Piper Archer carb heat
Bob Webster
Does anyone know when should carb heat be applied in a Piper Archer? I've been
told (a) just for a short period (20 seconds) during the landing checklist,
and (b) from the landing checklist until landing.
The POH says use carb heat "as needed", and mentions using it on descent. It
says not to use carb heat on approach because you may need the power in an
abort. I think I would rather abort with partial power (assuming I forget to
turn off the carb heat) instead of lose the engine because of carb ice, but
how likely is that in a Piper? I understand that once carb heat kills the
engine, it won't be restarting. When is "as needed"?
The only time I've experienced carb ice was in a 152 at 5500' and at cruise
speed. I've been told that the Piper Archer is not as susceptible because of
the placement of the carburetor. Is that right?
David Lindenauer
Bob Webster wrote:
> Does anyone know when should carb heat be applied in a Piper Archer?
1. As on any aircraft with fixed pitch propellor, when in conditions
conducive to carb icing (high humidity and low rpm), or when an rpm drop
is noticed when in constant throttle/airspeed situations.
2. Officially, any time operating below the green arc of the tachometer,
which on the Archer is low indeed.
In several hundred hours in PA28s (including the Archer), I've rarely
needed it, and you'll notice that it's not even on the landing
checklist, a la Cessna.
Paul Tomblin
In a previous article, b...@viagrafix.com (Bob Webster) said:
>Does anyone know when should carb heat be applied in a Piper Archer? I've been
>told (a) just for a short period (20 seconds) during the landing checklist,
>and (b) from the landing checklist until landing.
My instructor wanted me to use it from the landing checklist until landing,
mostly because he wanted me to develop the habit and carry it over if I ever
started flying Cessnas. In Cessnas, you are out of the green arc almost as
soon as you reduce power to descend, but Pipers have the carb in a position
where it is kept warmer by the engine, so the green arc actually goes right
down below flight idle.
After talking it over here on the net and with other pilots, I've changed my
habits and I "check carb" for 10 seconds on downwind (longer if I think it's
prime icing conditions), but then turn it off and leave it off for the rest of
the landing. But thanks to Geoff's drilling, checking "carb heat is cold" is
an ingrained part of my go-around procedure.
>engine, it won't be restarting. When is "as needed"?
I turn it on for 10-20 seconds every time I reset the DG to the compass. If I
get signs of carb ice, I run it more frequently. I also run it for a good 10
seconds on runup. The reason I do that is because last year, while a solo
student, I lost power at about 400 feet off the runway on a take-off in cold
weather. Fortunately, I followed the drill (tank, mixture, pump, carb-heat)
and the engine coughed twice and gained power again. It took my heart
considerably longer to recover.
--
Paul Tomblin, PP-ASEL _|_ Rochester Flying Club web page:
____/___\____ http://www.servtech.com/public/
___________[o0o]___________ ptomblin/rfc.html
ptom...@xcski.com O O O
Jim Wolper
>My instructor wanted me to use it from the landing checklist until landing,
>mostly because he wanted me to develop the habit and carry it over if I ever
>started flying Cessnas.
This is, in my opinion, bad instruction. You should fly the airplane
you are in today, not one you have flown before or might fly in the
future.
Jim Wolper CFI
John R. Johnson
I agree with Jim. The reason we do checkouts in a new type is to learn
about the differences. These generic habits can get you generically into
trouble. For example, the flap/gear position debate between Beech and
other retracts.
John
Jason Watson
In <Pine.SOL.3.91.970109125515.16195X-100000@reliant> "John R. Johnson"
<jo...@siu.edu> writes:
>
>On 9 Jan 1997, Jim Wolper wrote:
>
>> >My instructor wanted me to use it from the landing checklist until
landing,
>> >mostly because he wanted me to develop the habit and carry it over
if I ever
>> >started flying Cessnas.
>>
>> This is, in my opinion, bad instruction. You should fly the
airplane
>> you are in today, not one you have flown before or might fly in the
>> future.
