This is the second of two episodes of the 168 in which Newkirk does not appear (with actor Stewart Moss standing in for him here). The other is The Crittendon Plan (1967).
General Burkhalter (Leon Askin) and Colonel Leman (John Doucette) talk about the Albatross crew practicing for the first actual attack on Royal Air Force (RAF) airplanes on "the 12th" in honor of Herman Goering's birthday. Herman Goering was born January 12, 1893. This would place the date of this episode no later than January 1944 (prior to D-Day).
The exterior nighttime shot of the German airbase (at about 21 mins) is used again in Sergeant Schultz Meets Mata Hari (1967).
The exterior nighttime shot of the German airbase (at about 21 minutes) is used again in Sergeant Schultz Meets Mata Hari (1967).