Emergency

[Dan Luke]

It was the 3rd leg of an Angel Flight and I wasn't even supposed to be
flying it. I'd already flown the second leg from Natchez, MS to
Monroeville, AL, but the 3rd leg pilot had mysteriously failed to show--no
call, no nothin'. It was late, I was tired and I was mad. I had two pax
aboard.

We were in the clouds and in the dark in a Cutlass RG approaching Macon, GA
(MCN). The outside temperature was 13 C and moisture was streaming back on
the windshield. The throttle was fully open, the RPM was set for 2500 and
the mixture was leaned to 10.5 gph. The autopilot was holding course and
altitude. I was studying the ILS approach plate when I noticed the AP's
"up" trim warning light illuminate.

A quick scan of the instruments showed the IAS at 100 and falling; normally
it would indicate 125 at that altitude. I had detected no change in the
engine sound. I immediately hit the AP disable switch to prevent its
stalling the airplane. This was right and wrong, as I now had to do all the
flying while troubleshooting the problem. What I should have done was
disable the altitude hold and allow the AP to continue keeping us on course
and wings level.

Any attempt to lift the nose resulted in a sickening drop in airspeed. The
situation was now officially scary: we were going down on a dark, rainy
night over central Georgia.

I shoved the prop and mixture full forward, confirmed the throttle was wide
open and the primer was in. No improvement. There was no unusual
vibration. The engine still sounded good and was still making 2500 rpm, but
the prop was probably in flat pitch to do it. I tried the electric fuel
pump: no joy. I glanced at the JPI engine analyzer and saw that all four
cylinders showed roughly even EGTs. All this took much less than a minute;
maybe only 30 seconds.

Finally, I pulled the carb heat. Within a few seconds I felt a surge of
power and we began to climb. I don't know for sure what a death row inmate
feels like when the governor calls at the last minute, but I'm guessing it
feels something like that.

My heart was pounding in my chest and I was so stoked on adrenalin my hands
were shaking. The front seat passenger was looking at me wide-eyed--he
didn't know what was happening, but he had figured out *something* wasn't
right. I had wandered 40 deg. off course and Atlanta Approach was repeating
a frequency change instruction. In a few moments I had us back on course
and altitude but I was still somewhat rattled and blew the readback on
Atlanta's initial approach instructions. Got that sorted out and made an
uneventful ILS approach to runway 5 at MCN.

Not a totally satisfying performance. I ended up doing the right thing and
we lived; that's the good news. The bad news is that allowed myself to rush
things. A moment's thought would have prevented the autopilot mistake. A
calmer, more orderly flow through the engine controls would have led me to
the carb heat sooner and saved a few unnecessary extra seconds of high
anxiety. Next time I have an emergency (please: NO next time!) I'll try to
take it a little slower.

I'm still surprised that the carb iced up at full throttle. Conditions were
in the bad area of the carb ice chart, but my engine has never seemed prone
to the problem. In 650+ hours I've only detected carb ice once before, and
that was after a long taxi on a cool, rainy day.

--
Dan
C172RG at BFM

[Mark Hansen]

On 03/27/06 16:21, Dan Luke wrote:

[ great story snipped ]

I just wanted to thank you for sharing your experience and thoughts with
the rest of us.

I've often wondered how I will perform in an actual event, given the
practiced versions are so 'uneventful'. My hope is that I'll stay calm
and go through the 'checklists', but only time will tell.

Thanks again.


--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

[Peter R.]

Dan Luke > wrote:

> I'm still surprised that the carb iced up at full throttle. Conditions were
> in the bad area of the carb ice chart, but my engine has never seemed prone
> to the problem. In 650+ hours I've only detected carb ice once before, and
> that was after a long taxi on a cool, rainy day.

Thanks, Dan, for posting your experience. I have to admit that I never
gave the individual AP modes during an emergency much thought until reading
your post.

Very happy to read of your successful outcome.


--
Peter

[A Lieberman]

On Mon, 27 Mar 2006 16:51:29 -0800, Mark Hansen wrote:

> I've often wondered how I will perform in an actual event, given the
> practiced versions are so 'uneventful'. My hope is that I'll stay calm
> and go through the 'checklists', but only time will tell.

To be quite honest Mark, when it comes to an emergency, and referring to a
checklist, having myself been through a partial engine failure (exhaust
valve bit the dust) that check list really becomes a moot point when the
failure is not your standard failure as in Dan's case.

The best thing to do is commit the essential trouble shooting tips to
memory, as when it comes to the real deal, aviate will become your primary
focus of attention (in my case, establish 78 knot glide speed) and then
start trouble shooting by doing what you remember on the list. For me it
was check mags, change tanks, fuel pump, carb heat mixture and once I got
past that with no improvement, then navigated and communicated my
emergency. My only thing I didn't do, which the list would have reminded
me to do was open the cabin door.

All through this, I still heard my instructor say "Fly the plane". By
doing that, actually kept me focused and calm during the actual emergency.

Now, keep in mind, I was the sole occupant, had I had a passenger, I would
have enlisted their help in reading to me a laminated emergency checklist I
created. You can see what I posted at

http://groups.google.com/group/rec.aviation.owning/browse_frm/thread/834883a68766895/276bdfa0c25cc49d?tvc=1&q=first+emergency+lieberma&hl=en#276bdfa0c25cc49d

and the excellent feedback and suggestions I received.

Allen

[pgbnh]

I have long been convinced that becoming a truly proficient and competent
pilot is the result of the sum of a series of 'mini-emergencies' (not to
minimize yours - sounds like a REAL emergency). What I mean is that over
years of flying we all face small crises and we learn how to deal with them.
And each time we do, we become better crisis managers. A little ice this
time, a little low-fuel situation the next, two-out-of-three green on the
landing gear, strange sparks from the engine in-flight, and switching to the
wrong tanks at night. All recoverable, and all with lots of boring, 'normal'
flights in between. But each time, the ability to stay calm, aviate,
analyze, and correct makes for a better pilot, better able to handle the
'next one'.

