Carb heat broken, ok to fly?

fugazi885 said:
Hi, I am a student pilot with very low time. Today was my third flight and during the runup the carb heat knob pulled out much farther than normal and there was no drop in engine RPM indicating the linkage had broken or become disconnected. My instructor seemed OK to still fly the plane as it was a very hot day and we shouldn't really need it. I figured if it is on the checklist and fails, don't fly. We taxied back and did not fly because I didn't trust it, did I make the right call? Also, should I be billed for the hobbs time we were in the plane for something like this?
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Legality depends on if the POH lists it as a required equipment. Carb icing can occur in hot weather too. Someone posted here about carb icing during takeoff leading to an engine failure at night. In any case, it sounds like you showed better judgement than the CFI. You should nurture this character, and don't let someone else talk you into taking short cuts.
 
I’ll let somebody else look up the appropriate reference in CAR3, but I’m sure it reads very much the same...

§23.2415 Powerplant ice protection.
(a) The airplane design, including the induction and inlet system, must prevent foreseeable accumulation of ice or snow that adversely affects powerplant operation.

(b) The powerplant installation design must prevent any accumulation of ice or snow that adversely affects powerplant operation, in those icing conditions for which certification is requested.
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I’d say carb Heat is part of compliance with certification, so it’s required.
 
I think the question has been answered, so as per POA rules, Im gonna drift the thread. I trained in a Warrior II and the only time I every touched the carb heat was during the run-up. I would not fly if it failed and my reasoning is this, it is on the preflight checklist, if it wasnt important, it wouldnt be there. Would you go if the electric fuel pump failed during run-up? That is explicitly my opinion, not saying anything other than that. Cudos to the OP for having the wherewithal to tell his instructor "no", on my third lesson I would have just nodded my head and we would have been off.
 
The question I have is whether the CFI really would have flown with the broken carb heat, or if they were just testing your ADM. I have had CFIs play this testing game before, and it is very effective, because it forces you to understand that *you* are the PIC. Just because there is someone with more hours/ratings in the plane with you doesn't guarantee they will keep you from making a bad decision.

You did exactly the right thing.
 
Jeff Oslick said:
The question I have is whether the CFI really would have flown with the broken carb heat, or if they were just testing your ADM. I have had CFIs play this testing game before, and it is very effective, because it forces you to understand that *you* are the PIC. Just because there is someone with more hours/ratings in the plane with you doesn't guarantee they will keep you from making a bad decision.

You did exactly the right thing.
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More than likely, the instructor wanted to make his gas money for the week.

I heard an instructor years ago give a very good dissertation on 91.213. Afterwards, he started talking about his personal airplane, and some of he things he was flying without...he checked a bunch of trees, but missed the fact that there was a forest there.
 
Jeff Oslick said:
The question I have is whether the CFI really would have flown with the broken carb heat, or if they were just testing your ADM. I have had CFIs play this testing game before, and it is very effective, because it forces you to understand that *you* are the PIC. Just because there is someone with more hours/ratings in the plane with you doesn't guarantee they will keep you from making a bad decision.
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I regularly ask trainees to make "should we fly today" decisions like that.
 
Jeff Oslick said:
The question I have is whether the CFI really would have flown with the broken carb heat, or if they were just testing your ADM. I have had CFIs play this testing game before, and it is very effective, because it forces you to understand that *you* are the PIC. Just because there is someone with more hours/ratings in the plane with you doesn't guarantee they will keep you from making a bad decision.

You did exactly the right thing.
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But would they go as far as what the OP describes?
"My instructor seemed OK to still fly the plane as it was a very hot day and we shouldn't really need it."
Sounds a lot more pressure than the CFI asking "should we fly?"
 
Regardless of how you interpret regs, carb heat is a safety of flight issue. You don't need it until you need it. We've had a double fatal in a rental aircraft due to (likely) not using carb heat on a nice, not cold day, and I've personally encountered carb icing induced engine failure quite unexpectedly returning from a training flight. Otherwise I hardly ever use or have needed carb heat in my AA5. When you need it, you REALLY need it.
 
MauleSkinner said:
I’ll let somebody else look up the appropriate reference in CAR3, but I’m sure it reads very much the same...



