Forum: F-35 milestones

That looks like the hook point is closer to the main gear then the F-35 and it also looks to work just fine. I think LM have this issue under control.

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Screengrab of old hook from old video here:

X-47B UCAS Flight Test Highlights -- Summer 2011

http://www.youtube.com/watch?v=0Oq4qah5LQ0

"Uploaded by northropgrummanmedia on Sep 29, 2011
Two minute review of recent flight test activities for U.S. Navy's X-47B Unmanned Combat Air System demonstration aircraft at Edwards AFB, Calif. The X-47B was designed, developed and produced by Northrop Grumman, the leader in unmanned systems."

Tailhook redesign better, but not there yet:

"Bogdan said the program also had work to do on the F-35C-model being developed for use on board Navy aircraft carriers. He said a reworked tailhook system succeeded only five of eight times during flight tests earlier this year, but said he was confident that the issue would be fixed.
"That one is not rocket science," he said."

Read more: http://www.businessinsider.com/pentagon ... z26pNVVaca

A Lockheed Martin spokesman says recent tests on the redesigned arrestor hook were "highly successful," snagging the wire 3/5 (60%) of the time. The bolters were due to the pilot landing too far away from the wire, according to LM. The redesigned arresting system does not include a reengineered damper, which theoretically should keep the hook stable enough to grab the wire after the initial contact with the deck.

http://www.aviationweek.com/Article.asp ... 497526.xml

Thanks. Good to know from article above about the circumstances / conditions (best to read full article) but also...

"...Shipboard trials are set for 2014."

On another recent thread ('jw' post here: http://www.f-16.net/f-16_forum_viewtopic-t-20377.html ) it was mentioned that reporter needed to use correct terminology. I overlooked this doozy:

Frum (John Frum - look it up): http://www.aviationweek.com/Article.asp ... 497526.xml

"...The original design failed to snag the arresting wire in early testing owing to two problems: the point of the hook was not sharp enough to scoop under the wire and securely grab it, and a dampener device was not sufficient to maintain a hold on the wire. Essentially, the hook was bouncing upon landing, reducing the likelihood of a successful arrested landing.

Lockheed Martin, the F-35 prime contractor, has redesigned the hook to address those problems. An interim version, which has a sharpened point but lacks the dampener, was tested....

...The tailhook problems came to light nearly a year ago, and redesign work has been in progress since. Company officials hope to test the final version of the new arresting hook, and its dampener, next summer...."

"meaning of dampener - a device that dampens or moistens" Which is - of course - funny. Very Happy

But hey this is the internet baby! Anything goes. How about a recipe for 'damper'? http://alldownunder.com/oz-u/food-recipes/damper.htm

"hold down damper" seems to be the correct current terminology (gargle it) however 'meet the fokkers' have another device apparently. Which I gather is separate from the aforementioned.

Fokker Landing Gear B.V. is testing with BINDER Juli 2010

http://www.binder-world.com/us/news/fok ... g-gear-bv/

"...For the F-35 Lightning II JSF Fokker Landing Gear is system design responsible for the Arresting Hook of the F35 Conventional Take Off and Landing (CTOL) and the Carrier Version (CV). For the reliability of this arresting hook system Fokker needs to do climate testing. One of the parts of the arresting hook system is the Upswing Damper. It is mounted right under the engine of the F-35. This Upswing Damper adsorbs(sic) the energy during the landing from the hook...."

The use of "dampener" or "dampen" when "damper" and "damp" should be used is unfortunately very common and probably always will be, even among people who should know better.

A dampener acts somewhat as a shock absorber. It reduces the oscillation or in this case the hook bouncing up as it absorbs the energy imparted to the hook when it strikes the deck. You can dampen an electrical circuit as well.

marksengineer wrote:

A dampener acts somewhat as a shock absorber. It reduces the oscillation or in this case the hook bouncing up as it absorbs the energy imparted to the hook when it strikes the deck. You can dampen an electrical circuit as well.

Thus proving my point. Bang Head

In the same vein 'lightening' is not alternate spelling for 'lightning', neither is 'dampener' alternate spelling for whatever we are talking about here. As mentioned it seems today the USN use the term 'hold down damper' but 'damper' - by itself - is not a substitute either.

Well, at least they got it right on Star Trek.

I'm no Trekkie so had to google 'inertial dampers'? Thank goodness Star Trek is dead. Long Live Farscape - sadly also now dead. Oh well. Cool

johnwill wrote:

marksengineer wrote:

A dampener acts somewhat as a shock absorber. It reduces the oscillation or in this case the hook bouncing up as it absorbs the energy imparted to the hook when it strikes the deck. You can dampen an electrical circuit as well.

Thus proving my point. Bang Head

@Johnwill, actually the correct term is "dashpot".

http://en.wikipedia.org/wiki/Dashpot

This section of my recent post on another thread [ http://www.f-16.net/f-16_forum_viewtopi ... rt-15.html ] is more relevant here so it is repeated here, also because I saw another blogpost that seems to not understand the 'allround hook catching requirement in all kinds of situations and arrestor gear - which would be ashore'.

"I saw some comments to articles about the F-35C hook currently not engaging at every attempt (because not all fixes in place). However it must be remembered that the hook needs to perform in all situations. From landing early to drag the hook to the short field gear to dropping the hook (not too soon) before engaging long field gear at slower speed during landing OR high speed long field arrest in case of an aborted take off. To the carrier landing environment where a 'Taxi 1' (landing well short of the No.1 wire) or landing long to have almost an inflight arrest as the hook catches No.4 before main wheels touchdown AND every situation inbetween the wires is required.

Yes JPALS will ensure better hook placement midway between No.2 and No.3 wire with No.3 target wire. Which reminds me I have a screenshot from a low quality video of a Hornet approach to a 2 wire only setup. I forget now which wires were missing, vaguely recall the middle No.2 and No.3 were missing [actually No.1 & No.3 wire missing]. Anyway I guess that would be the minimum wire setup. If I can find the screenshot I'll post it.

The missing wires mean there is more chance for 'HookSkipBolter' inbetween."

http://www.f-16.net/attachments/onlyno2 ... ie_152.jpg

Forum: F-35 milestones

F-35C Lands at Lakehurst For Testing