I don’t pretend to be an expert, but not sure what you mean by this statement ? Could you please expand on this one for me ? I was not aware that airframes had to “look” a certain way to work ? Would have thought engineering etc would have a bigger input than looks ?

Cheers

OK, try to imagining cutting loads of slices of the JSF longitudinally, then measuring the cross-sectional area (CSA) of those slices. For simple modelling, the measured CSA can be lumped into a circle of suitable radius then attached back to the fore and aft CSAs.

Basically, with the Mach-area rule, you want the change in overall CSA as you move from nose to tail to be as gradual as possible and to peak around the middle of the jet*. The optimum is something similar to:

As you can imagine… slice the JSF up and its area change would look very little like the above. 🙂

*Note, this particular philosophy can be modified somewhat depending on how you integrate your engine nozzles.

What are the fundamental problems with the airframe of the F-35 – she looks like a nimble little ****** to me…

Aerodynamically:
Sustained turn rate is shocking (was an early snapshot not quoted as inferior to that great dogfighter… the F-4).
High speed drag is also poor; not a complete killer, but not good if, like Japan (or Canada), you will want to use the thing as an interceptor to stop inbounds from attacking your shipping/infrastructure.

Structurally:
Many fatigue issues becoming apparent on frames… already.
Buffeting of the vertical fins is an issue; fixing it will not be as “straightforward” as on the F/A-18 lineage.
The arrestor hook redesign will require major revamping of the load-paths from arrestor hook to airframe.

Misc:
The weapons bay is not big enough. As a result, combat persistence is extremely poor, or LO capabilities must be sacrificed.

I’m sure there are a host of others I am forgetting, but these will do for now.

you regularly read japanese language documents?

He’s a bullsh!tter.

All program managers like the sound of their own voices too much… regardless of the accuracy of the content their voices are producing.

For instance:

they’re regarded as Ti tubbed as the Ti is in areas designed to stop you copping some kinetic mike mike up the clacker

Squared with:

you do realise that the last armoured production asset was the A-10, and that the last heavy armoured asset post production in the west were the Swiss Hornets with titanium tubs? Physical armour was replaced some time ago, As in ships, the armour is about defeating and anticipating electronically rather than taking hits to the body. Hence why the swiss don’t seem to have seen a need for ti tubbed gripens.

and

the Swiss Hornets have some internal structural components manufactured from titanium which were aluminium alloy before, to meet service life requirements with Swiss-mandated 9g manoeuvring specifications.

gf has found out that a few fuselage frames around the wing root have been made from Ti… then extrapolates that to mean armour that prevents light ground fire penetrating key systems.

The Swiss Hornets used Ti bulkheads/frames entirely for fatigue issues. Ignore the bullsh!tter.

Do you understand a thin, minimal shape is not better than an arced, curved shape?

Do you know what the Mach-area rule is? Do you understand the consequences of the F-35’s large increase in area of the forebody immediately aft of the cockpit?

The body of the F-35 is a better shape than you give it credit; it is an excellent shape for high speed flight.

No its not – its a terrible shape. (Oh and very qualified to know.)

Add in the fact I’m also talking about this particular post that compares the internal carriage of weapons against the competitors that carry external loads.

Yet, look at the evidence. It still is amongst the slowest of all its contemporaries. So much for the excellent shape.

Accelerate to Mach 1.8 when that is above it’s design limit?

I’d be surprised if you extended the test out another hundred if the competitors had any advantage. You cannot maintain such high speeds without a relatively high fuel burn. Having that streamlined shape and the brute force at military power of an F135 is a big advantage.

What streamlined shape?

Do you not grasp the dire consequences of forcing the A and C versions to have the same fuselage outer mould line as the B version*?

*Which has to pack in the lift fan immediately behind the cockpit.