I’d say carb Heat is part of compliance with certification, so it’s required.
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I'm surprised we had to get this far to get around to certification requirements...

In my opinion, 91.205 and 91.213 are often abused to fly airplanes with broken equipment that really needs to be fixed. Let's be realistic, the carburetor heat muff and air box were installed because it is required. The OP's airplane, in my opinion, is unairworthy and needs to be fixed.
 
Tom-D said:
I'd say it could be legal when 91.405 and 43.11 were complied with.

91.405 Maintenance required.
Each owner or operator of an aircraft—

(a) Shall have that aircraft inspected as prescribed in subpart E of this part and shall between required inspections, except as provided in paragraph (c) of this section, have discrepancies repaired as prescribed in part 43 of this chapter;

(b) Shall ensure that maintenance personnel make appropriate entries in the aircraft maintenance records indicating the aircraft has been approved for return to service;

(c) Shall have any inoperative instrument or item of equipment, permitted to be inoperative by §91.213(d)(2) of this part, repaired, replaced, removed, or inspected at the next required inspection; and

(d) When listed discrepancies include inoperative instruments or equipment, shall ensure that a placard has been installed as required by §43.11 of this chapter.
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No, assuming we are dealing with a Cessna 172, it would not be legal to fly for the reason in @eetrojan's post discussing 91.213 and the airplane's equipment list. The carb heat is not permitted to be operative by 91.213(d)(2).
 
AggieMike88 said:
One of the FARs you need to know is §91.205. Read paragraph (b) and tell us what that said about required items.

And while that is the rules, there is zero issues with being appropriately cautious and scrubbing the flight due to a maintenance issue. Better safe and alive than macho and hurt.

Edit: oops.. forgot §91.213... thanks @Tantalum!
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Unfortunately, a certain horrible mnemonic variously involving burning a red fruit or doing strange things to a feline, is responsible for a lot of people* thinking 91.205 is the be-all and end-all, when it's really all about 91.213.

[*Perhaps even the OP's instructor (hopefully not). One of the many times I did my periodic survey over the past 25 or so years, the first one to incorrectly answer a question whether you can legally fly with a certain required piece of equipment was a CFI who replied, "It's not in [most hated mnemonic], so you're good to go!"]
 
midlifeflyer said:
Unfortunately, a certain horrible mnemonic variously involving burning a red fruit or doing strange things to a feline, is responsible for a lot of people* thinking 91.205 is the be-all and end-all, when it's really all about 91.213.

[*Perhaps even the OP's instructor (hopefully not). One of the many times I did my periodic survey over the past 25 or so years, the first one to incorrectly answer a question whether you can legally fly with a certain required piece of equipment was a CFI who replied, "It's not in [most hated mnemonic], so you're good to go!"]
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Sounds like one that we kicked around on the Red Board one time....

A popular example of how nonsensical the application of this regulation may be is if the cigarette lighter in the airplane doesn't work, or where the pilot has taken the cigarette lighter out of the aircraft and placed a cap in the receptacle. Strictly, technically, operation of that aircraft could place the pilot in jeopardy of an FAA enforcement action based on a violation of FAR 91.213. In our experience, FAA inspectors generally exercise good judgment when they come across these cases. They will consider what may be technically in violation of the regulation and what may be practically in violation of the regulation, and handle the matter sensibly. Some flight examiners like to make this issue a part of the oral examination to be sure that you are aware of your FAR responsibility, even though you may think that the legal answer is not the right answer.​

Which came from this AOPA article... SAFETY PUBLICATIONS/ARTICLES -- LEGAL BRIEFING: Inoperative equipment
 
AggieMike88 said:
Sounds like one that we kicked around on the Red Board one time....

A popular example of how nonsensical the application of this regulation may be is if the cigarette lighter in the airplane doesn't work, or where the pilot has taken the cigarette lighter out of the aircraft and placed a cap in the receptacle. Strictly, technically, operation of that aircraft could place the pilot in jeopardy of an FAA enforcement action based on a violation of FAR 91.213. In our experience, FAA inspectors generally exercise good judgment when they come across these cases. They will consider what may be technically in violation of the regulation and what may be practically in violation of the regulation, and handle the matter sensibly. Some flight examiners like to make this issue a part of the oral examination to be sure that you are aware of your FAR responsibility, even though you may think that the legal answer is not the right answer.​

Which came from this AOPA article... SAFETY PUBLICATIONS/ARTICLES -- LEGAL BRIEFING: Inoperative equipment
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The other side of this is that at some point the owner knew it was inop, and it would take all of 10 minutes to properly defer it...but being legal, no matter how quick and easy it is, is offensive to some people.

