Cry Terror!

Cry Terror is a 1958 thriller film starring James Mason, Inger Stevens, and Rod Steiger.

Paul Hoplin is mastermind of a crime to collect a 500,000 ransom, threatening to use an explosive device that Jim Molner designed. He and his gang are holding Molner, wife Joan and young daughter Patty hostage.FBI agents gather in New York with representatives of an airline. Hoplin has been sending anonymous notes, suggesting that a bomb will be planted on a plane. Joan Molner is forced to go alone to collect the ransom payment, while Hoplins accomplices, a woman named Kelly and a man named Vince, watch her husband and child in a Brooklyn penthouse apartment. ........

Source: Wikipedia