F-35 Program - General Discussion

John Newman

The Bunker Group
Since 2017 when the R.A.A.F confirmed all of its F35-A fighters had been upgraded to block 3f have further upgrades been planned , and is there a long term plan to upgrade to block 4?
Block 4 is extremely important to the RAAF.

Whilst the F-35A is a much more technologically advanced aircraft, compared to the Classic Hornets, we have actually gone backwards in two significant areas.

Those two areas are the ability to carry and launch long range strike weapons and anti-ship missiles.

With the retirement of the Classic fleet we lost their JASSM and Harpoon capabilities.

Block 4 adds JASSM-ER, LRASM and JSM to the Global F-35 fleet, the RAAF has both JASSM-ER and LRASM on order, no order as yet for JSM (JSM is currently planned for Norway and Japan).

The only anti-ship missile (Harpoon) capability currently in RAAF inventory is the Super Hornet and Poseidon fleets.

Block 4 can’t come soon enough for the RAAF.
 

Vivendi

Well-Known Member
Block 4 is extremely important to all F-35 users that faces a near-peer threat, not just the RAAF...

I am somewhat confused about the process -- I thought lot 15 and onwards would have the TR3 which is the main building block (pun not intended) for block 4. It was also my understanding that USAF had recently reduced F-35 buys because they are waiting for block 4. Why then are lots 16 and 17 so small? Is there much more to the "block 4" story than just TR 3? Perhaps it's just the new radar...?
 

John Newman

The Bunker Group
The journey from Block 3F to Block 4.

If the media headlines are to believed (and that also includes many Defence media outlets), Block 4 has been delayed by three years, eg 2029, instead of the original date of 2026.

But that’s all very misleading to say the least.

Block 4 has been reported to be made up of approx 80% software and 20% hardware (TR3).

The TR3 hardware upgrades will be introduced to the production line this year, 2023, and existing aircraft will be upgraded during depot level maintenance, existing users will no doubt schedule those upgrades at a time that suits and the hardware is available to install.

Now to the software.

Block 4 is already underway, it is made up of 90ish separate software drops, the first started in 2019, the last in 2029.


Yes the block 4 scheduled timeframe has ‘grown’ by three years, yes delays, but it has also been expanded and enlarged too.

There are improvements that will be fleet wide across the world, but other software drops will be for specific weapons for specific countries, eg, the UK has different weapons requirements to Australia, Norway and Japan require JSM integration, etc.

It may well be that some nations have their specific requirements prior to other nations and ‘complete’ Block 4 prior to 2029, all depends on when that upgrade is scheduled for.

It would be good to have a list of what each of those 90 individual software drops are, but I don’t think that info is in the public domain.

See the screen shot below:

20256A81-BA1C-4D9C-8943-26CB92ACD979.png
 
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Vivendi

Well-Known Member
Thanks for the update -- but none of that explains why the USAF are not increasing F-35 purchases in the coming lots. Installing new HW is normally much more expensive than updating the SW. So I could understand the delay in purchasing F-35 until TR3 became available. But I cannot understand the seemingly slow purchase rates after TR3. So something else is going on? Perhaps they are waiting for the new radar that will start arriving in lot 17?
 

John Newman

The Bunker Group
Thanks for the update -- but none of that explains why the USAF are not increasing F-35 purchases in the coming lots. Installing new HW is normally much more expensive than updating the SW. So I could understand the delay in purchasing F-35 until TR3 became available. But I cannot understand the seemingly slow purchase rates after TR3. So something else is going on? Perhaps they are waiting for the new radar that will start arriving in lot 17?
Not being a Yank I wouldn’t have a friggen clue why.

But....

US procurement is a bit of an odd animal, there always appears to be a large level of horse trading.

The services appear to put in their wish list (X number of this, X number of that, etc), Congress and the Senate appear to fiddle with those numbers, some times numbers are cut, sometimes they are added too (don’t they have a thing called the ‘unfunded’ list?).

Anyway, a lot of politics appear to be involved, and not just with the F-35, but across the board too.
 

OPSSG

Super Moderator
Staff member
Perhaps they [the USAF] are waiting for the new radar that will start arriving in lot 17?
1. I think that might be the case for the USAF — they are at a steady state of converting squadrons to F-35As. With the amount of new FMS orders, there will be a ramp up sooner or later.

