FlyingIrons Simulations A-7E

[Silver_Dragon 411]

A new 3rd party has incoming to DCS, FlyingIrons Simulations, a X-Plane developer turn to DCS and has making a A-7E Corsair II. Meanwhile, waiting a official news on ED forum

https://flyingironsimulations.com/blogs/news/dcs-a-7e-corsair-ii-by-flyingiron-sims

[Phantom88 3,282]

Greetings!

Today I'd like to share our 2022 end of year development report on the A7 Corsair, which has been extracted from our full company report which is available here

A7 Corsair II for DCS World

Artwork

The Corsair has had a tumultuous journey! 2022 saw the completion of our complete remake of the A7 3D model, which took a significant amount of time.  With the aid of Iakov, our new artist, both the external and internal models of the A7 have been completely remade from scratch as we've previously discussed. The remake started work in 2021 and was completed around Q3 in 2022. The remake is significantly more detailed than our original model, with almost all elements of the aircraft accurately modelled, including maintenance areas.

Having such a detailed model delivered by Iakov meant that lots of work was required in terms of optimizing the model to extract the maximum possible performance, without compromising much detail. This is still ongoing, however most of the exterior has now been optimized, as well as large chunks of the cockpit. Work is ongoing to optimize the remainder of the cockpit so it can then be textured.

Work has begun on UV mapping the exterior model and to that end we have created a dedicated Paint-Kit team, who are providing value feedback during the UV mapping process to ensure that our paint-kit is as easy to use as possible for livery artists.

Work is also well underway in animating the cockpit & exterior as well as setting up clickable areas, which has been very helpful in allowing us to start testing more systems in-flight using proper procedures. 

 

Flight Modelling

The A7 Flight Model has undergone extensive work this year, especially in the first half of the year, with much of that work being 'behind the scenes' so to speak. This year we've been working closely with Research in Flight, an aerospace & hydrodynamics analysis company that creates tools for aerospace engineering applications. They are the developers of Flightstream, a sophisticated numerical flow solver and one of our primary tools that we use for CFD analysis & data collection for the A7.

We have been working closely with them to enhance & improve our A7 Corsair model, to the point where we have been able to supply validation studies and case tests against the real wind-tunnel data we have gathered. The A7 model has also been used to test & assist in development of new control surface analysis techniques being integrated into Flightstream, in turn also enhancing our data collection capabilities for various control surface & damage configurations.

CFD Collaboration & NASA Presentation

As part of our collaboration, we spent some time this year developing some internal tools to aid in the collection of CFD data; not only for the A7 but also for any model we wish to analyze. One such tool that I developed personally was a utility that facilitated the conversion of an OpenVSP model into a solution-ready FlightStream model. Without going into too much detail, what this accomplished was an extremely fast & efficient method for simple OpenVSP geometry models to be analysed in great detail in FlightStream. For us, this allows us to gather CFD data in a fraction of the time required using traditional modelling techniques. Our work was shown off at the 2022 NASA OpenVSP workshop, and we have since made the tool publicly available, where it is now being used around the world in both academic & commercial design purposes. We have even been informed the utility is being used over at Boeing! It is our hope that this simple tool will make CFD modelling more accessible to all sim developers. For further reading, you can see the presentation slides that relate to the relevant Flightstream developments here.

Of course, all this only matters if it helps us to develop the A7! Although it's taken some time, these developments have been a worthy time investment. By forging a new workflow, we're able to tweak & experiment with our models in a fraction of the time to get the best results possible when testing unusual aircraft configurations. If you've worked with CFD or know alittle about it, you'll know that it is an enormously time-intensive process using conventional techniques, and almost always requires constant model tuning & tweaking to collect valid results. As we are now developing the advanced aspects of the A7 Flight Model, this has been absolutely essential when testing non-standard configurations.

For example, using our workflow we've been able to run tests and collect data on virtually every control surface interaction possible, in order to assess the relative significance of unusual interactions and determine how best to model them in-sim. Some examples include interactions between the flaps & elevator at various high Angle-of-Attack configs, forces in a spin and leading to a spin, spin recovery analysis and post-stall analysis. Furthermore, this new modelling workflow has provided us with a very efficient means to study the effects of airframe damage on flight dynamics, an aspect that is often modelled with only very simple approximations due to data limitations. Not so anymore!

