Watch the Trains Go By - S4-E19
Visible crew/equipment: As Carter and Newkirk are caught by the wire, the shadow of the camera pulling back is seen on the ground.
Visible crew/equipment: As Hogan and Carter approach the staff car, the crew and film equipment are reflected on the chrome of the lights and radiator.
Watch the Trains Go By - S4-E19
Visible crew/equipment: As Schultz stops the car, studio equipment is reflected in the windows.
Watch the Trains Go By - S4-E19
Visible crew/equipment: As Linkmeyer and Klink get in the car, a man in a white shirt can be seen moving around the camera position in the reflection on the car under her window.
Visible crew/equipment: As the car with the kidnapped Klink takes off, the Stalag 13 buildings are reflected in the windows, along with the camera equipment and lighting. (00:01:20)
Visible crew/equipment: As the two German officers come out of Klink's office and approach the radar truck after Kinch leaves, the shadow of the cameraman, the camera, and the camera tripod are plainly visible on the left side of the scene on the ground.
Visible crew/equipment: When the radar truck comes into the camp, as it slows, you can see the lighting rigs for the cameras.
Will the Real Colonel Klink Please Stand Up Against the Wall? - S4-E13
Visible crew/equipment: When Hogan opens the window, there is a reflection of the studio lighting on the top pane.
Watch the Trains Go By - S4-E19
Visible crew/equipment: When Klink is by the fence acting busy and talking to Schultz, twice you can see the shadow of the camera on Klink's overcoat.
Never Play Cards with Strangers - S4-E7
Visible crew/equipment: As Hogan takes off with Von Treger's car, the camera crew and equipment are reflected in the windows.
Answer: The core POWs regularly escaped the prison camp but they made it their mission to conduct espionage and commit sabotage in the surrounding German territory. They also collaborated with different underground resistance groups and used a network of secret tunnels to help prisoners from other POW camps to escape, who then relayed vital information back to the Allied forces. Hogan and his men maintained the illusion that Stalag 13 had never had any prisoners escape in order to avoid their covert operations being shut down. Being that the prison camp is set in Germany during WWII, there were no American embassies.
raywest
Hogan has mentioned to different characters that they are actually stationed at Stalag 13 to help allied soldiers and prisoners from other Stalags to escape Germany.