F-35 Variants (FS9, FSX and P3Dv4)

[VulcanDriver]

Quite a busy week with the F-35B. I did a lot of re-work of the nose to get a more accurate shape and also set up the aircraft for STOVL performance with the vertical land. Brent has tested that successfully on the short runway at the Yuma Auxilliary Landing Field.

While some testing of the F-35B was going on by Brent and Steve, I thought I would press ahead and work the F-35B into the F-35C. That meant taking out the unwanted cavities and doors of the “B” model, enlarging the wings, fins and horizontal stabilisers, lengthening and squeezing the cockpit, adding the arrestor hook fairing to the tail and building a new more robust nose gear with twin wheels, and of course, animating the folding wings.





If members here could keep an eye out for me please for a piece of information (evidence) I need for an alternative “B” model, that I want to set up for conventional take-off and landing, I'd be grateful. I’m assuming this mode will be used quite regularly in the real world. In the sim world, it would also give users the opportunity to view the “B” model in flight in a traffic window, which cannot capture the model when operating with an animated vertical lift, unless the window is zoomed right out.

The question is this – for a conventional take-off and landing, does the F-35B normally operate with all the lift doors open and the nozzle at about 45 degrees, or are all the doors closed and the nozzle left horizontally. I’ve found only a couple of videos of the “B” model operating conventionally – by the US Marine Corps. In those instances all the doors were open as if performing a vertical land. If you spot anything to confirm or negate that as standard practice, please let me know.

I’m just about ready to start the design of the texture sheet and start the mapping, so hopefully, some colour to show you in the next update.

John

Simulated conventional landing on QE class carrier. Useful data regarding speeds.

https://ukdefencejournal.org.uk/simulat ... -carriers/

Looks like they land clean.



STOL take off



HTH

Cheers

[hawk_sh]

Regarding that short take-off:

It looks like they are using a combination of elevator input and vectored thrust to get the right nose attitude for short takeoff.
That means that the nozzle is not at a constant angle during the short takeoff.

You can see this on this video during the ski-jump testing but I have also seen this on videos of USMC F-35Bs taking of from the LHDs:


It appears they start the takeoff run with a nozzle angle smaller than 45° to get more forward thrust for accelerating.
In the video for me it looks like ca. 30° nozzle angle at the moment the main wheels leave the ramp.
When the jet is in the air (weight off wheels?) the nozzle rotates to ca. 45°to get more lift.

I do not know whether it is possible to simulate this for an AI aircraft or whether it is worth the effort.

Here is another one where it can be clearly seen:

[Firebird]

What about the landings, Hartwig? Did you manage to find anything for that.

I think that this is key question. Our gut feeling is that the lift engine and nozzle mechanism is complicated and therefore we think that for normal airfield operations they may use the normal take off and landing as standard to save wear and tear, something like the fact that roller landings are severally reduced to save wear and tear on gear and tires.
Shipboard operation is another thing entirely.
The RAF/RN is to use rolling landings as standard on its carriers, not vertical ones, to increase the landing weight and therefore save weapons and fuel for further sorties. They are called SRVL which knowing the Armed Forces that is called 'shrivel'. What we don't know is what the RAF/RN will do on dry land.

The key question is what do the USMC do for standard landings on airfields, and for that matter the RAF/RN? I can appreciate that whilst we all want to cover every eventuality the reality is that modellers would much rather prefer to other models than produce basically 16 versions of the same one. So if the info is out there and we can find it then John can adapt his strategy accordingly.
In simple terms he would like to cover the largest percentage of operations with the smallest number of models.

So all you followers of military fashion this is your chance to influence how the project turns out.

[clickclickdoh]

Conventional landing during deployment arrival at MCAS Iwakuni


Long video of flight ops at MCAS Iwakuni has both conventional and STOVL operations:

[hawk_sh]

Steve, that were exactly my thoughts regarding the wear on the aircraft.

I think the following model+FDE variations would cover most of the real life operations:

1) conventional takeoff and landing
This could use same FDE as the F-35A?
There are several videos on youtube, search for F-35B + Iwakuni, showing F-35Bs operating like this.
So when there is an airfield available this would be the way to go.
--> clean model, no external loads
--> models with external loads

2) short takeoff + short/rolling landing
shipboard operation for the RN and short field operation for RN and USMC
land based operation in preparation for carrier deployment
--> clean model, no external loads
--> models with external loads

3) short takeoff + vertical landing
shipboard operation for the USMC
land based operation in preparation for carrier deployment
--> clean model, no external loads
--> external air-to-air missiles, gunpod
I have not seen any pictures or videos of vertical landings with external bombs yet.

4) vertical takeoff + vertical landing
It just looks too cool.
operation in testing or training environment, airshow
--> clean model, no external loads


Any other combination of takeoff and landing can be achieved with some flight planning tricks.
For example:
vertical takeoff with model #4, then fly away to a virtual waypoint,
return from virtual waypont to the takoff location using model #1 with the same repaint and loadout and do a conventional landing

[Firebird]

It does seem that they do operate in the CTOL config then.

The SRVL config is definitely confirmed for the UK carriers and may well be used for the large US carriers and small landing strips but it seems that space will be at a premium aboard USMC LHDs and may not be used.

The STOVL config seems to be destined primarily for the USMC shipbourne aircraft although it is very possible that the MM will also operate the same way as their carrier is smaller than conventional ones.