Then, in the intervening 10 years, there were ample opportunities to remove the cigarette lighter legally, but again, not worth the time or expense.

So what the inspector has to "exercise good judgement" about isn't just a minor piece of non-required equipment not working, but also the decade of known, intentional, illegal operation.

I've worked with (and for) people who had an MEL, but absolutely refused to use it. In fact, it's so important for them to not be legal that they don't even investigate why something suddenly doesn't work..."We'll deal with it when we get home next week." Stubborn a-hole that I am, I decided to investigate anyway, and less than a minute later I had the blue tape removed from the sensor. :rolleyes:
 
Not all 172's have an equipment list.
 
midlifeflyer said:
No, assuming we are dealing with a Cessna 172, it would not be legal to fly for the reason in @eetrojan's post discussing 91.213 and the airplane's equipment list. The carb heat is not permitted to be operative by 91.213(d)(2).
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Para :
(d) Except for operations conducted in accordance with paragraph (a) or (c) of this section, a person may takeoff an aircraft in operations conducted under this part with inoperative instruments and equipment without an approved Minimum Equipment List provided—

Shows me the equipment list for a 1957 Cessna 172.

Go back and read my post again and see why I worded it like I did.
 
Wow, thanks for all the replies. I'm probably going to have too read this thread a few more times, lots of great info. Just to clarify, the plane was a 1975 172M.
 
fugazi885 said:
Wow, thanks for all the replies. I'm probably going to have too read this thread a few more times, lots of great info. Just to clarify, the plane was a 1975 172M.
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I do not recall the year Cessna went to placing R & O items in the POH/Owners Manual. If you have a list, it is in the POH/OM.
It will list the items and their arm and weight and give you a check in the block as to which is what.
The better explanation is in the manual. READ it.
No List = NO MEL.
 
For OP: http://www.boldmethod.com/learn-to-fly/systems/carb-ice/

carb-ice-potential-chart.jpg
 
You should find another instructor that isn’t a dangerous idiot. A friend of mine almost died doing t&gs on a 95 degree day because of carb ice.
 
Tantalum said:
because you were still logging time.
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brcase said:
Did you Log the time?
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Kind of a side note to the discussion, but since logging the "flight" was mentioned twice, I thought it merited some discussion.

As we understand it, the airplane was taxied down to the runup area, they found the carb heat problem, and taxied back to the hangar. What part of this is loggable as flight time? None, if you ask me.

61.51 discusses logging of "flight time".
61.1 defines "flight time" as beginning "when the aircraft moves under its own power for the purpose of flight" and "ends when the aircraft comes to rest after landing".

The first clause in the definition is what we like to beat up to discuss whether you can do a three hour run up, one lap around the pattern and count it all. But the second clause, especially "after landing" is important too. If you don't have a landing, it doesn't meet the requirement for "flight time".

Is it valuable experience? Yes. Is it a great training opportunity? Yes (though sadly that was missed by the CFI). Could it be logged as ground instruction? Sure. But "flight time"? I don't think so.
 
I've canceled a flight because of a failed carb heat cable in a Warrior. Can't remember the details, but I think the cable bound up in some intermediate position. The local A&P came out to take a look (a buddy of mine). He messed with a few things and narrowed it down to a failed cable. Without carb heat, even in a PA-28, there's always that chance you'll either need the heat or need the power you lose if carb heat fails in the ON position. As far as legal? Dunno - but for me, common sense is as valid a reason as any.

Somewhere, someone asked about logging. I'm assuming, like RussR, that the plane taxied and then the runup was done and the carb heat problem was found. I'm no expert, but I'd log it. The reg says "moves under its own power for the purpose of flight", and your purpose was flight. It just didn't get that far (yeah, it does muddle up when the flight time ends if you never actually take off.) We all cheat on the .1 or .2 while we are on the ramp and before we start to move, but I've never known anyone to question that.

