Question for CFI's teaching in C-150's & C-172's


Well-Known Member
Question for CFI\'s teaching in C-150\'s & C-172\'s

I did all of my SE commercial and CFI training in Pipers (did my private in a 172) & now I am going to be teaching in 150's and 172's. I have been out flying quite a bit in both aircraft recently and I need a little info to tune up my instruction speak before taking on my first students.

When teaching pattern work & landings what airspeeds and power settings are folks out there teaching (sea level airport)? I have been using 80dw 70base 60 final for the 150 and more like 90 70 60 for the 172. Abeam the touchdown point setting the power to 1600-1700rpm until final seems to work out consistently. Do these numbers more or less match up with what everyone else is teaching?

Any thoughts or tweeks?

Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

Hi aca,
I'm not an instructor, but I just finished up my private, and those numbers are accurate with what my CFI teaches. I can only speak for the 172 though, since it was all I trained in. If you nail those numbers, the patterns are usually perfect!
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

I did my private in a 152. It was a long time ago, but I remember 80-70-60 and setting 1600 or 1700 at the key. I still have my old 152 checklist and maneuver guide. I'll dig it out if you want me to. Where are you instructing? Still here in FL?

Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

Thanks for all the quick responses. I figured I was pretty close, but I wanted to triple check.

Hey Chunk! I left Florida the day after my CFI checkride 8/25. Im back in Maine and I am starting to work at my local FBO. I can get plenty of single engine time here (700-800hrs a year), but I have not figured out a mulit solution yet. My only saving grace is that in the past the airlines serving this area have been taking local pilots on with pretty low multi time if they are willing to stay based in Maine for a while. I guess everyone else uses the commuter bases here to get time and get the hell out!

Where are you at these days? Are you still at FS?
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

One thing you will find different on the cessnas is that those fowler flaps will create more dramatic pitch changes than the slotted flaps on the cadets. The older 1970's vintage N model flaps go all the way to 40 degrees and this is like hanging a pair of barn doors out into the wind, can make for awsome short field landings and save a high approach but I never liked advocating full flap extension in these models unless necessary.
I would go out and play around in the pattern, should be fairly easy to make a power chart (like the FSI charts) for different combos of airspeed, rpms, flap settings, and rate of descent.
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

I'm finishing up CIME. I'll be doing my CFI here and trying very hard to get hired here. Good luck up north!

Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

</font><blockquote><font class="small">In reply to:</font><hr />
should be fairly easy to make a power chart (like the FSI charts)

[/ QUOTE ]

Thats pretty much what I have been trying to do. Yeah one of the 150's here has 40 degrees of flaps which like you said allows for some nifty steep approaches. I dont think I will demo that for students. Trial and error and some outside input lead me to the speed and power settings above. Im pretty much adapting the FS procedure and flap settings to the Cessna's.

Good luck finishing up CIME and CFI as well. I really had a lot of fun doing CFI there, it was a great course. I hope they have found a good ground school instructor since Al St.George is gone (he did a great job with that ground school). Keep us posted now and then.
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

Which cessnas have fowler type flaps? I've flown the 152 &amp; 172 and I'm getting ready to fly the 182. All three POH's describe the flaps as "single-slot type flaps". Aviator, I might have misread your post wrong.
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

Actually the 152,172, and 182 all have fowler flaps which incorporate a single slot.
The basic flap designs are plain, split, slotted, and fowler. It is common to see hybrids between the different designs. Fowler flaps are designed to increase the area of the wings as they move down and back. Notice the cessna flaps move on track system which is electrically driven by a jack screw. The addition of the slot further modifies the airflow camber, wing area, and airflow. The slot allows some of the high pressure air to come to the upper surface of the wing, serving to increase lift by accelerationg the air over the top of the wing, thus reducing the pressure. Slots also improve flow over the trailing edge, delaying separation of the airstream and reducing the stalling speed.
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

Speeds sound right to me. I teach in CO at an airport at almost 6000 feet. We fly the same speeds you guys at sea level do because we are all flying indicated airspeed. Our true speeds In CO are higher though. Not understanding this gets alot of sea level pilots killed when they come mountain flying.

