Panetta To Lift F-35B Probation at Pax River

Unread postPosted: 20 Jan 2012, 00:31
by 1st503rdsgt
:applause: The news is always mixed, but this is a step in the right direction.

http://defense.aol.com/2012/01/19/panet ... pax-river/

RE: Panetta To Lift F-35B Probation at Pax River

Unread postPosted: 20 Jan 2012, 03:34
by F16VIPER
I would had thought that the issue of the f-35b not having any provision for growth, or accepting additional weight, would be a pretty big issue and a deal breaker. From what I have been reading the design of the aircraft is pretty compromised already.

RE: Panetta To Lift F-35B Probation at Pax River

Unread postPosted: 20 Jan 2012, 04:01
by quicksilver
With a similar load, the F-35B is faster, accelerates much better (both subsonic and transonic) and has more range than a Super Hornet that is starting up on the ramp with 3500# more fuel. It has the same sensor capabilities as its F-35A and C (CTOL and CV) counterparts and has more basing options than either -- both ashore and afloat. Compromised design?

In spite of the most intense (and often deliberate and orchestrated) bashing in the history of aircraft development programs (save V-22), speculation is that the F-35B may be removed from 'probation' tomorrow by the current Secretary of Defense.

Compromised design? You may wanna reconsider what you typically read -- or at least what you choose to believe.

RE: Panetta To Lift F-35B Probation at Pax River

Unread postPosted: 20 Jan 2012, 04:16
by F16VIPER
Compromised design because of the design changes implemented to make the F-35B work and because it appears a "Jenny Craig" weight reduction exercise has already been carried out leaving no room to manoeuvre if weight creeps up. As far as I understand and in simple terms, with the -35B, if weight is gained, it has to be shaved off the plane itself. Where is that weight reduction going to come from.

RE: Panetta To Lift F-35B Probation at Pax River

Unread postPosted: 20 Jan 2012, 04:37
by quicksilver
Hmmm, "...if weight is gained, it has to be shaved off the plane itself." Holy crap -- make sure the test pilots eat a light breakfast.

Are you for real, or just drinking cheap wine? :poke:

Do you understand VLBB and how it is calculated for the purpose of determining performance relative to the KPP?

RE: Panetta To Lift F-35B Probation at Pax River

Unread postPosted: 20 Jan 2012, 05:17
by F16VIPER
i generally drink mid range cabernet souvignons or pinot noirs, never cask wine.
Well the weight it is going the pilots will need to eat astronaut food before flying the plane. No steak.
Read this:
http://www.f-16.net/index.php?name=PNph ... c&p=163550
and this:
http://www.f-16.net/f-16_forum_viewtopi ... rt-15.html
Salud!

Re: RE: Panetta To Lift F-35B Probation at Pax River

Unread postPosted: 20 Jan 2012, 05:33
by battleshipagincourt
quicksilver wrote:Hmmm, "...if weight is gained, it has to be shaved off the plane itself." Holy crap -- make sure the test pilots eat a light breakfast.

Are you for real, or just drinking cheap wine?


That's not going to help matters. The F-35B was a bad idea because the most significant challenge wasn't optimizing the aircraft to perform its mission... it's landing. The reason the F-35A is the best of the three variants is because it makes the fewest design compromises. Consider a simple thing like adding a 300 Ib module such as the EOTS to improve the aircraft's fighting capabilities... that's a reasonable addition to the F-35A or the F-35C.

Add such a module to the F-35B and now you're burdened with balancing the plane again to compensate for another 300 Ibs of dead weight to the front of the aircraft. Now you're forced either to add another 300 Ibs to the back of the plane, or remove 300 Ibs somewhere else. All the while you're designing the whole aircraft around the STOVL system, you've still got to maintain the stealth outline and meet your target performance goals.

I seriously don't think anyone here truly understands the burden the STOVL puts on designing the rest of the aircraft. The 'F-35B diet' hasn't been as beneficial to the other models' capabilities as people seem to think. The weight reduction measures weren't optimized for aircraft performance, but for making the ****** thing meet the STOVL requirements.