In my case, I never taxied. I pulled the plane out of the hangar, ran it up in front of the hangar and found a failed carb heat cable. The plane never moved under its own power for any reason, so nothing to log.
 
RussR said:
Kind of a side note to the discussion, but since logging the "flight" was mentioned twice, I thought it merited some discussion.

As we understand it, the airplane was taxied down to the runup area, they found the carb heat problem, and taxied back to the hangar. What part of this is loggable as flight time? None, if you ask me.

61.51 discusses logging of "flight time".
61.1 defines "flight time" as beginning "when the aircraft moves under its own power for the purpose of flight" and "ends when the aircraft comes to rest after landing".

The first clause in the definition is what we like to beat up to discuss whether you can do a three hour run up, one lap around the pattern and count it all. But the second clause, especially "after landing" is important too. If you don't have a landing, it doesn't meet the requirement for "flight time".

Is it valuable experience? Yes. Is it a great training opportunity? Yes (though sadly that was missed by the CFI). Could it be logged as ground instruction? Sure. But "flight time"? I don't think so.
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I agree I wouldn't log it as flight time.

Brian
 
Tom-D said:
I do not recall the year Cessna went to placing R & O items in the POH/Owners Manual. If you have a list, it is in the POH/OM.
It will list the items and their arm and weight and give you a check in the block as to which is what.
The better explanation is in the manual. READ it.
No List = NO MEL.
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I don't believe the portion I bolded is correct...the POH list is a Kinds of Operations Equipment List, which 91.213 refers to by saying that the item cannot be required by a KOEL. No KOEL simply means that's not where you're going to find the answer...the fact that a KOEL doesn't exist doesn't mean everything is required to be operational.
 
MauleSkinner said:
I don't believe the portion I bolded is correct...the POH list is a Kinds of Operations Equipment List, which 91.213 refers to by saying that the item cannot be required by a KOEL. No KOEL simply means that's not where you're going to find the answer...the fact that a KOEL doesn't exist doesn't mean everything is required to be operational.
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The equipment list in the POH is an equipment list, not a KOEL. Notice that the reg talks in terms of both, "indicated as required on the aircraft's equipment list, or on the Kinds of Operations Equipment List."

But I agree with you otherwise. The equipment list in the modern POH is not a MEL, so trying to equate them in some way is an error.

What makes the question in this case difficult is the age of the airplane. There is no "equipment list" in the sense of a POH table shoing what is required, standard, optional, etc. So you are king of left with the TCDS and CAR 3.

Edit: It would be interesting to see what CAR 3 says, but my WAG is that carb heat was required for carbureted engines. CAR 3.634.Carburetor Air Preheat Controls. Separate controls shall be provided to regulate the temperature of the carburetor air for each engine.
 
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MauleSkinner said:
I don't believe the portion I bolded is correct...the POH list is a Kinds of Operations Equipment List, which 91.213 refers to by saying that the item cannot be required by a KOEL. No KOEL simply means that's not where you're going to find the answer...the fact that a KOEL doesn't exist doesn't mean everything is required to be operational.
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The 172 is operated on Placards, The POH/OM is a required placard. What's in it is the law. If there is no list there is no requirement.
 
Tom-D said:
The 172 is operated on Placards, The POH/OM is a required placard. What's in it is the law. If there is no list there is no requirement.
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The 172 must be in conformity with its TCDS and/or any STCs on an individual airplane and/or any ADs applicable to it. The TCDS has this to say:

Equipment:
The basic required equipment as prescribed in the applicable airworthiness requirements (see Certification Basis) must be installed in the aircraft for certification. This equipment must include a current Airplane Flight Manual (AFM) effective S/N 17271035 and on.
1. Model 172 through 172G: Stall warning indicator, Dwg. 0511062.
2. Model 172H and on: Stall warning indictor, Dwg. 0523112.
The equipment portion of Aircraft Specification 3A12, Revision 17, or Cessna Publication TS1000-13 should be used for equipment references on all aircraft prior to the Model 172E.
Refer to applicable equipment list for the Model 172E and subsequent models.

