Wiktionary
on a wing and a prayer
phr. Describing a situation in which only a partially functioning system is preventing disaster, but the people involved are hoping for the best
Wikipedia
On a Wing and a Prayer
On a Wing and a Prayer is the seventh studio album by Gerry Rafferty. He asked his friend Joe Egan to collaborate on some of the album's songs, some of which were new renditions of Stealers Wheel-era songs. The album was heavily influenced by Rafferty's divorce from his wife Carla Ventilla in 1990. They were married for 20 years.