From The Internet Movie Plane Database
Joan Fontaine (Eve Graham)
Ida Lupino (Phyllis Martin)
Edmond O'Brien (Harry Graham / Harrison Graham)
Edmund Gwenn (Mr. Jordan)
Harry and Eve Graham are trying to adopt a baby. The head of the adoption agency senses that Harry is keeping a secret and does some investigating.
Flight between Los Angeles and San Francisco, with a Douglas DC-6 of United Airlines.
Seems unreal, maybe a scale model?