A VLO “bowtie” RCS is the defining quality of a 5th gen fighter, so I’m not sure what you expect a defining characteristic (that cannot be applied to a 4th gen airframe) to be. Just to be sure I will put up everything the F-35 has 😉

1. VLO RCS airframe
2. Active and passive IR reduction measures
3. Internal weapons bays (essential for VLO)
4. Advanced ESM gear
5. Internal space available for AESA jammers if ever required
6. Advanced AESA capable of active jamming in conjunction with the ESM
7. Full integration from ALL data sources
8. HMD with 3D audio cuing
9. Voice activated avionics
10. Fiber optic interconnect to all weapon stations and avionics
11. Ability to launch any weapon based on any weapon quality track from any data source.
12. Continuous 360 IIR WVR tracking of missiles and planes
13. Internal & automatic diagnostics and logistics
14. PnP weapons integration (via UAI)
15. Internal IRST and FLIR (essential for VLO)
16. Built-in training via simulated targets, linkable worldwide
17. Directional & LPI datalinks
18. When fully fueled and armed, it has better flight performance than many 4th gen assets that are loaded similarly.

1. Due to small surface features, the F-35 is going to have limited VLO characteristics.
2. The F-22 has active IR signature reduction methods. The F-35 does not. The F-35 will have active IR countermeasures – not the same thing.
3. OK – but it is of very limited size, meaning very limited combat persistence.
4. So the Rafale/EF-T/Gripen don’t have advanced ESM?
5. The AESA radar itself can function as a jammer.
6. What is the point of (5)? Unless you are saying the additional locations can greatly improve the spherical coverage?
7. 90% of data are already used collaboratively in 4th gen aircraft. The diminished returns are not something broadcast by LM. For instance, the EF-T can slave PIRATE off the RWR.
8. Whoops… right now it looks like F-35 will be using roughly the same one as the Typhoon/Gripen.
9. Big deal. Even so, the Typhoon has voice commands.
10. Are you serious? Unless there is an advantage in bandwidth or latency that can be utilised, then this is completely irrelevant.
11. Fair enough.
12. Most aircraft built since the 80s have had MAWs.
13. Whoopee. So when the F-35 tells the mechanics “hey, 4 of my main fuselage ribs are about to fail from fatigue” does that indicate a superlative 5th gen fighter?
14. You could do with finding out more about the competition. While the interface may not be the same, most sport plug and play capability.
15. Due to the F-35 having numerous other small surface features, the advantages of the internal IRST/FLIR are largely offset.
16. N/A
17. Fair enough.
18. See quote below:

Lockheed Martin has defended the air-to-air capabilities of the F-35 Lightning II Joint Strike Fighter (JSF) while conceding that the aircraft’s performance in combat within visual range (WVR) will only be marginally superior to that of its fourth-generation and advanced fourth-generation counterparts.

Briefing Australian journalists at Lockheed Martin’s Fort Worth facility on 2 February, Jerry Mazanowski, senior manager of air systems in the company’s strategic studies group, compared the air-to-air performance of the F-35 with that of the Eurofighter, Dassault Rafale, Saab Gripen, Boeing F/A-18 Super Hornet and Sukhoi Su-30MKI. He said that in a typical combat configuration carrying four internally stored AIM-120 Advanced Medium-Range Air-to-Air Missiles (AMRAAMs), the F-35 was marginally faster than the Su-30MKI carrying eight beyond-visual-range (BVR) missiles and no external fuel tanks; and that it was faster than the Eurofighter, Gripen C, Rafale and F/A-18 carrying four BVR and two WVR missiles and a single external fuel tank (two in the Eurofighter’s case).

On an air-to-air mission with a radius of 200 n miles, no external fuel tanks but the same missile load and a requirement to accelerate from Mach 0.8 to Mach 1.8 at 30,000 ft, the F-35 was shown coming second last. With a requirement involving the same acceleration and the aircraft tasked for a 600 n mile ‘out and back’ mission, Mazanowski said the F-35 was “nothing stellar but certainly not an underperformer in this category”.

simple simon says.

engineers designed the plane around requirements
engineers endorse any changes that are accepted as changes to scope
engineers are required to ensure that the whole platform works as expected and to the accredited level.
engineers have the obligation to make sure the specs are going to work as expected.
the engineers can stop the project at any stage if it doesn’t meet their requirements or fail the accreditation processes that they stipulate

Simon is simple as he still doesn’t get it.

If the engineers are not allowed to get their tools and databases up to speed then part 1 of the above is wrong – and everything else just gets worse from there.

Hence why validation of models and performing things like coupon tests up front are critical to a program’s good execution. Yet they are the things most often sacrificed in the name of “schedule”.