Carbs & accessories

[Jase]

OK:

I more or less kept my mouth shut as long as I could stand it. Scott, I am not meaning to stir anything up, I just want to set a few things straight.

1) Warbird manuals, and by this I mean the military manuals, assumed that the MILITARY personnel would do the work. The FAA does not have any oversight authority over the military, nor did the CAA which was in power at the time our round-engined beloveds were built.

2) If you read the tech orders, they give you instructions on overhauling the engine. IT IS **NOT** LEGAL TO "OVERHAUL" an aircraft engine or accessory unless the entity performing such work (repair station or certificated mechanic) has ALL of the proper & manufacturer required tools and training. For an R-985 or R-1340, those tools include a reassembly jig, which is dang near un-obtainable.

3) The term "overhaul" has specific legal and regulatory meanings, which can be found in the CFR's, FAR part 43.2. If an A&P makes a logbook entry attesting that a given part was "overhauled", he is guilty of falsification of records, which can be a jailable offense, unless he can prove that it was repaired and tested properly.
The key part is 43.2(a)(2), which references testing in accordance with approved standards and technical data.

4) So far as a carb is concerned: If your IA (or you!)doesn't have a flow bench, and the appropriate, documented training on the proper usage and calibrations, then he cannot "overhaul" a carb. Plain and simple. He *can* make a logbook entry stating that it was torn down, regasketed and reassembled, but he'd be a fool to do so, with no access to a flow bench, knowing that, if there was an accident, the Feds would be asking him exactly what did he do to the carb that he approved for return to service, and oh by the way, how did you flow check it?

5) I speak from a position of some little knowledge here: If you are restoring an aircraft, the Feds are gonna want to see proof of overhauls of most accessories within the recent past, by an appropriately rated repair station. If you can't show the FAA AI that paperwork, good luck getting a C of A.


Regards

Jase

[Jack Cook]

Amen brother-Amen!

[HarvardIV]

Finally, someone talking some sense.

[bdk]

2) If you read the tech orders, they give you instructions on overhauling the engine. IT IS **NOT** LEGAL TO "OVERHAUL" an aircraft engine or accessory unless the entity performing such work (repair station or certificated mechanic) has ALL of the proper & manufacturer required tools and training. For an R-985 or R-1340, those tools include a reassembly jig, which is dang near un-obtainable.

An A&P cannot overhaul an internal supercharger or a planetary gear nosecase. A tech order is only one source of approved data (for an ex-military aircraft in the standard or limited category). The P&W overhaul manual is another. What reassembly jig specifically are you referring to? Plenty of people overhaul R-985's and R-1340's, sending the supercharger out to a repair station for that part of the overhaul. Where does the FAA state that you must have the manufacturers required tools and training? Aftermarket tools are not OK? A&P school training is not OK?

4) ...He *can* make a logbook entry stating that it was torn down, regasketed and reassembled, but he'd be a fool to do so, with no access to a flow bench, knowing that, if there was an accident, the Feds would be asking him exactly what did he do to the carb that he approved for return to service, and oh by the way, how did you flow check it?

What is the requirement to flow check a float carburetor after reassembly? Is that in the tech order? Carb manual? Will a power check accomplish the same thing?

5) I speak from a position of some little knowledge here: If you are restoring an aircraft, the Feds are gonna want to see proof of overhauls of most accessories within the recent past, by an appropriately rated repair station. If you can't show the FAA AI that paperwork, good luck getting a C of A.

Assuming you don't already have one. For a new C of A you need to provide traceability. The aircraft logs are used to provide traceability thereafter. There is also no requirement to overhaul non-life limited components however, they are evaluated based upon condition. There are plenty of aircraft out there flying with 5000 hour accessories- legal, but probably not very smart.

[Jase]

2) If you read the tech orders, they give you instructions on overhauling the engine. IT IS **NOT** LEGAL TO "OVERHAUL" an aircraft engine or accessory unless the entity performing such work (repair station or certificated mechanic) has ALL of the proper & manufacturer required tools and training. For an R-985 or R-1340, those tools include a reassembly jig, which is dang near un-obtainable.

An A&P cannot overhaul an internal supercharger or a planetary gear nosecase. A tech order is only one source of approved data (for an ex-military aircraft in the standard or limited category). The P&W overhaul manual is another. What reassembly jig specifically are you referring to? Plenty of people overhaul R-985's and R-1340's, sending the supercharger out to a repair station for that part of the overhaul. Where does the FAA state that you must have the manufacturers required tools and training? Aftermarket tools are not OK? A&P school training is not OK?

