U.S. Navy and U.K. Royal Navy F-35 unable to get aboard ship

No Problemo Kids. Simple and relatively economical solution: F-35Bs for everyone. Don't need the A or C when the B model can do it all--The B can get on the boat, can't it?

No concurrency to worry about/one engine/one mind.

<a href="http://www.f-16.net/news_article4494.html">U.S. Navy and U.K. Royal Navy F-35 unable to get aboard ship</a>

Are you high?

handyman wrote:Are you high?

I suspect so. That made no sense whatsoever

I think you're going to have to expand a bit on that one as I don't quite follow you. What do you mean by "unable to get aboard ship" ?

He is talking about ELP's article.

The whole article hangs on the statements made by Peter Goon, one of the Airpower Australia guys. This is just more FUD.

Here are the references cited with the first one [MIL-A-81717C] incorrect I presume as shown (must be dyslexic).

http://www.everyspec.com/MIL-SPECS/MIL+SPECS+(MIL-A)/MIL-A-18717C_18182/

Should be MIL-A-18717C, MILITARY STANDARD: ARRESTING HOOK INSTALLATION, AIRCRAFT (20 SEP 1993)., This specification covers the design, development, construction, analysis, test and documentation requirements for arresting hook installations in aircraft for which detail specifications or pertinent contractural documents require that arresting hooks be fitted.

http://www.everyspec.com/MIL-SPECS/MIL+SPECS+(MIL-A)/download.php?spec=MIL-A-18717C.018182.PDF (5.2Mb)

SEE a TUN of info here (dyslexia creeps in) here: brief history of tailhook design

http://www.f-16.net/f-16_forum_viewtopi ... rt-30.html (scroll down)

_________________________

http://www.everyspec.com/MIL-SPECS/MIL+SPECS+(MIL-D)/MIL-D-8708C_7454/

MIL-D-8708C, MILITARY SPECIFICATION: DEMONSTRATION: AIRCRAFT WEAPON SYSTEMS, GENERAL SPECIFICATION FOR (12 AUG 1991)., This specification establishes the general requirements for demonstration of Naval aircraft weapon systems during full scale engineering development.

http://www.everyspec.com/MIL-SPECS/MIL+SPECS+(MIL-D)/download.php?spec=MIL-D-8708C.007454.PDF (9.3Mb)

As usual ELP doesn't know what he is talking about.

As of Nov. 3, F-35C carrier variant (CV) jets had executed 59 successful catapult launches and three arrestments.

So obviously the F-35C can make an arrestment it just needs to get better at it. I suspect this is Vice Admiral David Venlet kicking a$$ and bring in the Grumman engineers to get the arrestment system right as Grumman is expert on carrier arrestment.

alloycowboy the eight unsuccessful 'rollin' attempts on a runway arresting gear one assumes is what is at issue. The 3 successful attempts were made in unknown circumstances. However to add to your point and mine - the F-35C must be successful for all arresting gear suitable both ashore and afloat. Anyway here is a response to the original article cited above. I'll assume that our dear readers have read it - if not read it because I have not excerpted all relevant bits here below.

From ELP's initial article:

"...He also points to well known and well understood military specifications that address tail hook design requirements, such as MIL-A-81717C [incorrect it is MIL-A-18717C] and MIL-D-8708C.

When asked how such things could have been missed, Peter suggested they likely weren’t, at least by the engineers, [poor Peter must be an engineer ] but their concerns would have just as likely been ignored...."
THEN:
"...The program will attempt some more rolling tests with a different hook design, but this does not address the problem of the poor location of the tail hook on the airframe...." Where is the evidence for this assertion? Here are some text excerpts from the relevant MILSPEC as shown below. To my watery eyes there appears to be a lot of oversight by NAVAIR and one gathers the other mob at BASS (Basing and Shipboard Suitability). I guess the requirement to ARREST via any method is not on the list below:

http://www.globalsecurity.org/military/ ... /f-35c.htm

"...The B&SS IPT draws focus to basing compatibility considerations and issues by serving as a reference source to the JSF team for the design and development of the JSF family of variants. The B&SS team coordinates with other teams within the JSF program to maintain a "big picture" design perspective and to ensure all appropriate issues are addressed.