Many of the recent structural fatigue failures in all the F-35's can be traced to the weight-reduction measures they made for the F-35B.

RE: Re: RE: Panetta To Lift F-35B Probation at Pax River

Unread postPosted: 20 Jan 2012, 05:43
by spazsinbad
bsac, where have you been?

RE: Re: RE: Panetta To Lift F-35B Probation at Pax River

Unread postPosted: 20 Jan 2012, 06:19
by alloycowboy
Everyone is forgetting one little bitty fact. Just like aircraft weight can go up, so can aircraft thrust.

@Battleship...... How haven't the F-35A & F-35C model benefited from the F-35B's 3000 pound weight reduction. Even if they have a little weight back in to beef up some of the structural hotspots the F-35A and F-35C are still way better off because of the SWAT program.

Re: RE: Re: RE: Panetta To Lift F-35B Probation at Pax River

Unread postPosted: 20 Jan 2012, 06:49
by beepa
[quote="alloycowboy"]Everyone is forgetting one little bitty fact. Just like aircraft weight can go up, so can aircraft thrust.

Ok, as we know, increasing thrust causes lower engine life, more maint, more fuel etc etc...but is still possible on the F35 a/c. The F35b has gearboxes, shaft, clutch, fan and rotating nozzle... so the question is..can all these parts handle more thrust...and.. is the gain in thrust in the F135 from internal mods or afterburner mods or a combo of the two? ( i.e. during vertical landing afterburner can't be used)

RE: Re: RE: Re: RE: Panetta To Lift F-35B Probation at Pax R

Unread postPosted: 20 Jan 2012, 07:47
by spazsinbad
beepa, here is an answer in part with perhaps more to follow...

F-35B starts critical tests in comeback attempt Stephen Trimble 05 Oct 2011

http://www.flightglobal.com/news/articl ... pt-362941/

“...The cracked bulkhead has been patched up and redesigned and three of the five glitches in the propulsion system are already permanently fixed. Of the remaining two issues, one fix is scheduled to be approved in December, and the last problem should be resolved in February 2012, Robling added. Although the F-35 was grounded for 16 days in August, the electrical system at the root of the problem is common to all three variants.

Meanwhile, programme officials also appear to have resolved a 90.7kg performance shortfall in the vertical lift bring-back weight of the F-35B in hover while returning to a ship. Engine manufacturer Pratt & Whitney has confirmed the solution includes raising the output of the propulsion system by about 100lb-thrust (0.4kN)...."
______________________________

Pratt Advances On F135 Stovl Boost Plan – Apr 6, 2011 By Guy Norris

http://www.aviationweek.com/aw/generic/ ... line=Pratt Advances On F135 Stovl Boost Plan
-
“Pratt & Whitney has updated progress on a four-point plan to help Lockheed Martin correct issues with the F-35B short take-off and vertical landing (Stovl) variant, development of which has been placed "on probation" by Pentagon leadership....

...Describing additional details of the company's four-point plan for the F135-600 Stovl engine variant, Boley says first "we have to understand what role we have in any additional vertical lift bring back (VLBB). We can provide more thrust if that's desired." The overall VLBB requirement, which refers to returning for a vertical landing with an unused weapons load corresponding to two 1,000-lb. JDAMs and two Amraams, is around 3,000 lb.

Lockheed Martin "is not asking for more thrust, but if we did provide it, it will be 100 lb., which is easily accommodated," Boley says. The thrust delta, achieved through a scheduling change in the full authority digital engine control, is so small compared to the engine's overall max hover thrust capability that it could "almost be a production variability."

Thrust increase would necessarily have to be spread evenly throughout the system, which, in hover mode, diverts around 16,000 lb. through the engine's main nozzle, 20,000 lb. via the lift fan and an estimated 4,000 lb. through the roll posts. Pratt formerly indicated the main nozzle delivers 15,700 lb., the lift fan 20,000 lb. and roll posts some 3,700 lb., combining for a total of 39,400 lb. thrust. However, the company confirms total max hover thrust is now "greater" than 40,000 lb. In conventional up-and-away mode, the F135 is rated at 43,000 lb. thrust. Lockheed's "stack up" of items that will increase VLBB is mainly being tackled through further trimming of unspecified empty weight and other non-engine-related changes, Boley says...."

