Auto fuel for Lycoming engines

[Steve Job]

I know there are STCs available through Petersen and EAA for unleaded fuel approval (non-ethanol) on certain engine/airframe combinations, but Lycoming issued the following last April 2013 regarding approved fuels:

http://www.lycoming.com/Portals/0/Upload/SI1070S Specified Fuels.pdf

Does this change anything? Also I see that Piper has been testing 93UL on an Archer:

http://www.avweb.com/avwebflash/news/Piper-Completes-Flights-New-93-Octane-Automotive220546-1.html


I have a Piper Warrior with a O320-D3G, which requires modification to the fuel pump system for the Petersen STC. Do you think there's a chance that Piper might eventually allow 93UL on unaltered older airframes?

If this has been discussed previously on this forum, please accept my deepest apologies...

 

[poadeleted20]

For production certified aircraft, it changes nothing unless the airframe is also approved for those automotive fuels listed in Table 2 -- without that, you'll still need an STC for the airframe, albeit not for the engine. For Experimental aircraft using a certified Lycoming engine, whether or not you can use something else will depend on the FAA-issued Operating Limitations for that aircraft. However, note that you can't use anything with ethanol so be careful where you get your mogas.

As for what Piper may do in the future regarding their aircraft, you'd have to ask Piper. However, given the apparent nearness of an FAA-certified unleaded 100 octane avgas (I'm guessing by the end of 2014) that will be approved in all production airplanes which can run on 100LL, I don't think they'd have much incentive to spend the money to create approval for 93UL mogas in the Warrior.

 

[Steve Job]

Thanks Ron. Wishing thinking I guess, but it's interesting that Piper is working with "Airworthy AutoGas LLC" on a 93UL solution, rather than waiting for the 100LL replacement. I guess there's no money in it for Piper to retro-certify old airframes for this new fuel, so it probably won't happen.

 

[Henning]

Thanks Ron. Wishing thinking I guess, but it's interesting that Piper is working with "Airworthy AutoGas LLC" on a 93UL solution, rather than waiting for the 100LL replacement. I guess there's no money in it for Piper to retro-certify old airframes for this new fuel, so it probably won't happen.

Why not? If they can sell an STC to all the old Piper owners out there, that's pure profit.

 

[Geico266]

For production certified aircraft, it changes nothing unless the airframe is also approved for those automotive fuels listed in Table 2 -- without that, you'll still need an STC for the airframe, albeit not for the engine. For Experimental aircraft using a certified Lycoming engine, whether or not you can use something else will depend on the FAA-issued Operating Limitations for that aircraft. However, note that you can't use anything with ethanol so be careful where you get your mogas.

As for what Piper may do in the future regarding their aircraft, you'd have to ask Piper. However, given the apparent nearness of an FAA-certified unleaded 100 octane avgas (I'm guessing by the end of 2014) that will be approved in all production airplanes which can run on 100LL, I don't think they'd have much incentive to spend the money to create approval for 93UL mogas in the Warrior.

Just as a point of reference Ron, I have never seen operating limitations mention what fuel to burn in any experimentals. I'm not saying it never has happened, but since the home builder writes and submits the operating limitations (at least I had to write mine, they approved it) I doubt anyone would add it.

 

[poadeleted21]

Just as a point of reference Ron, I have never seen operating limitations mention what fuel to burn in any experimentals. I'm not saying it never has happened, but since the home builder writes and submits the operating limitations (at least I had to write mine, they approved it) I doubt anyone would add it.

Unless they're worried about liabilty issues when they sell it.

<ducks and runs>

 

[Ted]

However, note that you can't use anything with ethanol so be careful where you get your mogas.

For certified, that is correct. You have to stick to which fuels are approved for both the engine and the airframe.

For experimental, Gecko has it right. Now there might be technical reasons why you wouldn't want to use ethanol fuel, but there's a different between technical and legal.

 

[poadeleted20]

Just as a point of reference Ron, I have never seen operating limitations mention what fuel to burn in any experimentals. I'm not saying it never has happened, but since the home builder writes and submits the operating limitations (at least I had to write mine, they approved it) I doubt anyone would add it.

You don't get to just write your own and submit them and then have them approve whatever you felt like putting in. There is an advisory circular which specifies a lot of what must be in them, and if you don't start with that boilerplate, it's not likely they'll be approved as is. However, I'm willing to believe you on the fuel point.

 

[poadeleted20]

For experimental, Gecko has it right. Now there might be technical reasons why you wouldn't want to use ethanol fuel, but there's a different between technical and legal.

If you use a certified engine, and take the shortcuts which that allows, I believe you are still subject to AD's on the engine and limitations from the manufacturer. But I'm not sure on this, so I'm happy to be corrected if wrong.

 

[docmirror]

The logical answer is, possibly yes. The probable answer dealing with the FAA is - likely no, never. With an 8.5:1 C/R, a fuel with 93 octane(depending on how measured) should work just fine and suffer no detonation. As long as the RVP of the 93UL is equal to the comparable 100 octane fuel, the plane and the engine would work perfectly, even in the absence of the Petersen STC mods which reduce the potential for vapor lock in all conditions.

