F-35 at 20K, see's two enemy aircraft. What does he say? I CAN'T BREATHE!

An F-35 is cruising along at 20K feet spoiling for a fight and looking for the enemy.  What does he say?  I CAN'T BREATHE!

I'm being stupid but the sad reality is that the USAF has grounded F-35 flights at Luke AFB because pilots, in laymen's terms, can't breathe!  Check this out via Military.com

The Air Force has grounded all F-35 Joint Strike Fighters at Luke Air Force Base, Arizona, after pilots complained of hypoxia-related issues, officials said Friday.

"The 56th Fighter Wing at Luke Air Force Base, Arizona, canceled local flying operations today for F-35A Lightning II aircraft due to a series of five incidents in which pilots have experienced hypoxia-like symptoms," Air Force spokesman Capt. Mark Graff said in an email.

A total of 48 aircraft and 49 pilots are affected by the temporary stand-down, according to Maj. Rebecca Heyse, a spokeswoman for the base.

"Flying operations are planned to resume Monday, June 12," she said in an email.

The incident is "limited to Luke" at this time, meaning other bases aren't affected by the order, Graff said.

Why is this being limited to only one base and not suspending F-35 ops worldwide?