F-35 news roundup

[TaiidanTomcat]

Thanks for taking the time to explain that, Bob Very helpful

I think earlier in the thread you mentioned something about some kind of combat simulation/war game where the super hornet didn't perform so well a high threat environment? I thought that would have helped push the navy toward the JSF?

Edited August 28, 2011 by TaiidanTomcat

[ixgr1]

-I saw a great quote over the weekend

"Great recipe for failure - try to please everybody"

-just thought it was appropriate to this thread ?

[Spongebob]

TT,

Overall, it'll come down to what the current analysis effort yields. I'm sure the root questions are, what are the envisioned future missions, what capabilities are required, is the Navy best suited to provide those capabilities and are they best provided by the JSF or some other system?

HTH

Spongebob

[TaiidanTomcat]

TT,

Overall, it'll come down to what the current analysis effort yields. I'm sure the root questions are, what are the envisioned future missions, what capabilities are required, is the Navy best suited to provide those capabilities and are they best provided by the JSF or some other system?

HTH

Spongebob

Thanks Again

[Mark M.]

Spongebob, you bring up some good counterpoints, but I'll suggest there is middle ground.

STOVL doesn't mean you HAVE to land vertically. Much like a harrier you can come in with forward momentum at slower speeds than a full-out conventional landing, and come to a rolling stop with minimal distance.

You don't need to sit directly over the ship and lower down vertically.

So you have good points, but if considering efficiency and safety and turnaround times, there is a middle ground.

I also think the turnaround times you mention warrant 2 comments:

1) If the might of the US Navy had 100 years of practice pushing and striving to refine the turnaround time of vertical landings, it would rival or exceed the turnaround time on conventional arrestor hook landings.

2) While there may be more time taken up in vertical landings (assuming for the argument this isn't fixed with determined deck crews practicing all the time), that "time" might cost less than all the steel cables, constant wheel replacements, deck damage, gear strut damage, and all other parts, replacements, and on-ship storage required to maintain the arrestor system. So time is money but by spending a little money "here" you may save 10x more "there"... Especially on a big deck carrier, where you would free up 50% of the deck space by going purely SVTOL.

I'll add a #3. Assuming purely vertical landings (no rolling landings) on a 1000-foot long deck you could operate at least 3 different landings/takeoffs at the same time. With a wingspan of some 30-odd feet you would still have over 300 feet between aircraft in this example. That's an entire football field! More than enough safety margin. You may increase activity by simply accommodating for more personnel to control/coordinate the traffic. Just a thought.

[TaiidanTomcat]

Spongebob, you bring up some good counterpoints, but I'll suggest there is middle ground.

STOVL doesn't mean you HAVE to land vertically. Much like a harrier you can come in with forward momentum at slower speeds than a full-out conventional landing, and come to a rolling stop with minimal distance.

You don't need to sit directly over the ship and lower down vertically.

So you have good points, but if considering efficiency and safety and turnaround times, there is a middle ground.

I also think the turnaround times you mention warrant 2 comments:

1) If the might of the US Navy had 100 years of practice pushing and striving to refine the turnaround time of vertical landings, it would rival or exceed the turnaround time on conventional arrestor hook landings.

2) While there may be more time taken up in vertical landings (assuming for the argument this isn't fixed with determined deck crews practicing all the time), that "time" might cost less than all the steel cables, constant wheel replacements, deck damage, gear strut damage, and all other parts, replacements, and on-ship storage required to maintain the arrestor system. So time is money but by spending a little money "here" you may save 10x more "there"... Especially on a big deck carrier, where you would free up 50% of the deck space by going purely SVTOL.

I'll add a #3. Assuming purely vertical landings (no rolling landings) on a 1000-foot long deck you could operate at least 3 different landings/takeoffs at the same time. With a wingspan of some 30-odd feet you would still have over 300 feet between aircraft in this example. That's an entire football field! More than enough safety margin. You may increase activity by simply accommodating for more personnel to control/coordinate the traffic. Just a thought.

Interesting ideas! Again not saying the Navy doesn't have good reasons and other advantages of how they do it now. But it is interesting to ponder alternatives.

[11bee]

I'll add a #3. Assuming purely vertical landings (no rolling landings) on a 1000-foot long deck you could operate at least 3 different landings/takeoffs at the same time. With a wingspan of some 30-odd feet you would still have over 300 feet between aircraft in this example. That's an entire football field! More than enough safety margin. You may increase activity by simply accommodating for more personnel to control/coordinate the traffic. Just a thought.

What is the "bring-back" capacity of the B version vrs the C? Is it the same or does the B have some of the issues that the earlier Hornets had with possibly having to jettison very expensive weapons to get down to max landing weight?

