Cary wrote:...."avoid" isn't the same as "prohibited". When the Inspector told me to do the full flaps slip to a landing during my CFI ride and I questioned it, he directed my attention to the placard on the doorpost, which said "avoid" (same wording is on the placard on my airplane). ...

IMHO it's inappropriate for an FAA inspector (or any other FAA-sanctioned examiner) to direct the pilot being tested to ignore the manufacturer's safety recommendations- whether they're worded "avoid" or "prohibited".

I use 40 degrees flaps probably over 95% of the time, occasionally only 30 with a big crosswind.

I'm kinda surprised that many people feel the need to slip a Cessna with 40 degrees on.
I find that by pulling the nose up to somewhat lower than the normal final approach speed, but somewhat higher than stall speed,
I can achieve a high sink rate / steep angle descent, with very low forward speed-- all very easily controlled / moderated by adding power as required. Works much better for me than slipping.

I love it when a lawyer chooses to selectively ignore word definitions.

Definition of avoid
transitive verb
1
a : to keep away from : shun They have been avoiding me.
b : to prevent the occurrence or effectiveness of avoid further delays
c : to refrain from avoid overeating
2
law : to make legally void (see 1void 6a) : annul avoid a plea

Of course, the FAA legal counsel more than likely would choose the strictest interpretation of the term.......and that's the guy you're going to wind up arguing with in that definition game.

And you can bet big bucks that Cessna attorneys would argue that "avoid" means just that, not just when it's convenient.

Who would win? No idea.

Hot rod, the most likely situation where one might use a slip with full flaps would be in a crosswind, with a slip applied to counteract the drift.

But, in that case, common sense and good practice might suggest using less than full flap, and in any case, the slip might be minimal.

MTV

I agree with Hotrod180 that Cessna flaps are plenty adequate to get down most anywhere without need of forward slip. Also full flaps makes angle across the runway in strong crosswind easy and safe and requiring less side slip. Just a very capable airplane with those flaps.

I have to admit that when I referenced "slips", I meant forward slips- as in throwing the airplane sideways to direction of flight, with the controls crossed up.
I think of side slips as a "wing low" approach, even though it is actually a slip.

Gump is the Man !
Trim and flaps determines how fast I land.
Exposure to risk in time and distance can be short or long and scary for all aboard .
Hit the deer at 35 or 65, you won't have many options besides your landing speed.
I have deer at my home strip allot. I land under 40 MPH full flaps.
I met a guy who ran out of gas on floats, he used all down trim and full flaps to land in the trees
and it was so slow it hung in the trees. Sure its damaged but no one was hurt
and it was in one piece instead of rolled up in a ball for hundreds of feet.
I try to know wind direction all the time. I enjoy a landing on grass indicating 40 with a head wind.
I was cleared to land at RAP Intl. 55 X gusts more so I landed cross ways on the 60 ft. wide runway,
The tower went nuts on me, but there was no other traffic. An old FAA examiner told me
to do whatever you need to save the landing or abort.
Happy Day
https://www.facebook.com/lew.heurung/videos/10206451462804296/
https://www.facebook.com/lew.heurung/videos/10206456744216328/

From My C170b "Owners Manual" pg. 28;

Normal Landing.

(3) The flaps on the 170 allow steep, well controlled approaches making slips unnecessary. Slips with full flaps are to be avoided because if the slip is extreme enough at a relatively high airspeed the airflow disrupted over the tail surface resulting in a sudden and steep downward pitch of the nose.

This must be different for the C180?

I am always impressed at the wealth of info here.
Owned a Cessna 180 for 10 years and loved it and felt very comfortable flying it in most conditions.
Now have a new, to me, 185 which is a different beast. I had read that one should use all aft trim so as to have enough elevator when no weight in the tail. Do I understand it correctly that rolling in some nose down trim on final will allow a slower approach speed?

Tom

a3holerman wrote:I am always impressed at the wealth of info here.
Owned a Cessna 180 for 10 years and loved it and felt very comfortable flying it in most conditions.
Now have a new, to me, 185 which is a different beast. I had read that one should use all aft trim so as to have enough elevator when no weight in the tail. Do I understand it correctly that rolling in some nose down trim on final will allow a slower approach speed?

