Inflight letter
The Rahway, N.J. address suggests a New York or Newark departure and the postmark leaves little doubt about the destination.  The timetable from three months prior lists those flights with DC-4 equipment, which is consistent with Mrs. Rader's mention of the "navigator", not the flight engineer.  She evidently enjoyed her lunch and was treated very well.   One-class service on these schedules: Aircoach.