As others have said, thanks for sharing your story. Glad things turned out
well. You criticize yourself for what you did wrong - how about all the
things you did right?
"Dan Luke" > wrote in message
...
> It was the 3rd leg of an Angel Flight and I wasn't even supposed to be
> flying it. I'd already flown the second leg from Natchez, MS to
> Monroeville, AL, but the 3rd leg pilot had mysteriously failed to show--no
> call, no nothin'. It was late, I was tired and I was mad. I had two pax
> aboard.
>
> We were in the clouds and in the dark in a Cutlass RG approaching Macon,
> GA (MCN). The outside temperature was 13 C and moisture was streaming
> back on the windshield. The throttle was fully open, the RPM was set for
> 2500 and the mixture was leaned to 10.5 gph. The autopilot was holding
> course and altitude. I was studying the ILS approach plate when I noticed
> the AP's "up" trim warning light illuminate.
>
> A quick scan of the instruments showed the IAS at 100 and falling;
> normally it would indicate 125 at that altitude. I had detected no change
> in the engine sound. I immediately hit the AP disable switch to prevent
> its stalling the airplane. This was right and wrong, as I now had to do
> all the flying while troubleshooting the problem. What I should have done
> was disable the altitude hold and allow the AP to continue keeping us on
> course and wings level.
>
> Any attempt to lift the nose resulted in a sickening drop in airspeed.
> The situation was now officially scary: we were going down on a dark,
> rainy night over central Georgia.
>
> I shoved the prop and mixture full forward, confirmed the throttle was
> wide open and the primer was in. No improvement. There was no unusual
> vibration. The engine still sounded good and was still making 2500 rpm,
> but the prop was probably in flat pitch to do it. I tried the electric
> fuel pump: no joy. I glanced at the JPI engine analyzer and saw that all
> four cylinders showed roughly even EGTs. All this took much less than a
> minute; maybe only 30 seconds.
>
> Finally, I pulled the carb heat. Within a few seconds I felt a surge of
> power and we began to climb. I don't know for sure what a death row inmate
> feels like when the governor calls at the last minute, but I'm guessing it
> feels something like that.
>
> My heart was pounding in my chest and I was so stoked on adrenalin my
> hands were shaking. The front seat passenger was looking at me
> wide-eyed--he didn't know what was happening, but he had figured out
> *something* wasn't right. I had wandered 40 deg. off course and Atlanta
> Approach was repeating a frequency change instruction. In a few moments I
> had us back on course and altitude but I was still somewhat rattled and
> blew the readback on Atlanta's initial approach instructions. Got that
> sorted out and made an uneventful ILS approach to runway 5 at MCN.
>
> Not a totally satisfying performance. I ended up doing the right thing
> and we lived; that's the good news. The bad news is that allowed myself
> to rush things. A moment's thought would have prevented the autopilot
> mistake. A calmer, more orderly flow through the engine controls would
> have led me to the carb heat sooner and saved a few unnecessary extra
> seconds of high anxiety. Next time I have an emergency (please: NO next
> time!) I'll try to take it a little slower.
>
> I'm still surprised that the carb iced up at full throttle. Conditions
> were in the bad area of the carb ice chart, but my engine has never seemed
> prone to the problem. In 650+ hours I've only detected carb ice once
> before, and that was after a long taxi on a cool, rainy day.
>
> --
> Dan
> C172RG at BFM
>

[nrp]

Glad you found the problem in time. Did your manifold pressure drop?
Otherwise, those of you with constant speed props have to be more
sensitive to carb icing as you don't get any other clues except maybe a
falling EGT.

Personally I've found manifold pressure and EGT to be an excellent
cross check on engine performance even though I'm flying a fixed pitch
A/C.

[Peter R.]

Morgans > wrote:

> I have to disagree, on that one. A proficient pilot never puts himself in a
> situation like that, in the first place, ideally.

If one flies a lot, one is bound to experience an unplanned mechanical
failure of some type that could be classified as a minor emergency.

Proficiency is not always about "avoiding" a situation, but rather
sometimes it is about "handling" an unavoidable situation.


--
Peter

[Jack Allison]

Glad it worked out ok Dan. Thanks for posting the experience. Even
though I fly behind a fuel injected Lyc., it's a nice reminder that carb
ice (among other things) happens sometimes


--
Jack Allison
PP-ASEL-Instrument Airplane
Arrow N2104T

"When once you have tasted flight, you will forever walk the Earth
with your eyes turned skyward, for there you have been, and there
you will always long to return"
- Leonardo Da Vinci

(Remove the obvious from address to reply via e-mail)

[Mark Hansen]

On 03/27/06 17:30, A Lieberman wrote:
> On Mon, 27 Mar 2006 16:51:29 -0800, Mark Hansen wrote:
>
>> I've often wondered how I will perform in an actual event, given the
>> practiced versions are so 'uneventful'. My hope is that I'll stay calm
>> and go through the 'checklists', but only time will tell.
>
> To be quite honest Mark, when it comes to an emergency, and referring to a
> checklist, having myself been through a partial engine failure (exhaust
> valve bit the dust) that check list really becomes a moot point when the
> failure is not your standard failure as in Dan's case.

Yes, Allen. I put checklists in quotes in my attempt to mean what ever
is the appropriate thing to do in that situation.

>
> The best thing to do is commit the essential trouble shooting tips to
> memory, as when it comes to the real deal, aviate will become your primary
> focus of attention (in my case, establish 78 knot glide speed) and then
> start trouble shooting by doing what you remember on the list. For me it
> was check mags, change tanks, fuel pump, carb heat mixture and once I got
> past that with no improvement, then navigated and communicated my
> emergency. My only thing I didn't do, which the list would have reminded
> me to do was open the cabin door.
>
> All through this, I still heard my instructor say "Fly the plane". By
> doing that, actually kept me focused and calm during the actual emergency.
>
> Now, keep in mind, I was the sole occupant, had I had a passenger, I would
> have enlisted their help in reading to me a laminated emergency checklist I
> created. You can see what I posted at
>
> http://groups.google.com/group/rec.aviation.owning/browse_frm/thread/834883a68766895/276bdfa0c25cc49d?tvc=1&q=first+emergency+lieberma&hl=en#276bdfa0c25cc49d
>
> and the excellent feedback and suggestions I received.
>
> Allen


--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

[Mortimer Schnerd, RN]

Morgans wrote:
>> I have long been convinced that becoming a truly proficient and competent
>> pilot is the result of the sum of a series of 'mini-emergencies' (not to
>> minimize yours - sounds like a REAL emergency). What I mean is that over
>> years of flying we all face small crises and we learn how to deal with them.
>> And each time we do, we become better crisis managers.
>
> I have to disagree, on that one. A proficient pilot never puts himself in a
> situation like that, in the first place, ideally.


That's an overly idealistic point of view. Some problems aren't easily avoided.
Ever flown into an embedded cell? I know how to avoid them... never fly when
there's a cloud in the sky.

However, since I intend to get some utility out of the airplane and my
instrument rating, I better know what to do when that cloud suddenly gets BUMPY.
Or when the manifold pressure starts slipping down a bit at a time when you're
solid IFR. These are problems; you better be able to deal with them. Simply
saying a proficient pilot doesn't get himself into these jams doesn't really cut
it.


--
Mortimer Schnerd, RN

[Morgans]

"pgbnh" > wrote

> I have long been convinced that becoming a truly proficient and competent
> pilot is the result of the sum of a series of 'mini-emergencies' (not to
> minimize yours - sounds like a REAL emergency). What I mean is that over
> years of flying we all face small crises and we learn how to deal with
them.
> And each time we do, we become better crisis managers.

I have to disagree, on that one. A proficient pilot never puts himself in a
situation like that, in the first place, ideally.

Dealing with them is all spin control. (not the kind where you go round and
round)
--
Jim in NC

[Morgans]

"Peter R." > wrote

> If one flies a lot, one is bound to experience an unplanned mechanical
> failure of some type that could be classified as a minor emergency.
>
> Proficiency is not always about "avoiding" a situation, but rather
> sometimes it is about "handling" an unavoidable situation.

True, and I hesitated to write that, because of situations not of the
pilot's doing, but examples given (carb heat, poor fuel planning, switching
to wrong tank at night, ect) "should" not ever happen.
--
Jim in NC

[Morgans]

"Mortimer Schnerd, RN" > wrote

> That's an overly idealistic point of view.

