Flying with the Carb-Heat on for a long(er) tour?

Hi,
After taking two passengers on SF-Bay tours, I realized that I
want to take the tour slower... A north-bay tour (SF, GGB, Ocean
Beach, without the 101/Bravo transition) takes about 40min roundtrip
from OAK - a little quick.

I've been used to flying with the rpm around the bottom of the
green arc for this kind of thing, as my CFI used to always remind me
that "Carb-Heat introduces unfiltered air [into the carb]" which is a
bad thing...

Basically - is it bad for the aircraft (C172) to float around at
around 85kts with the power somewhere below the green arc (say
1800rpm) and the Carb-Heat on? Ok, there is a second benefit - my club
charges based on tach time, and I have to be honest about that -
although I really do wish for the tours to be slower.

Thanks for any comments,
Noah

"noah" wrote in message om...

Basically - is it bad for the aircraft (C172) to float around at
around 85kts with the power somewhere below the green arc (say
1800rpm) and the Carb-Heat on? Ok, there is a second benefit - my club
charges based on tach time, and I have to be honest about that -
although I really do wish for the tours to be slower.

Most of the dirt is pretty close to the ground. Unless you're flying through
a duststorm or volcanic erruption, at altitude there shouldn't be much harm
in leaving the heat on.

My thread isn't really on-topic, but I just had to chime in. The SF Bay
tour is such a charge to take friends with you on. While I've certainly
taken some on the $100 hamburger stops, nothing has quite inspired the oohs
and aahhs as the SF Bay Tour. I'm so glad that the Fatherland... oops I
mean Homeland security , hasn't been needlessly paranoid and allowed the SF
Bay Tours...

--
--
Good Flights!

Cecil E. Chapman, Jr.
PP-ASEL

"We who fly do so for the love of flying.
We are alive in the air with this miracle
that lies in our hands and beneath our feet"

- Cecil Day Lewis-

Check out my personal flying adventures: www.bayareapilot.com
"noah" wrote in message
om...
Hi,
After taking two passengers on SF-Bay tours, I realized that I
want to take the tour slower... A north-bay tour (SF, GGB, Ocean
Beach, without the 101/Bravo transition) takes about 40min roundtrip
from OAK - a little quick.

I've been used to flying with the rpm around the bottom of the
green arc for this kind of thing, as my CFI used to always remind me
that "Carb-Heat introduces unfiltered air [into the carb]" which is a
bad thing...

Basically - is it bad for the aircraft (C172) to float around at
around 85kts with the power somewhere below the green arc (say
1800rpm) and the Carb-Heat on? Ok, there is a second benefit - my club
charges based on tach time, and I have to be honest about that -
although I really do wish for the tours to be slower.

Thanks for any comments,
Noah

"noah" wrote in message
om...
Basically - is it bad for the aircraft (C172) to float around at
around 85kts with the power somewhere below the green arc (say
1800rpm) and the Carb-Heat on?

Just remember to lean the engine. Technically, at that altitude you
theoretically wouldn't need to, based on the POH. But in reality, even
without the carb heat, leaning in cruise regardless of altitude is a fine
thing, and especially with the enrichened mixture caused by the carb heat,
it's nice for the engine.

Pete

I just want to take this opportunity to totally, 100%, and unreservedly
agree with Peter

--
Roger Long

Peter Duniho wrote in message
...
"noah" wrote in message
om...
Basically - is it bad for the aircraft (C172) to float around at
around 85kts with the power somewhere below the green arc (say
1800rpm) and the Carb-Heat on?

Just remember to lean the engine. Technically, at that altitude you
theoretically wouldn't need to, based on the POH. But in reality, even
without the carb heat, leaning in cruise regardless of altitude is a fine
thing, and especially with the enrichened mixture caused by the carb heat,
it's nice for the engine.

Pete

"Roger Long" om wrote in
message ...
I just want to take this opportunity to totally, 100%, and unreservedly
agree with Peter

I know you do that just to **** me off!

Peter Duniho wrote:

"Roger Long" om wrote in
message ...
I just want to take this opportunity to totally, 100%, and unreservedly
agree with Peter

I know you do that just to **** me off!

You get upset when people agree with you?

That explains a lot.

George Patterson
If you're not part of the solution, you can make a lot of money prolonging
the problem.

"G.R. Patterson III" wrote in message
...
You get upset when people agree with you?

No, just Roger. I only get ****ed off because I know he's doing it to ****
me off.

(Smiley there. Just like in the last post, which you seemed to have
missed).

That explains a lot.

Like what?

Pete

Peter,

echnically, at that altitude you
theoretically wouldn't need to, based on the POH.


Wrong. Most all POHs tell you to lean at any altitude AT CRUISE POWER
SETTINGS.

--
Thomas Borchert (EDDH)

"Thomas Borchert" wrote in message
...
Peter,

echnically, at that altitude you
theoretically wouldn't need to, based on the POH.


Wrong. Most all POHs tell you to lean at any altitude AT CRUISE POWER
SETTINGS.

Wrong? Completely? So wrong that you found it so very important to follow
up to say so? Amazing. In any case...

Not all do. Many state or imply that leaning is not necessary below 3000'
or 5000', for example. And it may even be true that leaning isn't *really*
necessary, from an operational point of view. But engine will be much
happier if you do. I don't have the POH he's using, so I have no idea what
it says. My comments were offered purely in the hypothetical, so I don't
see how you can make an unqualified assertion that they were wrong.

My point is that, even if the POH says you don't need to lean, one ought to
anyway in this particular case. Do you disagree with the actual point, or
are you so hard up you find it necessary to critique embedded statements
that could be construed as being flatly incorrect, even when they aren't?

Pete