Some of Their Planes Are Missing - S3-E2
Visible crew/equipment: When LeBeau, Carter and Schultz enter the visiting Germans' quarters, when the door is open you can see the sound stage floorboards are uneven in front of the door to the neighbouring barracks.
Some of Their Planes Are Missing - S3-E2
Continuity mistake: Though six planes were supposed to be destroyed, only two were visible or bombed. At the fade out, the two planes blowing up were a reversed, re-used shot.
Some of Their Planes Are Missing - S3-E2
Continuity mistake: After getting out of the tunnel, Hogan, Carter, and Le Beau are in a truck travelling to the meeting. Hogan in in the right seat, Carter on the left. But as the pull up to the meeting, they have switched sides, Hogan on the left and Carter on the right.
Some of Their Planes Are Missing - S3-E2
Continuity mistake: In the tunnel, Le Beau picks up some darts and tosses one with green feathers at the target. When the camera looks at the target (a picture of Hitler) a blue winged dart hits the board.
Some of Their Planes Are Missing - S3-E2
Other mistake: While Carter starts shining boots, the disturbed stage flooring can be seen in front of the opposite building; the joint between the panels is markedly raised.
Some of Their Planes Are Missing - S3-E2
Continuity mistake: As the boys trade candy bars and Schultz reaches in, Hogan stops everything and his left hand is up with a bar in it, his right hand empty. A second later, his left is down, and the bar has jumped to his right hand.
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.