Yep, you're right. I can't completely argue that point, but still, many
emergencies, especially those caused by the pilot, should be avoided. I
guess it was the examples given that rubbed me the wrong way. :-)
--
Jim in NC

[Dylan Smith]

On 2006-03-28, Dan Luke > wrote:
> A quick scan of the instruments showed the IAS at 100 and falling; normally
> it would indicate 125 at that altitude.

As soon as I got this far in your story, I thought 'carb ice!' - I think
it comes from flying an old Apache IFR which would ice up on the slightest
hint of visible moisture...

--
Dylan Smith, Port St Mary, Isle of Man
Flying: http://www.dylansmith.net
Oolite-Linux: an Elite tribute: http://oolite-linux.berlios.de
Frontier Elite Universe: http://www.alioth.net

[Gary Drescher]

> The throttle was fully open, the RPM was set for 2500 and the mixture was
> leaned to 10.5 gph.

Thanks for the excellent story. Congratulations on handling the problem
well--I'm glad everything worked out ok!

One thing puzzles me though: if carb ice was limiting the fuel flow,
shouldn't the fuel flow gauge have shown a decrease?

--Gary

[Dan Luke]

"Dylan Smith" wrote:

>> A quick scan of the instruments showed the IAS at 100 and falling;
>> normally
>> it would indicate 125 at that altitude.
>
> As soon as I got this far in your story, I thought 'carb ice!' -


*Now* you tell me! ;)

[Denny]

As soon as I got this far in your story, I thought 'carb ice!'
************************************************** *********************

I have iced up, at least once, every carb I have flown behind and it
doesn't matter the brand of engine...

My son is learning to fly and I have been a casual instructor for him
in Fat Albert the Apache... In the Warrior he flies, his real
instructor makes him just pull the carb heat on to verify there is a
slight rpm drop and immediately shove it back in.. When he flies with
me I am constantly on his back about checking/using carb heat.. He
finally got exasperated with me one day and said to the effect: If you
are so smart why does Wally <instructor> make me keep the heat off...
My reply was two questions..
ME: Have you ever heard of an airplane crashing because of the pilot
failed to use carb heat?
HIM: Well, yeah, sure...
ME: Have you ever heard of a plane crashing because the pilot used
the carb heat?
HIM: Uuuh, let me think. <pause> No.
ME: I rest my case!

BTW Dan, ya did good!

denny

[Mike]

Dan Luke wrote:
> It was the 3rd leg of an Angel Flight and I wasn't even supposed to be
> flying it. I'd already flown the second leg from Natchez, MS to
> Monroeville, AL, but the 3rd leg pilot had mysteriously failed to show--no
> call, no nothin'. It was late, I was tired and I was mad. I had two pax
> aboard.
>
> We were in the clouds and in the dark in a Cutlass RG approaching Macon, GA
> (MCN). The outside temperature was 13 C and moisture was streaming back on
> the windshield. The throttle was fully open, the RPM was set for 2500 and
> the mixture was leaned to 10.5 gph. The autopilot was holding course and
> altitude. I was studying the ILS approach plate when I noticed the AP's
> "up" trim warning light illuminate.
>
> A quick scan of the instruments showed the IAS at 100 and falling; normally
> it would indicate 125 at that altitude. I had detected no change in the
> engine sound. I immediately hit the AP disable switch to prevent its
> stalling the airplane. This was right and wrong, as I now had to do all the
> flying while troubleshooting the problem. What I should have done was
> disable the altitude hold and allow the AP to continue keeping us on course
> and wings level.
>
> Any attempt to lift the nose resulted in a sickening drop in airspeed. The
> situation was now officially scary: we were going down on a dark, rainy
> night over central Georgia.
>
> I shoved the prop and mixture full forward, confirmed the throttle was wide
> open and the primer was in. No improvement. There was no unusual
> vibration. The engine still sounded good and was still making 2500 rpm, but
> the prop was probably in flat pitch to do it. I tried the electric fuel
> pump: no joy. I glanced at the JPI engine analyzer and saw that all four
> cylinders showed roughly even EGTs. All this took much less than a minute;
> maybe only 30 seconds.
>
> Finally, I pulled the carb heat. Within a few seconds I felt a surge of
> power and we began to climb. I don't know for sure what a death row inmate
> feels like when the governor calls at the last minute, but I'm guessing it
> feels something like that.
>
> My heart was pounding in my chest and I was so stoked on adrenalin my hands
> were shaking. The front seat passenger was looking at me wide-eyed--he
> didn't know what was happening, but he had figured out *something* wasn't
> right. I had wandered 40 deg. off course and Atlanta Approach was repeating
> a frequency change instruction. In a few moments I had us back on course
> and altitude but I was still somewhat rattled and blew the readback on
> Atlanta's initial approach instructions. Got that sorted out and made an
> uneventful ILS approach to runway 5 at MCN.
>
> Not a totally satisfying performance. I ended up doing the right thing and
> we lived; that's the good news. The bad news is that allowed myself to rush
> things. A moment's thought would have prevented the autopilot mistake. A
> calmer, more orderly flow through the engine controls would have led me to
> the carb heat sooner and saved a few unnecessary extra seconds of high
> anxiety. Next time I have an emergency (please: NO next time!) I'll try to
> take it a little slower.
>
> I'm still surprised that the carb iced up at full throttle. Conditions were
> in the bad area of the carb ice chart, but my engine has never seemed prone
> to the problem. In 650+ hours I've only detected carb ice once before, and
> that was after a long taxi on a cool, rainy day.
>

Happy to hear you pulled out of your emergency situation well and
without any drastic procedures. Icing can occur at any altitude. All you
need is high moisture and favorable temperatures, which is what you had.
Fuel/air passing the venturi in the carb can drop as much as 60 F.

Thanks for sharing your experience. It helps make all of us safer.

--
Mike

[Dan Luke]

"Gary Drescher" wrote:

>> The throttle was fully open, the RPM was set for 2500 and the mixture was
>> leaned to 10.5 gph.
>
> Thanks for the excellent story. Congratulations on handling the problem
> well--I'm glad everything worked out ok!
>
> One thing puzzles me though: if carb ice was limiting the fuel flow,
> shouldn't the fuel flow gauge have shown a decrease?

I never got around to looking at it (I keep it displayed on the KLN-90B).

--
Dan
C-172RG at BFM

[Dan Luke]

"Denny" wrote:

> As soon as I got this far in your story, I thought 'carb ice!'
> ************************************************** *********************
>
> I have iced up, at least once, every carb I have flown behind and it
> doesn't matter the brand of engine...
>
> My son is learning to fly and I have been a casual instructor for him
> in Fat Albert the Apache... In the Warrior he flies, his real
> instructor makes him just pull the carb heat on to verify there is a
> slight rpm drop and immediately shove it back in.. When he flies with
> me I am constantly on his back about checking/using carb heat.. He
> finally got exasperated with me one day and said to the effect: If you
> are so smart why does Wally <instructor> make me keep the heat off...
> My reply was two questions..
> ME: Have you ever heard of an airplane crashing because of the pilot
> failed to use carb heat?
> HIM: Well, yeah, sure...
> ME: Have you ever heard of a plane crashing because the pilot used
> the carb heat?
> HIM: Uuuh, let me think. <pause> No.
> ME: I rest my case!

Good point. Rest assured my carb heat is going to be on a lot more in the
future. It rained on me almost the whole way home from Macon that night; I
had the CH on the whole way.

> BTW Dan, ya did good!

