Continental PRIME IO-370 and Reiff

[IP076]

Anyone that's done the IO-370 conversion using a Reiff preheat unit? The folks at Reiff seemed to have never heard of the engine and since it's not listed on their applications list, it probably needs a field approval. Though, the list says "Lycoming (and clones)".

Just thought I'd see if anyone has used that combo yet?

[Bruce Fenstermacher]

Check with the guys doing the AOPA 170. They are probably the only people who've seen an IO-370.

A slight bit off topic but can you tell me any reason a Reiff or Tanis installation isn't a minor alteration? None of it is used in actual operation of the aircraft. None of it is tied into any aircraft system. Just because these companies have acquired an STC does not mean one is required at all.

And way off topic but likely applies to the IO-370. Recently I talked to a tool manufacturer who makes a Lycoming specialty tool we bought to work on our Lycoming IO-390s we own at work. Our parts/tool person had sourced the tool. After looking at and reading the instructions it was unclear exactly how this tool would work on a IO-390. So I gave the company a call and ended up talking to the owner/tool designer. My question simply, "does this tool fit a IO-390?". He didn't hesitate, "NO, I've never even seen an IO-390." I informed him I was looking at 5 of them currently in our shop and they have an airworthiness limitation which requires a tool such as his to keep it airworthy. Lycoming sells the tool for several thousand dollars. He may want to find and look at a IO-390 pretty quick.

[IP076]

Thanks Bruce.

I’m far from an expert, but your logic towards a minor alteration makes sense to me. But I get in trouble all the time when expecting logic from the Feds. I’ll talk to my IA.

I have some contacts at AOPA. I’ll reach out.

Stoots has sold 42 of these kits, so there’s a few out there! I believe the bulk of those are for 170s, the rest for 172s and 175s.

[IP076]

Bruce,

Talked to my IA and he’s in agreement with you. The installation is a minor alteration.

[Bruce Fenstermacher]

Bruce,

Talked to my IA and he’s in agreement with you. The installation is a minor alteration.

Well that makes two at least two of us.

Sitting around the lunch table yesterday with two IAs present I pulled up 14 CFR Appendix A to Part 43 and reviewed it. I then proclaimed an IA test in progress and asked them both if a Reiff or Tanis system is an engine accessory? (Installation of an unapproved engine accessory is a major alteration) They both quickly said no, it is a airframe modification. A review of Major Alterations to Airframes showed no obvious reason it would be a major airframe alteration.

They both looked at me and said it is because it comes with a STC. And I said because something comes with an STC does not make it a major alteration that I could find in 43 Appendix A. They both agreed and said they saw no reason either of the kits would be a major alteration.

So, maybe there are 4 of us.

Unless I've missed something in Appendix A, I think Reiff and Tanis (and some others for their products) obtain an STC to make their products more easily sold because there exists a clear path with little thought to the installer or anyone else in the future of the legality of the installation. A properly executed and documented STC is relatively clean. Someone else did the thinking and took responsibility. A minor alteration could be, but often, not so well documented. It's just a little bit messier for the installer who must take on some responsibility.

[n2582d]

From Reiff’s FAQ’S:

Does your system require an STC or Form 337?
No. FAA classifies engine heaters as minor alterations, so an STC or Form 337 is not needed, provided the product has PMA approval, which we have. Some preheaters on the market do not have a PMA. In those cases a Form 337 field approval is necessary. Since we have a PMA, only an engine logbook entry is required to document installation.

Not sure this is entirely true as Tanis has obtained STC approval for their preheaters. I have no experience with preheaters, but from what I’ve read the Tanis system is more of a permanent attachment than the Reiff system. Based on this answer to their FAQ I’d sign it off as a minor alteration and update the W&B and equipment list.

[GAHorn]

Bruce is correct, IMO,… the problem with the use of an STC for these devices is….that an STC changes the TYPE certification of the aircraft upon which it is installed…and THAT requires a FORM 337…which ONLY applies to a MAJOR ALTERATION or repair.

