Black & White Drama late 60's-70's

Saw movie in 70’s about a couple and pilot on plane that crashed and landed in unknown town. Woman found a glass wall that was surrounding the town and started to dig to try to get under the glass to escape. She may have been pregnant and had a baby. She was blonde/light hair.

Check out The Bubble (1966)
It has the same scenario, light plane crash with young expectant couple.
Science fiction movie starring Michael Cole (Mod Squad) and Deborah Walley.