Carb heat: my new policy. Any comments

On Sep 8, 12:54*pm, Bertie the Bunyip wrote:

That observation is in conflict with my experience. Everytime I've
gotten carb ice in the pattern has been on a clear day.

But not a clear dry one.

Well ok. Dry in the sense of visible moisture; yes, no visible
moisture. However, we know that humidy is the key to carb ice so there
had to be some humidy. But what type of solution is that? You teach
students to subtract the dew point from the temp in order to decide
when to turn off carb heat. That just sounds complicated for little
gain.

-Robert

On Sep 8, 9:55*am, "RandyL" wrote:

Then again, how hard is it to shove in the carb heat knob while you advance
the throttle in a Cessna? They are right next to each other. I have always
just pushed in the carb heat knob at the same time as I advance the
throttle, not that difficult to do, even using the same hand.

Bingo. Why risk carb ice just to not have to remember to push the carb
heat in?

-Robert

Robert M. Gary wrote:
On Sep 8, 9:55 am, "RandyL" wrote:

Then again, how hard is it to shove in the carb heat knob while you advance
the throttle in a Cessna? They are right next to each other. I have always
just pushed in the carb heat knob at the same time as I advance the
throttle, not that difficult to do, even using the same hand.

Bingo. Why risk carb ice just to not have to remember to push the carb
heat in?

-Robert

We have a similar thing going on right now in the Warbird community.
After the McKitrick go around torque roll mort in his P51 last year, we
have one very respected member of our community advocating making
approaches in the P51 Mustang using cruise settings on the prop instead
of the normal 2700RPM (Meto) setup used by pilots flying approach in
this airplane.
His theory is that on a go around, where torque is a huge issue on the
Mustang if power is misused, keeping the prop in cruise won't hurt the
engine if it's over boosted unintentionally and will deny the extremly
high torque moment associated with the application of too much power too
quickly.
He maintains this "safety valve" will help save lives.
I have a great respect for this pilot's opinion.....normally!
As someone involved in the Mustang community as a safety adviser, I find
his "theory" "interesting" to say the leat but I'm against it.
Doing this flies in the face of the normal Dash 1 approved go around
setup for the 51 which is to run the prop up to 2700 and DON'T ham hand
the throttle if needed! It as well inserts a "crutch" for pilots flying
this airplane that should NOT be needed. Proper checkout and proper
handling of the airplane is the right approach to saving lives in the
Mustang, NOT altering the way the airplane is normally flown to give
those pilots flying it a "safety valve".

I see a similarity in the approach to the two issues, the other being
the use of carb heat here.

--
Dudley Henriques

On Sep 8, 5:11 pm, "Robert M. Gary" wrote:
Well ok. Dry in the sense of visible moisture; yes, no visible
moisture. However, we know that humidy is the key to carb ice so there
had to be some humidy. But what type of solution is that? You teach
students to subtract the dew point from the temp in order to decide
when to turn off carb heat. That just sounds complicated for little
gain.

It's not complicated. If the temp and dewpoint are 3 or 5 or
8 degrees (Celcius) apart, ice is likely. If they're 25 degrees apart,
it's not. Anyone can print out the carb ice risk chart (Google "carb
ice") and stick it where it's handy.
Here in Canada, the regs say this:

"602.72 The pilot-in-command of an aircraft shall, before commencing a
flight, be familiar with the available weather information that is
appropriate to the intended flight."

I would imagine the FAA has something equivalent to that.

So some sort of weather information is mandatory, and that
would include temp and dewpoint. There's no excuse for being surprised
by carb ice. None at all. Like I tell my students, "You wouldn't dive
into water without making sure there were no hazards in it that might
injure you (hard or sharp pointy things under the surface, predators,
and so on) and that it wasn't one degree above freezing. Why would we
take off into air about which we know nothing?

Dan

"Dudley Henriques" wrote in message
...
wrote:
On Sep 8, 11:51 am, Dudley Henriques wrote:

I'd say a vast amount of engine "hiccups" on a go around are caused not
by carb heat but rather by over aggressive use of throttle. SMOOTH is
the key word for throttle use on a go around. Aggressive throttle use
might get you a "hiccup" in a 150 Cessna. It might even cause an engine
failure. It can kill you in a high performance prop airplane.


The hiccup is only one part of the risk when shoving the
throttle in too fast, too. When high manifold pressures are applied at
low RPM, the cylinder pressures get much too high and detonation
becomes a danger. Broken pistons and rings and other cylinder parts
can all result from this, as can overloaded bearings. The propeller is
a very heavy flywheel and we can't expect the same acceleration we get
in our cars. Further, even old cars had variable ignition timing that
would drop the spark advance to 10 or 6 degrees BTDC during
acceleration to avoid detonation, but our LyConts don't have that and
are stuck at 20 or 25 or 28 or whatever degrees. The pilot will never
hear the pinging because of all the other racket, but it's there if
they get too rough with the throttle.

Dan

As a pilot of Warbirds through the years I've run into the problem
consistently when advising new pilots on how to handle these airplanes.
Some SE warbirds will actually torque roll if high MP is applied on a go
around with the prop in full increase (Low pitch/high RPM), if the power
is ham handed in with the airplane under about 120 with high AOA involved
in the power up equation.


--
Dudley Henriques

Oh brother, here we go again.

"Bertie the Bunyip" wrote in message
...
"Lonnie" @_#~#@.^net wrote in :


"Bertie the Bunyip" wrote in message
...

