Canadian Manufacturing

Shell becomes first firm to remove lead from light aircraft fuel

Regulatory approval process now underway to bring lead-free Avgas to market, according to Shell

December 3, 2013  by Canadian Manufacturing Daily Staff

LONDON—Shell said its aviation division has developed a lead-free fuel for aviation gasoline (Avgas), making the firm the first major oil company to do so.

A regulatory approval process is now underway to bring to market a replacement for one of the last common transportation fuels to contain lead.

According to Shell, its researchers have been working on the lead-free Avgas for the last 10 years, the product spent the last two months undergoing testing by a pair of original equipment manufacturers working in the light aircraft and helicopter industries.

“We believe that with industry support, a stringent approvals process can be completed for this new lead-free product within a short time-frame,” Shell Aviation vice-president Xinsheng Zhang said in a statement.


Avgas currently includes lead in its formulation to meet fuel specifications and boost combustion performance (known as Motor Octane rating).

Shell said it has developed an unleaded Avgas that meets all key Avgas properties and that has a Motor Octane rating of over 100, an industry standard.

To get to this stage, Shell Aviation technologists carried out an intensive internal laboratory program, including in-house altitude rig and engine testing.

Working alliances were then formed with aviation engine manufacturer Lycoming Engines and light aircraft manufacturer Piper Aircraft Inc. in order to test the fuel outside of the Shell labs.

“Piper Aircraft is pleased to participate with Shell and Lycoming in this feasibility flight test program,” said Piper vice-president of engineering Jack Mill.

“Recently, we successfully flew an experimental non-production Piper Saratoga with Shell’s new formulation for about an hour. We appreciate the opportunity to work with Shell and Lycoming in this preliminary investigation of the technologies, which could in several years lead to flying unleaded fuel in our production airplanes.”

Shell will now engage the aviation industry, regulators and authorities, including the U.S Federal Aviation Administration, American Society for Testing and Materials (ASTM) and European Aviation Safety Agency (EASA) to achieve approvals for the unleaded Avgas.

Shell expects to also work with other OEMs to continue the testing and refinement program as the approvals process progresses.

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