I can't speak for John here, but my guess would be that the VTOVL model is not going to be justifiable, no matter how cool it would look. Purely from an fde perspective. The other 3 could very well be done but no doubt John will chat with a few people first about that.
It is all about the workload involved.

Thank you gentlemen.

If anybody else has some pertinent info then feel free to add to it but please refrain from talking about weapon fits as they are not relevant to this question.

[clickclickdoh]

The USMC has F-35Cs on order for the squadrons that will be doing duty on CVNs. The F-35B will be staying on the smaller ships.

[John Young]

Thanks for the input guys. The complication I was exploring was whether for a conventional F-35B take-off and landing on a long runway, the norm is to have the engine doors open or closed. It’s not primarily an FDE question, it’s a modelling question. It seems from all that I’ve seen of this type of landing, both doors open and doors closed are used on occasions.

I think 6 F-35B models are needed then:

STOVL (Short Take-off Vertical Land) no external load (uses the Harrier STOL FDE as a basis). Doors open.

VTOL (Vertical take-off, Vertical Land) no external load (uses the Harrier VTOL FDE as a basis). Doors open.

STOSL_1 (Short Take-off, Short Land) no external load (uses the Harrier STOL FDE, but will need tweaking to remove the full stop landing). Doors open, nozzle at 45 degrees.

STOSL_2 (Short Take-off, Short Land) with external load (uses the Harrier STOL FDE, but will need tweaking to remove the full stop landing). Doors open, nozzle at 45 degrees.

CTOL_1 (Conventional Take-off and Land) no external load (uses the F-35A FDE). Doors closed.

CTOL_2 (Conventional Take-off and Land) with external load (uses the F-35A FDE). Doors closed.

I’m unsure if a Vertical Landing with a full external weapons load is possible in practice on a carrier deck, but presumably pilots will need to be able to return in an emergency loaded, unless the load is jettisoned first. The F-35B doesn’t have an arrester hook. I’ll omit the vertical/loaded option I think.

If this make sense, I'll proceed on that basis.

John

[clickclickdoh]

If it helps any John, all the videos I have seen of F-35Bs doing rolling landings with the doors open are flight test aircraft. I suspect what the videos are showing is part of a progressive speed testing regiment where they start at high speed and gradually slow to VTOL.

[John Young]

So, we don't really need the STOSL_1 and STOSL_2 models. Is that right?

John

[clickclickdoh]

After reading up on what you crazy folks on that side of the pond are planning, it appears you might need it after all. It appears that some technique called SRVL has been developed to perform 70 knot rolling landings on the Queen Elizabeth....

Predictions on how long that lasts are just as long as it takes for the first anti skid failure, then it's right back to STOVL operations.

[Firebird]

Brent,
Its no problem. Power up and go around. If it is a permanent failure then you lose weight and land vertically, but this of course is well beyond the game. It may sound crazy but the UK has a history of crazy naval aviation ideas that eventually caught on.

John,
Yes the UK will use the STOSL_1 and STOSL_2 models.
Shrivel is purely designed to allow heavier landing weights and they are the mode that the RAF/RN will use.
I take Brent's point about the USMC versions and so they may not use it even on dry land strips. So as I understand it there would be two models STOSL_1/2 purely for the UK use.

In short due to the nature of the beast VL operations could be only internal weapons or no weapons, save the gun pod and, possibly, wing tanks as these will obviously be empty at time of landing. This does mean that most USMC operations on ships are going to be quite vanilla but there are likely to be that way in real life anyway most of the time.

As John says CTOL operations will be unlimited.

There is an interesting page showing a simulated SRVL approach at 57kts, if anybody is interested http://www.thedrive.com/the-war-zone/13 ... y-carriers.

[clickclickdoh]

It may sound crazy but the UK has a history of crazy naval aviation ideas that eventually caught on.

Oi, just because you guys invented almost every useful innovation in carrier aviation.... Oh, wait... good point.

[John Young]

No problem, 6 F-35B models it is.

The F-35C, I think is easier to figure. I think it needs 2 models (4 if external loads are an option)

Carrier ops - short take-off, arrested land, hook down, horizontal stabilisers to horizontal on touchdown (in case of a bolt) and wing fold.

Airfield ops - conventional (F-35A FDE) take-off and land, no hook, horizontal stabilisers down on touchdown (spoiler brake), no wing fold.

John

[Firebird]

Yep. What you are saying is that the A is a piece of cake after the other two.

[John Young]

Yes indeed, particularly for FSX/P3D. The "B" has 42 parts that require either animation or visibility tags or both for those sim versions. Multiply by the 6 LODs that have them and that's between 200 and 252 tags to be applied. Not as bad as the Osprey had I produced the FSX/P3D versions. That had 50 parts requiring tags. Tagging is the most boring job in all of AI aircraft design, but it's the one that needs the most concentration. Why Microsoft introduced them is beyond me. FS9 works perfectly well without them.

John

[John Young]

The F-35B took as long to map and paint as it did to build the model - very tricky with the RAM lines. I used an example of a US Marine Corps aircraft from VFMA-121, that will be used by Brent, along with 14 other F-35B's at Iwakuni Japan. The screen shots are FS9 during a flight from my test airfield:

















I'll paint up the UK examples next plus the ones for Hartwig at Pax River. Then I can make the LODs and then move on to paint the "C" model.

John

[mikewmac]

That looks fantastic John! You do amazing work my friend.

[clickclickdoh]

That is spectacular looking John

[DaleRFU]

Wow, that looks sensational