Why the F 35 C?

Unread postPosted: 11 May 2016, 20:06
by aquietguy
I'm a long time reader. Just joined up. The question I have is about Navy's variant. I know the Navy likes planes with good slow speed handing for carrier landings. But isn't the F 35 A model supposed to have great high alpha maneuvering? So why even design a C model which will be more expensive?

To the best of my knowledge.

Benefits of C model:

Bigger wings equal larger fuel storage and better range.
More lift.

Draw backs of C model:

Heavier(should mostly be balanced by more lift).
More expensive.
Lack of internal gun to save weight.

Correct me if I'm wrong but looks like the Navy would have been better off strengthening the air frame of the A model.

Re: Why the F 35 C?

Unread postPosted: 11 May 2016, 20:33
by basher54321
aquietguy wrote:Correct me if I'm wrong but looks like the Navy would have been better off strengthening the air frame of the A model.


Hi - pretty sure the C came last and they did essentially strengthen the A/B - but then they needed to add bigger wings for carrier ops.

Unique features of the CV variant include a wing with approximately 35% greater area than that on the other two variants, larger tail surfaces, and ailerons on the trailing edges of the wings. These features were added to improve the slow-speed performance and flying qualities required for carrier landings. Additionally, landing gear and other main structural components have been strengthened to withstand shipboard launch and recovery. A launch bar and arresting hook are incorporated to allow catapult takeoff and arrested landings.

The Influence of Ship Configuration on the Design of the JSF( Ryberg Eric S , 2002)

Re: Why the F 35 C?

Unread postPosted: 11 May 2016, 20:55
by spazsinbad
Thanks 'basher54321' :mrgreen: That PDF/article is a great resource and should answer all questions regarding why the F-35B/C are different for shipboard deck operations. viewtopic.php?f=61&t=26629&p=282930&hilit=Ryberg#p282930 & viewtopic.php?f=61&t=26629&p=282901&hilit=Ryberg#p282901 & viewtopic.php?f=22&t=26708&p=282596&hilit=Ryberg#p282596 & a bazillion more including: viewtopic.php?f=22&t=20426&p=274027&hilit=Ryberg#p274027 wherein the PDF is attached as

The Influence of Ship Configuration on the Design of the Joint Strike Fighter Mr. Eric S. Ryberg 26-27 Feb 2002 COMPLETEpp15.pdf

download/file.php?id=19105 (PDF 1.1Mb)
______________________

Original Resource: http://handle.dtic.mil/100.2/ADA399988 (1.1Mb PDF)


Re: Why the F 35 C?

Unread postPosted: 11 May 2016, 21:03
by sprstdlyscottsmn
aquietguy wrote:Correct me if I'm wrong but looks like the Navy would have been better off strengthening the air frame of the A model.

Welcome to the boards! You are wrong however. The wings, and thus the lift they can make, are not a little bigger. They are much bigger. This means the F-35C can fly slower approaches at lower angle of attacks even with the extra weight.

If the LM had just strengthened the body of the A to handle the cats and traps then the "C" would be heavier than the current A still. This means higher approach speeds and more strain on the arresting gear and violating the Navy approach speeds requirements. So you would have to increase the lift generation anyway via larger wing. Much of the weight increase is in the big wing.

Re: Why the F 35 C?

Unread postPosted: 11 May 2016, 21:31
by XanderCrews
as others have said Its not the Alpha, its the approach speed that matters. 8)

Re: Why the F 35 C?

Unread postPosted: 11 May 2016, 22:08
by geforcerfx
Didn't the bring back requirements require the larger wing design as well? Thought I read that at some point and time.

Re: Why the F 35 C?

Unread postPosted: 11 May 2016, 22:24
by Shaken
aquietguy wrote:So why even design a C model which will be more expensive?


