[2] They were the largest nuclear weapons ever put into service by the United States; only the Convair B-36 Peacemaker was capable of carrying them.

With the addition of in-flight insertion of the primary capsule to prevent a nuclear explosion in case of an accident, the weapons were upgraded to the Mod 1 standard.

On May 27, 1957 a Mark 17 was unintentionally jettisoned from a Convair B-36 Peacemaker just south of Albuquerque, New Mexico's Kirtland AFB.

The device fell through the closed bomb bay doors of the bomber, which was approaching Kirtland at an altitude of 520 metres (1,700 ft).

[5] Though a chain reaction was impossible because the plutonium pits were stored separately on the plane as a safety measure, the incident spread radioactive contamination and debris over a 1-mile-wide (1.6 km) area.