[Rant Warning] Tailwheel Training

In article ,
Bob Moore wrote:


Come down off your high horse sonny. No where in the airplane is there
a placard that states "prohibited" about anything. Doesn't say anything
about "unauthorized" either. I don't have the POH here in front of me
at the time, but as I recall it does say something about slips and flaps
during landing, but at 4,000' AGL, we wern't anywhere near landing.


Depends on which year 172it is. I was looking at Info Manuals a while
back concerning the slips with flaps stuff and found 2 years (66 and 67
I think it was) that do Prohibit slips with flaps. The year prior and
the years after do not prohibit slips -- which is odd since there are no
big changes to the airframe (the extended dorsal came along in '73).

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

On Thu, 20 May 2004 19:22:52 -0800, Dale wrote:

In article ,
Bob Moo re wrote:


Come down off your high horse sonny. No where in the airplane is there
a placard that states "prohibited" about anything. Doesn't say anything
about "unauthorized" either. I don't have the POH here in front of me
at the time, but as I recall it does say something about slips and flaps
during landing, but at 4,000' AGL, we wern't anywhere near landing.


Depends on which year 172it is. I was looking at Info Manuals a while
back concerning the slips with flaps stuff and found 2 years (66 and 67
I think it was) that do Prohibit slips with flaps. The year prior and
the years after do not prohibit slips -- which is odd since there are no
big changes to the airframe (the extended dorsal came along in '73).

I don't know squat about 172s (sorry, I'm a 170B guy), but are you
certain the 66 and 67 manuals say "prohibited"? I seem to recall (in
passing) that flaps 40 slips were suggested to be "avoided" (way
different animal than prohibited!).

I belong to the camp that says flaps 40 slips is no big deal, *if*
you're familiar with the airplane, it's limitations and your
limitations. In my opinion, the early 100 series Cessnas (with 40
degree flaps) speak volumes to you if you're willing to listen. The
pitch-over they speak of is very manageable (and easily
avoided) in the right hands. The airframe/controls lets you
know with plenty of warning when it is about to get unhappy, and when
that happens, all you have to do is back off in the slightest amount,
and you're back in business. I get the feeling the "avoided"
mention in the books was put in there to weed out the nerds
(and to aid in any lawsuits filed by same).

That being said, if you need to slip a 100 series Cessna
with flaps 40 hanging out, you didn't plan your approach
right, and you were too high / too fast anyway.... grins

Bela P. Havasreti

In article ,
Bela P. Havasreti wrote:


I don't know squat about 172s (sorry, I'm a 170B guy), but are you
certain the 66 and 67 manuals say "prohibited"? I seem to recall (in
passing) that flaps 40 slips were suggested to be "avoided" (way
different animal than prohibited!).

Yes, prohibited. Someone posted on rec.aviation saying it was
prohibited, I said BS....went to Pilot shop the next day and looked at
the Info Manuals...crow doesn't taste too bad if you use lots of salt
and pepper. G

I've slipped all the single engine Cessna's I've flown with flaps and
haven't run into any problems doing so. I agree that if you have to
slip with 40 flaps your planning might not have been the best...but it's
a nice tool to have in the bag if you have to put the airplane
somewhere...like after the engine quits. Engine out landing is why I
practice it....and I've had to use it.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

On Thu, 20 May 2004 23:10:18 -0800, Dale wrote:

Well, at least crow gets more palatable with each serving.... 8^)

I'm with the other guy who posted that perhaps Cessna lawyers
got the word "avoided" changed to "prohibited" in the manuals.

Then later, more Cessna lawyers talked the engineers into
limiting the flaps to 30 degrees (to weed out even more
nerds!).

Bela P. Havasreti

In article ,
Bela P. Havasreti wrote:


I don't know squat about 172s (sorry, I'm a 170B guy), but are you
certain the 66 and 67 manuals say "prohibited"? I seem to recall (in
passing) that flaps 40 slips were suggested to be "avoided" (way
different animal than prohibited!).

Yes, prohibited. Someone posted on rec.aviation saying it was
prohibited, I said BS....went to Pilot shop the next day and looked at
the Info Manuals...crow doesn't taste too bad if you use lots of salt
and pepper. G

I've slipped all the single engine Cessna's I've flown with flaps and
haven't run into any problems doing so. I agree that if you have to
slip with 40 flaps your planning might not have been the best...but it's
a nice tool to have in the bag if you have to put the airplane
somewhere...like after the engine quits. Engine out landing is why I
practice it....and I've had to use it.

I don't know if this is relevant, but given the broad range of model years
being discussed, it may be useful...

I recently read an article about the evolution of the POH since the 1970's.
The article touched on the changes to the format and the information
included, but it also discussed the changing legal implications of the data
in the POH.

Is it possible that Cessna's changing attitude toward slips has been due
less to changes in the aircraft and more to changes in the legal climate?