2. I suspect the USAF is vacating a few slots here & there, for some priority countries (like Finland & Poland), who are on the frontline with a Russian threat. There is no rush for the USAF, as they already have a large fleet of F-35As in service.

3. The USAF needs to fund the B-21 bomber and the Next Generation Air Dominance fighter, a slow down for 2-3 years makes sense, while waiting for software to mature & to upgrade older block 4s with the new AN/APG-85 AESA radar.

4. Again I suspect the AN/APG-85 AESA radar is a low hanging fruit from the Next Generation Air Dominance fighter, which is classified.

5. The F135 was designed to handle a 15 kilowatts cooling demand, but that requirement has already doubled to an estimated 30 kilowatts. Cooling air is generated primarily by pulling bleed air from the engine and running it through heat exchangers (see: 9 reasons why the F-35 needs a new engine).
  • The F135 meets the 30 kilowatts demand by pulling more bleed air from the engine, which further reduces thrust.
  • By the time Block 4 version of the F-35 is fully fielded in 2028, aircraft sub-systems will need a minimum of 47 kilowatts of cooling, and the amount required to meet follow-on capability demands range as high as 60 kilowatts.
  • The performance and tactical effective range of subsystems like a new AN/APG-85 radar [PDF] and enhanced electronic warfare systems that will come with the F-35 Block 4 will require more electrical power. Add upgrades that are on the horizon like directed energy weapons, and you start hitting voltage stops.
  • More than that the “first three increments of the [#F35] fighter’s Block 4 upgrade can function with the existing engine. Beyond that, we need to do something different. The jet can’t fully exploit Block 4’s capabilities without more power" said Lt. Gen. Eric Fick PEO F-35 (JPO) via: AF Magazine.
6. In view of the above, I speculate that the RSAF’s buy strategy may be, as follows:
  • batch 1 — 4 x F-35B
  • batch 2 — 2 x F-35B (lot 18)
  • batch 3 — 4 x F-35B (lot 19)
7. I suspect the RSAF will IOC the 1st squadron with 10 or more F-35Bs in the 2032 to 2035 time frame. In the meanwhile, Singapore will mature its fighter VLO tactics to use the cooperative battlespace with the F-15SGs while under the control of the G550AEW — with an upgrade of the F-15SGs in the late 2030s (with even more cooling and power), to keep them current to threats. By 2035, the RSAF’s F-35Bs can run primary or hand-off the missile strike to F-15SG.

8. The Pratt F135 engine was the only major F-35 sub-system that failed to cut its acquisition costs to reach weapons system program targets, which made bringing the cost of the F-35A below its US$80 million target that much more challenging.

9. Having Pratt and GE compete side by side for future engine contracts will force both to maximize the performance and minimize the cost of their engines.

10. I suspect that there is incentive to wait for a block 4, F-35A, in the 2036 to 2039 period, with:
  • an AN/APG-85 AESA radar; and
  • a GE engine from the Adaptive Engine Transition Program (if the USAF selects it).
11. To help the RSN secure our SLOCs, the RSAF badly needs a 2nd F-35A squadron with more range, given that the combat radius of all three variants some 15% below the program’s objectives.

12. The F-35 needs a more powerful, fuel-efficient engine.
 
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SolarisKenzo

Well-Known Member
Countries like the USA, Italy or Japan are in fact undergoing a slower delivery rate of their own aircraft.
These 3 countries, where the 3 F-35s assembly lines are, are prioritizing deliveries for export customers and building their own planes at a slower rate, for many reasons.
1- Industrial: They prefer to let the assembly line work on more profitable export planes, instead of having them working on national-bought ones, to satifiy export demands.
2- Economical: Export planes are more profitable because the government dont have to actually pay for them, doing so they can delay the payments for their own planes.
3- Tech: If you build export planes first, you will end up having less planes in the short term, but you will be able to assembly more advanced planes later. Later blocks, Tranches, more sofisticated hardware and software...
4- Strategic: Its better, as OPSSG said, to have F35s delivered to countries like Finland, Poland, Korea, Australia... that are closer to the frontline.

