https://www.defensenews.com/air/2019/06/12/supersonic-speeds-could-cause-big-problems-for-the-f-35s-stealth-coating/
Supersonic speeds could cause big problems for the F-35′s stealth coating
For example, an F-35C can only fly at Mach 1.3 in afterburner for 50 cumulative seconds, meaning that a pilot cannot clock 50 seconds at that speed, slow down for a couple seconds and then speed back up. However, the time requirements reset after the pilot operates at military power — an engine power setting that allows for less speed and thrust than afterburner — for a duration of three minutes.
The F-35B can fly for 80 cumulative seconds at Mach 1.2 or 40 seconds at Mach 1.3 without risking damage.
But for both the C and B models, flying at Mach 1.3 over the specified time limits poses the risk of inducing structural damage to the aircraft’s horizontal stabilizer.
It is infeasible for the Navy or Marine Corps to operate the F-35 against a near-peer threat under such restrictions, the documents acknowledge.
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F-35C : 마하1.3에서 50초.
F-35B : 마히1.3에서 40초.
애프터버너 가동후 3분간 밀추력으로 비행해야 다시 애프터버너 가동할수 있음.
이 문제 때문에 보고서에는 F-35B/C가 러시아나 중국의 주력기와 공중전이 어렵다고 인정.