Therefore, the devices being installed SHOULD be installed NOT in accordance with an STC…and without regard to any supplied by the mfr’r…..but in accordance with a “minor alteration” as suggested.

Therefore it would be a mistake to log the installation under any STC. IMO.

[n2582d]

Sitting around the lunch table yesterday with two IAs present I pulled up 14 CFR Appendix A to Part 43 and reviewed it. I then proclaimed an IA test in progress and asked them both if a Reiff or Tanis system is an engine accessory? (Installation of an unapproved engine accessory is a major alteration) They both quickly said no, it is a airframe modification. A review of Major Alterations to Airframes showed no obvious reason it would be a major airframe alteration.

If this is an airframe alteration rather than an engine alteration why is the AML on the Tanis STC for the O-300 (among many other engines) and not for an airframe such as the C-170, C-172, etc?

… And I said because something comes with an STC does not make it a major alteration that I could find in 43 Appendix A.

This is from AC21-40A:

1-6. Key Facts about Supplemental Type Certificates (STC).
a. An STC is the FAA’s approval of a major change in the type design of a previously type certificated product.

Bruce is correct, IMO,… the problem with the use of an STC for these devices is….that an STC changes the TYPE certification of the aircraft upon which it is installed…and THAT requires a FORM 337…which ONLY applies to a MAJOR ALTERATION or repair.

Therefore, the devices being installed SHOULD be installed NOT in accordance with an STC…and without regard to any supplied by the mfr’r…..but in accordance with a “minor alteration” as suggested.

Therefore it would be a mistake to log the installation under any STC. IMO.

George, I’d agree that there is a lot of room for interpretation on whether a certain modification should be considered a major or a minor alteration. One example would be C-Mod’s STC for the fuel selector drain valve. For whatever reason the FAA decided that was a major alteration and therefore gave C-Mod’s — now apparently sold to Saf-Air — an STC for that belly drain valve. Why is it that adding wing tank drain valves a minor alteration — there are no STC’s for valves on the wing tanks — and the belly valve a major alteration? Unless I’m mistaken, as an IA I cannot decide unilaterally to “Remove drain plug, Cessna Part Number AN913-1D, from the fuel selector valve, and replace with CAV-110D (CM-170) or CAV-110H-4D (CM-170L)” and call it a minor alteration; I must use their STC. I can however do that with some other valve that fits there or replace the wing tank plugs with appropriate drain valves as a minor alteration.

Same goes for adding this simple end to a carb heat bowden cable.

Dynamic Propeller has STC SA01454SE to install it on certain Cessna 152, 172, and 182 aircraft. While it’s obviously a minor alteration in my opinion, I must install it on these aircraft using their STC, which, by definition is a major alteration.

Similarly with the engine preheaters. I cannot legally install a Tanis preheaters on an O-300 without using their STC. I can however install Reiff’s SS6 or TXPS6 system as a minor alteration with just a logbook entry. Reiff parts are PMAed but they have no STCs.

IMO, in all three of these examples, the FAA should never have issued STC approval for these minor alterations. But since they have issued an STC, I cannot override the FAA and declare such a modification a minor alteration by simply installing the STCed part with just a logbook entry.

[GAHorn]

Gary, the way I am viewing this is: The FAA can issue an STC at the request of the mfr’r of the aftermarket product.
In an entirely separate action, an Owner or A&P can alter an airplane using the same product under the auspices of “minor alteration”.

The FAA does not tell an aftermarket product mfr’r that they MUST obtain an STC for their product. That request is originated at the mfr’r instigation…not the FAA. Therefore, If I wish to replace a bolt…. say a AN4-6 with a AN4-7 using a flat washer …. that is a minor alteration. But if I apply to FAA to make this as a permanent alteration of the type-certificated product in lieu of the OEM’s parts-list….FAA will tell me that I must make application for an STC approval….and they will look at that….(subsequently approving or disapproving of it.).
However, that would not preclude an owner simply buying that bolt and installing it with a washer as a minor alteration…. OR…could choose to do so under the STC.

