I love the smell of 100LL in the morning. Apologies to Colonel Kilgore. But my lot may be the last pilots who get to say it. Our KK runs on leaded fuel - 100LL and its soon going to be confined to the dustbin of history.
The History Lesson
Lead first went into petrol in the early 1920s, when a chap at General Motors found a dash of tetraethyl lead stopped engines pinking. By 1923 it was on the forecourt, sold as "Ethyl" because nobody fancied printing the word "lead" on the pump. They knew even then. Within a year the men brewing it were hallucinating, collapsing, dying, and the press christened it the looney gas. Nobody needs convincing lead's bad news. When I was small they stopped painting cots with the stuff, in the early days of will you think of the children.
Aviation, is where it earned its keep. The 100-octane that fed the Merlins in 1940 needed lead, and the very plant we're about to bury got its start blending anti-knock for wartime aero engines. War-winner to wind-down in one stroke.
Blame the Americans?
So why's it ending now, after years of "unleaded is the fuel of the future, and always will be"? The Americans have regulators and courts grinding away, good luck to them, but that's not what holds my attention. The bit that reaches Hertfordshire owes nothing to government. It's one factory.
Keep Calm and Carry on
The lead in 100LL is tetraethyl lead, and a single plant in the West still makes it. It sits on the Wirral and they plan to stop making it around 2028 to 2029, with just enough stock to limp blending to the 2030 sunset and no further. Read that again. Not 2030. Two years. Why not soldier on? Because the process is corrosive, poisonous work and the kit wears out, and nobody is going to reinvest in a product with its death certificate already printed. Lead is Bad. Shop elsewhere? Russia possibly still makes it, but good luck wiring the money. China makes some, but you wouldn't put it near an aero engine. No plan B.
Ban everything!!
We banned leaded petrol for cars at the millennium, so why are we still brewing the lead? Because aviation was let off. 100LL has always been the exception, legal lead in a clean world, kept in production largely for export long after the rest of us moved on. And its not the classic classic aircraft that are worried. A Sopwith Camel was sloshing castor oil and low-octane petrol decades before lead turned up, so it won't miss what it never needed.
Is KK off to the skip? I hope not. Nobody scrapped a 1963 Morris 1100 over fuel additives. It was the list of other issues. You ran unleaded, tipped in a bottle of Redex (other additives are available**), and maybe popped the engine out over a weekend to hardened the valve seats in your rivet counting classic car workshop dwelling mates workshop. job done. The catch for aircraft is the paperwork. A classic car driver brims the tank and goes. We get an STC for the exact engine, conformity papers, a placard at the filler, a flight-manual supplement, logbook entries, the lot. And regrinding valve seats on a certified aero engine costs more than a top-end refurb on a 1940s Bentley. On a Lycoming, mark you. An engine about as sophisticated as a ride-on mower: air-cooled, carburetted, four pots, a magneto off a wartime drawing board. Bolt on an airworthiness certificate and the bill takes off.
Electric Vegan Spitfire?
Which leaves the real flying thoroughbreds. Picture the new nightmare: a vegan Spitfire, low-lead, low-noise, burping llama breath over an airshow in 2033. Or we go the full F1, and you remember the fury when the grand prix lot swapped the screaming V10s for a noise like a fridge on the motorway. Do that to a Merlin and we'd all stand about calling it progress while quietly dying inside. None of it's happening. The new fuel is a full 100 octane on purpose, so the Merlin stays put and drinks from the same bowser. Same engine, same howl. The sound lives, the lead doesn't. The warbirds just wait longest for the sign-off, as the precious usually do.
Cold Start
The UK isn't starting cold, either. Unleaded already lives at some fields for the gentler engines. But "some fields, some engines" is a long way from "every pump, every aeroplane," and at the moment Elstree is not on that list.
So when do we start the change? No idea. This will be driven by supply. I'm not panicking. yet. But 2028 isn't someday. The writing's on the wall, in a factory in Cheshire, and I'd sooner read it early than get caught short on the line.
