna 172N

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Blueangel

Line Up and Wait
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Scott
So I'm using a Cessna 172N for my instrument training in San Diego. Found settings in PoH for Vx and Vy but nothing for instrument settings. My CFII asked me these for the following:

Maneuver Rpm Pitch setting ASI VSI
Climb
Cruise
Cruise Descent
Approach
Approach descent
Non precision descent

Any idea what these would be for instrument flying in the 172N?

Thanks!
Scott
 
Blueangel said:
So I'm using a Cessna 172N for my instrument training in San Diego. Found settings in PoH for Vx and Vy but nothing for instrument settings. My CFII asked me these for the following:

Maneuver Rpm Pitch setting ASI VSI
Climb
Cruise
Cruise Descent
Approach
Approach descent
Non precision descent
Click to expand...

Better learn to answer them...
 
Blueangel said:
So I'm using a Cessna 172N for my instrument training in San Diego. Found settings in PoH for Vx and Vy but nothing for instrument settings. My CFII asked me these for the following:

Maneuver Rpm Pitch setting ASI VSI
Climb
Cruise
Cruise Descent
Approach
Approach descent
Non precision descent

Any idea what these would be for instrument flying in the 172N?

Thanks!
Scott
Click to expand...

Yes, I have an idea as to what they should be. The should be what works for you in your airplane, and that is done by taking a lesson w/ your CFII and finding out for yourself what each of the settings should be. Otherwise, you'll be using generic settings that may or may not work for your particular airplane and prevailing atmospheric conditions. Good luck with your experiment.:D
 
Gotta go up in the plane and find out.

You can find cruise RPM numbers though in the POH.
 
Agree I just wanted a ball park estimate based on what your instrument flying experiences have been in a 172N. I usually climb at Vy but not sure on the approach settings.
 
Blueangel said:
So I'm using a Cessna 172N for my instrument training in San Diego. Found settings in PoH for Vx and Vy but nothing for instrument settings. My CFII asked me these for the following:

Maneuver Rpm Pitch setting ASI VSI
Climb
Cruise
Cruise Descent
Approach
Approach descent
Non precision descent

Any idea what these would be for instrument flying in the 172N?

Thanks!
Scott
Click to expand...

Pitch settings? It's a fixed prop

Also ask your CFI what numbers we would use at full gross? With ice on the airframe? 300lbs under gross? With a DA of 6k? With mod turb?

Use whatever settings yield the correct performance.
 
Those numbers are things you'll easily get a feel for in the beginning as you are working on stabilized flight, climbs, descents, A/B patterns, etc.

I'm not sure why your CFI would expect you to know before actually going up for a lesson.

I don't know if it's "proper" or not, but I tend to just fly whatever it takes to hold whatever number I want vs. immediately going to some pre-memorized number.
 
I'll get you in the right ballpark based on my 172N settings, but yours may vary by a few hundred RPM. Which is why everyone is (correctly) telling you to find out for your own airplane.

I fly approaches at 90kts and level flight at 2100RPM gives me that speed. When it's time to begin my descent, I throttle back to 1700RPM to get a 500fpm descent at 90kts (no flaps).

I'm guessing your settings will be close to that, but almost certainly WON'T be exactly the same. You should be able to fill out those numbers with a quick flight with your CFII, though.

Good luck in your training and keep us updated on your progress!
 
Blueangel said:
So I'm using a Cessna 172N for my instrument training in San Diego. Found settings in PoH for Vx and Vy but nothing for instrument settings. My CFII asked me these for the following:

Maneuver Rpm Pitch setting ASI VSI
Climb
Cruise
Cruise Descent
Approach
Approach descent
Non precision descent

Any idea what these would be for instrument flying in the 172N?

Thanks!
Scott
Click to expand...