A better example might be the B.A.S. tail-pull handles. You can buy the kit and STC from B.A.S. and install them and file a 337. Or you can buy the parts from Air Repair and perform the identical alteration and log it as a minor-alteration. Or you can file a 337 and ask for a field approval. Your choice.

[Bruce Fenstermacher]

Gary, the Tanis and Reiff systems have similarities and differences depending on the engines cylinders and perhaps customer preference. Both use pads glued to the engine in various places with high temp RTV. Tanis uses heat probes that are designed to replace a rocker box cover screw in the cylinder, and they may have a probe that will install in an appropriate boss if the cylinder has one. Reiff uses a heated band clamped around the base of the cylinder. Both use a mix of regular lamp wire with a molded 110AC plug or a 110AC plug receptacle made for the RV world with some UL rated wire mixed with various aerospace wire and plugs.

Of the two types I see the most the Tanis on an IO-550 may be the closest to requiring more approval as a rocker box cover screw is replaced with a heated stud/screw.

As 90% of our business is Cirrus and 80% of those are newer loaded SR-22 models which have the Tanis system installed by Cirrus (not under a STC), and 90% of all of our mechanics A&P experience is working exclusively on Cirrus aircraft they would never see an AML, they have considered the preheat system an airframe system not an accessory of the the engine. They've likely never installed a new preheat system on an aircraft.

As I stated when asked, both IAs knew there was an STC for some preheat system and therefor it must be a major alteration. This is kind of like what Gary has said that he feels once the FAA has issued an STC for a product, it is a major alteration for that product to be installed as instructed and approved on airframes, engines or propellors. But whether or not the FAA has issued an STC for a modification has no bearing on whether making the same modification without using the STC is a major or minor alteration. I do agree that if one chooses to use an STC then the process of doing that is considered a major alteration.

The example of the C-mods STC for the fuel drain is a bad example because the mod is to the fuel system which is nearly an automatic major alteration under FAR 43 Appendix A. So that sticky point has to be addressed.

Personally if I was asked to install a kitted preheat system which included cylinder heaters as well as crank case and oil sump heating pads and an AC receptacle, I'd be much happier doing it following an STC with instructions cause someone else has decided the legality so long as the instructions are followed. But gluing a simple 100w temp and circuit protected pad on the outside of the my A-65 kidney on my Vagabond is a minor alteration.

Wonder what now deceased Bill O'Brien from the FAA would have thought about this. Too bad we won't know.

[lowNslow]

Under 14 CFR Appendix A to Part 43(a)(2)(iii) the FAA defines a major alteration as "Installation of an accessory which is not approved for the engine."
Now what type of approval is required and what the definition of an "accessory" is the question.

[GAHorn]

Under 14 CFR Appendix A to Part 43(a)(2)(iii) the FAA defines a major alteration as "Installation of an accessory which is not approved for the engine."
Now what type of approval is required and what the definition of an "accessory" is the question.

Exactly. Is spray paint of a different color an “accessory”..? What about tie-wraps to secure wiring and such..? Does this mean a spark-plug-gasket thermocouple for a CHT is a major alteration..?

(rhetorical questions only)

[Bruce Fenstermacher]

You are right Karl. When I started this conversation with our IAs the question was “was a preheat system an engine accessory”? That is when they said it was an airframe accessory. I. Ever looked for the definition of accessory.

I wonder if appliance is the same as a accessory?

[Bruce Fenstermacher]

From 14 CFR 1.
Appliance means any instrument, mechanism, equipment, part, apparatus, appurtenance, or accessory, including communications equipment, that is used or intended to be used in operating or controlling an aircraft in flight, is installed in or attached to the aircraft, and is not part of an airframe, engine, or propeller.

So an appliance can be an accessory I wonder if visa versa? And so if they are one in the same, according to 1.1 they are only such when “ used or intended to be used in operating or controlling an aircraft in flight”

So a preheat system can’t be an accessory as I see it.

[n2582d]

... when “ used or intended to be used in operating or controlling an aircraft in flight”

So a preheat system can’t be an accessory as I see it.

Depends on how long the extension cord is!