>>
>> Jim Wolper CFI
>>
>
heat should not be used on landings simply because it robs the engine
of power on go-arounds. The POH further states that carb heat should
only be used if carb ice is suspected.
Jason
Paul Tomblin
In a previous article, "John R. Johnson" <jo...@siu.edu> said:
>On 9 Jan 1997, Jim Wolper wrote:
>> >My instructor wanted me to use it from the landing checklist until landing,
>> >mostly because he wanted me to develop the habit and carry it over if I ever
>> >started flying Cessnas.
>>
>> This is, in my opinion, bad instruction. You should fly the airplane
>> you are in today, not one you have flown before or might fly in the
>> future.
>
>about the differences. These generic habits can get you generically into
>trouble. For example, the flap/gear position debate between Beech and
>other retracts.
Well, yes and no. I agree that you should fly each plane the way it was meant
to be flown, and I don't use the carb heat the way I was taught, I use it the
way the POH says to. But in my CFI's defence, I would like to point out that
the way he taught is NOT in any way dangerous in Cherokees, because he also
taught me to automatically reach for the carb heat level and turn it to (or
make sure it already is) cold right after adding power in a go-around.
The POH gives as the only reason for not doing it that way the loss of power
on a go-around. I did dozens if not hundreds of go-arounds (at least one per
dual session, and usually more) and never had a problem with forgetting to
turn the carb heat to cold.
The reason I stopped doing it his way is because I'd read that the
non-filtered air can harm the engine by allowing bugs and dirt into the carb
and the cylinders. If it's not prime icing conditions, I'd just as soon do
what's right for the engine.
The three laws of Aeronautics, with apologies to Isaac Asimov:
1. The pilot shall not allow harm to come to him, his passengers, or other
people, either by action or inaction.
2. The pilot shall not allow harm to come to his aircraft or other people's
aircraft, either by action or inaction, except when to do so would conflict
with the First Law.
3. The pilot shall not piss off the FAA, other pilots, or groundlings either
by action or inaction, except when to do so would conflict with the First or
Second Laws.
(These are original to me)
--
Paul Tomblin (ptom...@xcski.com), Rochester Flying Club
<a href="http://www.servtech.com/public/ptomblin/rfc.html">RFC Web Page</a>
"Pilots are reminded to ensure that all surly bonds are slipped before
attempting taxi or take-off"
Clayton L. Cranor
Bob Webster wrote:
>
> Does anyone know when should carb heat be applied in a Piper Archer? I've been
> told (a) just for a short period (20 seconds) during the landing checklist,
>
> The POH says use carb heat "as needed", and mentions using it on descent. It
> says not to use carb heat on approach because you may need the power in an
> abort. I think I would rather abort with partial power (assuming I forget to
> turn off the carb heat) instead of lose the engine because of carb ice, but
> how likely is that in a Piper? I understand that once carb heat kills the
>
> speed. I've been told that the Piper Archer is not as susceptible because of
> the placement of the carburetor. Is that right?
As needed is just that. Apply it when ice is most likely to form. At
or near idle (approach...) the engine isn't producing enough heat to
melt ice anyway, and isn't likely to be producing ice at low power
outputs. Turn it on 30 or so before your first power reduction, and
turn it off after your final power reduction on short final. This
should protect your carb from ice, and leave power for aborted landing,
if needed.
Clay
sa...@execulink.com
>Bob Webster wrote:
>>
>> Does anyone know when should carb heat be applied in a Piper Archer? I've been
>> told (a) just for a short period (20 seconds) during the landing checklist,
>> and (b) from the landing checklist until landing.
>>
I was always told to have carb heat on
whenever the tachometer was below the green arc.
I was given this info when I checked out on the PA-28-140 and the 161
and the 181
_____________________________________________________
Negotiate when possible, fight and win when required.