[MarkW]

The answer is it depends, largely based on fuel state. For both the B & C, there are max landing weights. In both cases, if you have to go around right after launch, you got a problem that is more due to fuel weight than weapons. The B is being developed to maximize bring back via rolling landings.

[Spongebob]

1) If the might of the US Navy had 100 years of practice pushing and striving to refine the turnaround time of vertical landings, it would rival or exceed the turnaround time on conventional arrestor hook landings.

I'm not fully convinced because of the reason's below...but if US Naval Aviation was built around VTOL or even VSTOL the carrier would look quite different than it does today in order to be better optimized for it. However, since that's not the case, for at least the next 20 years the US Navy has to deal with what it has on hand.

2) While there may be more time taken up in vertical landings (assuming for the argument this isn't fixed with determined deck crews practicing all the time), that "time" might cost less than all the steel cables, constant wheel replacements, deck damage, gear strut damage, and all other parts, replacements, and on-ship storage required to maintain the arrestor system. So time is money but by spending a little money "here" you may save 10x more "there"... Especially on a big deck carrier, where you would free up 50% of the deck space by going purely SVTOL.

Most of the time in the trap evolution isn't taken up by the trap or resetting the gear. It's taken up by taxiing to the right, de-arming the forward firing ordnance and turning so the hot exhaust is not blowing the landing area (even at idle it tends to cause compressor stalls at in opportune moments, and probably just as much a concern for STOVL aircraft as you'd be sucking that hot air into the lift fan = less lift). Wheels are typically chunked by the locked-brake turns necessary when taxiing around the flight deck and over hatches, etc., so no saving there. And talking to the ship integration guys here (who constantly remind us to "not be like JSF") deck, deck edge equipment (like all the lifeboats there) and antenna damage from a STOVL JSF is a huge concern. Can't argue the gear support. Lastly, the actual arrestment takes up about 350ft of the deck space...you'd need at least that for a rolling recovery. The space between the ramp and the gear is there to give an acceptable crossing height over the ramp based on a normal glideslope (3.25 effective (adjusted for wind)) which you would want to keep for any platform.

'll add a #3. Assuming purely vertical landings (no rolling landings) on a 1000-foot long deck you could operate at least 3 different landings/takeoffs at the same time. With a wingspan of some 30-odd feet you would still have over 300 feet between aircraft in this example. That's an entire football field! More than enough safety margin. You may increase activity by simply accommodating for more personnel to control/coordinate the traffic. Just a thought.

With the current deck planform, you'd give up your maintenance, turnaround and arming areas if you did that, and the VTOL thrust patterns are nasty so you'd need room. Current LHA/D operations can/do use multiple spots for landings, but you still need to stagger them and they take as much time or more than cyclic CV ops. Now, if you had a planform like CV-58 was to have (Linky) you may be onto something.

Also, as you would still be with a slow roller landing, if you're below the stall speed on the wing, you are dependent on the amount of thrust you can generate, which limits the size of the aircraft.

HTH

Spongebob

Edited September 1, 2011 by Spongebob

[Mark M.]

Yes that was more along the lines of "what if they went fully STOVL" rather than mixed. Still, food for thought.

[TaiidanTomcat]

I'm not fully convinced because of the reason's below...but if US Naval Aviation was built around VTOL or even VSTOL the carrier would look quite different than it does today in order to be better optimized for it. However, since that's not the case, for at least the next 20 years the US Navy has to deal with what it has on hand.

In your opinion do you think it would be doable providing the navy was willing to redesign its carriers in the future? (this is all purely hypothetical, obviously) very nice of you to explain all of this, some i know is basic and some not so much.

[Spongebob]

In your opinion do you think it would be doable providing the navy was willing to redesign its carriers in the future? (this is all purely hypothetical, obviously) very nice of you to explain all of this, some i know is basic and some not so much.

Most definitely, if that decision was made.

[Antonov]

Meh... nevermind.

Edited September 2, 2011 by Antonov

[MarkW]

If it makes you feel any better, the Chinese hordes couldn't cross the bay bridge due to its miserable condition....

[Deke]

My link

Lockheed F-35 Fighter Has ‘Design Flaw’ in Wing Part, Pentagon Tester Says

QBy Tony Capaccio - Sep 1, 2011 2:49 PM ET

Two of three models of Lockheed Martin Corp. (LMT)’s F-35 jet have a “design flaw†that reduces the expected life of a wing structure to 1,200 hours, which is “significantly less than†the expected 8,000 hours, according to the U.S. Defense Department’s testing office.