4) ...He *can* make a logbook entry stating that it was torn down, regasketed and reassembled, but he'd be a fool to do so, with no access to a flow bench, knowing that, if there was an accident, the Feds would be asking him exactly what did he do to the carb that he approved for return to service, and oh by the way, how did you flow check it?

What is the requirement to flow check a float carburetor after reassembly? Is that in the tech order? Carb manual? Will a power check accomplish the same thing?

5) I speak from a position of some little knowledge here: If you are restoring an aircraft, the Feds are gonna want to see proof of overhauls of most accessories within the recent past, by an appropriately rated repair station. If you can't show the FAA AI that paperwork, good luck getting a C of A.

Assuming you don't already have one. For a new C of A you need to provide traceability. The aircraft logs are used to provide traceability thereafter. There is also no requirement to overhaul non-life limited components however, they are evaluated based upon condition. There are plenty of aircraft out there flying with 5000 hour accessories- legal, but probably not very smart.

FAR part 43.2, in its entirety:
"Sec. 43.2 - Records of overhaul and rebuilding.

(a) No person may describe in any required maintenance entry or form an aircraft, airframe, aircraft engine, propeller, appliance, or component part as being overhauled unless --

(1) Using methods, techniques, and practices acceptable to the Administrator, it has been disassembled, cleaned, inspected, repaired as necessary, and reassembled; and

(2) It has been tested in accordance with approved standards and technical data, or in accordance with current standards and technical data accepteble to the Administrator, which have been developed and documented by the holder of the type certificate, supplemental type certificate, or a material, part, process, or applicance approval under §21.305 of this chapter.

(b) No person may describe in any required maintenance entry or form an aircraft, airframe, aircraft engine, propeller, appliance, or component part as being rebuilt unless it has been disassembled, cleaned, inspected, repaired as necessary, reassembled, and tested to the same tolerances and limits as a new item, using either new parts or used parts that either conform to new part tolerances and limits or to approved oversized or undersized dimensions. "

I believe, in my own interpretation of the FAR's, that the controlling key here is "...and tested..." in (b). That's my opinion, and as such certainly isn't binding on anyone else.

Regarding O/H of round engines: According to Appendix A of Part 43, separation or disassembly of a crankcase or crankshaft of a reciprocating engine equipped with an integral supercharger is a major repair. Thus, an A&P CANNOT return it to service; only an appropriately rated repair station or IA can do that.

An extract of FAR 43.13: "Each person performing maintenance...shall use the tools, equipment, and test apparatus necessary to assure completion of the work in accordance with accepted industry practices. If special equipment or test apparatus is recommended by the manufacturer involved, he must use that equipment or apparatus or its equivalent acceptable to the Administrator." So this settles the mfr required tools, and answers the "aftermarket" question. So far as training, if your A&P school curriculum included overhaul or rebuilding of an R-1340, then absollutely you probably "can" do that legally.

FAR Part 65.81 references training and experience:
"Sec. 65.81 - General privileges and limitations.

(a) A certificated mechanic may perform or supervise the maintenance, preventive maintenance or alteration of an aircraft or appliance, or a part thereof, for which he is rated (but excluding major repairs to, and major alterations of, propellers, and any repair to, or alteration of, instruments), and may perform additional duties in accordance with §§65.85, 65.87, and 65.95. However, he may not supervise the maintenance, preventive maintenance, or alteration of, or approve and return to service, any aircraft or appliance, or part thereof, for which he is rated unless he has satisfactorily performed the work concerned at an earlier date. If he has not so performed that work at an earlier date, he may show his ability to do it by performing it to the satisfaction of the Administrator or under the direct supervision of a certificated and appropriately rated mechanic, or a certificated repairman, who has had previous experience in the specific operation concerned.

(b) A certificated mechanic may not exercise the privileges of his certificate and rating unless he understands the current instructions of the manufacturer, and the maintenance manuals, for the specific operation concerned. "

So the key above, is that a mechanic who has never done a given task can *attempt* it, but he CANNOT approve the aircraft/engine/appliance for return to service. If he DOES, then we're back to falsification of records.

I use that as my personal controlling authority on stuff. If you can find the USAAC T.O. on carbs, they reference in it using a flow bench after a teardown/reassembly, even on a float carb. That then, not to mention the liability involved if you happen to misadjust the float, or get the airflow between each barrel unbalanced, is grounds for me personally to send em to an appropriately rated repair station with experience, tools, and competence in the given carb.

And yes, I agree for aircraft flying under Part 91 (General Aviation), there are almost no time limits, it's usually all "on condition". I know a guy who's flying a 1340 with 2000 plus hours on it. Still makes good power and passes all the compression leakdowns, but I'd not trust it personally. It is *legal* though.