Thanks.

--
Dan
C-172RG at BFM

[John Theune]

Dan Luke wrote:
> "Denny" wrote:
>
>
>>As soon as I got this far in your story, I thought 'carb ice!'
>>************************************************** *********************
>>
>>I have iced up, at least once, every carb I have flown behind and it
>>doesn't matter the brand of engine...
>>
>>My son is learning to fly and I have been a casual instructor for him
>>in Fat Albert the Apache... In the Warrior he flies, his real
>>instructor makes him just pull the carb heat on to verify there is a
>>slight rpm drop and immediately shove it back in.. When he flies with
>>me I am constantly on his back about checking/using carb heat.. He
>>finally got exasperated with me one day and said to the effect: If you
>>are so smart why does Wally <instructor> make me keep the heat off...
>>My reply was two questions..
>>ME: Have you ever heard of an airplane crashing because of the pilot
>>failed to use carb heat?
>>HIM: Well, yeah, sure...
>>ME: Have you ever heard of a plane crashing because the pilot used
>>the carb heat?
>>HIM: Uuuh, let me think. <pause> No.
>>ME: I rest my case!
>
>
> Good point. Rest assured my carb heat is going to be on a lot more in the
> future. It rained on me almost the whole way home from Macon that night; I
> had the CH on the whole way.
>
>
>>BTW Dan, ya did good!
>
>
> Thanks.
>
I may be perpetuating a OWT but I seem to recall something about carb
heat putting unfiltered air into the carb and that was why it was not
always on in addition to the issue of the hotter air decreasing performance.

John

[Denny]

Hitting the ground in a nose low attitude tends to decrease performance
also...

denny

[Ron Lee]

John Theune > wrote:
>>
>I may be perpetuating a OWT but I seem to recall something about carb
>heat putting unfiltered air into the carb and that was why it was not
>always on in addition to the issue of the hotter air decreasing performance.

If you are flying who cares? Unless you are in a sandstorm or
volcanic ash downfall area my ASSUMPTION is that unfiltered air in
flight is not a hazard for the engine.

Ron Lee

[Ross Richardson]

Does the Cutlass have Lycoming in it?

Ross
C-172F
Lyc O-360

Dan Luke wrote:

> It was the 3rd leg of an Angel Flight and I wasn't even supposed to be
> flying it. I'd already flown the second leg from Natchez, MS to
> Monroeville, AL, but the 3rd leg pilot had mysteriously failed to show--no
> call, no nothin'. It was late, I was tired and I was mad. I had two pax
> aboard.
>
> We were in the clouds and in the dark in a Cutlass RG approaching Macon, GA
> (MCN). The outside temperature was 13 C and moisture was streaming back on
> the windshield. The throttle was fully open, the RPM was set for 2500 and
> the mixture was leaned to 10.5 gph. The autopilot was holding course and
> altitude. I was studying the ILS approach plate when I noticed the AP's
> "up" trim warning light illuminate.
>
> A quick scan of the instruments showed the IAS at 100 and falling; normally
> it would indicate 125 at that altitude. I had detected no change in the
> engine sound. I immediately hit the AP disable switch to prevent its
> stalling the airplane. This was right and wrong, as I now had to do all the
> flying while troubleshooting the problem. What I should have done was
> disable the altitude hold and allow the AP to continue keeping us on course
> and wings level.
>
> Any attempt to lift the nose resulted in a sickening drop in airspeed. The
> situation was now officially scary: we were going down on a dark, rainy
> night over central Georgia.
>
> I shoved the prop and mixture full forward, confirmed the throttle was wide
> open and the primer was in. No improvement. There was no unusual
> vibration. The engine still sounded good and was still making 2500 rpm, but
> the prop was probably in flat pitch to do it. I tried the electric fuel
> pump: no joy. I glanced at the JPI engine analyzer and saw that all four
> cylinders showed roughly even EGTs. All this took much less than a minute;
> maybe only 30 seconds.
>
> Finally, I pulled the carb heat. Within a few seconds I felt a surge of
> power and we began to climb. I don't know for sure what a death row inmate
> feels like when the governor calls at the last minute, but I'm guessing it
> feels something like that.
>
> My heart was pounding in my chest and I was so stoked on adrenalin my hands
> were shaking. The front seat passenger was looking at me wide-eyed--he
> didn't know what was happening, but he had figured out *something* wasn't
> right. I had wandered 40 deg. off course and Atlanta Approach was repeating
> a frequency change instruction. In a few moments I had us back on course
> and altitude but I was still somewhat rattled and blew the readback on
> Atlanta's initial approach instructions. Got that sorted out and made an
> uneventful ILS approach to runway 5 at MCN.
>
> Not a totally satisfying performance. I ended up doing the right thing and
> we lived; that's the good news. The bad news is that allowed myself to rush
> things. A moment's thought would have prevented the autopilot mistake. A
> calmer, more orderly flow through the engine controls would have led me to
> the carb heat sooner and saved a few unnecessary extra seconds of high
> anxiety. Next time I have an emergency (please: NO next time!) I'll try to
> take it a little slower.
>
> I'm still surprised that the carb iced up at full throttle. Conditions were
> in the bad area of the carb ice chart, but my engine has never seemed prone
> to the problem. In 650+ hours I've only detected carb ice once before, and
> that was after a long taxi on a cool, rainy day.
>

[Dan Luke]

"Ross Richardson" wrote:

> Does the Cutlass have Lycoming in it?
>
> Ross
> C-172F
> Lyc O-360

Yep. O-360 F1A6.

--
Dan
C-172RG at BFM

[Chris]

"Dan Luke" > wrote in message
...
>
> "Dylan Smith" wrote:
>
>>> A quick scan of the instruments showed the IAS at 100 and falling;
>>> normally
>>> it would indicate 125 at that altitude.
>>
>> As soon as I got this far in your story, I thought 'carb ice!' -
>
>
> *Now* you tell me! ;)
>
I was the same but then in the UK Carb icing happens all the time is the
first thing we look for.

[Marco Leon]

"Morgans" > wrote in message
...
>
> Yep, you're right. I can't completely argue that point, but still, many
> emergencies, especially those caused by the pilot, should be avoided. I
> guess it was the examples given that rubbed me the wrong way. :-)
> --
> Jim in NC

Therefore the proficiency goal of all pilots should be to know both how to
avoid the situation and how to get out of it. This also has a built-in
verification check in that too much experience in one area means that the
other area probably needs more attention.

Marco



Posted Via Usenet.com Premium Usenet Newsgroup Services
----------------------------------------------------------
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[Mortimer Schnerd, RN]

Marco Leon wrote:
> Therefore the proficiency goal of all pilots should be to know both how to
> avoid the situation and how to get out of it. This also has a built-in
> verification check in that too much experience in one area means that the
> other area probably needs more attention.



There you are: a succinct summation of the true goal of the proficient pilot.
The more tools we have to work with, the better the quality of our work.
Avoidance is always best but you better have an excape just in case you blunder
into something.



--
Mortimer Schnerd, RN

[B A R R Y]

Marco Leon wrote:
>
> Therefore the proficiency goal of all pilots should be to know both how to
> avoid the situation and how to get out of it. This also has a built-in
> verification check in that too much experience in one area means that the
> other area probably needs more attention.

Nicely put!