Tom

Tom,

No, that's not the point. The nose down trim prior to touch serves two purposes:

1. It provides a better trim condition in the event of a go around WITH 40 FLAPS APPLIED. Not necessary really with any other flap setting upon landing.

2. It helps to smooth out those wheel landings.

I realize that the Cessna 185 manual says that you should have full nose up trim applied prior to landing for the slowest possible touchdown speed, afforded by that trimmable stabilizer. But, frankly, the difference between full nose up trim and just a bit of nose down trim may not even be detectable in the difference in touchdown speed.

Go out and try an empty, full flap, full flap go around from a fully trimmed condition, and see how you like it.

Otherwise, in my opinion, virtually all WHEEL landings in these things should be tail low wheel landings, and one of the "crutches" available to make those tail low wheel landings is the procedure which I've described in this thread. If you're not having any problems with tail low wheel landings without using this procedure, good on you. But, for most folks, that little bit of nose down trim really makes the tail low wheel landing much easier and more consistent, as well as providing a slower touchdown.

MTV

Thank you,

I did realize the full flap go around takes a strong arm and thought that was part of it.
I will reread your post and see how it works. I was surprised the difference between the 58 180 and a 73 185 is. The 185 with the bigger dorsal fin is more of a handful in a x-wind it seems.

a3holerman wrote:Thank you,
I did realize the full flap go around takes a strong arm and thought that was part of it.
I will reread your post and see how it works. I was surprised the difference between the 58 180 and a 73 185 is. The 185 with the bigger dorsal fin is more of a handful in a x-wind it seems.

I agree but is the rudder the same size with both tail sizes ?
Its the same bigger dorsal fin 180/185 depending on the year and float kit.

winger wrote:

a3holerman wrote:Thank you,
I did realize the full flap go around takes a strong arm and thought that was part of it.
I will reread your post and see how it works. I was surprised the difference between the 58 180 and a 73 185 is. The 185 with the bigger dorsal fin is more of a handful in a x-wind it seems.

I agree but is the rudder the same size with both tail sizes ?
Its the same bigger dorsal fin 180/185 depending on the year and float kit.

Rudder is the same. The larger dorsal appeared on the later 180s as part of increased gross weight and probably as an economy measure.....Cessna only had to produce one fin for two models of airplane.

After that change, all 180s received the larger dorsal, not just float kit equipped 180s.

Certain STCs that install more power in the 180s may require the larger dorsal fin, but that's a gross weight thing. For example, Kenmore's O-520 conversion for the 180 increases HP, but only requires the bigger dorsal if you want the increased gross weight to the later model 180 GW.

But I don't think the bigger dorsal is a requirement of any float installation specifically.

MTV

As I mentioned, the larger dorsal fin on later model 172s and 182s materially reduces the pitch bobbling effect of a full flap, full rudder forward slip, pretty much eliminating it. But it's a 2 edged sword, because at slower airspeeds and on the ground, the weather-vaning effect of a crosswind is greater caused by the surface of the larger dorsal fin. It's sort of like trading one unpleasant effect for a different but equally unpleasant effect.

As for whether I'm dodging the dictionary definition of "avoid" vs. "prohibited", Mike, remember that it was the FAA Inspector during my CFI ride who did the defining. I haven't attempted any serious research to see if he was right, but he was adamant that if a given maneuver was prohibited, the word "prohibited" would be used. So don't get on the bash-the-lawyer kick; it's not necessary to make your point. Argue with the Inspector, not me.

I don't like forward slips, and I agree with several comments that they are rarely necessary in Cessnas. The barn door flaps, coupled with an appropriate slow airspeed, allow very steep approaches without slips. Slips are really unpleasant maneuvers for passengers, too--unless they're pilots, they're not accustomed to the awkwardness of the airplane flying banked and sideways. For that same reason, I don't use a side slip in a crosswind until just as I'm about to out, as a crab is more comfortable for both the passengers and for me. Whenever I see a Cessna being slipped, I conclude that it's either a training exercise, or the pilot woefully mis-planned his approach.

Cary