For example, I can speak about my country: We have a complete assembly line in Cameri building F35s for Italy, Netherlands, Switzerland and rumors are that Finland and Czech Republic will build part of their fighters here too.
Plus, Cameri produces 66 wings a year, with a capacity of 72 and 200 already delivered.
Italian Air Force, tho, is slowing as much as possible their own f35s deliveries.
33 dutch f35s were delivered against only 18 italian ones.
Why? for the reasons i told you before.
Now that Switzerland decided to build f35s here, their planes will be prioritize over italian ones.
Same thing if more countries ( very likely at least a couple more air forces will have their JSFs built in Cameri) decides to do so.
Its just politics and profit, nothing more.
 

swerve

Super Moderator
Countries like the USA, Italy or Japan are in fact undergoing a slower delivery rate of their own aircraft.
These 3 countries, where the 3 F-35s assembly lines are, are prioritizing deliveries for export customers and building their own planes at a slower rate, for many reasons.
Cameri was always intended to be a FACO site for European F-35 users, not just Italy, but I thought the Japanese would only be building their own. At 14 per year that'll take them over 10 years, while at 26 per year Cameri should be able to supply the Italian air force & Navy in less than 3.5 years, which could be quicker than Italy's armed forces can accept them. Cameri needs export work to be viable.
 

StingrayOZ

Super Moderator
Staff member
UK is also slowing F-35 deliveries.

Managing a large upgrade to blk 4 is an issue. Ideally you would get undelivered aircraft already in TR3 and not just that, in a much later configuration of TR3, and ideally with in place solutions for future growth.

Plenty of nations are waiting for weapons to be integrated as part of Blk4. Not having maritime strike for example, not particularly wonderful for island nations with coastlines, or nations with carriers. The delay in blk 4 is a significant issue. particularly when thinking about the strategic situation in asia the 2027-2030 period. How many Blk4 aircraft will be available during this time period? What if there are more delays? What if there is just a slow ramp on things like new engines and systems to allow existing aircraft to be upgraded?
 

Vivendi

Well-Known Member
Plenty of nations are waiting for weapons to be integrated as part of Blk4. Not having maritime strike for example, not particularly wonderful for island nations with coastlines, or nations with carriers. The delay in blk 4 is a significant issue. particularly when thinking about the strategic situation in asia the 2027-2030 period. How many Blk4 aircraft will be available during this time period? What if there are more delays? What if there is just a slow ramp on things like new engines and systems to allow existing aircraft to be upgraded?
I agree. Given the significant delays I am surprised they have not integrated some key capabilities in particular maritime strike into the current block. I recall many years ago I was told how easy it would be to integrate weapons into the F-35. I have previously linked to articles describing all the work that has been done already, integrating the JSM into the F-35. But it cannot be used with the F-35 yet since block 4 is not available yet!

Integrating HARMs into Mig-29 and Su-27 took 2 months -- I wonder how long it would take to integrate a weapon already integrated into a future F-35 block 4, also into 3F, and how much it would cost? Integration Of HARM On Ukraine’s MiG-29s, Su-27s Took 2 Months | Aviation Week Network

Since it's not been done, I am starting to question how easy it really is to integrate weapons into the F-35... perhaps an issue with the "temporary" 3F?

From the outside, it certainly does not look very impressive, considering considering how much it has cost to develop this thing, from scratch. I believe some of the requirements were even related to "ease of integration"?
 

StingrayOZ

Super Moderator
Staff member
TR-3 took its first flight yesterday.


I agree. Given the significant delays I am surprised they have not integrated some key capabilities in particular maritime strike into the current block. I recall many years ago I was told how easy it would be to integrate weapons into the F-35. I have previously linked to articles describing all the work that has been done already, integrating the JSM into the F-35. But it cannot be used with the F-35 yet since block 4 is not available yet!
It kind of will be, in the future. Obviously with the F-35 there is a lot going on right to get the program up to speed. Eventually weapon integration will be very easy across all three versions. It just takes time. Most countries aren't particularly concerned with maritime strike, most buy aircraft for air defence.

