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F-35 Cancelled, then what ?

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F-35 Cancelled, then what ?

Old 12th Jan 2013, 10:18
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Squirrel

Sorry nothing to report. A typical programme run through. Only what one would expect really given the public forum and the post of the speaker.

JF
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Old 12th Jan 2013, 19:12
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Saturday telegraph

Good, and informative article on the F35 in the telegraph magazine today. Worth a read to blow a few of the myths away.

Last edited by high spirits; 12th Jan 2013 at 19:13.
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Old 12th Jan 2013, 20:34
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Is there a link? Some of us are not conveniently placed to pop down to WH Smug.
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Old 12th Jan 2013, 21:02
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There's quite a lot of information on the F35, all of it critical, to be found at http://elpdefensenews.bl*gspot.com.au/

* as usual, delete '*', insert 'o' to make the link work. Well worth the look, especially for anyone who believes the hype put out by 'Lockmart', as the man who runs that site refers to the manufacturers of the jet.

Last edited by Andu; 12th Jan 2013 at 21:05.
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Old 12th Jan 2013, 22:56
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JF,

Thanks very much for this.

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Old 13th Jan 2013, 01:17
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an old problem resurfaced...

San Diego Source > News > F-35 Marine Model Stress-Testing Halted After Cracks Discovered

Jan. 12 (Bloomberg) -- Durability testing on the most complicated version of Lockheed Martin Corp.’s F-35 was halted last month after “multiple” cracks were discovered in the fighter jet, according to the Pentagon’s testing office.

The previously undisclosed halt in high-stress ground testing involves the F-35B, the Marine Corp’s version that must withstand short takeoffs and landings on carriers and amphibious warfare vessels, according to an annual report on the F-35 that Defense Department testing chief Michael Gilmore sent to Congress yesterday. Flight testing wasn’t affected.

.....

Durability testing is intended to stress an airframe, assessing its capability to achieve a projected aircraft lifetime of 8,000 “equivalent flight hours.”

Testing for the Marine short-takeoff-and-vertical landing version was progressing this year until last month’s halt “after multiple new cracks were found in a bulkhead flange” on the fuselage’s underside during an inspection after the equivalent of 7,000 hours of testing, according to the report to Congress. The cracks were confined to that area.

Testing of the F-35B model had been restarted in January 2012 after a 16-month delay caused by the discovery, analysis and repair of a previous crack in the plane’s bulkhead. All three models of the F-35 are required to go through ground testing to the equivalent of 16,000 hours of flight.

A bit unsettling news in light of the already paperthin weight margins as described by the latest pentagon rapport.

Last edited by kbrockman; 13th Jan 2013 at 01:20.
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Old 13th Jan 2013, 07:43
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A mixture of good and bad news, but I'd say (and I'm neutral on JSF overall) more bad than good:

Pentagon report cites "lack of maturity" of Lockheed F-35 jet - Yahoo! News UK



As I said many posts ago, don't underestimate the software issues involved in such a "software intense" aircraft.....



As for the process of overlapping development, production and testing, mad as cheese in terms of the customer obtaining aircraft with a decent functionality, and subsequent having to retro fit or scrap - but no doubt good for the company as they get some of the production money much earlier in the programme.
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Old 13th Jan 2013, 14:39
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Lots of stuff here:

http://media.bloomberg.com/bb/avfile/rboZtDuN4Gwk

The 20-second version:

A lot of remaining aero-mechanical problems on the B. No sign that they can't be fixed, but fixing to target lifetimes within the weight budget will not be easy. For example, clutch materials that avoid overheat while providing design lifetime are still in the research stage.

Still dealing with coatings on the H-tails getting heat damage at Max A/B.

Thermal management/aux power system still being pain in the a**.

Mach 0.8-1.2 accel time and sustained g specs relaxed. F-35C accel time increased by 43 seconds - I repeat BY not TO 43 seconds. (Total time is >110 sec by my calcs.)

Software continues to run late and fell further behind schedule in 2012.
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Old 13th Jan 2013, 16:36
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The C had a 5 out 8 success rate with the new hook design in simulated landings. Not looking good.

