From a distance, N73FR looks like any other 20-something-year-old Skyhawk. Upon closer inspection, the differences loom large. What’s a constant-speed, three-blade prop doing on a 172? And isn’t that exhaust pipe a little skinnier than normal? A couple of other differences are apparent, such as the cowling-mounted inspection port for gearbox lubricant and new fuel-filler caps next to placards calling for Jet A. And the thing smells…oily, like kerosene, not the sweet scent of avgas.

…