The International Cessna^® 170 Association

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Robert Eilers wrote:The proper use of flaps has been a discussion among flight instructors for as long as I can remember. I personally believe it is bad advice and lazy flight instruction to tell a student to always land with full flaps. The more responsible teaching technique is to instruct the student on the purpose of the flaps....

Robert,
I agree with all that you said here. I was always taught to adjust my flap setting to the conditions, and consider using less than full flaps in gusty winds. The point I was making when I reopened this discussion was for the particular case of a Horton STOL-equipped 170B. This is a very noticeably different beast from a stock 170B. I've had difficulties landing it, and so have a couple of my friends who have as much or more TW time in more diverse types than I have. One of them owns a stock 170B, and when he flew mine, he though he had forgotten how to land an airplane until he went back to his own 170 and did a few circuits. The difficult characteristic is that the thing just doesn't want to stop flying after it's on the runway, even after a 3-point, "full stall" landing (in which the airplane is apparently not actually stalled, just out of elevator and tailwheel travel).

I finally got consistently better landing results when I started using full flaps on all my landings. At this point, I think I would consider using partial flaps only in non-gusty conditions, where I'm not so likely to encounter a puff of wind that would lift the plane again after landing. What full flaps are doing for me here is to let me touch down slower and get the plane slowed down much more quickly after landing, so I'm past the danger point more quickly. I know this is backwards from standard teaching, and the reason it took me five years to figure this out was the mind-set I had: that full flaps are for gentle winds only. Mind-sets are another hazard that we have to educate students to look out for. In this case you're absolutely right, that you have to understand what flaps are doing for the airplanes flight characteristics at each setting. It seems to me that flaps 10 adds more lift than drag, and going from 30 to 40 adds mostly drag, very little lift. I really want that drag when I'm landing the Horton-modified wing.

Best Regards,

John

I am soaking up each of your responses so far...
I will practice those go-arounds; at altitude next time. And Mr. Eilers: I wish I'd gotten a bit of dual with you. I will do my best to learn more about flap settings and their appropriate uses. My time in sailplanes (since 1992) never introduced me to flap use, as our club gliders were all Standard Class without flaps. I have much to learn, and look forward to returning to the air in our pretty 170B this summer to pursue it.
Keep those thoughts comin'!
B.R.

170C wrote:Joe----650 ft strip! You must have been a Navy carrier pilot in another life

I wasn't, but maybe I could be one now!

Joe

I like the comments about removing carb heat on final. I use carb heat to remove any potentially built-up carb-ice (rarely found on my airplane) ... then remove it for the final approach because my carb now ain't iced....and I want filtered air down low... and I have one-less memory item for a go-around.

Flap retraction should only be as fast as airspeed can be traded for... or pitch-attitude can be accomodated. In other words, the 2 mph Miles mentioned is unlikely to be a serious factor (as he pointed out)... and if one is flying at flaps-40...then retraction to flaps 20 ..or even flaps-zero...should not cause a stall with full power applied (the FIRST thing to do in a go-around) ...and if the aircraft is pitched UP at the same speed as the flaps are retracted then no hazard due to stall should exist. Remember, flap application not only adds drag and lift... it also presents the wing with a theoretical increase in AOA (angle of attack). Therefore flap retraction is also a reduction in AOA (and is why a loss of alititude occurs ...or a need for increased speed at the new flap setting in order to maintain altitude) So if the AOA (pitch UP) matches the flap retraction....then no loss of altitude will occur...and the reduction of drag is offset by the previously-applied high-power setting.

To answer the question regarding whether or not full-flap application equates to a landing committment: No. Except in certain, lower-powered multi-engined aircraft with electric or hydraulic flaps.

gahorn wrote:

Flap retraction should only be as fast as airspeed can be traded for... or pitch-attitude can be accomodated. In other words, the 2 mph Miles mentioned is unlikely to be a serious factor (as he pointed out)... and if one is flying at flaps-40...then retraction to flaps 20 ..or even flaps-zero...should not cause a stall with full power applied (the FIRST thing to do in a go-around) ...and if the aircraft is pitched UP at the same speed as the flaps are retracted then no hazard due to stall should exist. Remember, flap application not only adds drag and lift... it also presents the wing with a theoretical increase in AOA (angle of attack). Therefore flap retraction is also a reduction in AOA (and is why a loss of alititude occurs ...or a need for increased speed at the new flap setting in order to maintain altitude) So if the AOA (pitch UP) matches the flap retraction....then no loss of altitude will occur...and the reduction of drag is offset by the previously-applied high-power setting.

To answer the question regarding whether or not full-flap application equates to a landing committment: No. Except in certain, lower-powered multi-engined aircraft with electric or hydraulic flaps.

Or to simplify during a go around......

Power up
Pitch up
Clean up (flaps)

gahorn wrote:I like the comments about removing carb heat on final. I use carb heat to remove any potentially built-up carb-ice (rarely found on my airplane) ... then remove it for the final approach because my carb now ain't iced....and I want filtered air down low... and I have one-less memory item for a go-around.

George,
When I instruct in my aircraft (O-300) or Dads (C-145) I teach.....check carb heat (pull on for several seconds...look and listen for differences) then push off....My reasoning isn't so much as to one more thing to think about, as, that we are running 100 LL and a rich mixture is going to fowl the plugs. If there is a real drop and maybe a good reason for carb ice I just leave it on......Brad

We're gonna have to be careful. Big Brother is going to find out that some folks can THINK ...AND fly! (instead of just going around the patch by rote.)