Glad, Courtney and others,
Please be as sceptical as you wish - open forum and all that. I don't 'always' cover things - if I don't know, i say so. Or try to.Sorry if I'm not clear enough sometimes.
Deck coefficient of friction is well understood and the expected values are known. The USN have always had much better deck coatings than the UK, at higher cost. The question of mu has been addressed - in that the team know what it should be if the coatings go on as per spec. And they know what the F-35B landing gear will produce. It's been tested - like most everything else.
A small point of clarification - I was on the deck of Invincible when the Sea Harrier went over the side. Wasn't all about mu. Here are the facts - be as sceptical as you want.
The aircraft was on the runway about to launch against a suspected incoming threat. (So no lashings fitted). Fully loaded. The ship had to manoeuvre quickly to get on to the flying course, and went hard starboard in a biggish sea. We started heeling over to port. Quickly. The angle of heel was somewhere around 10 to 15 degrees - possibly a bit more. Lots. Enough to get everyone on deck grabbing for something to hold on. High wind also from starboard, coming round on to the bow.
It was at this point that the FAA learned something about the Harrier nose leg not covered in any of the manuals. It had a break out design so that excessive side forces weren't fed into the airframe. So, even though it was centred for launch, as the side loads came on it suddenly (and I mean suddenly) castored, allowing the aircraft to (very quickly) rotate around the main wheel assembly to port. Deck was still heeling over to port.
This was the point at which mu came into play. The flight deck was, by this time, fairly dirty and slick. (We had no effective deck scrubbing kit at that time). So, as the aircraft nose wheel went over the side of the deck, there was very little to stop the aircraft sliding to port and simply jumping over the side, clearing the catwalk as it went. Pilot ejected at around 45 degrees nose down, recovered by a Sea King that was standing off waiting to recover. (Good work in hefty seas by the way).
Lessons learned very quickly:
1. Get the deck scrubbed and keep scrubbing. An old FAA routine that we had forgotten through not doing carrier aviation for a few years. Deck scrubbing machines were procured immediately and are still in constant use.
2. Restrict ship manoeuvring when aircraft not tied down on deck. See above.
3. Stuff happens in war.
It should (but probably won't) go without saying that the F-35B's landing gear is massively better for deck work than the Sea Harrier's somewhat 'hokey' 1950s style bicycle layout. Brakes that work, and a stable tricycle layout. Moreover, QEC will not move around at anything like the amount the CVs did.
But are there risks in SSLs? Sure there are. The team are working those with all the techniques at their disposal. Deck trials will be the final proof. But they won't even take place unless the teams have wrung out all the data as far as they can first. The fact that they are still going forward with SSLs should tell us that they haven't found a 'stopper' yet.
I hope this stuff helps a little. I'll now desist further posts on this subject, as I think I'm at the point when I'll start repeating myself. And few will listen - I don't blame them.
Best Regards as ever to those who have actually worked on seagoing STOVL and have the knowledge
Engines