Re: RE: Panetta To Lift F-35B Probation at Pax River

Unread postPosted: 20 Jan 2012, 08:18
by 1st503rdsgt
F16VIPER wrote:I would had thought that the issue of the f-35b not having any provision for growth, or accepting additional weight, would be a pretty big issue and a deal breaker. From what I have been reading the design of the aircraft is pretty compromised already.


Does anyone know what the AV-8's "provision for growth" was when it entered service? Seems to me that STOVL fighters will always be close to the margins (or "compromised" to those prone to panic), and it's apparently something we've lived with before.

RE: Re: RE: Re: RE: Panetta To Lift F-35B Probation at Pax R

Unread postPosted: 20 Jan 2012, 08:19
by F16VIPER
I would like to go back to my original comment. The design of the F-35B is compromised.
Please read this

http://defense.aol.com/2012/01/13/f-35b ... sters-say/

One other important detail surfaces in the report, the weight of the Marines F-35B. While the issue of weight is not new for the STOVL aircraft, the report says the weight margin is not huge, roughly 235 pounds as of November. "managing weight growth with such tight margins for the balance of SDD will be a significant challenge, especially with over 70 percent of the scheduled F-35B flight sciences test flights remaining to be accomplished in the next 60 months." The current F-35B weight allows for .36 percent weight growth per year, the report notes, compared to the F-18 E/F's gain of .69 percent per year for the first 42 months after first flight.

Re: RE: Re: RE: Re: RE: Panetta To Lift F-35B Probation at P

Unread postPosted: 20 Jan 2012, 08:23
by 1st503rdsgt
F16VIPER wrote:I would like to go back to my original comment. The design of the F-35B is compromised.
Please read this

http://defense.aol.com/2012/01/13/f-35b ... sters-say/

One other important detail surfaces in the report, the weight of the Marines F-35B. While the issue of weight is not new for the STOVL aircraft, the report says the weight margin is not huge, roughly 235 pounds as of November. "managing weight growth with such tight margins for the balance of SDD will be a significant challenge, especially with over 70 percent of the scheduled F-35B flight sciences test flights remaining to be accomplished in the next 60 months." The current F-35B weight allows for .36 percent weight growth per year, the report notes, compared to the F-18 E/F's gain of .69 percent per year for the first 42 months after first flight.


Again, I'm gonna need a STOVL point of reference (like the AV-8's initial weight margin) before I start to worry.

RE: Re: RE: Re: RE: Panetta To Lift F-35B Probation at Pax R

Unread postPosted: 20 Jan 2012, 08:27
by alloycowboy
@F16viper....... There are always ways to take weight out of an airplane, the question is how much will cost?

Panetta Lifts F-35B Probation

Unread postPosted: 20 Jan 2012, 22:02
by quicksilver

RE: Panetta Lifts F-35B Probation

Unread postPosted: 20 Jan 2012, 22:17
by spazsinbad
'quicksilver' lives up to moniker indeed! :D Some takeaway quotes from above Butler report from PaxRiver:

"...George Little, Panetta’s spokesman, said the secretary’s decision to lift the probation was underpinned by improvements in five key areas: structural shortcomings in the Stovl bulkhead, flutter in the auxiliary inlet door, problems in the lift-fan clutch, unexpected wear and tear on the drive shaft and heating on the roll post actuator.

The utility of Stovl aircraft — namely the AV-8B Harrier — in recent operations in Libya and Afghanistan has “made an impression on him,” one defense official said, speaking about Panetta....

...the test force is looking ahead to weapons separation trials this year, says Lt. Col. Matt Kelly, F-35 flight operations lead at the Patuxent River testing facility. The team has already conducted flights of the F-35B carrying weapons at subsonic and supersonic speeds. Initial flutter testing with the weapon bay doors open in flight have shown no significant problems, Kelly says. The major step, he says, is to drop weapons for the first time, a milestone expected in the second half of the year. Likely candidates will be the 500-lb. Joint Direct Attack Munition and the AIM-120 and AIM-9X missiles.