Obviously, all of this is one man's opinion, and others can feel free to disagree and have different personal standards, and I won't think any less of anyone who disagrees with me!

Thanks though, bdk, for making me jaunt through the FARs again. Very instructive, and I had forgotten some of what I relearned in this discussion.

[Jase]

Oh, just remembered, I know this started talking about 1340's.. There *is* what amounts to a hard TBO on R-985's, there's an AD on the crank flyweight liners every 1500 hours. Now, I suppose you could crack the cases and just perform the AD, but to me, I'd just send it to Covington and have it O/h'd.

[bdk]

FAR part 43.2, in its entirety:
"Sec. 43.2 - Records of overhaul and rebuilding.

(a) No person may describe in any required maintenance entry or form an aircraft, airframe, aircraft engine, propeller, appliance, or component part as being overhauled unless --

(1) Using methods, techniques, and practices acceptable to the Administrator, it has been disassembled, cleaned, inspected, repaired as necessary, and reassembled; and

(2) It has been tested in accordance with approved standards and technical data, or in accordance with current standards and technical data accepteble to the Administrator, which have been developed and documented by the holder of the type certificate, supplemental type certificate, or a material, part, process, or applicance approval under §21.305 of this chapter.

(b) No person may describe in any required maintenance entry or form an aircraft, airframe, aircraft engine, propeller, appliance, or component part as being rebuilt unless it has been disassembled, cleaned, inspected, repaired as necessary, reassembled, and tested to the same tolerances and limits as a new item, using either new parts or used parts that either conform to new part tolerances and limits or to approved oversized or undersized dimensions. "

Note that this says person. Not repair station, overhaul facility, etc.

I believe, in my own interpretation of the FAR's, that the controlling key here is "...and tested..." in (b). That's my opinion, and as such certainly isn't binding on anyone else.

And of course that includes ground testing- not only flow testing.

Regarding O/H of round engines: According to Appendix A of Part 43, separation or disassembly of a crankcase or crankshaft of a reciprocating engine equipped with an integral supercharger is a major repair. Thus, an A&P CANNOT return it to service; only an appropriately rated repair station or IA can do that.

Unless the supercharger section is detatchable from the power case.

An extract of FAR 43.13: "Each person performing maintenance...shall use the tools, equipment, and test apparatus necessary to assure completion of the work in accordance with accepted industry practices. If special equipment or test apparatus is recommended by the manufacturer involved, he must use that equipment or apparatus or its equivalent acceptable to the Administrator." So this settles the mfr required tools, and answers the "aftermarket" question. So far as training, if your A&P school curriculum included overhaul or rebuilding of an R-1340, then absollutely you probably "can" do that legally.

I don't think the FAA distinguishes between an R-1340 and an O-200. It's either a recip or a turbine. Don't forget, most of the FAA curriculum is still based on maintenance of R-2800's and PD-12 carbs and such.

FAR Part 65.81 references training and experience:
"Sec. 65.81 - General privileges and limitations.

(a) A certificated mechanic may perform or supervise the maintenance, preventive maintenance or alteration of an aircraft or appliance, or a part thereof, for which he is rated (but excluding major repairs to, and major alterations of, propellers, and any repair to, or alteration of, instruments), and may perform additional duties in accordance with §§65.85, 65.87, and 65.95. However, he may not supervise the maintenance, preventive maintenance, or alteration of, or approve and return to service, any aircraft or appliance, or part thereof, for which he is rated unless he has satisfactorily performed the work concerned at an earlier date. If he has not so performed that work at an earlier date, he may show his ability to do it by performing it to the satisfaction of the Administrator or under the direct supervision of a certificated and appropriately rated mechanic, or a certificated repairman, who has had previous experience in the specific operation concerned.

(b) A certificated mechanic may not exercise the privileges of his certificate and rating unless he understands the current instructions of the manufacturer, and the maintenance manuals, for the specific operation concerned. "

So the key above, is that a mechanic who has never done a given task can *attempt* it, but he CANNOT approve the aircraft/engine/appliance for return to service. If he DOES, then we're back to falsification of records.

Never would suggest falsifying records! Section (a) above refers to specific operations (not specific engines) which means that if you have overhauled an O-200 in A&P school you are as an A&P certified to do those operations on any aircraft engine without supervision.

I use that as my personal controlling authority on stuff. If you can find the USAAC T.O. on carbs, they reference in it using a flow bench after a teardown/reassembly, even on a float carb. That then, not to mention the liability involved if you happen to misadjust the float, or get the airflow between each barrel unbalanced, is grounds for me personally to send em to an appropriately rated repair station with experience, tools, and competence in the given carb.

