"The Great Oil Sniffer Hoax was a 1979 scandal involving French oil company Elf Aquitaine. The company spent millions of dollars to develop a new gravity wave-based oil detection system, which was later revealed to be a scam. Elf lost over $150 million to the hoax. In France, the scandal is known as the "Avions Renifleurs" ("Sniffer Aircraft")."
https://en.m.wikipedia.org/wiki/Great_Oil_Sniffer_Hoax
"The Great Oil Sniffer Hoax was a 1979 scandal involving French oil company Elf Aquitaine. The company spent millions of dollars to develop a new gravity wave-based oil detection system, which was later revealed to be a scam. Elf lost over $150 million to the hoax. In France, the scandal is known as the "Avions Renifleurs" ("Sniffer Aircraft")."