Thus far, the F-35B has been flown to Mach 1.4.

Kelly says he also expects to begin testing a redesigned tailhook for the F-35C in the second half of the year. The current design encountered problems last year when officials attempted rolling tests and the tailhook skipped over the wire owing to its weight [QUE???] and a problem with the dampening system. CF-3 will be the first test aircraft to have the new tailhook installed.

After the initial ship trials with the F-35B last fall, the B model is not expected to go to sea until 2013, with the C model following in 2015, [most recently C trials at sea was slated in 2013?] Kelly said.

Aircraft BF-4 is now operating the Block 1A software and BF-5 is using the 1B software package. Kelly said the Block 2 software, which will be used by the Marine Corps to declare operational capability, is not expected at Patuxent River until late this year.

In addition to having multi-level security, the 1B software also will have new voice recognition technology that will allow the pilot to conduct some hands-free operations, such as switching the radio channels and squawking identification codes to air traffic control. Eventually, Kelly says, pilots hope to use the voice recognition technology for such operations as changing multi-function displays or shifting modes in the aircraft...."

Re: RE: Panetta Lifts F-35B Probation

Unread postPosted: 20 Jan 2012, 22:29
by hotrampphotography
spazsinbad wrote:After the initial ship trials with the F-35B last fall, the B model is not expected to go to sea until 2013, with the C model following in 2015, [most recently C trials at sea was slated in 2013?] Kelly said.


Obviously there is a difference between "trials" and actual squadron deployment (not the right choice of words, someone help me out here). The C trials will still start next year provided the new arrestor gear passes spec.

RE: Re: RE: Panetta Lifts F-35B Probation

Unread postPosted: 20 Jan 2012, 23:07
by spazsinbad
Fair enough, thanks. Agree with your reading of that sentence. I got waylaid/belayed by the sentence starting phrase '...ship trials...'.

Re: Panetta Lifts F-35B Probation

Unread postPosted: 21 Jan 2012, 00:27
by Thumper3181
quicksilver wrote:http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=defense&id=news/awx/2012/01/20/awx_01_20_2012_p0-416683.xml&headline=Panetta%20Lifts%20F-35B%20Probation


So will we see a blog post about this from Sweetman on Monday?

RE: Re: Panetta Lifts F-35B Probation

Unread postPosted: 21 Jan 2012, 01:33
by spazsinbad
Panetta says military committed to F-35 fighter but program 'not out of the woods' January 20, 2012 | Associated Press

http://www.foxnews.com/politics/2012/01 ... out-woods/

"The U.S. military is committed to developing the Marine Corps version of the next-generation strike fighter jet, Defense Secretary Leon Panetta said Friday, but he warned that the program is "not out of the woods yet."

Standing in front of one of the fighter aircraft at Patuxent River Naval Air Station, where the program is run, Panetta said the Pentagon needs "to make sure we're on the cutting edge" of military technology.

"This fifth-generation fighter behind me is absolutely vital to maintaining our air superiority," Panetta told about 100 people inside an aircraft hangar at the air station. Many in his audience work on the test program.

Before his address, Panetta visited an F-35 flight test simulator. He "flew" it briefly and also got briefings on progress made to resolve technical problems with the Marine Corps and Navy versions of the F-35...."

RE: Re: Panetta Lifts F-35B Probation

Unread postPosted: 21 Jan 2012, 07:01
by stereospace
This is good news.

Re: Panetta Lifts F-35B Probation

Unread postPosted: 21 Jan 2012, 14:01
by joost
Thumper3181 wrote:
quicksilver wrote:http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=defense&id=news/awx/2012/01/20/awx_01_20_2012_p0-416683.xml&headline=Panetta%20Lifts%20F-35B%20Probation


So will we see a blog post about this from Sweetman on Monday?


Well, Eric Palmer seems to be furious. This in NOT what he wants to hear.

http://elpdefensenews.blogspot.com/2012 ... -hope.html

this is a cool comment on his blog:

nico said...
Great news, the JSF can (almost) fly at night, -B is off probation (what ever that means), it's years ahead of Su37 and Burbage assured us that -C will be able to land on a carrier.

