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16th April 2008, 02:12 AM

"WingFlaps" <Moreflaps@> wrote in message
news:b1442530-bb02-4c5e-8b38-7e252df3470b@q24g2000prf..com...
Hi Mike,

I don't think 40 degrees of flaps should be considered a normal
approach in a 172. I'd like to suggest you try to get used to using no
more than 30 and reserve the 40 for when you need a really short
(steep) field approach? With 40 flaps you need to hold on a lot of
power to hold a normal pattern glide slope and your ability to go
around is compromised a lot. In any case, if you have 40 out your
first move after applying full power should be to take 10 off to help
the aircraft accelerate -it won't make you sink as 40 flaps add mostly
drag and no significant lift compared to 30. I base this on my
somewhat limited experience of a 172M in which I just passed my
PPL(A) :-) -so some others here may have a different view. This is
all part of the reason why C dropped the 40 flaps option on later
models I think.

Cheers

NOPE. The FAA really likes you to use ALL of the flaps you have on
virtually every landing. There is no good reason I can think of not to use
40 degrees of flaps if you have them.

Cessna did cut back the flap travel to 30 degrees on later models. They did
that because marketing complained that there was not enough useful load in a
172. Since the gross weight on the Cessna 172 was actually determined by
the demonstrated rate of climb at gross weight with full flaps reducing the
flap travel allowed them to increase the gross weight by 100 pounds, which
made a significant increase in the useful load figure they can publish in
the POH.

On a goaround in a Cessna 172 I recommend cutting the flaps back to 20 to 30
degrees to facilitate the climb because the rate of climb with full flaps is
pretty marginal. At high density altitudes it may not even be positive! Do
not take them all the way off or you will lose significant altitude while
your speed comes up enough to fly with no flaps! The first 20 degrees adds
mostly lift and a little drag. The second 20 degrees adds lots of drag but
little lift.

There is no reason to carry lots of power to maintain a flat glideslope when
landing a Cessna 172. The only time you want a three degree glide slope is
when you are flying an ILS. If you are flying a three degree glide slope
and you lose power you will NOT make it to the airport. Why put yourself in
that position when you don't have to? If you can't get to the runway with
NO power from anywhere in the pattern, your pattern is too big.

Highflyer
Highflight Aviation Services
Pinckneyville Airport ( PJY )

16th April 2008, 02:12 AM	#8 (permalink)
Highflyer Guest Posts: n/a Classified Rating: % ()	close encounter "WingFlaps" <Moreflaps@> wrote in message news:b1442530-bb02-4c5e-8b38-7e252df3470b@q24g2000prf..com... Hi Mike, I don't think 40 degrees of flaps should be considered a normal approach in a 172. I'd like to suggest you try to get used to using no more than 30 and reserve the 40 for when you need a really short (steep) field approach? With 40 flaps you need to hold on a lot of power to hold a normal pattern glide slope and your ability to go around is compromised a lot. In any case, if you have 40 out your first move after applying full power should be to take 10 off to help the aircraft accelerate -it won't make you sink as 40 flaps add mostly drag and no significant lift compared to 30. I base this on my somewhat limited experience of a 172M in which I just passed my PPL(A) :-) -so some others here may have a different view. This is all part of the reason why C dropped the 40 flaps option on later models I think. Cheers NOPE. The FAA really likes you to use ALL of the flaps you have on virtually every landing. There is no good reason I can think of not to use 40 degrees of flaps if you have them. Cessna did cut back the flap travel to 30 degrees on later models. They did that because marketing complained that there was not enough useful load in a 172. Since the gross weight on the Cessna 172 was actually determined by the demonstrated rate of climb at gross weight with full flaps reducing the flap travel allowed them to increase the gross weight by 100 pounds, which made a significant increase in the useful load figure they can publish in the POH. On a goaround in a Cessna 172 I recommend cutting the flaps back to 20 to 30 degrees to facilitate the climb because the rate of climb with full flaps is pretty marginal. At high density altitudes it may not even be positive! Do not take them all the way off or you will lose significant altitude while your speed comes up enough to fly with no flaps! The first 20 degrees adds mostly lift and a little drag. The second 20 degrees adds lots of drag but little lift. There is no reason to carry lots of power to maintain a flat glideslope when landing a Cessna 172. The only time you want a three degree glide slope is when you are flying an ILS. If you are flying a three degree glide slope and you lose power you will NOT make it to the airport. Why put yourself in that position when you don't have to? If you can't get to the runway with NO power from anywhere in the pattern, your pattern is too big. Highflyer Highflight Aviation Services Pinckneyville Airport ( PJY )