Check this out:
http://www.pprune.org/military-aircr...ml#post8180517 [The amiable Butler quote]
AND... I'll look for more which
AFAIK explains further why the INTERIM testing of the INTERIM design of the new hook design is what it is. But wait we have covered that already.
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I'll assume that proper hook testing on the 'finished' hook system will look like this from Dec onwards? Probably this info posted already but worth repeating.... I'll look forward to future reports on the F-35C testing from VX-23 or anyone interested.
Naval Air Museum Association
The Kneeboard Mag'n Spring
2012
Unnatural Acts of Landing Patuxent River
“For most people, the idea of flight testing means seeing how fast an airplane can go or how quickly it can maneuver. While answering these questions may be part of a flight test program, there is more to flight testing than speed and agility. Navy carrier aircraft must also withstand the stressful loads of repeated arrested landings (traps) that can exceed 6 Gs on the aircraft.
The landing gear must:
- Survive thousands of landing shocks
- Reduce the loads reaching the aircraft structures and crew
- Allow the pilot to stay in control of the aircraft’s behavior
Ground Loads Testing shows that an aircraft structure can withstand carrier operations at maximum takeoff and landing weights. Normal landings at these conditions are no problem. But testing must also show that an aircraft can absorb these loads when:
- Its sink rate (how fast it descends) is high (as much as 26 feet per second!)
- Its wings are not level when it lands
- Its tailhook catches an arresting cable to the side of the center line
- The carrier deck pitches and heaves...
...During Super Hornet development, Ground Loads Testing required 125 test flights, 370 catapult launches, 471 traps, & 3 years to complete. Incidents included blown tires & various airplane parts (other than the wheels & tailhook) hitting the deck."
http://api.ning.com/files/8OBnZkm85r...Spring2012.pdf (0.8Mb)
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More?....
Lockheed’s comprehensive Q&A on the F-35 By Philip Ewing, June 19th,
2012
"...Q: All right, we’ve talked about the helmet & the software. What about the C’s tailhook redesign?
A: Here’s what O’Bryan said: “The distance between the main landing gear and the tailhook on the F-35C is the shortest of any naval aviation carrier airplane that we’ve had. Because we have to hide the hook — because if you had a hook exposed you wouldn’t be as stealthy airplane, that distance is tighter than any other. So it means when you roll over the wire when you land on the deck, the wire goes flush to the deck, and then you have to pick that wire up as it’s generally on the deck. So what we’ve had to do is re-design the hook shank.
Every airplane’s hook shank — as you’d imagine, you ground those things down, dragging it around, so it’s a remove-and-replace kind of thing. It has a bolt through the back of it and it holds on to the hook and we’ve redesigned that to have a lower center of gravity, or in a more mundane way, to make it a sharper hook point. And that allows us to pick up the wire. And we’ve already done testing on that. We’ve done it at 80, 90 and 100 knots and we’ve got a good design for the hook point now.
The other thing we need to do is, we need to make sure that the hook stays flush on the deck. So what you don’t want — and I was a Navy pilot, so I apologize if I’m using a lot of vernacular here – you want to keep that hook on the deck so it doesn’t bounce, or the words we used was skip. It can do that a couple different ways. It can move laterally and it can hit other stuff and just bounce, if you will. Another technical term. So what we’ve done is we’re going to modify what’s called the hold-down damper, kind of a good name for a thing because it does exactly that, it holds the hooks down, it dampens any oscillation. We’ll increase pressure on hook to do that.
The whole thing is a remove-and-replace assembly so any modifications we make to it is an easy fix.”"
http://www.dodbuzz.com/2012/06/19/lo...a-on-the-f-35/
&
The day of the unmanned aircraft. Dave Majumdar 15 May 2013
“...The X-47B guys have had to redesign their tail hook a number of times now due to the same inaccurate Navy-supplied wire dynamics model that was partly responsible for the F-35C's woes....”
The day of the unmanned aircraft. - The DEW Line