F-35 fighter jets have been grounded in Arizona for the second time this month.
One day after F-35s resumed flights at Luke Air Force Base in Glendale, they were canceled at the Marine Corps Air Station in Yuma.
The Air Force and Marines fly different F-35 models, both made by Lockheed Martin.
Flights temporarily stopped at Luke after pilots reported symptoms related to oxygen deprivation.
The Marine Corps grounded the jets in Yuma so crews can repair a software update to a ground-based system that military officials call the IT backbone of the F-35.
The Marine Corps said the jet is safe, but the software has to be fixed before flights can resume. Engineers are working around the clock to find a solution.
