Contrail, born Conway Trails, is an earth pony that designs and pilots his own flying machines.
 
He is the son of father Narrow Path (born Happy Trails) and mother Phoebe. He was raised in a fundamentalist earth pony community that shunned magic and technology. Phoebe was Narrow Path’s third wife, as the men of this community were quite polygamous and oppressive in their patriarchy. As it turns out, Phoebe was a Pegasus whose wings were lost in an magical mishap at the university she once worked at as a published astronomer. In her depression at being grounded, she found the abuse at the hooves of a bunch of misogynists to be well-deserved. Conway was her only child foal with Narrow Path, and at first she had felt guilty about bringing a foal into her sad little part of the world. But when she found her son trying to teach himself to fly, she made it her goal to get him away from that dour place. When he became the age to take up the esoterica of his community, he ran away from home with his forbidden colt-friend Knave.
 
From then on, he would go by the name Contrail. Out in the world, he searched for earth ponies that shared his ideas for flying machines and those that would be willing to sponsor his ventures. Through these years and adventures with his colt-friend, they eventually ended up in Ponyville. While Knave began dating the mail-pony (Knave and Conny are still great friends with benefits), Contrail set to making his workshop in an abandoned barn. This bit of land was acquired with help from the Apple family under the promise that Contrail would use a cider-based fuel for his aircraft, an idea he had hammered out long ago with his early interaction with engineers and mechanics he came to know. His first flight, while not the first for pony-kind, was a proud moment for him and his self-designed aeroplanes.
 
It wasn’t long until other earth ponies and unicorns would join him in Ponyville, bringing their own ideas, capital, and labor to turn the shabby farm into a respectable bit of tarmac and hangar space. One of the these ponies, a native balloonist by the name Cherry Berry, became Contrail’s most dedicated protégé. So close, in fact, that they eventually fell in love and had a foal. Currently, they are comanaging a courier and taxi line that plans to begin expanding outside of Equestria. On the side, Conny spends his time working with skilled engine mechanics on challenging the limits of speed and altitude with jet propulsion and rockets, while Cherry focuses on versatility with trying airframes from designs that focus on distance and endurance. A lot of their work puts the pair into harrowing situations. But in the end they are always there to clean, set and heavily bandage each others wounds.
 

 
The aircraft in the background is based on a Lockheed Vega. It might look more advanced than the current flight technology in Equestria, but really it’s quite simple in overall engineering on the inside. As for what these two are actually discussing in the image, it’s probably what kind of debauchery they’re going to get into after they get home ;3