Orla Twombley was born in Dun Laoghaire in 990 TE. She watched dare devil airships performing stunts over the sea. After having an arguement with her parents she fled the raft city on an airship. After a few years of learning how to be an aviatrix she became captain of the tea-clipper Cygnet Committee. In the same year the Green Storm began their war against the tractionists. When several Green Storm airships attacked the Cygnet Committee over Perfume Harbour she destroyed them with the Combat Wombat she had bought earlier. With the money that the Cygnet Committee gave her she left the air trade and joined the Junkyard Angels. During her time with the Junkyard Angels she shot down three Air Destroyers of the Green Storm. She then left the Junkyard Angels and formed her own air force; the Flying Ferrets.
When Wren and Fishcake are captured, Orla and the Flying Ferrets have been hired for defence by the raft city. At one point she and the Flying Ferrets try to stop Wren and Theo from stealing an airship, but Boo Boo Pennyroyal pretends that they were going to go to another raft city for her in order to save them. She and the Flying Ferrets fight in the Battle of Brighton. She takes down several Green Storm ships before she and the surviving Ferrets are forced to flee.
In A Darkling Plain she is helping the Traktionstadtsgesellschaft. She fights the Green Storm but doesn't fire upon the escape pods. When Manchester is destroyed by ODIN she turns back and said that they have lost.
After the war ended she, and some surviving Flying Ferrets remained in now static Murnau, patrolling the surrounding lands and helping Kriegsmarshal Von Kobold protect his lands from remaining predator cities.