Bruce McCulley
Two things. First, last week I flew our Archer the day after reading the
start of this thread, and decided to try giving a brief shot of carb heat
just as I began my let-down from cruising at 6500 - the engine almost
stopped! I went carb heat off, full rich and full throttle immediately
and it picked back up again, but it sure got my attention!
On the homeward bound leg I tried the same thing, somewhat hesitantly, and
got a slight stumble but nothing quite as dramatic, after clearing it
again the second application of carbheat gave nothing but a slight RPM
drop. Apparently I had picked up minor amounts of carb icing....
Second,
In article <E3rs4...@xcski.com>, Paul Tomblin <ptom...@xcski.com> wrote:
>[..SNIP...] But in my CFI's defence, I would like to point out that
>the way he taught is NOT in any way dangerous in Cherokees, because he also
>taught me to automatically reach for the carb heat level and turn it to (or
>make sure it already is) cold right after adding power in a go-around.
On a more abstract level, he was teaching his students to deviate from the
checklist - is that a good thing? I'd say not. Better to teach them to
religiously use the checklist for the airplane they are flying, then when
they fly Cessnas they will be okay for a much more fundamentally sound
reason than his rationale. And they will be better prepared to deal with
other differences that may not be as benign as the Cherokee's de-emphasis
of carb heat. Just my opinion, take it for what it's worth...
--bruce mcculley
Jake Brodsky
Having spent a couple hundred hours in Archers myself, I can vouch for
the fact that carb ice happens in that aircraft, regardless of where
the green arc ends. The green paint on that tachometer is not the
final word on whether you'll get carb ice.
The suggestion posted earlier about engaging carb heat 30 seconds
before the power reduction from cruise to flap deployment speed seems
very reasonable to me.
Jake Brodsky, mailto:fru...@erols.com
PP ASEL IA, Cessna Cardinal N30946, Based @ MD24
Amateur Radio Station AB3A
Paul Tomblin
In a previous article, sa...@execulink.com said:
> I was always told to have carb heat on
>whenever the tachometer was below the green arc.
>I was given this info when I checked out on the PA-28-140 and the 161
>and the 181
You should also check the carb by putting the carb heat on for 10 or 20
seconds every few minutes. In a PA28-161 or 181, I've NEVER seen the tach go
below the green arc while I was in the air. Even when you reduce power on
landing, it's still in the green arc. So test every so often in cruise, and
before any critical action like attempting a landing or doing a stall.
--
Paul Tomblin (ptom...@xcski.com), Rochester Flying Club
<a href="http://www.servtech.com/public/ptomblin/rfc.html">RFC Web Page</a>
RFC is selling one of our PA28-181 Piper Archer IIs. Contact me for details.
Rob Warnock
Bruce McCulley <bru...@mv.mv.com> wrote:
+---------------
| First, last week I flew our Archer the day after reading the
| start of this thread, and decided to try giving a brief shot of carb heat
| just as I began my let-down from cruising at 6500 - the engine almost
| stopped! I went carb heat off, full rich and full throttle immediately
| and it picked back up again, but it sure got my attention!
This actually may have had nothing to do with ice. Remember, when you
apply carb heat you are injecting warmed air into the mixture. Said air
is less dense than what was there before, thus the mixture is suddenly
leaned a bit. It you were already leaned for economy cruise, applying
carb heat may have over-leaned the engine to the point of cutout (or at
least significant power loss). Something to keep in mind...
-Rob
-----
Rob Warnock, 7L-551 rp...@sgi.com
Silicon Graphics, Inc. http://reality.sgi.com/rpw3/
2011 N. Shoreline Blvd. Phone: 415-933-1673 FAX: 415-933-0979
Mountain View, CA 94043 PP-ASEL-IA
Jeffrey M. Matthews
In article <E3zDu...@mv.mv.com>, Bruce McCulley <bru...@mv.mv.com> wrote:
[Discussion as to whether to apply carb heat regularly, or only as needed
deleted]
>
>On a more abstract level, he was teaching his students to deviate from the
>checklist - is that a good thing? I'd say not. Better to teach them to
>religiously use the checklist for the airplane they are flying, then when
On the other hand, he was teaching his students to think about what they
were doing. Perhaps there's some value in that.
