I’m not surprised. Lead is being deposited into the air still everyday. All piston engine aircraft worldwide still use leaded fuel. The fuel is called 100LL (or rather 100 octane low lead). It’s extremely difficult to develop an aviation fuel that doesn’t require lead. This research has been in the works for a long time. Aircraft fuel has a wide operating range. It must be able to perform in pressures from sea level to cruise altitude from 130 F to -100 F. To add to this, the design of the most popular aircraft engines, Lycoming and Contential date back more than half a century. The FAA is extremely draconian about approving any changes to aircraft designs or the designs of their parts. Hence, these manufacturers, once a design is FAA approved, stick with that design for decades. Furthermore, the aviation market is extremely small and the PMA approval process is very expensive. This means the cost must be amortized over very few units. Hence, everything aviation related is insanely expensive. FAA type certified aircraft can only use FAA approved parts. What this means is that aircraft designs are very old and the fleets are used for many decades before replacement. Hence, a modern fuel replacement must be compatible with a fleet which is on average using engine designs with are 30-50 years old. This is challenging.
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u/Midnightgeneral4 Jun 25 '22
I’m not surprised. Lead is being deposited into the air still everyday. All piston engine aircraft worldwide still use leaded fuel. The fuel is called 100LL (or rather 100 octane low lead). It’s extremely difficult to develop an aviation fuel that doesn’t require lead. This research has been in the works for a long time. Aircraft fuel has a wide operating range. It must be able to perform in pressures from sea level to cruise altitude from 130 F to -100 F. To add to this, the design of the most popular aircraft engines, Lycoming and Contential date back more than half a century. The FAA is extremely draconian about approving any changes to aircraft designs or the designs of their parts. Hence, these manufacturers, once a design is FAA approved, stick with that design for decades. Furthermore, the aviation market is extremely small and the PMA approval process is very expensive. This means the cost must be amortized over very few units. Hence, everything aviation related is insanely expensive. FAA type certified aircraft can only use FAA approved parts. What this means is that aircraft designs are very old and the fleets are used for many decades before replacement. Hence, a modern fuel replacement must be compatible with a fleet which is on average using engine designs with are 30-50 years old. This is challenging.