Landing aboard a carrier is very demanding. Getting the speed down acceptably low, while still being able to see the carrier on approach is a difficult design task and one that limits how much alpha you use without having the pilot's view obscured by the aircraft structure. Also, you don't want to be "right on the edge" performance-wise, as you need margin to deal with gusts and bumping through the turbulence generated by the large moving structure beside and underneath your landing strip.

Several very successful aircraft have made the transition from carrier aircraft to land-based aircraft. (The Phantom II stands out, but there have been a reasonable number.) There have been only a few to go the other direction and none with great success. If you were going to skip a variant of the JSF, it would be the "A". With greater sales volume, the cost of the "C" model would drop. And I'm sure that LM could fit the internal gun as an option.

Re: Why the F 35 C?

Unread postPosted: 11 May 2016, 23:13
by spazsinbad
To summarise some of the points made already: There are specific KPPs Key Performance Parameters for the F-35C in regard to CVN operations - maximum approach speed at the maximum bring back weight in a specific range of internal/external weapon load configurations. KPPs from SAR Dec 2015 for the F-35C: download/file.php?id=22832 (0.7Mb)

The F-35C must have excellent engine & control responses - also now there is Delta Flight Path or IDLC Integrated Direct Lift Control which with flaps/throttle moving automatically to keep the F-35C on speed and on glideslope the pilot can spend more time on accurate line up to arrest on target wire every time.

A bunch of quotes; whilst a tonne of info will be gleaned by searching the F-35 forum with Ryberg & RCLW separately.
F-35C Approach Criteria – Maximum Landing Weight, Optimum Angle of Attack & KIAS

"The C-model is as solid as a rock and pilots land at a much slower speed—high 120s to low 130s [KIAS]." http://www.codeonemagazine.com/f35_arti ... tem_id=110
____________________

"The Navy has added approach speed as a service specific key performance parameter. The threshold for approach speed is 145 knots with 15 knots of wind over the deck. This must be possible at Required Carrier Landing Weight (RCLW). The RCLW is the sum of the aircraft operating weight, the minimum required bringback, and enough fuel for two instrument approaches & a 100nm BINGO profile to arrive at a divert airfield with 1000 pounds of fuel. The minimum required bringback is two 2000 pound air-to-ground weapons and two AIM-120s.

The Navy further requires that the CV JSF be capable of carrier recovery with internal and external stores; the external stations must have 1000 pound capability on the outboard stations & maximum station carriage weight on the inboard." http://www.f-16.net/f-16_forum_download-id-14791.html
_______________

"The [F-35C] max trap weight will be around 46k lbs, with an empty weight of about 35k lbs. It will fly an on-speed AOA of 12.3° at 135-140 KCAS [Optimum AofA or Donut].

Due to the fact that flap scheduling is completely automatic, the cockpit was designed without a flaps switch.

Additionally, the tail hook retracts into the fuselage and is covered by hook doors that have an as-yet-to-be-determined airspeed limitation..." LT. Dan "Butters" Radocaj VX-23 Ship Suitability
http://www.hrana.org/documents/PaddlesM ... er2010.pdf
____________________

Knowles [test pilot] says the [C] aircraft approached at 135 kt., compared with 155 kt. for the smaller-winged F-35A & B variants at the same 40,000-lb. gross weight. Takeoff rotation speed was 15-20 kt. slower, he says.
http://web02.aviationweek.com/aw/generi ... ht%20Goals

Re: Why the F 35 C?

Unread postPosted: 12 May 2016, 01:30
by spazsinbad
Contrast 'how to land the F-35A' with some F-35C testing details. At 150 KIAS the F-35A is already too fast at ??? weight.
F-35 Achieves Three Major Flight Test Milestones On Same Day
29 May 2014 LM PR

"...The F-35C, designed for aircraft carrier operations, completed a landing at its maximum sink speed to test the aircraft’s landing gear, airframe and arrestment system at Naval Air Station Patuxent River, Maryland. “Five sorties were conducted, building up the maximum sink rate test condition of 21.4 feet per second, which represents the maximum sink speed planned for this test,” McFarlan said. During the tests, the F-35C did three arrestments, several touch and goes and one bolter. The landings were to demonstrate structural readiness for arrested landings on an aircraft carrier at sea..."