F-35C
• A redesign of the arresting hook system for the F-35C
to correct the inability to consistently catch cables and
compensate for greater than predicted loads took place in
2012. The redesign includes modified hook point shape to
catch the wire, one-inch longer shank to improve point of
entry, addition of damper for end-of-stroke loads, increased
size of upswing damper and impact plate, addition of
end‑of‑stroke snubber. In 2012, the following occurred:
-- Initial loads and sizing study completed showed higher
than predicted loads, impacting the upper portion of the
arresting hook system (referred to as the “Y frame,” where
loads are translated from the hook point to the aircraft) and
hold down damper (January 2012)
-- Risk reduction activities, including cable rollover
dynamics testing at Patuxent River (March 2012), deck
obstruction loads tests at Lakehurst (April 2012)
-- Flight tests with CF-3 using new hook point and new hold
down damper design at Lakehurst (August 2012)
-- 72 of 72 successful roll-in tests with MK-7 and E-28 gear
-- 5 of 8 successful fly-in tests; 3 of 8 bolters (missed wire)

They have also reduced the turn performance for all three models.

The worst problem is the software, its way behind.

Last edited by peter we; 13th Jan 2013 at 16:42.
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Old 13th Jan 2013, 16:58
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I remember when the predicted sustained g performance of the more sprightly F-35A was just over 7.3g with a nod that more could be expected.

Then it was just under 7g.

Then it was a little above 5g.

Now I see the max sustained g for the F-35A is just 4.6g.

Awesome or what.
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Old 13th Jan 2013, 18:53
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Software, software, software......


It's a software centric aircraft, the software is behind most (not all, but most) of the clever stuff it does, and I'm not sure the airforces and politicians of the world (and maybe not even the aircraft manufacturers) have got their heads around the issues (i.e. problems), as opposed to just the benefits, that software brings with it....
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Old 13th Jan 2013, 19:17
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I remember when the predicted sustained g performance of the more sprightly F-35A was just over 7.3g.....now I see the max sustained g for the F-35A is just 4.6g.
And the original performance was the equivalent of the F-16. The new performance is equivalent to?
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Old 13th Jan 2013, 19:46
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ORAC, no idea but as a blast from the past this is what it was supposed to do, back in the day:

http://www.nps.edu/Academics/Institu...%20fighter.pdf

Slide 12 promised more sustained g for the USAF variant than the F-16C...
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Old 13th Jan 2013, 21:24
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JTO - They promised a lot of things...


Oh, and who could have expected acceleration issues with the F-35C?




Last edited by LowObservable; 13th Jan 2013 at 21:25.
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Old 13th Jan 2013, 22:55
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What is the sustained G limit on, say, the F-18?

Military aircraft's G-limits - SgForums.com

Last edited by peter we; 13th Jan 2013 at 22:55.
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Old 13th Jan 2013, 23:06
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Buy Mirage 2000, must be a few secondhand. Try E-Baie.
11.2G, guns tracking an F-16 pulling 9G - I've seen it.

At some point, the political realities of deficits will mean a program this far over-budget and behind schedule will outweigh the military arguments. I think that point is less than 15 months away. If there is no significant increase in the threat from China/Russia,it will go in the budget cuts following next year's fiscal cliff, which will be even steeper than this year's. A couple of big money drains like Hurricane Sandy and it'll go sooner.

Last edited by Fox3WheresMyBanana; 13th Jan 2013 at 23:39.
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Old 14th Jan 2013, 07:15
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I think this is a refreshing approach on this programme, releasing details of technical challenges and resulting delays. Far better than MoD's head in the sand policy, denials and outright lies on the likes of Nimrod, while pouring money down the drain. It leaves room for an informed, cut-our-losses decision, galling as that may be.
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Old 14th Jan 2013, 18:12
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Originally Posted by peter we
What is the sustained G limit on, say, the F-18?
Depends on fit, AUW, etc. But it's not a 4.5g jet. As you know.
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Old 14th Jan 2013, 19:49
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Courtesy of defense-aerospace.com, I’ve just had sight of what seems to be an about-to-be-released official US Government report that is absolutely excoriating about the current progress of the F-35 - all versions. It’s Michael Gilmore’s annual report - he’s Undersecretary at the Pentagon for Operational Test & Evaluation, OT&E.

