(AP) — A Kansas-based medical transport service that has had three deadly helicopter crashes in Oklahoma since 2010 says it has advanced to a higher level of a voluntary federal safety program.

Wichita, Kan.-based EagleMed LLC announced Tuesday it has entered the second level of the Federal Aviation Administration’s Safety Management System. The company says it has been working with the FAA for more than 18 months on the process that is designed as a higher standard for safety in air medical transport services.

The company’s third deadly crash happened last month when a patient died after a medical helicopter crashed near the Choctaw National Health Care Center in Talihina in southeastern Oklahoma.

Two other double-fatality EagleMed helicopter crashes happened in Oklahoma City in February and near Kingfisher in 2010.