[Peter Duniho]

"John Theune" > wrote in message
news:8obWf.14186$ES3.7989@trnddc02...
> I may be perpetuating a OWT but I seem to recall something about carb heat
> putting unfiltered air into the carb and that was why it was not always on
> in addition to the issue of the hotter air decreasing performance.

I can't speak for all airplanes -- maybe there's one out there that uses a
filter with carb heat -- but yes, generally speaking carb heat means the air
is not filtered.

However, that is primarily a concern while on the ground, where all sorts of
dust and dirt can get blown up and into the air intake. Once you get aloft,
it's unusual for the air to contain enough stuff to cause harm to the
engine. Not impossible, but unusual.

A better argument against constant use of carb heat is that doing so can
take a non-icing situation and turn it into an icing one. I think this
would be very rare, but I don't believe you can rule it out. Of course,
carb heat also reduces performance, since it lowers the density of the air
coming into the engine. Better to wait for signs of carb ice and use the
carb heat as needed, rather than as a general prophylactic.

Pete

[Peter Duniho]

"Ron Lee" > wrote in message
...
> If you are flying who cares? Unless you are in a sandstorm or
> volcanic ash downfall area my ASSUMPTION is that unfiltered air in
> flight is not a hazard for the engine.

Most of the time, that's true. However, I wouldn't limit the conditions to
rare events like "sandstorm or volcanic ash". I have flown through
significant dust plumes, cause by nothing other than winds aloft carrying
dirt from terrain. One time, I could see the plume stretch all the way from
Mt St Helens out to the coast, some 100 miles away.

Clearly this sort of condition isn't nearly as harmful as the more dense
events, like a sandstorm or volcanic ash. But still, I was happy to have my
engine breathing filtered air when I went through it, and this sort of thing
is quite a bit more common than the more dense events. :)

Pete

[Dan Luke]

"Peter Duniho" wrote:

> Of course, carb heat also reduces performance, since it lowers the density
> of the air coming into the engine. Better to wait for signs of carb ice
> and use the carb heat as needed, rather than as a general prophylactic.

In future I will be using carb heat as a matter of course when ambient
conditions are in the "severe" area of the chart. I definitely will not be
waiting for symptoms in such cases.

--
Dan
C-172RG at BFM

[Alan]

Dan, I wouldn't be so hard on yourself. Sounds like you did a great
job with the situation. Found the problem. Fixed it. Got the plane
down. Kept your cool. I'd say you were successful. Thanks for the
report. Helps all of us who never have been in this position, yet.

My only input. Carb heat is the #2 item on my emergency checklist.


Alan Bloom
Dogs can fly.
www.flyingmutts.com




On Mon, 27 Mar 2006 18:21:40 -0600, "Dan Luke"
> wrote:

>It was the 3rd leg of an Angel Flight and I wasn't even supposed to be
>flying it. I'd already flown the second leg from Natchez, MS to
>Monroeville, AL, but the 3rd leg pilot had mysteriously failed to show--no
>call, no nothin'. It was late, I was tired and I was mad. I had two pax
>aboard.
>
>We were in the clouds and in the dark in a Cutlass RG approaching Macon, GA
>(MCN). The outside temperature was 13 C and moisture was streaming back on
>the windshield. The throttle was fully open, the RPM was set for 2500 and
>the mixture was leaned to 10.5 gph. The autopilot was holding course and
>altitude. I was studying the ILS approach plate when I noticed the AP's
>"up" trim warning light illuminate.
>
>A quick scan of the instruments showed the IAS at 100 and falling; normally
>it would indicate 125 at that altitude. I had detected no change in the
>engine sound. I immediately hit the AP disable switch to prevent its
>stalling the airplane. This was right and wrong, as I now had to do all the
>flying while troubleshooting the problem. What I should have done was
>disable the altitude hold and allow the AP to continue keeping us on course
>and wings level.
>
>Any attempt to lift the nose resulted in a sickening drop in airspeed. The
>situation was now officially scary: we were going down on a dark, rainy
>night over central Georgia.
>
>I shoved the prop and mixture full forward, confirmed the throttle was wide
>open and the primer was in. No improvement. There was no unusual
>vibration. The engine still sounded good and was still making 2500 rpm, but
>the prop was probably in flat pitch to do it. I tried the electric fuel
>pump: no joy. I glanced at the JPI engine analyzer and saw that all four
>cylinders showed roughly even EGTs. All this took much less than a minute;
>maybe only 30 seconds.
>
>Finally, I pulled the carb heat. Within a few seconds I felt a surge of
>power and we began to climb. I don't know for sure what a death row inmate
>feels like when the governor calls at the last minute, but I'm guessing it
>feels something like that.
>
>My heart was pounding in my chest and I was so stoked on adrenalin my hands
>were shaking. The front seat passenger was looking at me wide-eyed--he
>didn't know what was happening, but he had figured out *something* wasn't
>right. I had wandered 40 deg. off course and Atlanta Approach was repeating
>a frequency change instruction. In a few moments I had us back on course
>and altitude but I was still somewhat rattled and blew the readback on
>Atlanta's initial approach instructions. Got that sorted out and made an
>uneventful ILS approach to runway 5 at MCN.
>
>Not a totally satisfying performance. I ended up doing the right thing and
>we lived; that's the good news. The bad news is that allowed myself to rush
>things. A moment's thought would have prevented the autopilot mistake. A
>calmer, more orderly flow through the engine controls would have led me to
>the carb heat sooner and saved a few unnecessary extra seconds of high
>anxiety. Next time I have an emergency (please: NO next time!) I'll try to
>take it a little slower.
>
>I'm still surprised that the carb iced up at full throttle. Conditions were
>in the bad area of the carb ice chart, but my engine has never seemed prone
>to the problem. In 650+ hours I've only detected carb ice once before, and
>that was after a long taxi on a cool, rainy day.

[Peter R.]

Alan > wrote:

> Helps all of us who never have been in this position, yet.

Perhaps "a subset of us" would be a more accurate than "all of us." I fly
an aircraft with a fuel-injected engine. No carb heat. ;)


--
Peter

[Alan]

On Tue, 28 Mar 2006 17:00:58 -0500, T o d d P a t t i s t
> wrote:

>
>I've never quite figured out why carb heat is designed this
>way. I've always got carb heat on during landing,

I'm curious as to why you keep your carb heat on during landing. I
usually pull it on during my GUMP check approaching an airport but
then shut it off. If you have to do a go around, you're not going to
get full power with it on.

Alan Bloom
Dogs can fly.
www.flyingmutts.com

[Jose]

> I'm still surprised that the carb iced up at full throttle. Conditions were
> in the bad area of the carb ice chart, but my engine has never seemed prone
> to the problem. In 650+ hours I've only detected carb ice once before, and
> that was after a long taxi on a cool, rainy day.

I had carb ice in the =runup= in a Dakota that had never had any kind of
carb ice problems before. It was warm and humid, ideal conditions, but
the engine hadn't been running for ten minutes yet. I applied runup
power and checked mags and such, no issue. Then I pulled the power all
the way back and the engine died. Tried it a few times, then took it
back to have it looked at. Nothing amiss. Final conclusion is that it
was probably carb ice.

Never happened before, or since.

Jose
--
Nothing takes longer than a shortcut.
for Email, make the obvious change in the address.

