Engine out practice

On Oct 16, 11:25 am, Scott wrote:
Seems if one must use full flaps AND slip in landing, I would say the
approach was an abortion that lived. I prefer slips to flaps as you can
instantly remove a slip but the same can't be said for flaps...

Just MY personal opinion...not trying to slam anybody.

Need to know how to do it for forced approaches. The stress
of an actual failure (I've had two) will make things difficult enough,
and slipping with flap might be the only way to get down soon enough
in the only field available.
I miss manual flaps. They were handy. You could dump them
right at touchdown and get weight on the mains for braking. Electric
flaps are so slow that they are passing through 20°, the max-lift/min
drag position, just when you want to brake, so it's better to leave
them alone. My old Auster had huge Zap flaps that lowered the stall by
a wide margin, and dumping them right at a minimum-speed touchdown
allowed full braking and stopping in unbelievably short spaces.

Dan

wrote

I miss manual flaps. They were handy. You could dump them
right at touchdown and get weight on the mains for braking. Electric
flaps are so slow that they are passing through 20°, the max-lift/min
drag position, just when you want to brake, so it's better to leave
them alone. My old Auster had huge Zap flaps that lowered the stall by
a wide margin, and dumping them right at a minimum-speed touchdown
allowed full braking and stopping in unbelievably short spaces.

It would be nice if there was a manual release, something like the manual
release on an automatic garage door, then a spring and aerodynamic forces
could pull them back to "dumped."

Hey, something new to add to your design! g
--
Jim in NC

I think I would still use an agressive slip and then dump the full
flaps as close to touchdown as possible to be SURE you have the field
made. Of course, there will be a fly in the oitment if the forced
landing is due to smoke in the cockpit and you have those electric flaps...

$0.02 worth of free advice

Scott

wrote:
On Oct 16, 11:25 am, Scott wrote:

Seems if one must use full flaps AND slip in landing, I would say the
approach was an abortion that lived. I prefer slips to flaps as you can
instantly remove a slip but the same can't be said for flaps...

Just MY personal opinion...not trying to slam anybody.


Need to know how to do it for forced approaches. The stress
of an actual failure (I've had two) will make things difficult enough,
and slipping with flap might be the only way to get down soon enough
in the only field available.
I miss manual flaps. They were handy. You could dump them
right at touchdown and get weight on the mains for braking. Electric
flaps are so slow that they are passing through 20°, the max-lift/min
drag position, just when you want to brake, so it's better to leave
them alone. My old Auster had huge Zap flaps that lowered the stall by
a wide margin, and dumping them right at a minimum-speed touchdown
allowed full braking and stopping in unbelievably short spaces.

Dan


--
Scott
http://corbenflyer.tripod.com/
Gotta Fly or Gonna Die
Building RV-4 (Super Slow Build Version)

Of course, that system would lead to dumps on short final at about 50
feet up on a nice day under other than emergency conditions (except for
the one just created)...

Scott


Morgans wrote:

wrote

I miss manual flaps. They were handy. You could dump them
right at touchdown and get weight on the mains for braking. Electric
flaps are so slow that they are passing through 20°, the max-lift/min
drag position, just when you want to brake, so it's better to leave
them alone. My old Auster had huge Zap flaps that lowered the stall by
a wide margin, and dumping them right at a minimum-speed touchdown
allowed full braking and stopping in unbelievably short spaces.

It would be nice if there was a manual release, something like the manual
release on an automatic garage door, then a spring and aerodynamic forces
could pull them back to "dumped."

Hey, something new to add to your design! g

--
Scott
http://corbenflyer.tripod.com/
Gotta Fly or Gonna Die
Building RV-4 (Super Slow Build Version)

Ernest Christley wrote:
Bertie the Bunyip wrote:

It's the same either way. Cooling and heating are two sides of th
esame coin. It takes time to disapate heat and it's not so much the
passage of heat from one area to another (or the disappation, it's
irrelevant) but the speed at which the cooling or heating is taking
place and thus the gradient across the material. In short, you take
a frozen lump of metal and apply a torch to one
side you have a problem. Take a cherry red pice of metal and put
some ice on side and you have
the same problem (more or less, and disregading crystalisation)
It is the same if the same delta T is present, but my point is that it
is easier to heat something quickly than cool it quickly. Even at 250
C, you are only 523 degrees above absolute zero. So, this the
absolute largest delta T you can induce for cooling, and it is very
hard to get absolute zero, so you are more likely to have a cool temp
closer to 0 C yielding a delta T of only 250 degrees.

On the hot side things are more open-ended. It isn't too hard to get
450 C exhaust gas temperatures. For an engine that is started at say
20 C ambient temperature, you now have a delta T of 430 degrees which
is much greater than the 250 likely on the cooling side of the cycle.


