I’ve been deep in the research for Hugh Ross’s war lately, and I keep finding details the memoirs mention only sidelong.
One is the smell. Hot castor oil, sweetish and persistent. It soaked into flying coats and scarves and followed a man from the aerodrome to the mess.
In the rotary engines of the Great War—the Gnome, the Le Rhône, the Clerget—the cylinders and crankcase spun with the propeller around a fixed crankshaft. Fuel passed through the crankcase, so the lubricant had to do its work without dissolving in petrol. Castor oil was well suited to the job.
One catch. The oil wasn’t collected and circulated again. It passed through the engine and out with the exhaust. Total-loss lubrication.
And where did the mist go? Some of it reached the pilot’s face.
Castor oil on the goggles was a nuisance. Castor oil in the mouth presented another problem: this was also the stuff the chemist sold as a purgative.
There are stories of pilots taking blackberry brandy to counter the effects. Those deserve a little more scrutiny before we stock Hugh’s mess with it. The engine’s appetite for oil is better documented than any particular pilot’s remedy.
But the detail belongs in an account of the flying: oil on the goggles, oil on the clothes, and the prospect of swallowing some of it throughout a patrol. Even when the engine was behaving perfectly, its lubricant could give a pilot something else to worry about.
The Flying Log, indeed.