[Jose]

> I'm curious as to why you keep your carb heat on during landing.

Some aircraft (certain Cessna singles for example) specify carb heat
below 2000 RPM. Others (certain Pipers) specify no carb heat for landing.

Jose
--
Nothing takes longer than a shortcut.
for Email, make the obvious change in the address.

[Dan Luke]

"Jose" wrote:

>> I'm still surprised that the carb iced up at full throttle. Conditions
>> were in the bad area of the carb ice chart, but my engine has never seemed
>> prone to the problem. In 650+ hours I've only detected carb ice once
>> before, and that was after a long taxi on a cool, rainy day.
>
> I had carb ice in the =runup= in a Dakota that had never had any kind of
> carb ice problems before. It was warm and humid, ideal conditions, but the
> engine hadn't been running for ten minutes yet. I applied runup power and
> checked mags and such, no issue. Then I pulled the power all the way back
> and the engine died.

In my case a couple of years ago I could not get the engine to rev past 1,000
rpm for the runup. That time I immediately suspected carb ice because of the
long taxi in the rain. I applied carb heat and finished the runup ok.

>
> Never happened before, or since.

Not to me, either--until that flight to Macon last week.

--
Dan
C-172RG at BFM

[Tony]

Dan, this is one of those "for what it's worth" stories.

About 30 years ago I flew a Mooney ranger that was pulled around by a
normally carberated engine that loved to develop carb ice. The first
clue it was happening was that the EGT began falling really fast. Carb
ice drives the engine towards a richer mixture.

The same thing may happen in your airplane. If it does, include the EGT
in your instrument scan when you're at cruise. I was amazed when I
started doing that how often a 50 degree drop in EGT happened, and how
often it was recovered by yanking on the carb heat knob.

I'm glad it turned out OK -- angel flights should get lots of second
chances.

[Peter Duniho]

"T o d d P a t t i s t" > wrote in message
...
> "Peter Duniho" > wrote:
>
>>I can't speak for all airplanes -- maybe there's one out there that uses a
>>filter with carb heat -- but yes, generally speaking carb heat means the
>>air
>>is not filtered.
>
> I've never quite figured out why carb heat is designed this
> way.

I suspect it's a matter of keeping the design simple. FAR 23.1091(b)
requires an alternate air source. FAR 23.1093(a) requires an induction air
heating source. It makes some sense to ensure that the alternate air source
would not be compromised by the same thing that required its use (such as
icing of the air filter), and it also makes sense to combine the two systems
into a single system.

> I've always got carb heat on during landing, and as
> soon as I land, I've got to start worrying about pulling
> dust and debris into my expensive engine. I mean really!

I suspect that at the usual power settings used for landing (ie idle) that
sucking dirty air into the engine is less of a worry. Of more concern to me
is during the runup, when you are standing still (not getting a fresh supply
of air) and have the engine power set higher than idle.

> [...]
> I recognize that there are rare circumstances when one would
> want to bypass the filter (impact iced over). Nonetheless,
> it seems to me that accidents due to fiddling with the carb
> heat after landing are at least as much of a concern.

How so? Induction icing can cause a forced landing, if not a crash.
Assuming the pilot has their priorities straight, fiddling with the carb
heat after landing should pose no risk at all.

Yes, there seems to be a window of opportunity for unfiltered air to get
into the engine, but that should not cause the pilot to forget about
controlling the airplane (and I think most airplanes have the carb heat
control in a more practical place anyway...I wouldn't denigrate the basic
idea of combining the carb heat and alternate air source on the sole basis
of one single aircraft type).

Is there some risk with the design as is? No doubt. But I have seen no
evidence that suggests that using the carb heat as the alternate, unfiltered
air source leads to any significant reduction in engine life, never mind any
traumatic failure of the engine.

Oddly enough, in reviewing the certification requirements, I found two
paragraphs that my own airplane doesn't appear to meet. My automatic
alternate air source (not carb heat, since I have no carb) does not provide
for a manual override by the pilot, nor is there any indication in the
cockpit to show that the alternate air source has been activated. Now I'm
curious how the airplane got certified. The type is new enough to be under
Part 23, but perhaps elements of the TC got grandfathered in via the
previous type on which this airplane was based. Or maybe there's a waiver
of some sort? I don't know. A new mystery...fun. :)

Pete

[MaulePilot]

And what became of the 'no-show' 3rd leg pilot? I hope you called
your dispatcher and mentioned it.

[ET]

T o d d P a t t i s t > wrote in
:

> "Peter Duniho" > wrote:
>
>>> I've never quite figured out why carb heat is designed this
>>> way.
>>
>>I suspect it's a matter of keeping the design simple.
>
> I'm sure you're right.
>
>>> I recognize that there are rare circumstances when one would
>>> want to bypass the filter (impact iced over). Nonetheless,
>>> it seems to me that accidents due to fiddling with the carb
>>> heat after landing are at least as much of a concern.
>>
>>How so? Induction icing can cause a forced landing, if not a crash.
>>Assuming the pilot has their priorities straight, fiddling with the
>>carb heat after landing should pose no risk at all.
>
> As for the induction icing issue, I wasn't proposing getting
> rid of the alternate air. As for the pilot's priorities, I
> agree, if you do it right, you shouldn't have an issue, but
> it is always a competing concern. I'd like my engine to get
> filtered air as soon as possible, particularly when the dirt
> is flying, yet I know I've got to fly the taildragger until
> it's absolutely safe to reach for the carb heat.
>
>>Oddly enough, in reviewing the certification requirements, I found two
>>paragraphs that my own airplane doesn't appear to meet.
>
> Very interesting.


You may find interesting as well, the Rotex 912UL (80 or 100hp)version
has as an option full time "carb heat". coolent from the engine is
circulated up to a fitting that is attached to the carb body. This
heats the carb body, but not the incoming air. "Carb heat" is always on
with no drop in performance since the air stays cool. I suppose it's
still possible for ice crystals to form in the incoming air, but they
will not stick to the warm pieces of the carborator. This engine is
almost the defacto standard for now in most of the new light sport
aircraft (although the full time carb heat is not "standard" on any but
the StingSport)

--
-- ET >:-)

"A common mistake people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools."---- Douglas Adams

[Bob Gardner]

I can't find anything in the discussion of carb ice in The Lycoming Flyer to
make me think that full throttle somehow obviates carb ice when conditions
are conducive to icing. If ice is forming on the interior of the venturi,
the position of the throttle plate won't make much difference. Lycoming does
say that ice is more likely at low power settings, but I think we all know
that.