I guess Eric you can close shop now. :)

January 21, 2012 2:25 PM

Unread postPosted: 21 Jan 2012, 22:43
by southernphantom
How funny is this?? The temperamental version actually seems the second-least $&@#ed, while the theoretically simple C may need a major redesign of the lower rear fuselage??

I wouldn't be surprised to see the C cancelled and a huge USN buy of Block III Super Hornets, which is actually a shame since IMO the C is the most-needed variant.

Unread postPosted: 21 Jan 2012, 23:01
by spazsinbad
southernphantom, have a read of this thread - thanks: (and there are others recent)

http://www.f-16.net/f-16_forum_viewtopi ... t-120.html
&
http://www.f-16.net/f-16_forum_viewtopi ... t-105.html

This last one outlines the fix in text whilst the thread pages illustrate issues with the fix also outlined in the QLR PDF - best one to view is:

http://s3.documentcloud.org/documents/2 ... report.pdf (~18Mb)
____________________

This AvWeek version of the QLR does not have the hook graphics for some reason:
http://www.aviationweek.com/media/pdf/awst_pdf/ (~18Mb)
VIA go here first to then download the pdf:
http://www.aviationweek.com/aw/generic/extra.jsp

"December 2011
(Dec. 14) DOD F-35 Joint Strike Fighter Concurrency Quick Look Review"

Unread postPosted: 23 Jan 2012, 16:15
by maus92

Unread postPosted: 23 Jan 2012, 20:44
by spazsinbad
Some analysis: “...Ten years after building a prototype, the company has belatedly figured out that the retractable tailhook is badly positioned for snagging arresting wires, and will require a serious redesign....” Nope [oh no - not another doom and gloomer]. Just what is being done is hardly serious and we know that it took an actual test to find the problem but all the design work/analysis beforehand has an easy solution. We'll see of course.

Unread postPosted: 23 Jan 2012, 21:33
by spazsinbad
Long excerpts from a long post here which is also about lifting F-35B probation but not included below. These excerpts reference the F-35C hook solutions (poorly referenced in the analysis above) so don't read them if youse are not interested. Thanks.

Good Week For F-35 (DEFENSE NEWS 23 JAN 12) ... Dave Majumdar
STOVL Version Escapes Probation, Fix Found For Carrier Variant

http://www.hrana.org/news.asp#GoodWeekForF35

"...Meanwhile, Lockheed has traced the potential problems in carrier landings experienced by the Navy's F-35C to the design of the aircraft's tailhook.

Efforts to fix the problem on the F-35C are well underway, said Tom Burbage, Lockheed's program manager for the F-35 program. Like other warplanes, the single-engine stealth fighter will land on carriers by using its tailhook to catch arresting gear wires strung across the ship's deck

"The good news is that it's fairly straightforward and isolated to the hook itself," Burbage said. "It doesn't have secondary effects going into the rest of the airplane."

Moreover, the rest of the design of the tail-hook system, which includes the doors and bay that conceal the device and other ancillary hardware, is sound, Burbage said.

"What we are trying to do is make sure that we got the actual design of the hook optimized so that it, in fact, repeatedly picks up the wire, as long the airplane puts itself in position to do that," he said.

Besides the F35C, designed for carrier-based operations, the other F-35 variants include the F35A, designed for the U.S. Air Force, and the Marines' F-35B.

A preliminary review of the F-35C tailhook has been completed in conjunction with the Naval Air Systems Command and the Pentagon's F-35 Joint Program Office.

Burbage said the hook system is being modified in accordance with new test data "We're modifying the hook to accommodate what we found so far in test," he said. 'The new parts, we expect to have them back in the next couple of months."

Tests with the newly modified tailhook should start at Lakehurst, N.J., in the second quarter of this year, Burbage said. That will give the F-35 program another set of data to study to ensure the new design works as promised.

However, until those tests are done, there is no ironclad guarantee that the redesign of the tailhook will work. But Burbage said he is confident the modified design will be successful.

"The big test for this airplane is not until the summer of '13, when we take the Navy jet out to the big deck carrier and do actual traps at sea," Burbage said.

