F-35C Lands at Lakehurst For Testing

[popcorn]

Shirley this is not correct....

Pentagon focused on weapons, data fusion as F-35 nears combat use 04 Dec 2013 Andrea Shalal-Esa

"...Bogdan said the Navy version of the new fighter was also making progress, and testing of a redesigned tail hook that allows the plane to land on aircraft carriers would begin in coming months after completion of a critical design review."

http://www.reuters.com/article/2013/12/ ... 1Y20131205

Yes, very odd. I note that this part of the report was not in quotes and possible the writer or editors (yes, there are 2 of them) simply got it wrong i.e. the tests would begin as the jet had completed a critical design review.

[spazsinbad]

See Bogdan and Shalal-Esa in this video (recent I would guess).... Not about the hook at all but has the main characters we read about so often in the one frame....

Inside the Pentagon's $1 trillion jet-fueled piñata (5:33)

"The F-35 fighter jet has drawn heavy fire from critics, not the least of whom was Pentagon program chief Lt. Gen. Chris Bogdan. Now he says the plane is on track to be combat-ready in 2015."

http://www.reuters.com/video/2013/12/05 ... nel=117850

[spazsinbad]

'Call me an ambulance' or 'perhaps Shirley I just forgot' but NG is responsible for the AHS :

"...The [NG] mission systems team has responsibility for the design and procurement of the...arresting hook system..."

http://www.northropgrumman.com/Capabili ... ochure.pdf (0.3Mb)

[spazsinbad]

Lakehurst not ready for hooking yet (later) with Pax River hooking now?

Lockheed: New Carrier Hook for F-35 12 Dec 2013 Dave Majumdar

"Lockheed Martin is set to deliver a production version of the tailhook for the carrier-based F-35C Joint Strike Fighter after an engineering glitch forced a partial redesign of the system.

“CF-3 is the test aircraft that is modified to conduct tailhook testing,” Lockheed spokeswoman Laura Siebert wrote in an email to USNI News on Dec. 12. “The airplane is in the final stages of preparation for test with the new tailhook module installed.”

The modified F-35C test aircraft will conduct flight test at Naval Air Station Patuxent River, Md., until facilities are ready for trials at Naval Air Engineering Station Lakehurst in New Jersey to conduct roll-in testing.

“It will be ready for planned testing when the facilities at Lakehurst are ready,” Siebert said. “In the interim, expect checkout flights at Pax River this month.”

Roll-in testing is required to verify that the F-35C will be able catch a cable on a set of carrier arresting gear installed onshore at the Lakehurst facility. After the aircraft demonstrates that it can catch a wire on land, the F-35C will have to be tested at sea.

Arrested recoveries at sea should take place onboard the USS Nimitz (CVN-68) in the first part of 2014 according to Lockheed officials. However, while the current plan calls for the F-35 to perform its sea-trials onboard the Nimitz, it could be another ship depending on the availability of carriers at the time.

Demonstrating that the F-35C can recover onboard a carrier is critical for a naval aircraft. The tailhook has been a vexing problem on the F-35C variant when it was discovered in 2012 that the hook could not reliably engage an arresting wire.

Lockheed and the Joint Strike Fighter program office ultimately traced the problem back to the shape of the hook and a faulty wire dynamics model supplied by the Naval Air Systems Command.

The solution was to reshape the hook point and adjust the system’s hold-down damper, which helps prevent the hook from bouncing around upon touchdown...."

http://news.usni.org/2013/12/12/lockhee ... -hook-f-35

[neptune]

'Call me an ambulance' or 'perhaps Shirley I just forgot' but NG is responsible for the AHS :

"...The [NG] mission systems team has responsibility for the design and procurement of the...arresting hook system..."

http://www.northropgrumman.com/Capabili ... ochure.pdf (0.3Mb)

The same folks who brought you the "bad hook" on the X-47B, for the same reason!

PS, looks like they've got that one fixed!

[spazsinbad]

Navy’s F-35 Starts New Tailhook Tests 23 Dec 2013 Dave Majumdar

"The Naval Air Systems Command (NAVAIR) has begun testing a new carrier arresting hook for the Navy’s version of the Lockheed Martin F-35 Lighting II Joint Strike Fighter at Naval Air Station Patuxent River, Md.

Aircraft CF-3, which is the first F-35C fitted with a production tailhook, caught an arresting wire at a shore-based test rig on Dec. 19 at the Navy’s primary flight test center according to Naval Air Systems Command. The aircraft was flow by Lt. Cmdr. Tony Wilson.