Overall, the JSF Basing & Shipboard Suitability IPT is responsible for ensuring that the requirements are met. The JSF must be able to operate from US and allied shore-based facilities. Considerations for basing suitability, and shipboard compatibility in particular, include of a wide range of complex integration issues such as:

Approach flying qualities
Catapult hookup
Deck handling
Deck spotting
Elevator compatibility
Flight deck servicing
Hangar deck maintenance
Jet blast effects
Landing systems
Ship motion
Shipboard environment
Steam ingestion..."

Then from the MILSPEC about arrestor hooks we have:

From ARRESTING HOOK INSTALLATION AIRCRAFT: http://www.everyspec.com/MIL-SPECS/MIL+SPECS+(MIL-A)/download.php?spec=MIL-A-18717C.018182.PDF

"3.5.3 Deck pendant displacement. The arresting hook shall be the[sic] designed and located with respect to the landing gear to ensure engagement of deck pendant by the hook after displacement by the nose wheel, main wheels or tail bumper of the aircraft passing over it." [page 3]

Further text states that contractor needs to do testing and NAVAIR needs to do a lot of inspection.

Then on page 20: "APPENDIX A
PROCEDURES FOR ARRESTING HOOK INSTALLATION ANALYSIS
10. SCOPE
10.1 Scope. This appendix is not a mandatory part of the specification. The
information contained herein is intended for guidance only concerning the following:
a . Arresting hook location and installation geometry
b . Arrested landing analysis conditions
c . Recommended analytical procedures
d . Conventional arresting hook installations
e . Arresting hook and arresting hook components design
f . Shock absorber and hold down criteria

30 . ARRESTING HOOK LOCATION [continuing on page 21]

30.1 Hook location. In determining the location of the arresting hook, the effect of such location on nose wheel loads, propeller or store clearances, and main wheel / deck contact, as applicable to the type of aircraft involved, must be considered. The following paragraphs present general information about various types of arresting gear and general recommendations for determining the adequacy of the hook location.

30.5 Preliminary arresting hook location. The following paragraphs present
criteria for checking the effect of the proposed arresting hook location on the
factors of 30.1 in the preliminary design stages of the hook. The acceptability of
the final hook location must be verified by a full dynamic analysis of all forces
(including aerodynamic forces) acting on the aircraft during runout and by test as
required by the basic specification..." [Have a look at relevant text here: http://www.f-16.net/f-16_forum_viewtopi ... rt-30.html - graphic titled 'ArrestHookLocation.gif'] OR here: http://www.f-16.net/attachments/arresth ... on_864.gif AND seen below repeated....

Then the MILSPEC goes on amongst a lot of other details that can be seen in the same thread page or in the original PDF...

"30.5.4 Selection of new hook location. If the preliminary calculations of
30.5.3 show excessive nose gear loads or insufficient propeller or store clearance, a new hook location should be selected and the preliminary analysis repeated.

40. ARRESTING HOOK INSTALLATION ARRANGEMENTS
40.1 Design stage. The location and arrangement of the hook should be
considered at an early stage of the design before the final configuration of the
aircraft is set, to insure that the simplest and most reliable installation can be
incorporated.

40.2 Proven hook installations. Incorporate a proven hook installation where practicable. Preliminary layouts should be discussed with NAVAIR at an early design stage to determine what proven and standard hook installation components can be incorporated."

Why is all the above relevant? I would suggest that the problem will be fixed given the oversight necessary to get to the stage the F-35C hook installation is at moment. But who knows - certainly not ELP and his GOON mate. But shouting the sky is falling and that the F-35C cannot land on a conventional aircraft carrier is a stretch eh. We'll see.

The relevant 'hook problem section' of the QLR Report excerpt here is worth reading in light of above:
F-35C Lands at Lakehurst For Testing

http://www.f-16.net/index.php?name=PNph ... k&start=30

"Arresting Hook System (CV variant): There are significant issues with respect to how the CV variant’s AHS interoperates with aircraft carrier based MK -7 arresting gear. Roll-in arrestment testing at NAWC-­AD, Lakehurst, resulted in no successful MK-7 engagements (0 successes in 8 attempts). Root cause analysis identified three key AHS design issues: (1) the aircraft geometry has a relatively short distance between the aircraft’s main landing gear tires and tailhook point (when lowered), (2) tailhook point design was overemphasized for cable shredding features versus ability to scoop low positioned cables, and (3) tailhook hold-down damper performance is ineffective to support damping of small bounces relative to runway/deck surface profiles....

...To address these issues, the program is designing modifications to the tailhook point and hold down damper components..."