Bob Gardner

"Dan Luke" > wrote in message
...
> It was the 3rd leg of an Angel Flight and I wasn't even supposed to be
> flying it. I'd already flown the second leg from Natchez, MS to
> Monroeville, AL, but the 3rd leg pilot had mysteriously failed to show--no
> call, no nothin'. It was late, I was tired and I was mad. I had two pax
> aboard.
>
> We were in the clouds and in the dark in a Cutlass RG approaching Macon,
> GA (MCN). The outside temperature was 13 C and moisture was streaming
> back on the windshield. The throttle was fully open, the RPM was set for
> 2500 and the mixture was leaned to 10.5 gph. The autopilot was holding
> course and altitude. I was studying the ILS approach plate when I noticed
> the AP's "up" trim warning light illuminate.
>
> A quick scan of the instruments showed the IAS at 100 and falling;
> normally it would indicate 125 at that altitude. I had detected no change
> in the engine sound. I immediately hit the AP disable switch to prevent
> its stalling the airplane. This was right and wrong, as I now had to do
> all the flying while troubleshooting the problem. What I should have done
> was disable the altitude hold and allow the AP to continue keeping us on
> course and wings level.
>
> Any attempt to lift the nose resulted in a sickening drop in airspeed.
> The situation was now officially scary: we were going down on a dark,
> rainy night over central Georgia.
>
> I shoved the prop and mixture full forward, confirmed the throttle was
> wide open and the primer was in. No improvement. There was no unusual
> vibration. The engine still sounded good and was still making 2500 rpm,
> but the prop was probably in flat pitch to do it. I tried the electric
> fuel pump: no joy. I glanced at the JPI engine analyzer and saw that all
> four cylinders showed roughly even EGTs. All this took much less than a
> minute; maybe only 30 seconds.
>
> Finally, I pulled the carb heat. Within a few seconds I felt a surge of
> power and we began to climb. I don't know for sure what a death row inmate
> feels like when the governor calls at the last minute, but I'm guessing it
> feels something like that.
>
> My heart was pounding in my chest and I was so stoked on adrenalin my
> hands were shaking. The front seat passenger was looking at me
> wide-eyed--he didn't know what was happening, but he had figured out
> *something* wasn't right. I had wandered 40 deg. off course and Atlanta
> Approach was repeating a frequency change instruction. In a few moments I
> had us back on course and altitude but I was still somewhat rattled and
> blew the readback on Atlanta's initial approach instructions. Got that
> sorted out and made an uneventful ILS approach to runway 5 at MCN.
>
> Not a totally satisfying performance. I ended up doing the right thing
> and we lived; that's the good news. The bad news is that allowed myself
> to rush things. A moment's thought would have prevented the autopilot
> mistake. A calmer, more orderly flow through the engine controls would
> have led me to the carb heat sooner and saved a few unnecessary extra
> seconds of high anxiety. Next time I have an emergency (please: NO next
> time!) I'll try to take it a little slower.
>
> I'm still surprised that the carb iced up at full throttle. Conditions
> were in the bad area of the carb ice chart, but my engine has never seemed
> prone to the problem. In 650+ hours I've only detected carb ice once
> before, and that was after a long taxi on a cool, rainy day.
>
> --
> Dan
> C172RG at BFM
>

[Dan Luke]

"MaulePilot" wrote:

> And what became of the 'no-show' 3rd leg pilot?

Never heard from the guy, despite several messages left on cell & home
phones.

> I hope you called
> your dispatcher and mentioned it.

I did. I also mentioned it in the remarks on the mission report.

--
Dan
C-172RG at BFM

[Dan Luke]

"Bob Gardner" wrote:

>I can't find anything in the discussion of carb ice in The Lycoming Flyer to
>make me think that full throttle somehow obviates carb ice when conditions
>are conducive to icing. If ice is forming on the interior of the venturi,
>the position of the throttle plate won't make much difference. Lycoming does
>say that ice is more likely at low power settings, but I think we all know
>that.

Apparently I'm guilty of believing what I was told by instructors without
checking the facts. Carbs can ice any time ambient conditions are right for
it. My tiedown neighbor with a Skylane tells me I'd have figured this out a
long time ago if I had a TCM O-470 182.

--
Dan
C-172RG at BFM

[Mike]

Jose wrote:
> I had carb ice in the =runup= in a Dakota that had never had any kind of
> carb ice problems before. It was warm and humid, ideal conditions, but
> the engine hadn't been running for ten minutes yet. I applied runup
> power and checked mags and such, no issue. Then I pulled the power all
> the way back and the engine died. Tried it a few times, then took it
> back to have it looked at. Nothing amiss. Final conclusion is that it
> was probably carb ice.
>
> Never happened before, or since.
>
> Jose

In beautiful MN in the winter months I occasionally get carb ice while
on the ground checking ATIS. It's just like in the textbook ... an
unexplained loss of RPM. Usually the dew point spread is at least a few
degrees, so it is odd (and memorable) when it happens.

This has happened in both C172s and a Piper (can't remember if it was
the Archer or the Warrior).




Mike

[Icebound]

"Dan Luke" > wrote in message
...
>
> "Bob Gardner" wrote:
>
>>I can't find anything in the discussion of carb ice in The Lycoming Flyer
>>to make me think that full throttle somehow obviates carb ice when
>>conditions are conducive to icing. If ice is forming on the interior of
>>the venturi, the position of the throttle plate won't make much
>>difference. Lycoming does say that ice is more likely at low power
>>settings, but I think we all know that.
>
> Apparently I'm guilty of believing what I was told by instructors without
> checking the facts. Carbs can ice any time ambient conditions are right
> for it. My tiedown neighbor with a Skylane tells me I'd have figured this
> out a long time ago if I had a TCM O-470 182.
>
> --


That is because iced carbs will have the motor *stop* at idle settings
simply because the venturi is "choked", while they may continue to run quite
well at cruise settings with the venturi open. So they kept telling us to
carb heat at low power and eventually we started to believe we only *needed*
carb heat at low power because nobody told us different.

I finally found an instructor in the latter stages of my training who set me
straight on a number of things, including that one.

....and he was the one who emphasized the need to use a "cruise checklist"
every 15 minutes at least, which would be approximately like:

HI to compass heading
oil temps and pressures
fuel gauges; fuel switch correct tank as necessary
rpm/MP; pull carb head momentarily and check drop
tweak power; tweak mixture

[Michael]

> have to disagree, on that one. A proficient pilot never puts himself in a
>situation like that, in the first place, ideally.

Yeah, that sounds great - in theory.

The difference between theory and practice is much greater in practice
than it is in theory.

In theory, it may be possible to become a capable, experienced, and
proficient pilot by taking a cautious approach, not making boneheaded
mistakes, and not scaring oneself. But in practice, I've never seen it
happen. In practice, capable and proficient pilots are the ones who
survive their many little crises - usually of their own making, at
least in part.

Michael

[Peter Duniho]

"T o d d P a t t i s t" > wrote in message
...
> [...]
>>Oddly enough, in reviewing the certification requirements, I found two
>>paragraphs that my own airplane doesn't appear to meet.
>
> Very interesting.

Well, I had a chance to ask my mechanic about this today. Unfortunately, he
wasn't completely certain about the answer either. However, it *appears*
that it's related to the original type certificate being issued under CAR 3,
rather than FAR 23.

The thing that he couldn't figure out (nor could I) is that on the TC Data
Sheet says (for my airplane type) "Certification Basis: 1. 14 CFR Part 23,
18 December 1964, Amendments 23-1 to and including 23-23, Subparts A, B, D,
E, F, and G." It goes on to also say "2. CAR 3...", but I don't understand
why they would list all the bits of FAR 23 if the type doesn't actually have
to meet the requirements of that Part.