Here are a few bullet points. (mostly my bold)

F-35 doesn’t meet the Operational Requirements Document (ORD) requirement to have a vulnerability posture better than analogous legacy aircraft. This refers to the removal of “fueldraulic fuses, the PAO shutoff valve, and the dry bay fire suppression” as part of a weight-reduction program.

For the F-35A, changing performance specs to reduce “turn performance from 5.3 to 4.6 sustained Gs and extending the time for acceleration from 0.8 Mach to 1.2 Mach by 8 seconds.”

For the F-35B, changing performance specs to reduce “turn performance from 5.0 to 4.5 sustained Gs and extending the time for acceleration from 0.8 Mach to 1.2 Mach by 8 seconds.”

For the F-35C, changing performance specs to reduce “turn performance from 5.1 to 5.0 sustained Gs and extending the time for acceleration from 0.8 Mach to 1.2 Mach by at least 43 seconds.

For both A & B, “delamination and scorching of the [horizontal tail] surface coatings and structure.” because of unexpected high temperatures in sustained high-speed, high-altitude flight.

In the F-35C, “transonic buffet becomes severe in different portions of the flight envelope and is more severe in the F-35C than the other variants.”

In the F-35B, the program halted testing in December 2012 after multiple cracks were found in a bulkhead flangeon the underside of the fuselage during the 7,000-hour inspection. Root cause analysis, correlation to previous model predictions, and corrective action planning were ongoing at the time of this report
Other cracks were previously discovered in the B-model test article; one on the right side of the fuselage support frame in February and one at a wing pylon station in August, both of which were predicted by modeling. Another crack in the shear web tab that attaches to the support frame was discovered in March.
Also, excessive wear was found on the nose landing gear retractor actuator lugs and weapons bay door hinges. All of these discoveries will require mitigation plans and may include redesigning parts and additional weight.

In a live ballistic fire test, a ruptured line containing flammable PAO avionics coolant caused a sustained fire with a leak rate of 2.2 gallons per minute (gpm). The program assessed that a similar event in flight would likely cause an immediate incapacitation and loss of the pilot and aircraft.


The defense-aerospace report, which contains a link to the original 43-page OT&E document. is at
OT&E Reports New F-35 Problems

Scary stuff, even though we have heard of some of these things before. This appears to put an official seal on them.

airsound

Last edited by airsound; 14th Jan 2013 at 20:02. Reason: adding previous material comment at end
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Old 15th Jan 2013, 09:12
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More of the same, but more software details and a timeline.....

Ares: Lagging JSF Software Development Worries Pentagon DOT&E

The latest report on the F-35 program by Michael Gilmore, the Pentagon’s director of operational test and evaluation (DOT&E), spotlights growing problems with late software deliveries for the stealthy fighter.

Software releases in 2012, the report says, ran late as compared to the schedule adopted after the 2010 technical baseline review, which was carried out in part to correct optimistic projections made before that date. (The program’s leaders had underestimated the amount of regression testing — tests to make sure that changes had not induced problems in previously tested functions — and overestimated test rates and productivity.)

Block 1 software is not complete. Lot 2 and Lot 3 aircraft have been delivered “with major variances against the expected capabilities,” the report says.

Block 2A, the initial training software, was four months late and less than half of it was available at the point where the report was written. Block 2B, intended to be the first combat-capable software, is late. Block 3i (interim), a bridge between 2B and the service-standard Block 3F, “has lagged in integration and laboratory testing.”

Software problems are part but not all of the reason for slow progress with weapons integration, along with optimistic and inaccurate assumptions about the need for margins and the availability of instrumentation and range support. “The impact of these delays will potentially require an additional 18 months added to the schedule for weapons integration events,” the report warns.

The report adds to the uncertainty surrounding the F-35’s initial operational capability (IOC) dates. Last summer, Congress added language to the 2013 budget that called on the U.S. Air Force and Navy to name IOC dates for all three versions by year’s end — then changed the deadline to June 1 at the last minute. The most recent Selected Acquisition Report disclosed that Block 3F initial operational test and evaluation, a necessary event for IOC, would not be finished until 2019 — and that does not include any additional weapons integration time.............
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