Of course, we're talking about the FAA, which has a bad case of GA-haterade so the probability that it would ever be approved through normal process channels is about the same as me bedding Beyonce this Sat night.

 

[kyleb]

If you use a certified engine, and take the shortcuts which that allows, I believe you are still subject to AD's on the engine and limitations from the manufacturer. But I'm not sure on this, so I'm happy to be corrected if wrong.

There are a couple of opinions on that.

One is that you are subject to the AD's and limitations.

The other is that you're not.

It probably comes down to the FSDO or the FAA rep you're dealing with.

 

[docmirror]

There are a couple of opinions on that.

One is that you are subject to the AD's and limitations.

The other is that you're not.

It probably comes down to the FSDO or the FAA rep you're dealing with.

A senior A&P asplained it this way to me: Conforming rule. If you use an airframe, engine or prop which has a TCDS, and you 'conform' to that TCDS, you are subject to the restrictions, limitations, ADs, and compliance regulations for that make and model listed on the TCDS. However, if you go 'off the reservation', you are no longer bound by the conforming rule.

Example: You build a belchfire out of tissue paper, Aluminum foil and spit. You attach a Lycoming O-200-A, in accordance with TCDS E-252 and the engine conforms to the TCDS with respect to major components, ignition, carb, timing, etc. You carve your own homebrewed prop, and hang that. The Belchfire has no AD compliance, the prop has no AD compliance, but should there be an AD issued against the O-200-A(or it's component parts), you are responsible for compliance with that AD as your engine 'conforms' to the TCDS. However, if you take the jugs off, and replace them with Corvair jugs, and remove the carb and put a Holley progressive 2 barrel, and remove one of the ignition systems and replace with a CDI, it is no longer an 'O-200-A' it is now a 'U-made-it' engine brand, and any ADs or restrictions and limitations are now moot.

I think that's how it works.

 

[Tom-D]

If you use a certified engine, and take the shortcuts which that allows, I believe you are still subject to AD's on the engine and limitations from the manufacturer. But I'm not sure on this, so I'm happy to be corrected if wrong.

A typical letter of limitations on the new format.

http://home.provide.net/~pratt1/ambuilt/exhibyak.htm

unless the EXP owner wants the ability to resell the engine as a used engine able to be placed in a production aircraft they are not required to maintain it under FAR part 43, but must be inspected IAW FAR 43-D, during their yearly inspection.

FAR part 39.

39.7 What is the legal effect of failing to comply with an airworthiness directive?
Anyone who operates a product that does not meet the requirements of an applicable airworthiness directive is in violation of this section.

IF the AD says it applies,,,, it applies. watch the wording of the AD, the compliance requirements are in the AD.

You can bet that if a kit manufacturer discovered they made a part that was a hazard they can and would request an AD to protect the company.

 

[Geico266]

You don't get to just write your own and submit them and then have them approve whatever you felt like putting in. There is an advisory circular which specifies a lot of what must be in them, and if you don't start with that boilerplate, it's not likely they'll be approved as is. However, I'm willing to believe you on the fuel point.

Correct, there is a boiler plate of data that must be included or they won't be approved. Basically, cut & paste. The limitations cover operations stuff, not usually fuel, oil, ect. If that were the case I would have made mine mandatory to carry Bud Lite for the crew!

 

[Geico266]

You can bet that if a kit manufacturer discovered they made a part that was a hazard they can and would request an AD to protect the company.

They would issue an SB ( Service Bulletin). I believe only the FAA can issue an AD.

Van's is very good about making sure all registered owners (even if you didn't build the RV you should register it with Vans) get or have access to SB's. When you buy a used RV you can check their web site and find all applicable SB's to that airframe. The engine and prop is a different search.

Oh, BTW, most ( if not all) Van's SB parts are free. . If they require parts they send you the parts no charge. What ever hardware is needed to complete the SB is included also, along with very detailed iinstructions. Free is good.

 

[Geico266]

Unless they're worried about liabilty issues when they sell it.

<ducks and runs>

I'm not worried about liability remember?

 

[Tom-D]

They would issue an SB ( Service Bulletin). I believe only the FAA can issue an AD.

That's very true but they would beg the FAA to issue an emergency safety AD.


Van's is very good about making sure all registered owners (even if you didn't build the RV you should register it with Vans) get or have access to SB's. When you buy a used RV you can check their web site and find all applicable SB's to that airframe. The engine and prop is a different search.

Oh, BTW, most ( if not all) Van's SB parts are free. . If they require parts they send you the parts no charge. What ever hardware is needed to complete the SB is included also, along with very detailed iinstructions. Free is good.

This is why I stated the post as I did to avoid naming manufacturers. Point being, any manufacturer is legal to use part 39 to expose hazards.

The wording in part 39 does not make exception for EXP/AB aircraft. Thusly, it does not require mention in the letter of limitations we were talking about.