The “defective†aluminum beam was detected in November on Air Force and Marine Corps test aircraft after an unrelated bulkhead crack surfaced in the Marine Corps model, the office said. The Air Force plans to buy 1,763 of the 2,443 total in the $382 billion U.S. program, the Marines 371.

The flawed part is the forward root rib, an aluminum beam at the forward-inboard corner of the wing that supports a fuselage fairing panel on the Joint Strike Fighter’s leading edge flap, according to Lockheed.

“Structural analysis predicted†that the root rib will have “less than the desired fatigue life,†Pentagon Director of Operational Test and Evaluation Michael Gilmore said in an e- mail statement. “Its short predicted life relative to the stated requirement is a design flaw,†he said.

The heretofore undisclosed flaw underscores the potential for additional cost growth and schedule delays on the Pentagon’s largest weapons program. Previous problems caused former Secretary of Defense Robert Gates to put the jet into an extended development phase not scheduled to end until 2016, four years later than the original schedule.

Wing Won’t Fail

The issue is one of long-term durability that, were the part not fixed, would add to maintenance and support cost. A preliminary Pentagon estimate already pegs F-35 operating costs at as much as $1 trillion, based on a model used by 107 squadrons at 50 sites through 2065, according to Lockheed.

The F-35 program office and Lockheed Martin have conducted a safety assessment and concluded that a root rib failure would not lead to wing failure, F-35 program spokesman Joseph DellaVedova said in an e-mail.

“This is not considered a serious issue,†DellaVedova said. The program office and Lockheed have developed retrofits and new production improvements designed to extend the beam’s life and correct “durability deficiencies,†he said.

“Resolving durability test findings is a well understood process,†he said. Durability testing is conducted early “to avoid costly sustainment later,†he said.

The Air Force’s principle military deputy for acquisition, Lieutenant General Mark Shackelford, said in an interview today the “unanticipated bill†for the fixes will likely come from program funding.

Retrofits Planned

The root rib must be redesigned for future production aircraft, Gilmore said. Inspection and repair procedures are being created for the existing test and production aircraft, Gilmore said.

DellaVedova said in an e-mail statement that about 30 Air Force and 30 Marine Corps versions will be retrofitted. A new design will be incorporated on the assembly line in the upcoming fifth low-rate production contract. The Navy aircraft carrier version does not have this durability issue, he said.

Lockheed Martin spokeswoman Laurie Quincy said the F-35 program office statement speaks for the company.

Shackelford said “while you don’t want to have that type of discovery, it’s a fact of life when you are building new aircraft.â€

The defect “is not serious enough to be a danger of a loss of a wing -- not a catastrophic failure,†said Shackelford, a former F-22 test pilot. “But there will be some flying-hour limit,†on current jets and “inspections to monitor that structural member. That has some implication in terms of our maintenance work on the aircraft.â€

‘Difficult’ Fix

Gilmore said “it remains to be seen how disruptive†retrofitting aircraft will be to the ongoing flight test and field operations. “The needed modification is understood to be a difficult and complex process,†Gilmore said.

“Little durability testing has actually been completed; therefore, more discovery is possible,†Gilmore said.

Aircraft produced with the original root rib “must be inspected periodically†and have required repair before approximately 1,000 flight hours, Gilmore said.

Durability testing of the wing area was resumed in May but halted last month for about a week when a crack was discovered in a predicted area of the root rib after about 2,800 hours of testing, DellaVedova said. The test was resumed a week later and is ongoing for completion of 3,000 hours, he said. The crack is being monitored.

[Guest Hoban Washburne]

1,200 hours seems a bit low, eh? Haven't many US fighters been extended through various SLEPS and STARS to fly towards the 12,000 hour mark and beyond?

[Mark S.]

It would be helpful if the article included such information as whether or not the part is in the primary load carrying structure. Seems to me it is part of the structure to support the leading edge flap. Would be interesting to know if the loads on that flap are greater than anticipated in the original design and why. That's the nitty-gritty that won't leave the engineering offices of L-M and the AF.

Mark S.

[MarkW]

What makes you think it is related to the leading edge?

[GreyGhost]

I really don't see this one as a big deal ...

Sounds like a minor design flaw has shown up through testing(exactly what testing is for) and is being rectified ...

Gregg

[GreyGhost]

Here's a photo that shows the size of the F-35A off well ...

>>> Link to the slideshow <<<

Gregg

[TaiidanTomcat]

I really don't see this one as a big deal ...

Sounds like a minor design flaw has shown up through testing(exactly what testing is for) and is being rectified ...

