Re: There's an old saying.....
If the engines are Pratt & Whitney the seat better be Martin Baker.
I wasn't aware of the saying, or the justification for it, if any: but the fact is, there's only one engine. ISTR some Candian idiot (=politician) being asked a few years back, during controversy over that country's deeply incompetent F-35 acquisition process*¹, what he thought about an eyewateringly expensive single-engined fighter experiencing an engine failure in the far north—his response: "It won't." Facepalm, anyone?
I'd be particularly concerned about the F-35B, with its fearsomely complicated gearing and transmission for the lift fan (which is deadweight and wasted space for 99% of the mission), which has to reliably transfer enormous horsepower in the most testing conditions of temperature and stress at the most critical times (landing on a flight deck already a-gaggle with birds swilling with fuel and laden with ordnance).
Despite their (absurdly premature) declaration of initial operational status, the US Marine Corps may be the best hope for the RN not to have an early tragedy on one of its carriers: with luck, USMC will get the bad news before we do, and some kind of risk mitigation can be put in place. (Though what that will be, considering our government was too stupid to specify CATOBAR carriers, I just don't know.)
Either way, it would be embarrassing to put one of our carriers out of action even before it's seen the full 24 hours of life expectancy it can hope for in a war involving anyone who has subs and/or anti-ship missiles. (Lousy planes + too few escorts = carriers fit only for Third World ADPTO*² missions. There's nothing like a £275,000 strike resulting in the write-off of one rusty SUV and a cannabis-steeped goat-fondler.)
*¹ Yes, I accept that any procurement which results in an F-35 purchase must by definition be incompetent, but even so ...
*² Do try to keep up with the military terminology: ADPTO = Anti-Datsun-Pickup-Truck Operations. A very important component of the Global War on Terror™