Testing will eventually move to Naval Air Engineering Station Lakehurst in New Jersey in January 2014 for additional testing with a shore-based arresting gear. Fly-in testing is required to verify that the F-35C will be able to consistently catch an arresting wire....

...Lockheed and the Joint Strike Fighter program office ultimately traced the problem back to the shape of the hook and a faulty wire dynamics model supplied by the Naval Air Systems Command. The solution was to reshape the hook point and adjust the system’s hold-down damper, which helps prevent the hook from bouncing around upon touchdown...."

http://news.usni.org/2013/12/23/navys-f ... hook-tests

CAPTION: "Navy F-35C test plane CF-3 successfully catches a wire during testing at Naval Air Station Patuxent River, Md. Lockheed Martin Photo"

[smsgtmac]

Navy’s F-35 Starts New Tailhook Tests 23 Dec 2013 Dave Majumdar

...Lockheed and the Joint Strike Fighter program office ultimately traced the problem back to the shape of the hook and a faulty wire dynamics model supplied by the Naval Air Systems Command. The solution was to reshape the hook point and adjust the system’s hold-down damper, which helps prevent the hook from bouncing around upon touchdown...."

LOVE the phrasing of the last passage. It reads as if the shape of the hook and the flaw in the dynamics model were independent variables. It should read the use of a faulty dynamics model drove the wrong shape design for the hook. But then someone would have to ask themselves why was the Program and contractor eviscerated for months on this issue when it was a NAVAIR error'? I suspect (actually a little more than suspect but we won't go into it) that the arresting gear has now been over-engineered, since just changing the hook allowed 5 of 8 arrestments against the single wire test setup and the other 3 were outside the zone. Do we now have to worry about the hook system piercing the carrier deck? (I kid)

Seriously. I remember cries to make the contractors pay for the re-engineering. Bring this up as a case study every time somebody blames a program or contractor before the root cause of some bad development is known. Classic GIGO episode.
Oh, and somebody is tweaking ELP in the comments at the link Spaz provided. That is pretty funny in its own right.

[spazsinbad]

ELP is not a master of mixing / matching his 'buzz word' phrases that are used over and over on his 'driveby' comments all over the web. This thread has a ton of info about the hook issue and (of course) about the A-4 hook (natch). Yet ELP hangs on to the arguments presented now two years ago in the face of evidence that the F-35C hook issue is being solved. Wow. And just for the record again:

ELP comment at USNI: "...The A-4 was designed from the start as a carrier aircraft...."

And so was the F-35C. A summary now mentioned a few times in this thread / forum highlights the effort here:

The Influence of Ship Configuration on the Design of the Joint Strike Fighter

"...SHIP SUITABILITY DESIGN "PENALTY"
Because of the numerous factors that influence the design of a ship-based aircraft, many assume these considerations have significantly compromised the mission performance of the CV and STOVL variants. Correspondingly, it is assumed that the remaining CTOL variant carries appreciable "scar impacts" to maintain commonality with its sea-going siblings. However, the JSF design solution has been quite successful in minimizing the "penalty" of ship suitability. As was discussed earlier, the most notable evidence of the CV variant's carrier suitability requirement is its increased wing size and strengthened structural components. These features increase the weight and drag characteristics of the air vehicle, which in turn diminish slightly its maximum speed capability and acceleration performance. However, turn performance is actually improved, and the larger wing provides more fuel volume for a longer range and greater endurance. Similar impacts are seen in the STOVL variant, the result of the incorporation of a vertical lift capability.

However, numerous trade studies and operational analyses have confirmed that these small performance impacts have negligible impacts on the mission effectiveness of the CV and STOVL variants. And, since commonality is achieved largely through the use of "cousin" components (those identical in shape, but scaled in size to meet variant-specific requirements), the CTOL variant carries virtually no scars as the result of the ship suitability of the other two variants. The JSF program has clearly shown that shipboard compatibility does not have to come at the expense of such critical attributes as lethality and survivability...."

http://handle.dtic.mil/100.2/ADA399988 (1Mb PDF)

It is funny how even the A-4 mockup had a dissimilar yoked hook to the one used so successfully in production as per:

http://a4skyhawk.org/sites/a4skyhawk.or ... 7812m1.jpg
http://a4skyhawk.org/content/137812-dou ... t-photo-13

Reality has never bothered ELP though.

