It is 1928. With questionable judgement, the parents of an eleven year old girl are letting her fly to see her grandfather - in a mailplane, in the mail bin, with no seat, no belts, no chute - rather than take the train. For reasons best known to themselves, the pilot and flight ops manager decide to go along with this, though they're aware that her route is the riskiest of their line. Needless to say, something goes wrong, and a forced landing ensues which wrecks the airplane beyond any repair and leaves one person injured. To complicate matters, the pilot had (for good enough reason, or so it seemed) deviated from the usual route and has gone down in mountain terrain, in the American west, in winter. Barring early rescue, (highly unlikely), we know that these twos' life spans can be measured in days.
What a splendid plot to build a book around! A shame that Gann doesn't. Instead, we have such inessentials as a pilot with Lester's face and Dan Roman's tragic past, a one-legged Gafferty from "Blaze of Noon," a timid, self-centered pilot who puts his own safety ahead of others' survival, etc, etc. We really learn little about pilot Jerry, and though he comes across neither as the fictional Dooley or the real-life O'Connor, he's a man we could clearly learn much from. Even more from 11 year old Heather. Alas, we end knowing less about her than the one-legged Moravia.
Given the contacts Gann had in the flying world, it's entirely possible that this story is based on truth. If so, here's hoping we read it someday.