Lycomings, no problem with your plan at all. Continentals ice a bit
more easily, and on a clear dry day, there won't be a problem either,
though I'd be inclined to leave it on just a bit longer. I'd also get
in the habit of pushing the carb heat in with the throttle if you go
around..

Bertie

Your a dumb ass. What next, practicing emergency landings by turning
off the fuel?

If you don't like an engines throttle response with carb heat on,
turning off the carb heat is NOT the solution.


Didn't say it was, fjukkktard.


Bertie

Liar. Are you so stupid you can't follow a thread one post long.

"Robert M. Gary" wrote in message
...
On Sep 8, 12:54 pm, Bertie the Bunyip wrote:

That observation is in conflict with my experience. Everytime I've
gotten carb ice in the pattern has been on a clear day.

But not a clear dry one.

Well ok. Dry in the sense of visible moisture; yes, no visible
moisture. However, we know that humidy is the key to carb ice so there
had to be some humidy. But what type of solution is that? You teach
students to subtract the dew point from the temp in order to decide
when to turn off carb heat. That just sounds complicated for little
gain.

-Robert

Exacty.

wrote in message
...
On Sep 8, 5:11 pm, "Robert M. Gary" wrote:
Well ok. Dry in the sense of visible moisture; yes, no visible
moisture. However, we know that humidy is the key to carb ice so there
had to be some humidy. But what type of solution is that? You teach
students to subtract the dew point from the temp in order to decide
when to turn off carb heat. That just sounds complicated for little
gain.

It's not complicated. If the temp and dewpoint are 3 or 5 or
8 degrees (Celcius) apart, ice is likely. If they're 25 degrees apart,
it's not. Anyone can print out the carb ice risk chart (Google "carb
ice") and stick it where it's handy.
Here in Canada, the regs say this:

"602.72 The pilot-in-command of an aircraft shall, before commencing a
flight, be familiar with the available weather information that is
appropriate to the intended flight."

I would imagine the FAA has something equivalent to that.

So some sort of weather information is mandatory, and that
would include temp and dewpoint. There's no excuse for being surprised
by carb ice. None at all. Like I tell my students, "You wouldn't dive
into water without making sure there were no hazards in it that might
injure you (hard or sharp pointy things under the surface, predators,
and so on) and that it wasn't one degree above freezing. Why would we
take off into air about which we know nothing?

Dan

You want to argue awareness of conditions to justify dropping carb heat,
when dropping carb heat is not necessary to solve the OP's issue?

"Dudley Henriques" wrote in message
...

We have a similar thing going on right now in the Warbird community. After
the McKitrick go around torque roll mort in his P51 last year, we have one
very respected member of our community advocating making approaches in the
P51 Mustang using cruise settings on the prop instead of the normal
2700RPM (Meto) setup used by pilots flying approach in this airplane.
His theory is that on a go around, where torque is a huge issue on the
Mustang if power is misused, keeping the prop in cruise won't hurt the
engine if it's over boosted unintentionally and will deny the extremly
high torque moment associated with the application of too much power too
quickly.
He maintains this "safety valve" will help save lives.
I have a great respect for this pilot's opinion.....normally!
As someone involved in the Mustang community as a safety adviser, I find
his "theory" "interesting" to say the leat but I'm against it.
Doing this flies in the face of the normal Dash 1 approved go around setup
for the 51 which is to run the prop up to 2700 and DON'T ham hand the
throttle if needed! It as well inserts a "crutch" for pilots flying this
airplane that should NOT be needed. Proper checkout and proper handling of
the airplane is the right approach to saving lives in the Mustang, NOT
altering the way the airplane is normally flown to give those pilots
flying it a "safety valve".

I see a similarity in the approach to the two issues, the other being the
use of carb heat here.

--
Dudley Henriques

Geeez Dudley, how the hell did you get from dropping carb heat on short
final, to an essay like this in only two posts?

Put the O2 mask back on.

Lonnie wrote:
"Dudley Henriques" wrote in message
...
wrote:
On Sep 8, 11:51 am, Dudley Henriques wrote:

I'd say a vast amount of engine "hiccups" on a go around are caused not
by carb heat but rather by over aggressive use of throttle. SMOOTH is
the key word for throttle use on a go around. Aggressive throttle use
might get you a "hiccup" in a 150 Cessna. It might even cause an engine
failure. It can kill you in a high performance prop airplane.

The hiccup is only one part of the risk when shoving the
throttle in too fast, too. When high manifold pressures are applied at
low RPM, the cylinder pressures get much too high and detonation
becomes a danger. Broken pistons and rings and other cylinder parts
can all result from this, as can overloaded bearings. The propeller is
a very heavy flywheel and we can't expect the same acceleration we get
in our cars. Further, even old cars had variable ignition timing that
would drop the spark advance to 10 or 6 degrees BTDC during
acceleration to avoid detonation, but our LyConts don't have that and
are stuck at 20 or 25 or 28 or whatever degrees. The pilot will never
hear the pinging because of all the other racket, but it's there if
they get too rough with the throttle.

Dan
As a pilot of Warbirds through the years I've run into the problem
consistently when advising new pilots on how to handle these airplanes.
Some SE warbirds will actually torque roll if high MP is applied on a go
around with the prop in full increase (Low pitch/high RPM), if the power
is ham handed in with the airplane under about 120 with high AOA involved
in the power up equation.


--
Dudley Henriques

Oh brother, here we go again.


Well hello Max. What took you so long? :-)

--
Dudley Henriques