And of course one should read all the information. My excerpts only POINT to it rather than attempt to explain what is complicated.

Perhaps the Brits and USN will co-ooperate better on how not to get aboard (I jest) given that they are now in the same boat (I jest again)....

Panetta, Hammond Discuss Strategy in Pentagon Meeting Jan, 07, 2012 TendersInfo (India)

http://www.poten.com/NewsDetails.aspx?id=11970710

"Defense Secretary Leon E. Panetta and British Defense Secretary Phillip Hammond talked defense strategy and the way ahead during a meeting yesterday at the Pentagon.

It was Panetta s first meeting with Hammond, and it came following President Barack Obama's announcement of the new U.S. strategic defense guidance....

...The defense leaders also signed a Statement of Intent on Carrier Cooperation and Maritime Power Projection that will serve as the framework for increased cooperation and interoperability on the use of aircraft carriers. It also provides the basis for the U.S. Navy to assist the Royal Navy in developing its next generation of aircraft carriers, Little said.

This cooperation is a cutting-edge example of close allies working together in a time of fiscal austerity to deliver a capability needed to maintain our global military edge, he added.

Britain is building two angled-deck aircraft carriers that are scheduled to enter service in 2016 and 2018. The carrier version of the F-35 joint strike fighter will fly off the new ships."

Well, a tail hook is a bent bit of metal - it's not rocket science - it maybe needs bending a bit more or a bit less. Just toss a marine with a sledgehammer at it.

Compared to the rest of the complexities solved, I don't see any problem.

For perspective, go look at the history of getting the Goshawk to launch and trap successfully. Goshawk works fine right now so one assumes those issues were overcome?

Ian

alloycowboy wrote:As usual ELP doesn't know what he is talking about.

As of Nov. 3, F-35C carrier variant (CV) jets had executed 59 successful catapult launches and three arrestments.

So obviously the F-35C can make an arrestment it just needs to get better at it. I suspect this is Vice Admiral David Venlet kicking a$$ and bring in the Grumman engineers to get the arrestment system right as Grumman is expert on carrier arrestment.

You mean the video below which states it in writing? It has a lot of glowing statements in it, including deliveries to Eglin (to be parked).

I suspect that had there been no serious issues with the F-35C and the idea of trapping that the quick-look report would not have brought it up; given all the other damning issues that need attention.

Cool thing in the video is at the end, looks like they have a Senior Airman involved as (an assistant crew chief?) which is operationally relevant. Until then enjoy the rose colored glasses story...

http://www.youtube.com/watch?v=S4noaLSJNQE

Sorry, I cannot hear sound to hear video on this computer but anyway.... [OK I see the three traps is stated in writing in text below the video, from a report elsewhere.] No one is denying there is an issue with the hook - that will be fixed however. If it cannot be fixed then that is another matter. No one is saying that there is not a fix for the hook problem. Why jump the gun? Perhaps your article headline will be relevant then?

spazsinbad wrote:Sorry, I cannot hear sound to hear video on this computer but anyway.... No one is denying there is an issue with the hook - that will be fixed however. If it cannot be fixed then that is another matter. No one is saying that there is not a fix for the hook problem. Why jump the gun? Perhaps your article headline will be relevant then?

I am curious why someone would go to all the trouble to make a chart that shows tail hook configurations from many previous aircraft and then use words like "outlier".

It all looks so simple; and things have been fixed before. What baffles the mind is how is "The Caped Crusader" (Adm Venlet) is going to get out of this one? He has to take ownership of this resolution (not so much the cause although... he was in NAVAIR previously. One would have thought the program would consult with those people)...but anyway I think this one is more scary than any of the other problems including the IPP and helmet/cockpit interface issues. But what works against a fix is the basic aircraft design and the need for commonality but worse, the paper-thin weight margins.

An interesting question for structural engineers? Did they use a yoke configuration because they had to lower stress on an already minimal strength airframe or some other issues?

If they pull a rabbit out of their hat I will be amazed and thank them.

My thoughts is that they are against the wall on this one.

spazsinbad wrote:Sorry, I cannot hear sound to hear video on this computer but anyway.... [OK I see the three traps is stated in writing in text below the video, from a report elsewhere.] No one is denying there is an issue with the hook - that will be fixed however. If it cannot be fixed then that is another matter. No one is saying that there is not a fix for the hook problem. Why jump the gun? Perhaps your article headline will be relevant then?

The video only has music so you don't miss any relevant content with no sound