Commercial PTS ?'s and 172RG

[midlifeflyer]

I do know that a lot of people are under the mistaken belief that you can't do slips in 172s because it says "avoid slips with full flaps" on the panel in some of them. That is advisory in nature because it isn't in the limitations section of the POH.

That's right. Another thing that contributes to the error is that while the flap/slip advisory is not in the limitations, the =placard= that says "avoid slips with flaps extended" =is=. In other words, the airplane must have the advisory placard in place in order to be considered airworthy, although the contents of the placard are only advisory.

 

[cookmg]

Actually, the AFMs of both the 1980 and 1981 172RGs that I fly, do NOT require the placard of "avoid slips with flaps extended." The idea of slips with flaps is no where to be found in the AFMs. That's what's most confusing to me.

 

[Traumahawk]

The problem is that the garage door flaps disturb the airflow over the horizontal stabilizer and cause a loss of control. Below 30 degrees is still okay for slips.

Nothing could be farther from the truth regarding control issues. IF you lose control of a CESSNA due to an intermittent mild tail buffet, then you would also qualify among the people that "lose control" while chewing gum or sneezing.

This advisory note dates as far back as the taildragging cessnas that first got the barn-door (i.e. effective) flaps and only serves as a heads up to a characteristic that is not as apparent in other types. Heed the caution but know the legal performace envelope of your airplane to all ends.

By the way, if this is truly dangerous and borderline 'loss of control', then every time you executed a textbook crosswind landing with full flaps you were living on the edge, and for those who think this is a limitation, you would have busted your checkride. "Avoid SLIPS with flaps extended." Forward, sideways backwards, whatever.

T-hawk

 

[bobbysamd]

Slips in 172s

Unless some examiner or something is being hypertechnical and super anal, there is nothing wrong with slipping in a 172 with flaps extended, as long as there is no specific prohibition against it.

I learned to fly in what I believe was a 172M (my manual is stored and I can't get at it now). It was an older aircraft, perhaps 1969, and had the ASI calibrated in mph. The manual was more like a pamphlet. I do not recall any placards prohibiting slips with flaps. I also recall it recommending to use "the minimum flap setting for runway length" for crosswind landings.

My instructor taught me to use 20 degrees of flaps for normal landings and crosswind landings. No examiner ever gave me flak for my landings. I instructed in 172s and 182s for four years and taught flaps-down as appropriate for crosswind landings. No examiner gave my students problems. Some of these Cessnas had the placard.

If you were to follow the "avoid" advisory strictly, then nearly every 172 crosswind landing should be executed no-flaps because the wing-low method technically is a slip. That would take away a great amount of the aircraft's utiilty. That would make short-field crosswind landings in 172 difficult, and perhaps unsafe.

You can make safe crosswind landings in 172s with flaps extended. I don't know if I'd try it with 40 degrees of flaps because I would lose airflow over the rudder. You can do it just fine with 30 degrees. Of course, it would be different if the POH prohibited slips with flaps extended.

 

[Buzo]

At least the 1975-77 150's do not prohibit slips with flaps. They have the same placard as the 172's. The 152's I learned in say the same thing.

 

[cookmg]

If a placard is in an airplane, it must be there per some authority I assume. If the AFM does NOT require it or even mention it, and (according to DOC) the type certificate for the 172RG does not list it as a placard for the aircraft, under what authority is the placard in the plane? Couldn't this placard be removed from the plane all together and still be airworthy?

Curious . . . .

Thanks

Mike

 

[BeachBum]

Nothing could be farther from the truth regarding control issues. IF you lose control of a CESSNA due to an intermittent mild tail buffet, then you would also qualify among the people that "lose control" while chewing gum or sneezing.

It's completely true. I didn't say you would fall out of the sky and the world would come to an end, but the fact is that there will be control issues. Take a cessna with 40 degrees of flaps down, put it is a decent slip, and you get tail buffeting. The plane still flies and it's not a big problem, but the fact is you don't have the full control authority that you would in normal situations. The plane is doing something that you don't want it to do. It's not a myth.

 

[N8157B]

I own a '57 172 with 40 degrees of flaps. I have slipped the living daylights out of the thing with 10-40 degrees of flaps. In the worst case scenario the buffeting is mild and you still have full control, but boy do you come down fast. Let go of the controls and you are back to "normal" flying. I have also done this in C140, C170, C180, C185. Same results. If you lost rudder control you wouldn't be able to hold it in a slip, would you? If you lost elevator control you would pitch down and speed up, right? The placard says avoid only(on all I have seen). I teach in a 172RG and have no concerns with slipping it with flaps, nor does my boss, a former DPE. Just a couple thoughts.

 

[Traumahawk]

AMEN