The Wings of Time Vol 2 - Frederic Zumbiehl, Patrice Buendia

Duncan and Lucie, marooned in 1917, are determined to return to their own time. While Lucie poses as her own great-great-aunt and attempts to find out what happened to them, Dunc joins the Lafayette Squadron, a unit of American volunteers, in hope of finding a plane suited to using the experimental device that pulled them into the past. But this is the time of the Red Baron, and the skies of France are deadly to Allied pilots...