Secretary of State Antony Blinken switched planes in Zurich, Switzerland, on Wednesday after his original plane was grounded. 

He first boarded a Boeing C-40, which is part of the U.S. military service, but that aircraft suffered a critical failure related to an oxygen leak.  

A new plane was arranged for Blinken. The press pool traveling with him was advised to make commercial flight arrangements because the new aircraft was unable to accommodate journalists. 

Blinken was in Davos, Switzerland, this week to attend the World Economic Forum, a summit of government and business leaders.

Boeing has been the center of much controversy and scrutiny since the door plug of an Alaska Airlines flight detached midair, prompting the Federal Aviation Administration to temporarily ground Boeing 737 Max 9 airplanes operated in the U.S. or by U.S. airlines.

The FAA on Wednesday widened its probe into Boeing, saying it will pay special attention to the work of Spirit AeroSystems, a Wichita, Kansas, aerospace company that makes and installs plug doors for Boeing 737 Max 9 airplanes.

This is a developing story. Please check back for updates.