Source: http://www.lockheedmartin.com/us/news/p ... e-day.html

Shake Rattle and Roll
July 2014 Air International F-35 Special Edition

"...Shake testing includes catapults and arrested landings. Catapults build up in longitudinal acceleration up to 5.5g and include shots with the aircraft deliberately off the centre in the shuttle. Arrested landings include high sink rates up to 20 feet per second (1,200 feet per minute or about a 5-degree flight path angle), maximum deceleration points and free flight engagements.

“Here at the field we don’t have the ability to heave or roll the runway pitch like the boat does so we high sink the aircraft up to its limits and simulate a very hard landing. We come down at various roll and yaw attitudes, and a combination of both, to simulate pitching and rolling of the deck.

“And finally we do what we call ‘max Nx’ [maximum engagement speed] – really hit the gear hard to see the effects on the aircraft and the gear and whether we can get the hook to engage the wire prior to the aircraft coming down. “We do that in a very controlled manner. We call it a free flight [inflight arrest], to ensure that both the arresting wire and aircraft can handle the stress in the event that a pilot tries to fly away from the boat and grabs the wire while the ‘plane is either going straight [ordinary] or on an upward vector [inflight arrest].”….

Source: Air International July 2014 F-35 special edition

F-35 Lightning public debut shows the right stuff
04 Aug 2015 David Tulis

“...[Col. Chris] Niemi has eight years in the cockpit of an F-22 and is one of the few Air Force pilots who is qualified in both the Raptor and the F-35 Lightning II...." ...Niemi said typical approach speeds are 150 knots and strictly by a 13-degree angle of attack all the way to the ground. “It’s a real easy plane to fly and it has good powerful [air] [the author inserted "air" mistakenly – should read "wheel" brakes]. At 100 knots it will sit down pretty good,” he said....” [Pilot means 'powerful computer controlled wheel carbon brakes' used after initial 'aero braking' [nosewheel off] from 150 knots at touchdown, reducing during airbraking to 100 knots, then brake when three wheels are down on the runway.] - - [The benefits of approaching at a constant AoA is that as the weight decreases so will the airspeed. I cannot guess by how much however for F-35A...."

Source: http://www.aopa.org/News-and-Video/All- ... ight-stuff

Re: Why the F 35 C?

Unread postPosted: 12 May 2016, 01:56
by madrat
I think it's backwards, Navy designs tend to become Air Force designs because the former tends to have a better grasp on future-proofing. C should become the common model

Re: Why the F 35 C?

Unread postPosted: 12 May 2016, 01:59
by XanderCrews
madrat wrote:I think it's backwards, Navy designs tend to become Air Force designs because the former tends to have a better grasp on future-proofing. C should become the common model


Wut?

Re: Why the F 35 C?

Unread postPosted: 12 May 2016, 03:19
by sprstdlyscottsmn
XanderCrews wrote:
madrat wrote:I think it's backwards, Navy designs tend to become Air Force designs because the former tends to have a better grasp on future-proofing. C should become the common model


Wut?

A-7 and F-4 are examples what madrat is saying. But no, the F-35C has poor supersonic performance (which the Navy stopped caring about after they retired the F-14) so it does not meet the needs of the Air Force.

Re: Why the F 35 C?

Unread postPosted: 12 May 2016, 03:50
by vanshilar
Shaken wrote:Landing aboard a carrier is very demanding. Getting the speed down acceptably low, while still being able to see the carrier on approach is a difficult design task and one that limits how much alpha you use without having the pilot's view obscured by the aircraft structure.