[quicksilver]

Navy’s F-35 Starts New Tailhook Tests 23 Dec 2013 Dave Majumdar

...Lockheed and the Joint Strike Fighter program office ultimately traced the problem back to the shape of the hook and a faulty wire dynamics model supplied by the Naval Air Systems Command. The solution was to reshape the hook point and adjust the system’s hold-down damper, which helps prevent the hook from bouncing around upon touchdown...."

LOVE the phrasing of the last passage. It reads as if the shape of the hook and the flaw in the dynamics model were independent variables. It should read the use of a faulty dynamics model drove the wrong shape design for the hook. But then someone would have to ask themselves why was the Program and contractor eviscerated for months on this issue when it was a NAVAIR error'? I suspect (actually a little more than suspect but we won't go into it) that the arresting gear has now been over-engineered, since just changing the hook allowed 5 of 8 arrestments against the single wire test setup and the other 3 were outside the zone. Do we now have to worry about the hook system piercing the carrier deck? (I kid)

Seriously. I remember cries to make the contractors pay for the re-engineering. Bring this up as a case study every time somebody blames a program or contractor before the root cause of some bad development is known. Classic GIGO episode.
Oh, and somebody is tweaking ELP in the comments at the link Spaz provided. That is pretty funny in its own right.

A little quibbling if I may -- When one considers the intent of the testing (to validate the new model they had developed to assess the probability of arrestment for the new AHS design) the "5 of 8" was really a 7 of 8. Based on the predictions of the model, they targeted touchdown points where they expected arrestments, and they targeted touchdown points where they expected bolters. IIRC, where they expected arrestments they got 5 of 6; where they expected bolters they were 2 for 2 (i.e. the jet boltered -- as the model predicted).

[spazsinbad]

This is a question raised on another forum. What constitutes a 'roll-in' arrest? I have searched the internet to find no info and I'll continue to search later today. An 'authoritative' source said a 'roll-in' is with the nosewheel off the tarmac as we see in the F-35C arresting photo above. That must be fun to do and is this correct? Thanks.

And thanks for the info 'quicksilver' from last test re bolters etc. Dave Majumdar needs to get on the case I reckon.

[quicksilver]

This is a question raised on another forum. What constitutes a 'roll-in' arrest? I have searched the internet to find no info and I'll continue to search later today. An 'authoritative' source said a 'roll-in' is with the nosewheel off the tarmac as we see in the F-35C arresting photo above. That must be fun to do and is this correct? Thanks.

And thanks for the info 'quicksilver' from last test re bolters etc. Dave Majumdar needs to get on the case I reckon.

Roll-in --

Jet is on the rwy at a target ground speed and the hook is dropped at a predetermined distance in front of the wire…not unlike taking the long field gear, or a precautionary arrestment like the USAF would do at mid-field.

[spazsinbad]

Thanks 'quickie' for that info: that would be my guess (without any other knowledge about such tests). My imagination says that accelerating any Naval Aircraft to a groundspeed where the nose can be raised and held up with hook dropped is fraught with undesirable possibilities - especially any non-view over the nose, ahead - and leaving the runway unintentionally.

Hooks do not like being dragged too far on a runway - I'll guess the pilots doing roll-in tests are good at dropping the hook exactly as required.

[quicksilver]

Thanks 'quickie' for that info: that would be my guess (without any other knowledge about such tests). My imagination says that accelerating any Naval Aircraft to a groundspeed where the nose can be raised and held up with hook dropped is fraught with undesirable possibilities - especially any non-view over the nose, ahead - and leaving the runway unintentionally.

Hooks do not like being dragged too far on a runway - I'll guess the pilots doing roll-in tests are good at dropping the hook exactly as required.

Well, the pic provides the answer about roll-in or fly-in -- the smoke from the touchdown.

Tis a fly-in.

[spazsinbad]

No question - I thought it was a fly-in all along - just wanted to know about the ROLL-IN scenario. It was a comment on pPrune actually by two 'UK experts' who both claim that the pic shows a roll-in with one claiming "all roll-ins are done with nose off the tarmac". I guess I should be more clear about what I thought when I thought it was clear. I have not seen the reaction there yet - not really that concerned - we know what we know and the internet has a zillion opinions. Again thanks for the info on the Roll-In criteria. I like to find out as best I can from the other side of the world sitting at a computer but with NavAv experience from another time etc.

From my earlier comment 'that would be my guess' I was referring to your 'roll-in' definition being as such with the 'fly-in' shown in the photo being the only other explanation and my guess all along. It would have helped if the photo had had a better caption but such is life.

[quicksilver]

Not questioning your questions -- I had simply not really paid much attention to the idea until you asked.

Conspicuously, it was LO who made the comment…