It's not something you'd find in the POH although the information to calculate a lot of it is in the POH. It's about knowing what power and airspeed settings to make to achieve someting so you can just do it and not be spending a lot of time "chasing" them. In a C172 it's basically just what RPM and Airspeed should I start with to: climb at 500fpm, descend at 500fpm, fly a 3 degree glideslope, etc. etc. You're going to be plenty busy enough with other instruments that you'll not be wanting your attention diverted to "chase" power settings and airspeeds. You can get a good start on it in the Performance section of the POH. Lots of info there that will tell you what RPM at what temperature will get you rate of climb at what altitude. Don't overthink it. Just start thinking about it.
 
These questions are irrelevant, you use the setting the conditions warrant for the speed you want. Cruise numbers are irrelevant in a 172, you leave the throttle wide open. Approach I typically fly at 90. I almost never climb at Vy unless there is a pressing reason to do so.
 
Find the airspeed and rate of descent numbers you want and either lookup (or better determine in flight) the power setting necessary to attain them. The process is detailed in an early chapter of Peter Dogan's book. The PIC curriculum teaches this on the stimulator in the first lesson and in your aircraft the second.
 
Blueangel said:
So I'm using a Cessna 172N for my instrument training in San Diego. Found settings in PoH for Vx and Vy but nothing for instrument settings. My CFII asked me these for the following:

Maneuver Rpm Pitch setting ASI VSI
Climb
Cruise
Cruise Descent
Approach
Approach descent
Non precision descent

Any idea what these would be for instrument flying in the 172N?

Thanks!
Scott
Click to expand...

Scott, for any given flight condition, my school teaches us to think about the "four fundamentals" of pitch-power-rudder-trim. With a 172, I think power and RPM are synonymous for this purpose.

I haven't even started my instrument flight training yet, but for what it's worth, this partially-completed table for a Cessna 172 is from my flight school's instrument syllabus. I wouldn't put too much weight on its content, but maybe you can glean something useful from it?

I assume that you specify pitch (your "pitch setting") in terms of the attitude indicator's horizon. Page 6-5 of the IFH talks about very subtle positioning of the AI's horizon bar relative to the miniature airplane for climbs or descents, i.e. starting with no more than one-half the bar width.

Your instructor's interest in having you understand what the ASI and VSI should show makes good sense too. Some airspeeds are embedded in the table below.

Cessna172_PPRT_Settings_for_IFR.jpg
 
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flyingron said:
Find the airspeed and rate of descent numbers you want and either lookup (or better determine in flight) the power setting necessary to attain them. The process is detailed in an early chapter of Peter Dogan's book. The PIC curriculum teaches this on the stimulator in the first lesson and in your aircraft the second.
Click to expand...

Nailed it.
No disrespect to you, but this is one of those times where the "other" Ron would chime in.

For the OP, I think the paper test is about getting the trainee acquainted with Chap 5 of the POH, looking for every bit of data than can possibly be extrapolated.
 
James331 said:
Pitch settings? It's a fixed prop

Also ask your CFI what numbers we would use at full gross? With ice on the airframe? 300lbs under gross? With a DA of 6k? With mod turb?

Use whatever settings yield the correct performance.
Click to expand...

Pitch setting means degrees above level, measured by bar widths on the AI.

Every instrument student should go up with a CFI (there is a lot of head-down time) and develop these numbers for the airplane they will be training in. If Cap'n Ron were around he would tell you that the PIC courses use this approach. I discuss it in THE COMPLETE ADVANCED PILOT as well. Once the student has "the numbers" memorized, aircraft control is pretty much second nature and s/he can devote their attention to navigation and communication.

Bob Gardner
 
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Thanks for the tips. Well just back from testing out the various settings from today's flight in the Cessna 172N. Here is what I found worked:

RPM AI pitch setting ASI VSI

Climb 2500 FT + 1 bar +75 +700
Cruise 2300-2400 Horizon. 90 0
Cruise descent 2400 -3/4 to -1 105 -500
Approach. 2450 Horizon 90 0
Appch Desc. 1750 -1/2 90 -500
Non prec Desc. 1600-1700 -1 90 -700 to -900

Note: this is in a 160-180HP C172N and speed in knots so 172S will differ.
 
