Guys,
Further to my last on 17 Dec (Thanks Courtney!),
Having quickly looked at the arresting gear Mil Spec, I can't find a specific gear/hook distance requirement. There are a zillion other parameters there for various angles, clearances, etc., and the F-35C hook, as far as I remember, meets those.
I can confirm that the team designing the hook (which is LO - it retracts under a complex set of covers) were certainly fully aware of all the various specs. They had a couple of goes at getting a hook that did that, and one of the redesigns addressed a problem you can see on the Crusader picture (nice pic) which shows an effect called 'wheelbarrowing', where the hook is too low down on the aircraft. When it engages the wire, the effect is to pull up on the fuselage, lifting the mains off the deck, and leaving the aircraft sitting unstably on its front leg. The first hook design sat it too low, so a redesigned mounting yoke system was then used.
The hook system design was also exhaustively checked by the US Navy NAVAIR engineering and flying specialists before it was approved for manufacture.
THe USN specs are largely empirical and actually reflect the experience gained on aircraft like the F-7U and F-8U. By the way, the Cutlass landings were on a straight deck, and they had up to 12 wires at one stage to make sure they caught a wire - the options weren't too goog if they didn't.
The lesson here (sorry if I sound a bit schoolmasterish) is that getting 'cat and trap' to work with large high performance combat aircraft is really, really difficult. The USN make it look easy because they are damned good at it. It's also risky and takes a high degree of skill to do even when you get the kit right. I wonder whether our lords and masters really understood all that when they went for the C. (John Farley would have plenty to say on this, I'm sure). I'm not saying it's a wrong decision, we just need to get our heads around the reality of it. This thread is really helping to do that.
Best Regards as ever to all those on land and sea and air who are doing the job for real,
Engines