There may be some, but I have never seen a (certified) two-barreled float carb on an aircraft. Again, this is all basic A&P school stuff, not rocket science. I wouldn't trust any A&P that wouldn't accept a flight in an aircraft he worked on.

And yes, I agree for aircraft flying under Part 91 (General Aviation), there are almost no time limits, it's usually all "on condition". I know a guy who's flying a 1340 with 2000 plus hours on it. Still makes good power and passes all the compression leakdowns, but I'd not trust it personally. It is *legal* though.

Obviously, all of this is one man's opinion, and others can feel free to disagree and have different personal standards, and I won't think any less of anyone who disagrees with me!

I think we agree far more than we disagree. Thanks for keeping the discussion civil. Despite what I have said above, I don't have the time to overhaul the engine (or carburetor) in my T-6, I'm sending it out- although I did overhaul the engine in my Stearman. I also have two other people inspecting my work (and I theirs)- one an IA and another an Airframe mechanic. No ratings can keep you from overlooking things, especially when you are so close to them. I am not afraid to have anyone inspect my aircraft anytime- especially if they want to fly in it.

Thanks though, bdk, for making me jaunt through the FARs again. Very instructive, and I had forgotten some of what I relearned in this discussion.

[HarvardIV]

These are the kind of posts I had intended to see when I posted "R-1340 carburator". Hopefully logical, unbiased, lawful and scientific responses like these will follow in the future.

Chris

[Jase]

Hi BDK:

No problem at all, I think that we *do* agree on more stuff than we disagree on, and I likewise appreciate the civility on your end as well. With that in mind, let me address a couple points to your counterpoints (or is that your point to my counterpoint?:) )

"Note that this says person. Not repair station, overhaul facility, etc. "

From FAR Part 1.1, General Definitions: "Person means an individual, firm, partnership, corporation, company, association, joint-stock association, or governmental entity. It includes a trustee, receiver, assignee, or similar representative of any of them." So, yes, it *does* mean repair station, overhaul facility, etc. In any case, for any repair station there is at least one "Designated Inspector" who must sign off all work, so the person could reference that inspector.

"And of course that includes ground testing- not only flow testing."
Whatever testing the manufacturer in question recommends, be it flow testing, ground runs only, or asking the part a multiple choice exam!

"Unless the supercharger section is detatchable from the power case. "
Appendix A does not address this, and I believe you are mistaken. If you can find an FAR that proves I'm wrong, I will happily apologize and will have learned more than I knew before. Reference Part 43, Appendix A, (b)(2)(i)is the cite: "(2) Powerplant major repairs. Repairs of the following parts of an engine and repairs of the following types, are powerplant major repairs:

(i) Separation or disassembly of a crankcase or crankshaft of a reciprocating engine equipped with an integral supercharger.

(ii) Separation or disassembly of a crankcase or crankshaft of a reciprocating engine equipped with other than spur-type propeller reduction gearing. "

I don't think the FAA distinguishes between an R-1340 and an O-200. It's either a recip or a turbine. Don't forget, most of the FAA curriculum is still based on maintenance of R-2800's and PD-12 carbs and such.
Oh, I know they used to, but a *lot* of the 143 schools are finally coming into the last half of the 20th century. I've a friend in A&P school who swears the school has no radial engines, just O-540's and the like for recip training. I suspect you are right, that there is little distinction between the "type" of recip engines in the FAR's, other than 65.81's training requirements. Nonetheless, I would bet that an A&P who worked on his first radial, that subsequently met with an incident, would be quizzed pretty hard by the Feds about his training and who trained the trainer, as it were.

Never would suggest falsifying records! Section (a) above refers to specific operations (not specific engines) which means that if you have overhauled an O-200 in A&P school you are as an A&P certified to do those operations on any aircraft engine without supervision.
Sure, concur, so long as the "overhauling" is done in accordance with 43.2, and the equipment required in 43.13. And, to set the record straight, I wouldn't at all suggest falsifying records either. However, the "hook" the Feds will get a careless A&P on is just that, if he signs off on something that he wasn't authorised to, he has then falsified aircraft records under 43.12, because he was not in compliance with the requirements of 65.81. Whew, my brain is beginning to ache!

I think we agree far more than we disagree. Thanks for keeping the discussion civil. Despite what I have said above, I don't have the time to overhaul the engine (or carburetor) in my T-6, I'm sending it out- although I did overhaul the engine in my Stearman. I also have two other people inspecting my work (and I theirs)- one an IA and another an Airframe mechanic. No ratings can keep you from overlooking things, especially when you are so close to them. I am not afraid to have anyone inspect my aircraft anytime- especially if they want to fly in it.

