You are reading the second book of the Saskia Brandt series. It may be read as a standalone novel, but it will spoil aspects of the first book, Déjà Vu. If you intend to read Déjà Vu at all, I recommend reading it first.
The second of the two aeroplanes described in this book—British South American Airways’ Star Dust—was real. It did indeed disappear in August, 1947, on a daytime trans-Andean flight between Buenos Aires and Santiago. The aircraft was well maintained; the crew was experienced and capable; weather conditions were good. Its last transmission was a single word that the radio operator keyed fast and clear, twice: ‘STENDEC’. I have cast my story with the actual people involved in that flight: BSAA staff, the crew of the Star Dust, and her passengers.
DFU323 is entirely fictional.