He dismisses claims that the F-35C will be unable to land on a carrier.

'That's patently not true," he said.

Richard Aboulafia, an analyst at the Teal Group, Fairfax, Va., said the claim that the F 35C could never land on a ship was always highly dubious.

"This does not appear to be a killer problem," Aboulafia said.

Flight testing is designed to uncover and fix problems with a new aircraft, Aboulafia said. "This is the kind of problem that might come out during the flight testing of a carrier-based plane," he said.

The problem with the plane's tailhook arose in the first place because of the inherent constraints of building a stealth fighter, Burbage said. The F-35 is the first naval stealth fighter and as such, Lockheed had the unique challenge of designing the jet with a tailhook that has to be concealed when it's not being used.

Because the tailhook has to fit within the outer mold line of the F35, the device had to be fitted farther forward on the jet's ventral surface than on other naval aircraft, Burbage said. The result is that the hook behaves differently than on previous carrier-based fighters, such as the F/A-18.

In an ideal world, an arresting hook will catch a wire 100 percent of the lime. However, in the real world, that doesn't happen due to various dynamic forces, the veteran former Navy test pilot said.

In the case of the F-35, one of those dynamic forces includes the way the wires react when the jet passes over them, in a sine wave pattern, Burbage said.

"The time differential between when the main gear rolls over the cable and the time the hook picks up the cable on a more conventional airplane, there is more time for that wave to damp out," he said. "but the case of the F-35, one of our design constraints is that hook just has to be closer to the main landing gear than on a conventional aircraft because of the requirement to hide it inside the airplane."

Another factor that affects landing on a carrier is the sheer force of the impact. Unlike conventional land-based aircraft, naval aircraft don't flare on landing. While the landing is on a more precise spot, it causes the tailhook to oscillate vertically, which increases the chances that it won't catch a wire, Burbage said. The dampening of that motion on the F-35 has to be tweaked, he said.

The shape of the hook itself also has an effect on the probability of catching a wire, he added. All of these factors are being tweaked to increase the chances that the F-35C will catch a wire on a carrier's deck.

"We're doing a redesign of the hook to increase the probability the hook will engage the wire a high percentage of the time," Burbage said...."

Unread postPosted: 23 Jan 2012, 23:55
by spazsinbad
Defense Secretary Panetta Lifts F-35B Probation PATUXENT RIVER NAVAL AIR STATION - Jan/20/2012
By Dick Myers

http://www.thebaynet.com/news/index.cfm ... y_ID/25925

"...Panetta credited the hard work of the Integrated Test Team at Pax River that consists of 550 contractor personnel and 250 civil service employees. “This generation of fighter behind me is absolutely vital to maintaining our air superiority,” the secretary said. He said he and the defense department were committed to the development of the F-35, which was good news for the community that is one of the key locations for testing the various JSF variants....

...VADM David Venlet, program executive officer for the F-35 Joint Fighter Program Office, issued the following statement upon Panetta’s release of the F-35B probation: “Secretary Panetta’s decision to take the F-35B Lightning II short takeoff, vertical landing (STOVL) variant off probation was a hard-earned and rewarding announcement for the entire DoD/Industry team that worked very hard last year. Successful F-35B performance ashore and at sea has very positively advanced the state of demonstrated capability in 2011. The positive momentum generated during 2011 will continue as testing proceeds, production aircraft are delivered, and fleet training begins in 2012.”..."
_______________

Panetta: Pax River Critical To New Defense Strategy Patuxent River, MD - Jan/23/2012 By Dick Myers

http://www.thebaynet.com/news/index.cfm ... y_ID/25932

"“This is a very unique facility. It is a national treasure that is important for us to maintain. These are world class facilities,” said U.S. Secretary of Defense Leon Panetta during a visit Friday to Patuxent River Naval Air Station.

“It is important that the U.S. military be on the technological edge of the future,” Panetta said during a visit with several hundred Pax River workers and community leaders at the Joint Strike Fighter facility. He added, “Because of you, because of the very unique testing and capability that are offered here we are able to maintain that technological edge.” Panetta toured Pax River’s facilities prior to the talk...."