I'm not saying this is wrong (I'm aware that in past aircraft this was a significant issue, leading to things like planes taking a gentle turn as their approach to the carrier, so the pilot can keep his eyes on the carrier as long as possible), but for the F-35, wouldn't the pilot be able to look "through" the aircraft due to the helmet and DAS? (I don't know if at close range i.e. carrier landing the angle difference between the DAS and the pilot's head is big enough to be noticeable). I would imagine that -- depending on the software -- the helmet could be doing something like projecting the carrier's outline as a wireframe, and show all the pertinent info the pilot needs to know (like if he's above or below the target glideslope) regardless of if the nose is in the way.

I always thought (and I may be wrong on this) the maximum alpha is due not only to the pilot's need to see the carrier on landing, but also things like the tailhook and to make sure the elevators and engine don't hit the deck (since a carrier's deck is not always horizontal, unlike a runway on land). At any rate (for the OP), yes the F-35C is needed because the bigger wings and other changes allow for better low-speed handling, the folding wing means it saves space in the hangar, etc.

Re: Why the F 35 C?

Unread postPosted: 12 May 2016, 04:18
by spazsinbad
'vanshilar' IF you read the first referenced PDF by Ryberg you will understand about what is needed. Visual reference is required IF the HUD goes pear shaped. Then the pilot has a chance to recover visually OR probably he can recover Automatically via JPALs & Delta Flight Path / IDLC - under LSO supervision - however JPALS for the F-35C is not certified, nor installed as yet. An initial version of JPALS - OK for the X-47B - was installed on suitable CVNS however it ain't qualified for humans in Super Hornets or F-35Cs but soon will be (however long 'soon' may be). And yet that was a great demonstration of the future of Auto Landings if it all works out well. Graphic below is called 'Over-the-nose Field-of-View Approach Speed Criterion' on page 10-11 of my version of the PDF: download/file.php?id=19105 (PDF 1.1Mb)


Re: Why the F 35 C?

Unread postPosted: 12 May 2016, 04:21
by yeswepromise
speaking of the hook...
Image

Re: Why the F 35 C?

Unread postPosted: 12 May 2016, 04:36
by spazsinbad
Thanks - not seen that emergency hook short field arrest photo before. There is quite a bit of info about it on this forum. I see the link to photo shows it is at Edwards AFB - so I'll guess there is a story about AF-04 testing it or wotnot MAY 2016?

http://www.edwards.af.mil/shared/media/ ... 99-461.jpg
JSF tailhook testing begins at Edwards
11 May 2016 Kenji Thuloweit 412th Test Wing Public Affairs

"5/11/2016 - EDWARDS AIR FORCE BASE, Calif. -- When most people hear "tailhook" they think of U.S. Navy planes and aircraft carriers. However, almost all U.S. combat aircraft have a tailhook.

That also goes for the Air Force's new F-35A Joint Strike Fighter.

The JSF Integrated Test Force here conducted the first set of tests for the F-35A's tailhook. F-35s have landed using a tailhook before, but not at the speeds and weights being tested now.

By nature, Navy aircraft need tailhooks to catch arresting wires on aircraft carriers. The Navy's version of the JSF - the F-35C - has a significantly more robust tailhook that is designed differently for Navy purposes.

On Air Force planes tailhooks are only used to help the jet stop when landing distance is insufficient or if the jet has a brake malfunction or directional control issue. They are designed as a one-time use device whereas Navy tailhooks like on the F-35C can deploy, retract and stow.

"In the big picture, the F-35A tailhook is designed to stop the jet in an emergency primarily," said Maj. Corey Florendo, 461st Flight Test Squadron project test pilot. "We have to make sure the system works as designed and as specified. We're out there to verify the performance of the system, up to and including the worst case conditions we can possibly envision."

The initial testing included powering the F-35A at 180 knots over the ground; about 200 miles an hour.

As high speed cameras record, AF-04 from the 461st FLTS speeds down the runway. Engineers plan the time to deploy the tailhook, and when the time comes, the test pilot deploys the hook to catch an arresting cable in place to safely stop the fighter. Data is collected and the video footage is reviewed.

