close encounter

On Apr 10, 12:58 pm, Mike Sierra <paysands_at_yahoo_dot_com> wrote:

> We were both on short final to the same runway.  I continued to fly
> the airplane.  As soon as I saw him, I started my procedure to go
> around.  Throttle to the wall, carb heat off.  Waiting on retracting
> flaps until the airplane is ready.  My CFI calls (hollers) tower, and
> the Geronimo must have heard the call, as he very quickly started his
> go around to the right.  My instructor saw this before I did, so he
> told me to land the airplane.  I had to immediately get back into land
> mode:  airspeed, pitch, throttle, etc.  All this with 40 deg. flaps
> down on the 172.  The landing itself wasn't elegant, but it was safe.
> Fortunately, we had about 8000' of pavement in front of us.
>

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

On Thu, 10 Apr 2008 04:09:19 -0700 (PDT), WingFlaps
<Moreflaps@> wrote:

>On Apr 10, 12:58 pm, Mike Sierra <paysands_at_yahoo_dot_com> wrote:
>
>> We were both on short final to the same runway.  I continued to fly
>> the airplane.  As soon as I saw him, I started my procedure to go
>> around.  Throttle to the wall, carb heat off.  Waiting on retracting
>> flaps until the airplane is ready.  My CFI calls (hollers) tower, and
>> the Geronimo must have heard the call, as he very quickly started his
>> go around to the right.  My instructor saw this before I did, so he
>> told me to land the airplane.  I had to immediately get back into land
>> mode:  airspeed, pitch, throttle, etc.  All this with 40 deg. flaps
>> down on the 172.  The landing itself wasn't elegant, but it was safe.
>> Fortunately, we had about 8000' of pavement in front of us.
>>
>
>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

Hi Flaps,
My instructor wants me to learn to land with all the various flap
configurations. Tuesday, I was practicing landings with full flaps.
I agree with your post, that anything over twenty degrees adds drag
without much lift. Depending on winds, I normally fly final with
twenty degrees flaps.
ms

Mike,
Any time you hear other aircraft cleared to land on the same runway as
has been assigned to you subsequent to your landing clearance, request
clarification from ATC immediately to acertain who has priority in the
sequence.

This will get ATC's attention to the potential threat and probably earn
you a well deserved thanks.

Barry wrote:

> To be more general - I hear a lot of pilots and instructors talk about a
> stabilized approach, but then chop the power "over the fence" or at 50 feet.
> The purpose of a stabilized approach is to put the plane in a good and
> predictable situation for the flare. So if power is cut a few seconds before
> the flare, the work done to keep the approach stabilized before that point is
> mostly wasted. I have no problem with people wanting a steep final approach,
> but I ask, again, why not make it steep all the way down, instead of just the
> last few seconds?

On a cool day and flying solo, flaps 15 or 30,
my plane won't land with any appreciable power
above idle.

I generally try to plan my approach so that I
can go to idle downwind abeam the numbers and
keep it there all way to the ground.

Barry wrote:
However, I'd say that cutting power "200 yards out," as in
> the original post (or "over the fence" as many pilots do) is NOT a stabilized
> approach,

Depends how high you are when you are 200 yds out. I could be a mile
out, if I have the altitude. I could be on a standard downwind if I fly
a close pattern. Stabilized descent and airspeed to the landing without
power. Don't know how to sat it any other way so I'll quit trying. Each
to his own.

Barry wrote:
> I guess this is where we disagree. Ideally with a stabilized approach,
> everything (power, pitch attitude, airspeed, descent rate) stays constant
> until ready to start the flare. The pilot can then make one smooth transition
> to the landing. On the other hand, if you cut power at 50 or 100 feet, you
> have to lower the nose to maintain airspeed, which increases the descent rate.


I don't believe that cutting the power at 50 or 100 feet requires you to do
anything other than maintain the descent for a few seconds more until it's time
to flare. If I cross the threshold of the runway in a C-172 at 65 knots I'm
going to float for a ways. I prefer to disappate much of that energy just
before I cross the threshold and touch down either on or just past the
numbers.... not 500-1000 feet later.

Chopping the power is not going to cause you to just fall out of the sky lacking
enough energy to raise the nose for a short flare. I seem to have managed to do
this successfully hundreds of times and I have yet to land short; nor do I land
hard.



--
Mortimer Schnerd, RN
mschnerdatcarolina.

Barry wrote:
In that case, the nose will drop just before the
> flare, and the flare will then require a greater pitch change, which makes it
> harder to do well.
>
>

It doesn't have to be that way, but I rode with a pilot who made these
kinds of abrupt pitch changes, and while the touchdown was soft enough,
the arrival was very uncomfortable for me as passenger, and it was more
risky. It felt like he was going to pancake the plane on the runway.
Remember that we are talking about a C-172. As with any approach, proper
management of the energy results in a good landing. We've probably
gotten to the point that we would have to ride with each other to
resolve our disagreement. Regards.

"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 )

"Mike Sierra" <paysands_at_yahoo_dot_com> wrote in message
news:806sv3ln5kgkk22o49jv8ji3g9qn207bub@...
> Hi Flaps,
> My instructor wants me to learn to land with all the various flap
> configurations. Tuesday, I was practicing landings with full flaps.
> I agree with your post, that anything over twenty degrees adds drag
> without much lift. Depending on winds, I normally fly final with
> twenty degrees flaps.
> ms

Hey guys, the reason we put the flaps on the airplane was to increase the
drag. This allows a steeper and more accurate approach and shortens the
landing. With most airplanes and flap types the difference in stall speed
is pretty much negligible. It does happed that the huge Fowlers on Cessnas
do lower the stall speed noticeably, but they are still there for the drag
more than the lift.

My airplane is NOT a Cessna. My flaps have two positions. UP and DOWN.
They are vacuum operated so you can't stop in the middle if you try! Down
is 52 degrees! Lots of drag. Of course, if I put the prop into flat pitch
that 10 foot prop in low gear is like throwing out a drag chute also! I
usually make my base leg pretty close to the airport! :-) With the power
off, I come down final at 90 mph and slightly over 2000 feet per minute.
Since it really falls out of the sky at 80 mph I try to keep the speed up
until I cross the threshold. I use the energy stored in that airspeed to
stop my sink and level out over the runway. I can usually get it on and
slow enough to turn off the runway in 700 to 800 feet if my weight is under
4000 pounds. At that weight I need abouat 900 feet to get off again, so I
generally avoid runways shorter than 1200 feet to keep my accellerate/stop
distance in line! :-)

Highflyer
Highflight Aviation Services
Pinckneyville Airport ( PJY )