Design & Development of Control Augmentation System (CAS) and Automatic Flight Control Systems (AFCS)

In terms of Flight modelling, the latter half of 2022 has been heavily focused on designing & developing the CAS for the A7 Corsair. This has been a huge undertaking and admittedly has required a large amount of time on my part devoted to studying advanced engineering control system design principles.

Although we don't have the exact equations used in the real aircraft CAS, we do fortunately have enough information on the inputs & outputs of the system to be able to reverse engineer it. This has required us to approach the situation in much the same way as the original aircraft designers, attempting to carefully craft a control system that meets the requirements of the airframe and pilots.

Although work is still ongoing, we are quite pleased with how things are shaping up and are confident that with the feedback from our SME's we will be able to fine-tune the CAS to operate almost exactly as the real system would. Flying with the CAS switched on is a completely different experience than flying with it off; the airframe is incredibly difficult to control without it. Therefore, it is absolutely critical that we get this right and we are dedicating an appropriate amount of time & resources to try and achieve this.

The CAS is only one part of the A7's AFCS, which is used not only to enhance flight stability but also for Autopilot control of the aircraft. The AFCS is being developed in tandem with the CAS and has made significant progress in 2022. The primary Autopilot modes (HDG, ALT, ATT, Airspeed) have all been developed & implemented. We are currently in the process of refining the Yaw Stab system, which stabilizes and corrects for aircraft slip and assists in turn coordination.

CAS & AFCS naturally have a strong interconnection with the control surfaces and thus required a complete rewrite of all of our control surface models. This was completed in 2022 and are controls are now working in harmony with the AFCS, respecting defined authority limits and behaviours. As a pilot you will need to be aware of & respect these limits to ensure that you are working with, and not against, the AFCS.

The A7 Corsair is not a simple airframe to fly; it has extensive quirks that need to be understood and mastered for the aircraft to be flown effectively. The AFCS is a quintessential part of this; understanding & mastering it will be a key component of flying the A7 well.

Other FM Developments

On top of everything discussed above, this year we have been working to refine our mathematical classes & methods implemented in our codebase. Focusing on optimization, we have been spending time implementing new methods of data processing that require less computational resources to achieve the same result. An example of this is interpolation and look-up table (LUT) modelling, which is the foundation of data processing in a simulator and one of the primary methods used to implement CFD & aerodynamics data. These calculations happen thousands of times every second and have thus been a big priority for us in terms of code optimization.

As discussed in the CFD section, we have developed a new workflow that has allowed us to quickly and efficiently analyze aircraft damage scenarios and the impact of damage on Flight dynamics. While still in-progress, we have been very pleased with the data we've been able to collect and are currently busy expanding the Flight Model to include damage modelling.

Sound Design

Although still only in the very early stages of development, work has begun on sound design for Corsair! Thanks to the collaboration from some amazing people in the community, we've been able to organise the recording of a real A7 during a maintenance engine run. This is of course an extremely rare opportunity, and we are so grateful to the good people at Tulsa Tech University for making this possible!

Thanks to some collaborative efforts from 'Armorine' in our community discord (who has also been invaluable in helping us to secure certain documents. Thank you Armorine!), we were able to organise a professional field recording of the A7. The recording was carried out by Tulsa Tech's team of sound engineers & sound engineering students, with the entire engine run captured from various positions by professional grade equipment. The team even went so far as to produce an excellent master of the samples for us! In total we were given an amazing 29 high-quality aircraft samples from various mic positions, as well as 4 completed mixdown tracks.

Below you can see some shots from the recording process

 

Tulsa Tech sound engineering team, responsible for the excellent recordings provided.
Images provided by Tulsa Tech & Armorine

System & Weapons Development

Alongside all of this, work has continued throughout the year to develop and flesh out the cockpit systems of the Corsair. Once again, we owe our thanks to 'Armorine' for assisting in helping us to acquire some missing documentation. Unfortunately, due to the nature of systems development, we don't have a wealth of flashy screenshots to show here, but I will do my best to explain the various systems under development and the state they are in.