"There's a lot of parameters that we're looking at. Obviously, we're curious about the forces on the hook. Aside from just the numbers, we're also curious if the tailhook system is going to be safe. 'Is the cable going to do something like hook the main landing gear and not the cable?' No one has done this before, and before this happens to someone out in the Air Force, we want to see it and make sure it works," Florendo said.

AF-04 had several successful engagements with the tailhook and arresting cable, which will clear the path for additional tests coming up. Florendo said they will be looking at different "offsets" in future tests.

"Ideally you want to be in the center of the runway, but we want to also test to see what happens when the pilot is not in the center," he said.

Like most other test projects on Edwards, JSF tailhook testing requires heavy coordination throughout different organizations on base and off.

"Obviously, we're not the only program that executes here at Edwards," said Andrew Soundy, Lockheed Martin experimental test pilot. "We have the main runway that has the permanent cables attached, so if we're doing cable testing or landing gear testing, we really need sole use of the runway. If we used the permanent cables, we would severely impact the outer runway."

That's where the Air Force's 820th RED HORSE Airmen from Nellis Air Force Base, Nevada, come in. RED HORSE stands for rapid engineer deployable heavy operational repair squadron engineers. The team set up the mobile aircraft arresting system on Edwards' 12,000-foot inside runway so impact on other flight operations is minimal during testing.

"I've been involved in a lot of test projects over the year, this one has probably the most input from multiple different agencies and it's great to see the way it's all come together," said Soundy.

"The big thing to me is the team effort that's been going on here at Edwards. This is a great place to be doing testing with the weather that we get here and the experience we have here; all those teams coming together to make this happen has been great."

Testing will continue this summer."

Source: http://www.edwards.af.mil/news/story.asp?id=123473739

Re: Why the F 35 C?

Unread postPosted: 12 May 2016, 07:50
by 35_aoa
spazsinbad wrote:The F-35C must have excellent engine & control responses - also now there is Delta Flight Path or IDLC Integrated Direct Lift Control which with flaps/throttle moving automatically to keep the F-35C on speed and on glideslope the pilot can spend more time on accurate line up to arrest on target wire every time.


You had me at "DLC"……seriously, that will be huge and I am glad someone aside from Grumman has given that concept a rebirth. I have been known to use a little "Hornet DLC" here and there, i.e. a little rocking/wagging of the wings from in close to at the ramp, but that technique can get a guy in a lot of trouble real fast if they aren't careful, especially in a combat loaded F/A-18C at max trap in the persian gulf. Couple IDLC with "magic carpet" and I think there will be a lot of kids out there who won't have to suffer through the school of hard knocks that you or I did behind the boat at night. Which in my opinion is a good thing. Landing shouldn't be the biggest thing on your mind when you are still over bad guy land at night or as the sun goes down and you know you are about to head home.

Re: Why the F 35 C?

Unread postPosted: 12 May 2016, 08:36
by aquietguy
Thanks for all the responses. I wondered about that after learning about the excellent slow speed handing.

Re: Why the F 35 C?

Unread postPosted: 12 May 2016, 08:59
by spazsinbad
Mention NavAv (Naval Aviation - especially conventional) and I'll have a Video or PDF or two about it from my research/own experience now a long time ago. Searching the F-35 forum for IDLC will find some good results such as: viewtopic.php?f=57&t=28046&p=311220&hilit=IDLC#p311220

Only a few years ago now a lot of good NavAv info was taken offline for whatever reason. APPROACH magazines of yore have gone offline also which is a real shame for the old bastards like me. So my PDFs have info/stories (from APPROACH) that is no longer at the URLs of origin. Delta Flight Path would be another F-35 forum search term.

There are some good videos about IDLC/Delta Flight Path - I'll post some of them below - usually from TAILHOOKs.

















