Flaps 40 Degrees

This is a great group and I'd like to ask another question that's been burning me. I rent a 172N which has the capability of 40 degrees of flaps. My instructor says, depending on wind conditions, I should use 40 degrees every chance I get. It allows me to slow the plane as much as possible before touching down. I always seem to have a harder time landing with 40 degrees. Either I will bounce a little (I think because of the steep descent) or balloon with a little too much back pressure in the flare. After doing a little research on the web, I found out that Cessna reduced the flap range on the next model 172P to 30 degrees max. They said it was to add a little more to the max takeoff weight. I have read that there were several accidents during go arounds because the 172N barely climbs with 40 degrees and you have to retract to 20 degrees immediately during a go around. Anyways, my instructor still says use 40 if wind conditions permit. I find I make smoother landings with 20 degrees and don't have to worry about flap adjustments if a go around is called for. Does anyone have an opinion on this?

Used to have a 172A before I bought the Bonanza. It was an OK plane, but
I really loved the 40 degrees of manual (johnson bar) flaps. No flaps to full
flaps and back in just few seconds. The N model has electric flaps, doesn't
it? That would kinda take some of the fun out of it.

The only comment I have is to watch your flap setting in relation to
density altitude. I remember getting suprised once at Tahoe. The plane
was not going to go around with 40, or even 30 degrees of flaps. I couldn't
even get it to maintain level flight.



--
Frank Stutzman
Bonanza N494B "Hula Girl"
Boise, ID

I bought into a 1978 C-172N partnership almost a year ago, and was having a
similar problem. I finally figured out that selecting 30 degrees flaps max
until very short final, then bumping it to 40 degrees allows a flatter
approach and much easier landings. My landings have been MUCH better since I
started doing it this way. FWIW, I trim for 85 knots at 1900 RPM when
entering the pattern, select 10 degrees flaps and reduce power to a little
less than 1400 RPM abeam the touchdown point, the speed comes down to 65
knots pretty much all by itself when the 10 degrees goes out. I usually
don't have to touch the trim, just push on the yoke to keep it from
ballooning as the flaps go out. Once the 10 degrees are out, it'll hold 65
with no pressure on the yoke. Then 20 degrees flaps on base, again holding
65 kts. Then select 30 degrees after turning final, then 40 degrees crossing
the fence or thereabouts, slowing from 65 to 60 but no slower until I start
the roundout. See if this doesn't work for you. Your RPM settings might not
be exactly the same as mine, I think our tach is reading a bit low. Good
luck!
Scott Wilson

This becomes an issue of personal preference. If you feel more comfortable
with 20-30 degrees of flaps, that's fine. There may be occasions you'll
want to use full flaps (short runway, for example).
I have a lot of time instructing in 172s, and I own a 182. I rarely use
more 20 degrees of flaps on landing. I find that a slightly higher pitch
angle results in a more consistently gentle touchdown.
My opinion, for what it's worth.
Pat Brown
CFII Airplane/Glider


"Ken Kose" wrote in message
...

This is a great group and I'd like to ask another question that's been
burning me. I rent a 172N which has the capability of 40 degrees of
flaps. My instructor says, depending on wind conditions, I should use
40 degrees every chance I get. It allows me to slow the plane as much
as possible before touching down. I always seem to have a harder time
landing with 40 degrees. Either I will bounce a little (I think because
of the steep descent) or balloon with a little too much back pressure in
the flare. After doing a little research on the web, I found out that
Cessna reduced the flap range on the next model 172P to 30 degrees max.
They said it was to add a little more to the max takeoff weight. I have
read that there were several accidents during go arounds because the
172N barely climbs with 40 degrees and you have to retract to 20
degrees immediately during a go around. Anyways, my instructor still
says use 40 if wind conditions permit. I find I make smoother landings
with 20 degrees and don't have to worry about flap adjustments if a go
around is called for. Does anyone have an opinion on this?




--
Ken Kose