That attitude will never get you elected. Can you manufacture some false outrage?

On a serious note, thanks for sharing the pic Greg

[11bee]

The answer is it depends, largely based on fuel state. For both the B & C, there are max landing weights. In both cases, if you have to go around right after launch, you got a problem that is more due to fuel weight than weapons. The B is being developed to maximize bring back via rolling landings.

FWIW, the latest Aviation Week has an article about the potential cancellation of the B. They quote the Brits as being less than pleased with the B's bring-back capability. They also mention that the exhaust is much more damaging to semi-prepared surfaces than that of the Harrier, to the point that it must land on specially poured high temp concrete. Kinda ruins the USMC PR image of fleets of B models flying out of parking lots and basic forward bases. Maybe the Corp can convert some of their new CH-53K's into airborne cement mixers so special teams of elite combat concrete technicians can form up and pour 100' x 100' concrete mats for these birds?

[MarkW]

The B was never spec'd to operate in STOVL mode on any surface. It can do short takeoff from asphalt, like the Harrier, but also like the Harrier it can't do vertical landings on asphalt. Main operating bases always envisioned using concrete pads for VLs, and asphalt runways for STO and conventional takeoff/landing. The expeditionary role always envisioned using AM2 matting at forward locations for STOVL ops.

Testing to date has shown the VL profile is ok on ship decks, this will be further proven during upcoming testing on the U.S.S. Wasp.

As for the Brits, they have been out of the STOVL discussion for some time. Why are they suddenly relevant?

But hey, why let facts ruin a good story...

Edited September 3, 2011 by MarkW

[TaiidanTomcat]

FWIW, the latest Aviation Week has an article about the potential cancellation of the B. They quote the Brits as being less than pleased with the B's bring-back capability. They also mention that the exhaust is much more damaging to semi-prepared surfaces than that of the Harrier, to the point that it must land on specially poured high temp concrete. Kinda ruins the USMC PR image of fleets of B models flying out of parking lots and basic forward bases. Maybe the Corp can convert some of their new CH-53K's into airborne cement mixers so special teams of elite combat concrete technicians can form up and pour 100' x 100' concrete mats for these birds?

Wow really? Thats a good point, I mean there is no way we could somehow develop new matting or anything. Clearly all hope is lost. We have boxed ourselves into the coffin corner of concrete, with no logical escape. Doomed I say Doomed. Sure you can develop a top of the line fighter that hovers and is invisible to radar, but yeah developing new matting is beyond all human capability. Thats why the Navy can't have jets, because their carriers have small, wooden decks and its limited them ever since.

we were surprised to see the only photo in the story as showing an F-35B landing on AM-2 matting at Pax River. And here we learn that “Aluminum matting is used to protect the surface from the F135 engine exhaust.”

Having watched many Harriers land on AM-2 matting last week at an airfield in North Carolina, we were surprised to learn that AM-2 matting in the photo was being deployed for engine exhaust of another aircraft.

So we decided to call the USMC HQ specialist on the matter. Major Brad Alello and he told us that “AM-2 matting has been used by the USMC since BEFORE the Vietnam War.” But for Av Week’s imaginative purpose they make this a modification for the F-35B. Perhaps some facts checking in the rest of the article might be called for.

Second point; Reporter Sweetman quoted Undersecretary Work as his saying-the case for the F-35B would be much more hazardous in the presence of G_RAMM (guided rockets, artillery, mortars and missiles) threats—I guess the Marine concept of building an agility response group with MV-22s and F-35Bs to go where the enemy isn’t concentrated escaped analysis or comment

A retort for this:

http://www.sldforum.com/2011/08/under-secretary-of-the-navy-robert-works-july-tac-air-memo/

which uses Bill Sweetman analysis, which is a man who is completely unbiased toward the USMC and the F-35B especially. His articles are gospel. book it, done.

And seriously the UK gave it up a long time ago, sighting "bring back capability" is a much easier out than "yeah we pretty much retired our whole FAA years ago," or "our navy force is a shadow of itself!" At this point they are looking at not even buying the F-35C so they can sight whatever they want, No one was surprised that the country that merged its Fleet Air Arm into the air force and then retired its air force in whole chunks, would suddenly back away from the most expensive variant. and then surprise again! is looking into even cheaper options now. the UK currently relies on the Apache helicopter as its primary carrier borne combat aircraft. I guess Harriers, Tornado F.3s, and all those other aircraft had "poor bring back capability" as well. The UK is cutting some of its Gurkhas as well, and we all know how they suck.

Edited September 3, 2011 by TaiidanTomcat

[Litvyak]

Rule, Britannia! indeed... :(