Jeff Matthews
Patrick W. P. Dirks
In article <5bho9k$2...@tokyo.engr.sgi.com>, rp...@rigden.engr.sgi.com (Rob
Warnock) wrote:
> Bruce McCulley <bru...@mv.mv.com> wrote:
> | First, last week I flew our Archer the day after reading the
> | start of this thread, and decided to try giving a brief shot of carb heat
> | just as I began my let-down from cruising at 6500 - the engine almost
> | stopped! I went carb heat off, full rich and full throttle immediately
> | and it picked back up again, but it sure got my attention!
>
> This actually may have had nothing to do with ice. Remember, when you
> apply carb heat you are injecting warmed air into the mixture. Said air
> is less dense than what was there before, thus the mixture is suddenly
> leaned a bit. It you were already leaned for economy cruise, applying
> carb heat may have over-leaned the engine to the point of cutout (or at
> least significant power loss). Something to keep in mind...
>
Um, I believe you've got that last part backwards. You're right that
warmer air is less dense, but that means you get fewer air molecules mixed
with the same amount of fuel, producing a *RICHER* mixture!
Cheers,
-Pat Dirks.
Ryan R. Healy
Bob Webster wrote:
>
> Does anyone know when should carb heat be applied in a Piper Archer? I've been
> told (a) just for a short period (20 seconds) during the landing checklist,
> and (b) from the landing checklist until landing.
Use the carb heat only when carb ice is suspected or present as
indicated by the operation of the engine. A Cessna is a Cessna and a
Piper is a Piper. Both have different procedures because of different
installation peculiarities.
--
Blue Skies,
*************************************************************
* Ryan R. Healy, C-ASMEL-I, CFI-ASMEL-I, AGI, IGI *
* AOPA PROJECT PILOT INSTRUCTOR *
* E-Mail: rhea...@sprynet.com *
* Web Page: http://home.sprynet.com/sprynet/rhealy707 *
*************************************************************
Jeffrey M. Matthews
In article <5bho9k$2...@tokyo.engr.sgi.com>,>+---------------
>| First, last week I flew our Archer the day after reading the
>| start of this thread, and decided to try giving a brief shot of carb heat
>| just as I began my let-down from cruising at 6500 - the engine almost
>| stopped! I went carb heat off, full rich and full throttle immediately
>| and it picked back up again, but it sure got my attention!
>
>This actually may have had nothing to do with ice. Remember, when you
>apply carb heat you are injecting warmed air into the mixture. Said air
>is less dense than what was there before, thus the mixture is suddenly
>leaned a bit. It you were already leaned for economy cruise, applying
>carb heat may have over-leaned the engine to the point of cutout (or at
>least significant power loss). Something to keep in mind...
>
No, the warmed air, being less dense, gives a richer mixture. When I
ferried my Super Cub home (with a newish private ticket and all of my
flying down low), I made the mistake of setting up for a descent from
seven or eight thousand feet by pushing the mixture rich and adding carb
heat, just like I'd been taught. The engine dern near strangled. Lean-
ing made it right again. After a while I caught on that that particular
installation didn't want carb heat most of the time. Many Lycoming in-
stallations react that way.
Since the mixture is richer, leaning will help out if the carb heat sticks
on, for example in a touch and go. You may want to break off the climb
before reaching pattern altitude if the engine is showing signs of distress,
but leaning might keep you out of the trees.
I would take issue with a check list that specified full rich mixture in
a descent. At low power, the engine isn't putting out enough heat to hurt
itself, so the only result of an excessively lean mixture will be a rough
engine, which may eventually quit if the pilot is so far behind the air-
plane as to fail to take action. And if the descent is made with a rela-
tively lean mixture, when power is needed the plugs won't be all fouled
up.