However, it is true that my airplane shares the exact same TCDS number as
the original CAR 3 airplane from which it was derived (in spite of being
about as similar to it as a Cessna 206 is to a Cessna 150). So maybe that's
the answer, regardless of the mention of Part 23 in the TCDS. I have to
admit, it's a bit entertaining reading through the TCDS, seeing the
evolution of the type. Each new version is described as "exactly like the
previous, except...". Some of the exceptions are pretty broad. :)

It does appear that generally the requirements in question (manual override,
pilot indication) are met by other aircraft with automatic alternate air
induction sources, or at least two of them. The guys at the shop all agreed
that the Piper Navajo and Seneca both have those features to go along with
their automatic alternate air (I don't know firsthand myself...I'm just
taking their word for it).

If there's anyone out there who actually knows something about how aircraft
type certificates are granted who wants to take a look, here's the TCDS:
http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/e906cc8a49ec031586256f7e0064e791/$FILE/1a13.pdf

The URL looks suspiciously to me as though it may contain a session ID, and
so it may not be valid by the time anyone else reads this post. But you can
navigate to the sheet by going here:
http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/MainFrame?OpenFrameSet
and then looking up the TCDS direction (it's 1A13, just like the name of the
PDF file in the previous link).

Anyway, fun with type certificates... :)

Pete

[Jay Honeck]

> Glad you found the problem in time. Did your manifold pressure drop?

That was my first question, too. Dan?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Dan Luke]

"Jay Honeck" > wrote:

>> Glad you found the problem in time. Did your manifold pressure drop?
>
> That was my first question, too. Dan?

I must have looked, but what I remember is being mystified at why I couldn't
hold altitude when the engine seemed fine. Perhaps I mis-read the gauge. I
was doing several things at once and rushing everything.

It was all over so quickly I didn't have much time to really examine the
data!

--
Dan
C172RG at BFM

[john smith]

> In future I will be using carb heat as a matter of course when ambient
> conditions are in the "severe" area of the chart. I definitely will not be
> waiting for symptoms in such cases.

Dan, I have a couple hundred hours behind the normally aspirated 0-470
Continental in C182's.
Anytime there is significant moisture in the air, the carb will ice up.
The trick is to constantly monitor the manifold pressure. As soon as you
see a one-inch drop, you apply carb heat. When the pressure comes back
up, turn the carb heat off. Repeat as necessary.
I will not fly with carb heat on constantly.
I read somewhere in the past (years ago, don't recall where) that flying
with constant carb heat moves the ice farther down the throat where no
heat will be available to melt it.
SPORT AVIATION had an excellent article on carb ice back in the early
90's. The author had all the math and discussed latent heat of
vaporization and all the other technical stuff, but he made it
understandable by anyone with an eighth grade education.

[Dan Luke]

"john smith" wrote:

>> In future I will be using carb heat as a matter of course when ambient
>> conditions are in the "severe" area of the chart. I definitely will not
>> be
>> waiting for symptoms in such cases.
>
> Dan, I have a couple hundred hours behind the normally aspirated 0-470
> Continental in C182's.
> Anytime there is significant moisture in the air, the carb will ice up.

As I understand it, the carburetor arrangement on the TCM O-470 does not
provide for conduction of as much engine heat to the carburetor as the LYC
O-360s and O-540s, thus the O-470's notorious reputation for carb icing.

> The trick is to constantly monitor the manifold pressure. As soon as you
> see a one-inch drop, you apply carb heat. When the pressure comes back
> up, turn the carb heat off. Repeat as necessary.

That's pretty much what my buddy Filipo told me about his 182. Carb ice is
a regular fact of life for him; it's a rare event for me (twice in six
years with this airplane).

--
Dan
C172RG at BFM

[Newps]

john smith wrote:

>
>
> Dan, I have a couple hundred hours behind the normally aspirated 0-470
> Continental in C182's.
> Anytime there is significant moisture in the air, the carb will ice up.

Not true. I recently sold my 182 after having put 1000 hours on it.
Never had it ice up, even after trying. I would go out on those rare
days here when we had fog and fly just as it lifts, still 90 somethun'
percent humidity. Couldn't make it happen.


> I will not fly with carb heat on constantly.
> I read somewhere in the past (years ago, don't recall where) that flying
> with constant carb heat moves the ice farther down the throat where no
> heat will be available to melt it.

Old wives tale. Cessna Pilots Assoc reccomends whatever amount of carb
heat is necessary to keep the carb at about 45 degrees in cruise. Also
has the effect of evening out the fuel mixture so the engine ran smoother.

[john smith]

In article >,
Newps > wrote:

> john smith wrote:
>
> >
> >
> > Dan, I have a couple hundred hours behind the normally aspirated 0-470
> > Continental in C182's.
> > Anytime there is significant moisture in the air, the carb will ice up.

> Not true. I recently sold my 182 after having put 1000 hours on it.
> Never had it ice up, even after trying. I would go out on those rare
> days here when we had fog and fly just as it lifts, still 90 somethun'
> percent humidity. Couldn't make it happen.

Okay, I will rephrase my statement, temperature and humidity have to be
in the proper range. It can be too warm or too cold, but with
significant moisture in the proper range, the O-470 Continental in a
Cessna 182 will likely form carb ice.

[Greg Copeland]

On Mon, 27 Mar 2006 18:21:40 -0600, Dan Luke wrote:

> vibration. The engine still sounded good and was still making 2500 rpm, but
> the prop was probably in flat pitch to do it. I tried the electric fuel
> pump: no joy. I glanced at the JPI engine analyzer and saw that all four
> cylinders showed roughly even EGTs. All this took much less than a minute;
> maybe only 30 seconds.
>
> Finally, I pulled the carb heat. Within a few seconds I felt a surge of
> power and we began to climb. I don't know for sure what a death row inmate
> feels like when the governor calls at the last minute, but I'm guessing it
> feels something like that.

I thought with a fixed speed prop, the clues for carb ice were reduced MP
and possibly decreased EGTs from a richer fuel burn? Where as on a fixed
pitch prop, rpm drop was the first clue.

Is this not correct?

Greg

[Greg Copeland]

On Tue, 28 Mar 2006 22:14:24 +0000, Alan wrote:

> On Tue, 28 Mar 2006 17:00:58 -0500, T o d d P a t t i s t
> > wrote:
>
>>
>>I've never quite figured out why carb heat is designed this
>>way. I've always got carb heat on during landing,
>
> I'm curious as to why you keep your carb heat on during landing. I
> usually pull it on during my GUMP check approaching an airport but
> then shut it off. If you have to do a go around, you're not going to
> get full power with it on.

For us, carb heat goes in (with my thumb) as the throttle is pushed
forward. Thus, you get full power in the same stroke you push the
throttle forward. Next, is reaching for the flaps...

Greg

[john smith]

> > vibration. The engine still sounded good and was still making 2500 rpm,
> > but
> > the prop was probably in flat pitch to do it. I tried the electric fuel
> > pump: no joy. I glanced at the JPI engine analyzer and saw that all four
> > cylinders showed roughly even EGTs. All this took much less than a minute;
> > maybe only 30 seconds.
> > Finally, I pulled the carb heat. Within a few seconds I felt a surge of
> > power and we began to climb. I don't know for sure what a death row inmate
> > feels like when the governor calls at the last minute, but I'm guessing it
> > feels something like that.

> I thought with a fixed speed prop, the clues for carb ice were reduced MP
> and possibly decreased EGTs from a richer fuel burn? Where as on a fixed
> pitch prop, rpm drop was the first clue.
> Is this not correct?

Yes.