Another tid bit, I never teach my students to use full flaps until later in their training. Here's my reasoning. A go round with full flaps (especially 40 degrees in older N model 172) isn't going to work. My biggest fear is a student pilot on their first solo bringing down 40 degrees of flaps and then being instructed to go around by tower. If they forget to bring up the flaps they won't be able to climb out. They could keep pulling up trying to climb and have a stall spin accident. my two cents.
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

I got my private license in an archer and the rest of my ratings in a 172. I'd say the power settings are about the same. The biggest difference is having to rock the wings when looking for traffic and actually having to lean forward in the seat to be able to see the runway on base to final! When I switched to high wings, I wasn't used to having to physically move in the seat just to see the runway!
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

Thanks for all of the responses folks. This helps polish up my knowledge of these aircraft a bit.
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

I like having 40 degrees of flaps but as mentioned above you have to be very careful with them. I only put them down when coming over the numbers (it really slows you down nicely!), and only if I am fairly certain I will not have to go around (although I am always prepared to pull them up quickly if I need to go around). I also never use them when it is windy; I prefer 20 in times like that!
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

To the guy who claims Cessnas have Fowler flaps:

In fact, the flaps are of the single slot type and are driven by an electric motor thru cables and pulleys. This is from the Cessna POH. If you disagree, I would suggest sending a letter to the good folks in Wichita.

Giving students information contradictory to their flight manuals is like nominating them for the "Golden Shovel Award" at their checkrides.

By the way, look at the diagram, there is no jack screw!!
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

Uh ok Mr. expert,

From Jeppessen- Aircraft Systems For Pilots , Author Dale De Remer, PHD

P. 334
Fowler Flaps are a popular design of wing flap that not only changes the camber of the wing, but also increases the wing area. Instead of rotating down on a hinge, these flaps slide backwards on tracks, and in the first portion of their extension, drag is very little but lift increases a great deal as both the area and camber are increased. As the extension continues, the flap deflects downward, and during the last portion of its travel, it increases the drag with little additional increase in lift.

The flaps are connected to their hinges and actuator rods in a manner similiar to that of the ailerons. However, Fowler flaps are normally mounted on rollers that ride in tracks, and these must be adjusted so they ride up and down smoothly with no binding or interference.

There are a number of actuation methods for wing flaps. The simplest flaps are actuated by either cables or a torque tube directly from a hand lever in the cockpit. Other airplanes use electric motors to drive jackscrews that move the flaps up or down, and many of the larger aircraft use hydraulic actuators to provide the muscle to move the flaps against the air loads.

Figure 15-54 (as fate would have it the diagram is from a Cessna 172 POH) shows the flap system used in a single engine airplane. These flaps are moved by cables from an electric motor-driven jackscrew . Limit switches shut the motor off at the full up down position, and a cam-operated follow-up system allows the pilot to select various intermediate flap positions. When the flaps reach the selected deflection, the motor will stop.

I currently teach only in Pipers not Cessnas. But I do have 200 hours in 172's and I had a 172R POH lying around so I pulled it out. The wing flap system description consists of a small paragraph that I was able to read in about 20 secounds. Not to sound crazy here but I don't think the boys in Wichita wrote a complete dissertation on their flap system for the POH, and I would not limit my students knowledge to these 10 lines of text. I'm a little confused about the whole golden shovel thing, but this does appear to be an accurate description of fowler flaps on Cessnas.
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

I never claimed to be an expert, but I do have a lot of time in Cessnas, both single and twin.
As far as fowler flaps go......
Nope, youre wrong, they are clearly stated in the POH as slotted flaps. Just because they have rollers does not make them fowler flaps. Take a good look at a set of Fowler flaps on an airliner and you will quickly see the difference. The fowler flaps slide out and down from underneath the wings, and it is easy for some to mistake the Cessna flaps action on the tracks for fowler flaps. They are not. Like I said, you can argue the point with Cessna, pal. By the way, you werent so descriptive of jack screws before, making it seem like the flaps are directly driven by one. This new revelation coming after you mislead student pilots into the incorrect idea of the method of acutation and the type of flaps.
Please find us a quote, not your opinion, on the type of flaps in a Cessna, and maybe I will listen to you. All you have done here is re-type paragraphs on the description of fowler flaps from a textbook. Once again, it may be confusing for somebody like yourself with relatively little experience.

Heres your Golden Shovel
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

I was always told (and agree with) the description being slotted flaps with fowler characteristics. They're definitely slotted, and they do work similar to fowler's. Anyone else agree?
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

I agree with the idea of being slotted w/ Fowler characteristics. I look at it like this. When your extend the flaps to 20 degrees for instance, take a look up at the portion of the wing where the retracted flap was. With the flap extended you see a sectoin of the wing that was previously covered and now is exposed! It looks like a little more wing area to me.

No, it's not as complex a system as found on the transport style aircraft but we're talking about a Cessna here!
Just my $.02
Re: Question for CFI\'s teaching in C-150\'s & C-172\'s

You know I visit this board to discuss aviation and really try hard to avoid flame wars. How I got sucked into this one I don't know. If you want to debate or share information one flight instructor to another thats fine. If you want to take condescending personal swings- I have better things to do with my time.