Carb heat is another matter. There's not a heck of a lot of heat stored
in the muffler--at least the part of it that's providing carburetor heat.
Getting a couple of pounds of carburetor nice and warm will stave off the
formation of ice for a few more seconds with an idling engine, but a long
power-off descent can leave things pretty cold. Keeping a bit of power
on is friendlier to the top end of the cylinder, as well as keeping Jack
Frost at bay.
Flying is full of over-simplifications--has to be, to avoid overwhelming
the student. In time, some of the "rules" can be replaced by knowledge,
to the advantage of pilot and airplane.
Jeff Matthews
Rich Hare
I quote:
"thus the mixture is suddenly leaned a bit. "
I think that should read... "thus the mixture is suddenly ENRICHENED"
Fuel stays the same, the warmer air is thinner... mixture is ENRICHENED.
Alexander Beck
Sorry, Pat, but carb heat does not lean the mixture, it enrichens! As
the air is less dense when warm, you get less oxygen into the engine
when you pull carb heat on. So, if the engine suddenly quits (or near
so) at high altitude (6500) when carb heat is applied, I guess the
mixture was over rich anyway, and with the even less dense warm air
the plugs may have trouble igniting the stuff - and power drops
sharply.
Before you apply carb heat at altitude, you must make sure your
engine is running at proper mixture. Pulling the mixture back a bit
would have prevented the engine to quit, but be sure to adjust
(enrichen) the mixture as you descend.
Same problem when taking off from hot-and-high airports. When you
check your carb heat during run-up, and the engine runs rough with
carb heat on, that means you mixture is too rich. Apply full power,
adjust mixture to max rpm, and then try again.
Alex
Rob Warnock
Rich Hare <rh...@mich.com> wrote:
+---------------
| Rob Warnock wrote:
| > apply carb heat you are injecting warmed air into the mixture. Said air
| > is less dense than what was there before, thus the mixture is suddenly
| > leaned a bit.
|
| Fuel stays the same, the warmer air is thinner... mixture is ENRICHENED.
(*blush*) Oops! Right you are.
works...@gmail.com
> Does anyone know when should carb heat be applied in a Piper Archer? I've been
> told (a) just for a short period (20 seconds) during the landing checklist,
> and (b) from the landing checklist until landing.
>
> says not to use carb heat on approach because you may need the power in an
> abort. I think I would rather abort with partial power (assuming I forget to
> turn off the carb heat) instead of lose the engine because of carb ice, but
> how likely is that in a Piper? I understand that once carb heat kills the
> engine, it won't be restarting. When is "as needed"?
>
> The only time I've experienced carb ice was in a 152 at 5500' and at cruise
> speed. I've been told that the Piper Archer is not as susceptible because of
> the placement of the carburetor. Is that right?
> Does anyone know when should carb heat be applied in a Piper Archer? I've been
> told (a) just for a short period (20 seconds) during the landing checklist,
> and (b) from the landing checklist until landing.
>
> says not to use carb heat on approach because you may need the power in an
> abort. I think I would rather abort with partial power (assuming I forget to
> turn off the carb heat) instead of lose the engine because of carb ice, but
> how likely is that in a Piper? I understand that once carb heat kills the
> engine, it won't be restarting. When is "as needed"?
>
> The only time I've experienced carb ice was in a 152 at 5500' and at cruise
> speed. I've been told that the Piper Archer is not as susceptible because of
> the placement of the carburetor. Is that right?
My name is Joe and I just bought a Cherokee 180 archer to replace the Cherokee 140 I had that was blown away by the storm Sandy.
As far has carb heat goes when I flew the 140 I only used it for the simulated engine out practice that we do. For normal landing never use it and never had problem. I have been flying the 180 for now using the numbers from 140 so far so good. Let me know if you come across anything that says we should use it for landing the P.O.H. says as need I am also confused. you can reach me at this e-mail I am based at 39N Princeton NJ and still getting used to the 180 archer.
Thanks,
Joe