I can't find Revision 17 of TCDS 3A12. The site only goes back to Revision 63 (1998). The quote above is from the current revision, Rev. 84. It would be interesting to see what Rev 17 looked like.
 
MauleSkinner said:
So what exactly do you mean by "no list=no Mel"?
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Figure it out, If ya can't call FSDO.
Pretty simple to figure out, If the POH/OM does not give a MEL, there ain't one. that is why the FAR was written like it was, Many aircraft do not have MELs.

That is why we have 91.213. equipment can be disable by properly authorized persons, and the maintenance records requirements complied with.
 
Dan Thomas said:
The equipment portion of Aircraft Specification 3A12, Revision 17, or Cessna Publication TS1000-13 should be used for equipment references on all aircraft prior to the Model 172E.
Refer to applicable equipment list for the Model 172E and subsequent models.
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Like I've said over and over, some 172s have a items list in the POH/OM and some don't.
The ones that do have a list in the POH/OM you must comply with it. The ones that don't, 91.213 must be used to remove equipment / or fly with inop-equipment.
 
Dan Thomas said:
The 172 must be in conformity with its TCDS and/or any STCs on an individual airplane and/or any ADs applicable to it. The TCDS has this to say:

Equipment:
The basic required equipment as prescribed in the applicable airworthiness requirements (see Certification Basis) must be installed in the aircraft for certification. This equipment must include a current Airplane Flight Manual (AFM) effective S/N 17271035 and on.
1. Model 172 through 172G: Stall warning indicator, Dwg. 0511062.
2. Model 172H and on: Stall warning indictor, Dwg. 0523112.
The equipment portion of Aircraft Specification 3A12, Revision 17, or Cessna Publication TS1000-13 should be used for equipment references on all aircraft prior to the Model 172E.
Refer to applicable equipment list for the Model 172E and subsequent models.

I can't find Revision 17 of TCDS 3A12. The site only goes back to Revision 63 (1998). The quote above is from the current revision, Rev. 84. It would be interesting to see what Rev 17 looked like.
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Yada yada yak yak yak, Cessna Publication TS1000-13, is the POH/OM It is a required placard and must be followed just like the weight and balance portion.
 
Dan Thomas said:
The 172 must be in conformity with its TCDS and/or any STCs on an individual airplane and/or any ADs applicable to it. The TCDS has this to say:
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Any aircraft can be in a properly altered condition when in compliance with 91.213 You should know that, when the regulation says so:

(4) A determination is made by a pilot, who is certificated and appropriately rated under part 61 of this chapter, or by a person, who is certificated and appropriately rated to perform maintenance on the aircraft, that the inoperative instrument or equipment does not constitute a hazard to the aircraft.

An aircraft with inoperative instruments or equipment as provided in paragraph (d) of this section is considered to be in a properly altered condition acceptable to the Administrator.

And it doesn't matter one bit which STC is installed or what the TCDS says.
 
MauleSkinner said:
I’ll let somebody else look up the appropriate reference in CAR3, but I’m sure it reads very much the same...



I’d say carb Heat is part of compliance with certification, so it’s required.
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both should read FAR 91.213 it disagrees with ya.
 
When a Cessna 172 DOES have a Items list in the POH/OM and the carb heat is not mentioned, what rule can you use to disable and fly with it placarded out.?
 
Tom-D said:
When a Cessna 172 DOES have a Items list in the POH/OM and the carb heat is not mentioned, what rule can you use to disable and fly with it placarded out.?
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You legally can't. It is required by the certification basis (CAR3.XXXX mentioned earlier, post #66).
 
fugazi885 said:
Hi, I am a student pilot with very low time. Today was my third flight and during the runup the carb heat knob pulled out much farther than normal and there was no drop in engine RPM indicating the linkage had broken or become disconnected. My instructor seemed OK to still fly the plane as it was a very hot day and we shouldn't really need it. I figured if it is on the checklist and fails, don't fly. We taxied back and did not fly because I didn't trust it, did I make the right call? Also, should I be billed for the hobbs time we were in the plane for something like this?
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I scrubbed a solo rental flight for this reason. I noticed that the carb heat cable was obviously loose/broken before starting. I didn't even try to fire it up at that point, so I didn't have the billing issue.
 
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