With the heating, you only have the few hundred CFM of air passing
through the engine to heat it. With the cooling, you have all of the
great outdoors to do the trick. To tie it into your anology, you have a
butane lighter to heat the metal, and the Atlantic Ocean to cool it.

The heat doesn't come from the air, but from the fuel.

Matt

Bertie the Bunyip wrote:
Ernest Christley wrote in news:47142123$0$32479
:

Bertie the Bunyip wrote:

It's the same either way. Cooling and heating are two sides of th
esame coin. It takes time to disapate heat and it's not so much the
passage of heat from one area to another (or the disappation, it's
irrelevant) but the speed at which the cooling or heating is taking
place and thus the gradient across the material.
In short, you take a frozen lump of metal and apply a torch to one
side you have a problem.
Take a cherry red pice of metal and put some ice on side and you have
the same problem (more or less, and disregading crystalisation)
It is the same if the same delta T is present, but my point is that it
is easier to heat something quickly than cool it quickly. Even at 250
C, you are only 523 degrees above absolute zero. So, this the
absolute largest delta T you can induce for cooling, and it is very
hard to get absolute zero, so you are more likely to have a cool temp
closer to 0 C yielding a delta T of only 250 degrees.

On the hot side things are more open-ended. It isn't too hard to get
450 C exhaust gas temperatures. For an engine that is started at say
20 C ambient temperature, you now have a delta T of 430 degrees which
is much greater than the 250 likely on the cooling side of the cycle.

With the heating, you only have the few hundred CFM of air passing
through the engine to heat it. With the cooling, you have all of the
great outdoors to do the trick. To tie it into your anology, you have a
butane lighter to heat the metal, and the Atlantic Ocean to cool it.


Kind of besides th point. you coudl say the same thing about an oxy
acetylene setup and we all know what that will do to a bit of metal.

Bertie, he thinks the heat comes from the air so trying to explain an
acetylene torch will be a real challenge! :-)

Matt

Steve Hix wrote:

So they went out one morning, got plenty of cushion between themselves
and the ground, set the 172 into a landing configuration with full
flaps, and slipped it.

It shook a bit and then went inverted on them. They recovered and came
back home.

Got to love those urban legends!

Matt

"Bob Moore" wrote in message
46.128...
Bertie the Bunyip wrote
This examiner had had a fright in a 172 and
did not alow anyone to slip with flaps out.
While I am firmly in the camp that says some
cessnas can get a litle fuzzy in pitch with
full flaps, this is just stupidity incarnate.

About once-a-year I post the following excerpt from "Cessna, Wings for
the World", a book by William D. Thompson.

Bill Thompson is an Aeronautical engineer from Purdue University and
worked for Cessna Aircraft Company for 28 years as an engineering test
pilot and later as the Manager of Flight Test & Aerodynamics.

-------------------------------------------------------------------
"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

great stuff snipped...



I wear my "Slips with Flaps" T-Shirt proudly!

Bob Moore
12 years instructing in Skyhawks



Thanks Bob.

Al G, 30 years instructing in Skyhawks

Matt Whiting wrote in
:

Bertie the Bunyip wrote:
Ernest Christley wrote in
news:47142123$0$32479 :

Bertie the Bunyip wrote:

It's the same either way. Cooling and heating are two sides of th
esame coin. It takes time to disapate heat and it's not so much
the passage of heat from one area to another (or the disappation,
it's irrelevant) but the speed at which the cooling or heating is
taking place and thus the gradient across the material.
In short, you take a frozen lump of metal and apply a torch to
one side you have a problem.
Take a cherry red pice of metal and put some ice on side and you
have the same problem (more or less, and disregading
crystalisation)
It is the same if the same delta T is present, but my point is
that it is easier to heat something quickly than cool it quickly.
Even at 250 C, you are only 523 degrees above absolute zero. So,
this the absolute largest delta T you can induce for cooling, and
it is very hard to get absolute zero, so you are more likely to
have a cool temp closer to 0 C yielding a delta T of only 250
degrees.

On the hot side things are more open-ended. It isn't too hard to
get 450 C exhaust gas temperatures. For an engine that is started
at say 20 C ambient temperature, you now have a delta T of 430
degrees which is much greater than the 250 likely on the cooling
side of the cycle.

With the heating, you only have the few hundred CFM of air passing
through the engine to heat it. With the cooling, you have all of
the great outdoors to do the trick. To tie it into your anology,
you have a butane lighter to heat the metal, and the Atlantic Ocean
to cool it.


Kind of besides th point. you coudl say the same thing about an oxy
acetylene setup and we all know what that will do to a bit of metal.

Bertie, he thinks the heat comes from the air so trying to explain an
acetylene torch will be a real challenge! :-)


Mm, possibly..

but to be fair it is partly the air !

Bertie

"Bertie the Bunyip" wrote

but to be fair it is partly the air !

Only if you consider the oxy in the tank, as air.
--
Jim in NC