Slow cruise is higher RPM than fast cruise? Really?

My slow cruise works out to closer to 2100 RPM and nearly 5 deg pitch.

That's a slow 172N. I can get 100 knots out of 2400 RPM level. Barely.
 
Blueangel said:
Note: this is in a 160-180HP C172N and speed in knots so 172S will differ.
Click to expand...

Something to remember is that each individual aircraft needs its own set of info on this. If you were to use a different 172N, these numbers would get you close, but something will require tweak and change. But now that you know the method, you can reproduce as required.

Just bring a safety pilot or CFI to assist with both See and Avoid and the precision flying.
 
Yeah it is a very slow 172N! Then again at 90-100/hr wet rate far less than most places to rent for training. Ok so now I need to find a new instructor who can train early weekday mornings. The initial CFII has to take a month vacation next month and cannot train early weekday mornings. I enjoyed my San Diego aircraft checkout flights with the instructor so now harm done.
 
Blueangel said:
Note: this is in a 160-180HP C172N and speed in knots so 172S will differ.
Click to expand...

Do you mean it's a 180 conversion? Mines a 180 Conversion and at 2400 I can get 115 knots. I typically cruise at 2300 at 110 Knots. It's also a STOL so on approach I start with 1700 and adjust from there depending on all the other factors.
 
The club 172N are 160HP so very slow compared to the 180HP conversion 172N I used to fly in Sacramento. Yesterday we tried all settings to arrive at the instrument flying numbers. I would imagine a Piper Warrior or Piper Archer would post similar numbers.
 
Blueangel said:
The club 172N are 160HP so very slow compared to the 180HP conversion 172N I used to fly in Sacramento. Yesterday we tried all settings to arrive at the instrument flying numbers. I would imagine a Piper Warrior or Piper Archer would post similar numbers.
Click to expand...

I've occasionally used a Warrior for instrument training.

It's not all that appropriate for a real clearance. It won't do 500 FPM above about 5000 DA at Vy, full throttle, and leaned for best power. So, if you do use it, remember to notify ATC. See AIM 4-4-10.

An Archer is better. I've flown three 172Ns (one with a 180 conversion) and two 172Ps for instrument training. They are all faster than the OP reports, and all perform better than the Warrior.

The favorite is the 180 HP conversion, largely because it's the best rigged and has rudder trim. It will do 115 TAS at altitude, but not IAS, at 2400 RPM. More like 100-105.

The 177RG will go that fast, but I haven't used it for instrument training yet.
 
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Agree MAKG the Warrior is a dog. I would prefer to use the 180HP Archer or Cessna 172 if one is ever available for the bargain prices I am paying now to train for my IR in.
 
MAKG1 said:
I've occasionally used a Warrior for instrument training.

It's not all that appropriate for a real clearance. It won't do 500 FPM above about 5000 DA at Vy, full throttle, and leaned for best power. So, if you do use it, remember to notify ATC. See AIM 4-4-10.

An Archer is better. I've flown three 172Ns (one with a 180 conversion) and two 172Ps for instrument training. They are all faster than the OP reports, and all perform better than the Warrior.

The favorite is the 180 HP conversion, largely because it's the best rigged and has rudder trim. It will do 115 TAS at altitude, but not IAS, at 2400 RPM. More like 100-105.

The 177RG will go that fast, but I haven't used it for instrument training yet.
Click to expand...

Blueangel said:
Agree MAKG the Warrior is a dog. I would prefer to use the 180HP Archer or Cessna 172 if one is ever available for the bargain prices I am paying now to train for my IR in.
Click to expand...

One of the shadier clubs at Centennial has a Warrior. I refused to fly it. KAPA, 5850 ish elevation and 9,000' DA at times. Nope. Then again, we took their Gutless 172RG up to Leadville. 200-300 fpm all the way up. :eek: :dunno::no: lol
 
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