Phase 1 testing of four possible replacements for 100LL begins this month at the FAA’s William J. Hughes Technical Center in Atlantic City.
The four unleaded fuels — one from Shell, one from TOTAL, and two from Swift Fuels — will undergo laboratory and rig testing to analyze a number of factors, including materials compatibility issues with aircraft components, such as fuel bladders, fuel gauges, pumps and more.
“They will circulate the fuel through and see if there is any deterioration under varying temperatures and conditions,” said Rob Hackman, vice president of regulatory affairs for the Aircraft Owners and Pilots Association. “They will be using multiple rigs and multiple runs.”
AOPA is part of the Piston Aviation Fuels Initiative (PAFI), a joint industry-government effort to oversee the development and distribution of a new unleaded avgas. In addition to AOPA and the FAA, the PAFI steering group includes the American Petroleum Institute, the Experimental Aircraft Association, the General Aviation Manufacturers Association, the National Air Transportation Association, and the National Business Aviation Association.
Phase 1 of the program is expected to take about a year, at which point the FAA will evaluate the fuels for continued participation in Phase 2 of the test program, according to FAA officials.
Agency officials estimate that two or three of the Phase 1 fuels will be selected for the Phase 2 engine and aircraft test program. That test program is expected to take approximately two years, and will generate data that can be used to obtain an ASTM Production Specification for the fuels, and to certify most of the existing fleet to operate on these fuels, FAA officials said.
AOPA’s Hackman explained that the testing is not a research program, but more of a certification program to ensure the fuels will work in the existing aircraft fleet of about 167,000 piston aircraft.
“The FAA is working towards generating data for the transition of the existing fleet to unleaded fuel,” he said.
He added that PAFI and the FAA are aiming for “as transparent” a transition as possible, with as little impact on individual aircraft owners as possible.
“A big part of what is being tested is the ability to co-mingle the new fuels with 100LL,” he said. “We’re not anticipating that we’ll turn off 100LL one day and be pumping a new fuel the next day.”
But before that day comes, aircraft owners and pilots can be assured that the resulting fuel — or fuels — will be safe.
“We’re not looking for people to be test pilots when this hits the market,” he said. “That’s why we have this multi-year test program to ensure safety.”
In fact, he said, aircraft owners and pilots would be impressed if they could see the level of scrutiny the fuels are being put through.
“The amount of preparation and coordination between the industry and the FAA is staggering,” he said, noting just to determine what would be included in the rig testing was “staggering, amounting to pages and pages and pages of documents.”
“There is an amazing breadth and indepthness just in Phase 1,” he added.
He notes that the “robust” testing plan now in place has given aircraft owners a measure of comfort.
“There was a significant amount of questions and concerns prior to the establishment of the program,” he said.
That uncertainty even had some questioning whether to buy an aircraft, with concerns that there wouldn’t be an acceptable unleaded fuel available. But those fears seem to be allayed now that the testing program has begun.
“The goal is that anybody who buys an airplane today will have fuel to fly it with as little impact as possible,” he said.
And while some in the GA community still bristle at the thought of giving up 100LL — the only leaded fuel still used today — those in the industry say that when all is said and done, it will be a good thing for everyone.
Engine manufacturers and others point out that going to an unleaded fuel will actually make our engines run better, with no lead fouling and build-up.
Others note that the lead component added to the fuel — Tetra Ethyl Lead (TEL) — has been banned in many countries. Additionally, it is produced by only one company, Innospec, creating a different concern that the company could discontinue making it.
“There are a host of reasons for going to unleaded fuel — not to mention the PR aspects,” Hackman said. “The last thing general aviation needs is another reason to give the anti-airport people to hold against us.”
The two-phase testing program initiated by the FAA this week after years of preparation has been funded by Congress to the tune of about $6 million a year.
And even as the FAA begins it testing, the fuel companies continue their own testing and research, which has been going on for some companies for more than a decade (See additional story on Shell’s efforts).
Once the FAA completes its testing and the winning fuel given the OK, most expect it will be introduced to the market soon after.
“The companies will want to get it to market to begin to recoup their costs,” Hackman noted.