Continental has submitted a formal application to the FAA, that if approved, would authorize the use of unleaded aviation gasoline in more than 100 engine models, including select O-200s, IO-360s, O-470s, and IO-470s.
As the industry searches for a long-term unleaded fuel solution, Continental officials said they consider 91UL and 94UL fuel “as a transitional step in a long-term strategy to reach a more sustainable aviation,” company officials said.
“While Continental offers Jet-A engines that utilize readily available heavy fuels, the majority of Continental aviators are flying behind an engine fueled by a lead avgas like 100LL,” said Dr. David Dörner, vice president of global research and development. “If we want the future generations of aviators to enjoy the beauty of flight, it is imperative that the industry collaboratively evaluate alternatives and identify viable solutions. Unfortunately, not everyone has access to quality fuels, but by expanding fuel sources, aviators can choose to fly while being more environmentally responsible.”
Continental officials noted the company prioritized this group of engine models to conduct an extensive review on the impacts of alternative fuels in lower compression ratio engines. This performance study, held in conjunction with the Eliminate Aviation Gasoline Lead Emissions’ (EAGLE) initiative, verified that the these engines perform as designed with the lower octane fuels.
Company officials added that testing includes other engine models and they anticipate additional approvals in the future.
A 250% Increase in R&D
The latest initiative is part of a pledge by Continental officials to increase its funding for research and development by 250% compared to previous years.
“While Continental has made great progress in recent years to continuously innovate our piston engines and engine components, we are ready to accelerate the R&D dedicated to future technological advances in our industry,” said Karen Hong, CEO and president. “By investing the time and resources now, we are also preparing for the future of general aviation, which could look vastly different from today.”
Continental’s investment plans focus on current avgas and Jet-A piston engine applications, future engine designs and applications, and sustainable/alternative fuels.
Even though this financial commitment is for 2023, the company is already executing the accelerated multi-year R&D approach, officials noted.
For example, Continental announced the Time Between Replacement (TBR) extension for the CD-300 earlier this year.
“This was achieved through countless hours of testing and analysis and is one of the types of continuous improvements that customers can expect to see more of from Continental’s engineering group that solidifies Continental’s position as the first choice in GA power,” said Dörner.
As an Automotive Mechanic with 51 years experience and a private pilot for the last 32 years………. I have yet to have read or seen in any of the latest articles regarding “getting the lead out’………. as to .what is being used as the “lead’ substitute. Lead has multiple uses in fuel. The one Im most concerned with is damage to exhaust valve seats in the cylinder heads. This was a very common problem in the automotive industry when lead was removed in 1996. It doesn’t occur immediately…..but will occur with time. When i see 150hour tests using the new AV Gas with no engine damage……………….I laugh! Give me the data at 1500- 1700 hours……………….along with using this fuel in engines that have already logged in 1500 hours existing.The majority of the GA Fleet are planes 30-60 years old ……….they don’t have hardened valves seats . Engine rebuilds are 40-50k on the most common Lycoming. I will wait for ‘someone’ to step forward and shed light on this for me.
Paul Milner explains what is in the G100ul in a youtube video.
https://www.youtube.com/watch?v=6h9gYND3xFo
It is essentially a formulation using Xylene vs Toluene to get the octane rating. .
Furthermore, -and I confess to not being the sharpest knife in the drawer…but logically it seems a further refinement of a current premium auto gas for aircraft could come quicker and easier than developing a whole new fuel. No?
Straight run gasoline has an octane rating of about 70, and is then catalytic reformed to get about 90 octane. This is ok for most low compression aircraft engines.
But an ‘octane booster’ has to be added to get to 100/130 octane….using TEL or alcohol. MTBE was used for a few years in auto gas until it was found to contaminate ground water if tanks leaked.
So, the two, formulated 100 octane avgas products proposed would be great for all aircraft engines.
Why is the unleaded aviation fuel developed by GAMI in Ada, Oklahoma over the last 10 years not sharing in this movement forward during the interim before the Eagle initiative is concluded, perhaps, in another 10 years. The looser for not moving forward with this fuel is our environment. This fuel has been 100% tested, met all the requirements established by the program, and proven to operate as a successful substitute for 100 LL on practically all of the internal combustion piston engines currently in service. It is a travesty for not utilizing this fuel program, at least in combination with others, right away. I fail to see why this approval has not already been endorsed. I have no horse in this race as I utilize ethanol free fuel in my aviation engine via an STC. However, I would like to have the option of utilizing this fuel on a cross country trip.
A-Gree!