Cool!! I have been known to turn down flights in a/c I'm not comfortable with as well. Our SOP in the CAF squadron I volunteer with is that at least 1 other person must inspect any operation performed, ESPECIALLY if it involves fasteners or safetying, for just the reasons you mention above. Two sets of eyeballs beat one tired set.

All candour, thank you again for making me trek thru the FAR's. As I said, I relearned a bunch of info. Now, having said that, I don't think I wanna curl up at night with the FAR's.... <G>

[Jase]

These are the kind of posts I had intended to see when I posted "R-1340 carburator". Hopefully logical, unbiased, lawful and scientific responses like these will follow in the future.

Chris

Chris: A lot of us are kind of fussy, as you may have noticed(!), about certain things. Float level settings are fairly critical, and can result in running out of fuel at the worst possible time, about 200' AGL. Our L-5 suffered this fate, for just this reason, before we bought her. Here's a pic of the results of a botched float setting, which CANNOT be found on a ground run!! (luckily no personnel injury): http://www.natlcapsq.org/images/crash.jpg

[HarvardIV]

Jase, Thanks.

[bdk]

What kind of ground run, a mag check or a takeoff power run with the tail tied down?

[HarvardIV]

Guys:

A friend told me that doctors, lawyers, and such shouldn't take care of family and good friends since a level of sloppyness (unprofessionalism)takes place. Could be the same on these carburators when the same professionals do their own. Kind of a tendency to be self forgiving of ones own work? ie, sloppy floats, ignoring metal chips, etc.

[Jase]

What kind of ground run, a mag check or a takeoff power run with the tail tied down?

Way it was told to me, was the pilot was the mechanic who had diddled with the float setting. He did a full power run in the blocks, for how long I dunno, and then went and took off as normal. 200' AGL or so, and silence descended. He wound up deadsticking into the trees, ended upside down as shown. Said he wasn't hurt at all till he pulled his harness release, then he bonked his head on the fuze tubing! Forgot about the glider he had to do a 360 around, too.

However, I wasn't there, so all I can tell you is the way it was told to me, and submit the end result photo. Here's the NTSB report extract: NTSB Identification: CHI85LA317 .
The docket is stored on NTSB microfiche number 28426.
14 CFR Part 91: General Aviation
Accident occurred Sunday, July 28, 1985 in WAYNESVILLE, OH
Aircraft: STINSON L-5, registration: N1156V
Injuries: 1 Uninjured.

THE PLT TOOK OFF ON A TEST FLT TO CHECK THE ENG AFTER IT HAD BEEN INSPECTED & THE CARBURETOR HAD BEEN OVERHAULED. HE MADE A GROUND CHECK & FULL ENG RUN-UP BEFORE TAKING OFF. INTENDING TO STAY IN A CLOSED TRAFFIC PATTERN, HE TOOK OFF, MADE A NORMAL CLIMB IN THE TRAFFIC PATTERN, THEN TURNED ONTO A DOWNWIND. WHILE ON DOWNWIND, THE ENG SPUTTERED. THE PLT SWITCHED FUEL TANKS & PUMPED THE THROTTLE, & THE ENG RESTARTED, BUT A FEW SECONDS LATER, IT LOST POWER AGAIN. WHILE ATTEMPTING TO RETURN TO THE RWY, THE PLT MADE A 360 DEG TURN TO AVOID A GLIDER & TO LOSE ALT. HE STATED THAT DURING THE MANEUVER, HE LOST SIGHT OF THE GLIDER, & WHILE TRYING TO RELOCATE IT, HE LOST TOO MUCH ALT. SUBSEQUENTLY, THE ACFT CRASH LANDED IN TREES ABOUT 50 FEET SHORT OF THE RWY. AN EXAM REVEALED THAT THE CARBURETOR FLOAT HAD BEEN ADJUSTED FOR 0.25' OF TRAVEL. THE MINIMUM TRAVEL PER INSTALLATION INSTRUCTIONS SHOULD HAVE BEEN 0.50'.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
FUEL SYSTEM,CARBURETOR..INCORRECT
MAINTENANCE,ADJUSTMENT..IMPROPER..OTHER MAINTENANCE PERSONNEL


Contributing Factors

OBJECT..TREE(S)

Index for Jul1985 | Index of months

[HarvardIV]

Jase and BDK:

Really exhaustive data on your part. I hope you didn't burn up too much time on that..

Chris