[youtube[X-pWG4T65f0[/youtube]






Re: Why the F 35 C?

Unread postPosted: 12 May 2016, 09:49
by 35_aoa
I've said it before, but I will say it again Spaz…….you need to carve out some time in your life to come to 'Hook. It is worth the 15 hour flight. There is even an A-4 admin, mostly manned by old grey haired guys, but at least sometimes visited by lost much younger ladies :)

Re: Why the F 35 C?

Unread postPosted: 12 May 2016, 10:01
by spazsinbad
:doh: Freck :devil: :mrgreen: Who do you think I am but an old grey haired bearded git?! :roll: Thanks for the invite but as mentioned at beginning of this year I had a health scare which may be an issue; whilst I was not likely to travel to TAILHOOK - except virtually (with the ladies virtue intact). :twisted: :shock: Probably about a decade or more ago now one of our most senior experienced RAN FAA pilots went to TAILHOOK (he had flown Sea Furies in Korea off HMAS Sydney, then became CO of 805 Sea Venoms off HMAS Melbourne then the first CO again now with VF-805 off MELBOURNE in 1969). Anyway he said he was 'overwhelmed'. :wink:

I spent a month at NAS Miramar with VFP-63 back in early 1973 (not flying though) and I was overwhelmed at the 'O' Club also. :mrgreen: Not to mention visits to NAS Cubi Point early 1972 and NAS Barbers Point late 1971 with VF-805 so I have experience at the 'tired and emotional' aspect of it all. :) These days I need to be healthy to HARANGUE people here. 8)

A lady on the MAGIC CARPET.


Re: Why the F 35 C?

Unread postPosted: 13 May 2016, 10:45
by spazsinbad
Pity we ended up with this F-35A emergency hook testing on an unrelated thread so bear with... THEN ZOOOOOOMMMMM!

http://www.edwards.af.mil/shared/media/ ... 99-413.jpg

SO TO COMPENSATE here is the video which shoulda bin in the other list above.
F-35 New Flight Control Software
Published on Jul 24, 2012 NAVAIRSYSCOM

"A F-35 Joint Strike Fighter test pilot discusses new flight control software
to aid in carrier approaches. Video courtesy of Lockheed Martin."


Re: Why the F 35 C?

Unread postPosted: 13 May 2016, 16:54
by madrat
I understand that the F-35C will have more drag and weight, but why wouldn't an F-35C body built with USAF-specific kit (internal gun, boom receptacle, etc.) be a better all around option? The F-35A has a bigger internal bay, but at Max loads it's going to be hard on its gear and it's fuel burn is going to be relatively high with it's higher wing loading. The level acceleration difference should be much less different at those weights, too, because the A is going to be in higher trim. As the program matures and the available engine power gets further opened up, it would seem the bigger wing will only be more of a plus.

Re: Why the F 35 C?

Unread postPosted: 13 May 2016, 17:02
by slapshot!
madrat wrote:I understand that the F-35C will have more drag and weight, but why wouldn't an F-35C body built with USAF-specific kit (internal gun, boom receptacle, etc.) be a better all around option? The F-35A has a bigger internal bay, but at Max loads it's going to be hard on its gear and it's fuel burn is going to be relatively high with it's higher wing loading. The level acceleration difference should be much less different at those weights, too, because the A is going to be in higher trim. As the program matures and the available engine power gets further opened up, it would seem the bigger wing will only be more of a plus.


Because the F35A is built to what the Air Force actually wants.

Re: Why the F 35 C?

Unread postPosted: 13 May 2016, 18:41
by spazsinbad
The F-35B has the smaller internal bays compared to the same same F-35A & C bays AFAIK - same load capacity anyway.

Re: Why the F 35 C?

Unread postPosted: 13 May 2016, 20:48
by popcorn
Because the F-35C is going to weigh more and you are paying by the pound. The extra weight does not add any significant capability to the AF but the cost burden would add up and almost certainly result in a smaller fleet.