But the problem is now it isn't there. Blk IV is really the first proper warfighting version, IMO. For Australia the lack of maritime strike is critical. The USN has a large Superhornet fleet so its priority isn't on the F-35.

Things should progress much quicker now TR3 is flying. As the earlier computer and systems setup really were quite limited and flat out with the capabilities they were trying to offer.

But the F-35 program is just late in general. Perhaps showing the weakness of a giant combined program. Also there is usually a bit of competitiveness between USAF and USN programs that kind of doesn't happen with the F-35. Certainly a stoppage in one program doesn't usually stop both USAF and USN programs, but with the F-35, that does happen. USAF is the bigger customer so tends to win out on priorities, and USAF isn't particularly concerned about anti-shipping capability.
 

SolarisKenzo

Well-Known Member
We should also never forget that this is the biggest fighter program since the f16.
Even after all the troubles at the start of the program, the costs ramping up and all the anti-f35 propaganda, we reached 2022 with more than 870 machines delivered and most of them in service.
Will we reach the more than 3300/3500 planes planned? Difficult to say, we could even go higher. ( 3700?)
But even if we stop at, let's say, 2000 or 2500, we will have learned a lot.
Not for free, of course, but the west didnt really launch any mass-scale fighter program for decades...And we now have a plane that is CTOL, STOVL and CATOBAR with still relatively small differences between versions.
And 3 assembly lines in 3 different continents...
 

John Fedup

The Bunker Group
We should also never forget that this is the biggest fighter program since the f16.
Even after all the troubles at the start of the program, the costs ramping up and all the anti-f35 propaganda, we reached 2022 with more than 870 machines delivered and most of them in service.
Will we reach the more than 3300/3500 planes planned? Difficult to say, we could even go higher. ( 3700?)
But even if we stop at, let's say, 2000 or 2500, we will have learned a lot.
Not for free, of course, but the west didnt really launch any mass-scale fighter program for decades...And we now have a plane that is CTOL, STOVL and CATOBAR with still relatively small differences between versions.
And 3 assembly lines in 3 different continents...
For people with long memories, the F-16 introduction wasn’t a smooth introduction either. I can still vaguely recall a US 60 Minutes episode detailing how GD hid (or ignored) fraying insulation wiring that resulted in a a pilot death. Stuff happens with any complex product, the F-35, given its vastly more complex design is doing quite well IMO.
 

John Fedup

The Bunker Group
A rather confusing article about the recent F-35 crash. Apparently a harmonic resonance occurred in the F135 engine. This problem supposedly is limited to a small number of aircraft and was previously identified but other factors somehow made it a system problem(?). No indication of it being a model issue although the recent incident was a B version. A simple hardware fix will solve this. This must give GE some encouragement wrt their adaptive cycle engine promotion.
 

John Fedup

The Bunker Group
It is poorly described - the fleet has flown 600,000 hours. The aeroplane that crashed was in acceptance testing where it is flown fresh out of the factory, (test flights to check for any gremlins) prior to delivery to the customer.
Indeed, poorly described. My understanding from the article is some kind of issue had been identified before the 600,000 hour mark but something else enhanced the harmonic resonance issue.
 

John Fedup

The Bunker Group
It seems the fix won’t be limited to a few aircraft, it will be applied to the entire F-35 fleet. Apparently the 30 minute install for the fix is more like 4-8 hours. There must have been a significant reason as to why the fix went from a few to the entire fleet besides being cheap and quick.

 

Rob c

The Bunker Group
Verified Defense Pro
It seems the fix won’t be limited to a few aircraft, it will be applied to the entire F-35 fleet. Apparently the 30 minute install for the fix is more like 4-8 hours. There must have been a significant reason as to why the fix went from a few to the entire fleet besides being cheap and quick.

It probably is only 30 min to install on the engine but access and the follow up tests take up the rest of the time.

I remember once having the job with my team of replacing the de-icing valve on a Skyhawk. This had 4 bolts, one clamp and an electrical plug to be removed; only problem one bolt was completely inaccessible. So to complete the job (on a Saturday) we had to take the tail off, slide the engine back, fit the new valve, reassemble it all, then test every thing we had disturbed and do low power engine checks. Totally stuffed my Saturday because of one bolt.:mad:
 
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