"Bela P. Havasreti" wrote in message
...
On Thu, 20 May 2004 19:22:52 -0800, Dale wrote:

In article ,
Bob Moo re wrote:


Come down off your high horse sonny. No where in the airplane is there
a placard that states "prohibited" about anything. Doesn't say
anything
about "unauthorized" either. I don't have the POH here in front of me
at the time, but as I recall it does say something about slips and
flaps
during landing, but at 4,000' AGL, we wern't anywhere near landing.


Depends on which year 172it is. I was looking at Info Manuals a while
back concerning the slips with flaps stuff and found 2 years (66 and 67
I think it was) that do Prohibit slips with flaps. The year prior and
the years after do not prohibit slips -- which is odd since there are no
big changes to the airframe (the extended dorsal came along in '73).

I don't know squat about 172s (sorry, I'm a 170B guy), but are you
certain the 66 and 67 manuals say "prohibited"? I seem to recall (in
passing) that flaps 40 slips were suggested to be "avoided" (way
different animal than prohibited!).

I belong to the camp that says flaps 40 slips is no big deal, *if*
you're familiar with the airplane, it's limitations and your
limitations. In my opinion, the early 100 series Cessnas (with 40
degree flaps) speak volumes to you if you're willing to listen. The
pitch-over they speak of is very manageable (and easily
avoided) in the right hands. The airframe/controls lets you
know with plenty of warning when it is about to get unhappy, and when
that happens, all you have to do is back off in the slightest amount,
and you're back in business. I get the feeling the "avoided"
mention in the books was put in there to weed out the nerds
(and to aid in any lawsuits filed by same).

That being said, if you need to slip a 100 series Cessna
with flaps 40 hanging out, you didn't plan your approach
right, and you were too high / too fast anyway.... grins

Bela P. Havasreti

found 2 years (66 and 67 I think it was) that do Prohibit slips
with flaps.

Was it actually in the "Operating Limitations" section, or just
mentioned somewhere in the text of the POH? I'm just wondering if the
pilot who wrote the procedures of the book exceeded his authority in
using the word "prohibited". I couldn't find a "prohibited" placard
on my CD of type certificates for any 172 model.

Greg Esres wrote

found 2 years (66 and 67 I think it was) that do Prohibit slips
with flaps.

Was it actually in the "Operating Limitations" section, or just
mentioned somewhere in the text of the POH? I'm just wondering if the
pilot who wrote the procedures of the book exceeded his authority in
using the word "prohibited". I couldn't find a "prohibited" placard
on my CD of type certificates for any 172 model.

I think that Greg has hit the nail on the head! I have just returned
from the airport where I retreived the "Owner's Manual" for the 1959
Cessna 172A that I regularly fly. While at the airport, I inspected
the cockpit for a placard pertaining to flaps and slips and found none.
Reviewing Section IV of the "Owner's Manual" titled "Operating
Limitations", which is the only *regulatory* section, I find no reference
to flaps other than the speeds for the flap operating range.
In Section III, "Operating Details", the following appears in a paragraph
titled "LANDING":
"Normal landings are made power off with any flap setting. Slips are
prohibited in full flap approaches because of a downward pitch encountered
under certain combinations of airspeed and sideslip angle."

Section III is not regulatory and I feel, just as Greg, that the
author probably came under the influence of Rick Durden or one of his
predecessors. :-)

I still believe William Thompson's writings on the subject are as close to
the truth as we will discover. Posted below once again.

With the advent of the large slotted flaps in the C-170, C-180, and C-172
we encountered a nose down pitch in forward slips with the wing flaps
deflected. In some cases it was severe enough to lift the pilot against his
seat belt if he was slow in checking the motion. For this reason a caution
note was placed in most of the owner's manuals under "Landings" reading
"Slips should be avoided with flap settings greater than 30° due to a
downward pitch encountered under certain combinations of airspeed, side-
slip angle, and center of gravity loadings". Since wing-low drift
correction in cross-wind landings is normally performed with a minimum flap
setting (for better rudder control) this limitation did not apply to that
maneuver. The cause of the pitching motion is the transition of a strong
wing downwash over the tail in straight flight to a lessened downwash angle
over part of the horizontal tail caused by the influence of a relative
"upwash increment" from the upturned aileron in slipping flight. Although
not stated in the owner's manuals, we privately encouraged flight
instructors to explore these effects at high altitude, and to pass on the
information to their students. This phenomenon was elusive and sometimes
hard to duplicate, but it was thought that a pilot should be aware of its
existence and know how to counter-act it if it occurs close to the ground.
When the larger dorsal fin was adopted in the 1972 C-172L, this side-slip
pitch phenomenon was eliminated, but the cautionary placard was retained.
In the higher-powered C-172P and C-R172 the placard was applicable to a
mild pitch "pumping" motion resulting from flap outboard-end vortex
impingement on the horizontal tail at some combinations of side-slip angle,
power, and airspeed.


Bob Moore

Section III is not regulatory

Ah, thank you. Perhaps that solves the mystery.