Re: Why the F 35 C?

Unread postPosted: 13 May 2016, 23:42
by XanderCrews
madrat wrote:I understand that the F-35C will have more drag and weight, but why wouldn't an F-35C body built with USAF-specific kit (internal gun, boom receptacle, etc.) be a better all around option? The F-35A has a bigger internal bay, but at Max loads it's going to be hard on its gear and it's fuel burn is going to be relatively high with it's higher wing loading. The level acceleration difference should be much less different at those weights, too, because the A is going to be in higher trim. As the program matures and the available engine power gets further opened up, it would seem the bigger wing will only be more of a plus.


[/quote]


If anything I would be curious to see if the gun pod is more attractive over time and the gun removed on later A variants <shrug>

Re: Why the F 35 C?

Unread postPosted: 13 May 2016, 23:49
by count_to_10
XanderCrews wrote:
madrat wrote:I understand that the F-35C will have more drag and weight, but why wouldn't an F-35C body built with USAF-specific kit (internal gun, boom receptacle, etc.) be a better all around option? The F-35A has a bigger internal bay, but at Max loads it's going to be hard on its gear and it's fuel burn is going to be relatively high with it's higher wing loading. The level acceleration difference should be much less different at those weights, too, because the A is going to be in higher trim. As the program matures and the available engine power gets further opened up, it would seem the bigger wing will only be more of a plus.



If anything I would be curious to see if the gun pod is more attractive over time and the gun removed on later A variants <shrug>

Well, how much would have to be re-tested for an 'A variant with the B/C fuel tanks instead of a gun?

Re: Why the F 35 C?

Unread postPosted: 14 May 2016, 01:00
by yeswepromise
perhaps i should have put af04 in its own thread huh

Re: Why the F 35 C?

Unread postPosted: 15 May 2016, 13:11
by spazsinbad
:mrgreen: This is a tricky forum eh but what the hey... HERE is some more INFO on why the F-35C IS SOOOO HEAVY - MAN. :devil:
The C at Sea: The F-35 Aboard the USS Dwight D. Eisenhower
02 Oct 2015 USS DWIGHT D. EISENHOWER (CVN-69)

"...Jim Gigliotti, a Navy Veteran whose 28-year Naval Aviation career included aircraft operations and test tours of duty as well as Command of the Aircraft Carrier USS Harry S Truman.... gave us a few more details about DT-II.

Tough Enough
A standard airframe for a fighter jet is made out of the lightest but strongest materials possible. But for the F-35C, those standard materials won’t cut it. Carrier-based operations are very unforgiving to an aircraft because of the roughness of arrested landings and catapult takeoffs. Aircraft not specifically designed for ship operations would be unable to cope with the harsh carrier environment and would not survive the loads and stresses put on the vehicle. So the airframe, or the “skeleton,” of the F-35C contains a significant amount of titanium, one of the strongest metals available.

As a result, the F-35C weighs 5,500 pounds more than an A variant
, which is designed to perform conventional takeoff and landings – on land. The B-variant (which is also capable of ship operations) contains titanium as well, but because the short takeoffs and vertical landings it performs aren’t as stressing as arrested landings and catapult takeoffs, not as much titanium is necessary.

In addition to needing a sturdier airframe, the F-35’s stealth coatings must be capable of standing up to the harsh and sometimes unpredictable weather conditions in an at-sea environment. So how does the F-35’s stealth coating hold up?

“For almost the last decade, we’ve been putting panels that are made the same way F-35 panels are made on legacy aircraft that are deployed at-sea,” explains Gigliotti. “This was meant to check just that – how well do the coatings wear on this aircraft?” In addition, climactic tests have been conducted on the aircraft to ensure it can withstand extreme heat, cold and moisture...."

Photo: https://a855196877272cb14560-2a4fa819a6 ... _main.jpeg

Source: https://www.f35.com/in-depth/detail/the ... eisenhower