Shell’s announcement that it has an unleaded avgas formula that is working well at a full 100 octane caused a commotion this week. It’s the first time any major oil company has said it has a solution to the lead problem. And a company the size of Shell brings credibility to the effort to transition to lead-free avgas.
I had a chance to speak with Michael Sargeant who is Shell’s Avgas Commercialization Manager. Michael’s title fully describes the hard part of the conversion to unleaded avgas which is to get a fuel out of the laboratory and into airplane fuel tanks.
Shell has been working on a 100LL replacement for the past 10 years and recently began engine testing with Lycoming and flight testing with Piper. Though Shell is tightlipped about its lead-free avgas formula it would be a safe guess that the company’s development of 100 octane plus auto racing fuel contributed to the new aviation fuel creation. Most of the development work was done at Shell labs in the UK.
Here are the headline concerns we all have for the unleaded replacement fuel and I asked Shell’s Sargeant about them:
Full 100 octane performance: Shell is convinced that its new fuel formula will provide the same or better octane performance as 100LL. That means all piston airplanes that require 100 octane can potentially use the new fuel without performance loses.
Compatibility with 100LL. Any unleaded avgas will be phased into the fuel distribution system so for a long time we will fly with a mixture of the new fuel and 100LL in our tanks depending on where we fueled last. Sargeant says Shell’s testing shows the unleaded fuel mixes with 100LL successfully.
Compatibility with fuel system materials: Chemicals that boost octane can attack and even dissolve some hoses, sealants and other materials used in an airplane fuel system. Shell has done testing of its new formula that, so far, shows compatibility of the fuel with popular fuel system materials. Sargeant said Shell has room to “tweak” the fuel formula if further testing shows incompatibility.
Producibility: To be economically effective an unleaded avgas must be producible without big investments in refineries or chemical plants. The market is so small that it would be hard to justify investing millions in new equipment to serve the shrinking avgas market. Shell says its new formula is producible without major investment in existing equipment. Shell will make the fuel formula available to others under licensing or some other agreements so the fuel will not be a regional or single-brand product.
Certification: The quickest path to certifying a new fuel would be to obtain STCs for specific airplane models much as the EAA and others did with autofuel a number of years ago. But that would restrict use of the new fuel to only those models with an STC and would provide virtually no incentive for the national fuel distribution system to stock the new fuel.
The only truly effective certification of a new fuel is to gain fleet wide approval, even if certain modifications, even if only paperwork, are required. Shell says it will seek fleet wide approval instead of STCs in individual airplane models. The first step is to present the new fuel to ASTM, the international body of material standards, which Shell is doing next week. Once an ASTM specification is in place Shell says it will work with the FAA and other aviation certification authorities around the world to gain approval for the new fuel as a 100LL replacement.
How long will it take? Shell’s Sargeant says the company is confident in the performance of the fuel based on the 10 years of development and testing already invested. The hard work ahead is testing the fuel in real airplanes under a variety of conditions to convince regulators the fuel is safe and effective. Sargeant acknowledges there is much to do, but says Shell’s focus now is on the approval process and estimates that if all goes well the new fuel could be in the FBO network within 2 to 3 years.
How much will it cost? Shell’s Sargeant says it’s too early to know precisely what the new unleaded avgas will cost, but says it must be, and will be, competitive with 100LL prices. He said Shell knew from the beginning that a new fuel had to be price competitive and they would not have continued development if they didn’t believe they could achieve that goal.
The bottom line: Shell’s announcement has created a new urgency among fuel producers, fuel distributors and aviation regulators in the drive toward unleaded avgas. When one of the world’s major energy companies says it has an unleaded formula that works, it knows how to make the fuel in necessary volumes, and that the price will be competitive with 100LL all ears perk up. The way I look at it Shell has turned the situation upside down. Suddenly we have gone from a “prove you can do it” stance to a “prove you can’t do it” outlook.
The hard work now moves into endless meetings, actual flight testing, and negotiations with all players involved. We won’t know anything for sure for years even if the new fuel progresses toward certification and delivery as quickly as Shell hopes. But in aviation terms, 2 to 3 years to certify and deliver a new airplane or engine, much less a new fuel, is lightning speed. All we can do now is watch and wait.