One of the biggest priorities this year has been developing the codebase & logic underlying the A7's targeting and weapon delivery systems. To this end, lots of time has been spent refining and further developing the armament control systems: developing correct pylon release cues & logic, release inhibition conditions, developing calculations for interval drops and developing the core logic that underpins the sophisticated weapons systems of the A7. The culmination of this has been the development and integration of CCIP & CCRP weapon release modes; both of which draw heavily from various sensors and targeting systems in the aircraft before making real-time calculations to determine an impact point. We are pleased to say our A7 can now accurately release unguided weapons on target, using both CCIP & CCRP methods that are unique to different weapon types. Work is ongoing to further develop both weapon release modes to include inhibition cues as well as to develop the navigational modes of weapon release, such as Bomb on Coordinates (BOC) and offset bombing modes.

Navigation systems also received some development time in 2022, with the INS and tactical computer systems currently being expanded upon and developed. We have developed the aircrafts waypoint system, including storage, recall and editing of flight plan waypoints. We've also made progress integrating information from the navigation systems into other aircraft avionics; most importantly the HUD and PMDS. 2023 will see the detailing & expansion of the INS system; expanding on current modelling of the Inertial Measurement Unit (IMS) and the development of the Doppler Radar, both of which feed information to the INS. We will also be working to implement mark-points, target points and other in-flight navigational systems. As a pilot flying the A7 will require careful monitoring and management via positional updates and pilot corrections; the A7 requires navigational updates to correct for INS drift, in a similar fashion to the Viggen.

 As we've shown throughout the year, 2022 has seen the development of most of the A7's key avionic systems in various states of completion. The Projected Map Display (PMDS) is integrated and functioning, with current work focused on integrating navigational data from the Tactical Computer, as well as integrating some of the lesser used functionalities. The RWR has been on the backburner for some time due to some limitations in documentation, however we have now obtained the necessary documents and work is now ongoing in developing the RWR fully! The aircrafts multiple radio systems are also well in development, with the primary functionality of all radios already implemented and work ongoing to implement cockpit controls, presets and other functions. The A7 Radar systems are also well in-development as we've previously showcased, with current work focused on radar targeting functionalities as well as navigational cues.

As well as all the above, our current codebase is being constantly refined, expanded upon and rewritten in order to be more realistic with its flow of information. To elaborate, we are aiming to mimic the flow of data as it occurs in the real A7 avionic systems, with many avionics being dependent on other systems and prone to certain failures and accuracy limitations. For example, the tactical computer relies upon information from the Air Data Computer (ADC) as well as IMS systems in order to complete navigational and targeting calculations; any inaccuracies in data supplied from either the ADC or IMS will result in flow on errors and inaccuracies further down the avionics chain. In practical terms, this means that simple things like damage or icing to your pitot tubes can result in inaccurate data being supplied to the ADC and thus the Tactical Computer, creating targeting & instrumentation inaccuracies. We want each system to be interacting with each other as organically and realistically as possible, allowing for the accurate simulation of failures, errors and inaccuracies as they can occur throughout the aircraft.

To summarise the state of systems development in the A7 Corsair: most if not all systems have been developed and integrated to at least a basic extent, with work now being focused on expanding and developing the advanced functions of each system as well as the interconnections between each system. This will happen in-tandem with the art, as more & more cockpit controls and displays become available and ready to be tied to code work; we anticipate this will be ongoing for much of 2023.

What's next?

We've previously discussed our 4-phase development roadmap for the A7, which roughly translates to the following 4 phases:

1. SFM Based model
2. Basic EFM & flight systems
3. Advanced EFM & advanced flight/weapon/avionic systems
4. SME testing & tuning + damage modelling

We are currently approaching the tail-end of phase 3, which as expected has been the longest development phase by quite a margin. Our goal is to complete phase 3 and move into phase 4 of development at some point in 2023. We know it's been a long wait and it seems to still be forever away, but we want to say thank you for your patience and hopefully this report can give you some insight into what's been happening behind the scenes.

 

Thanks for reading!

Sincerely,
Dan K.
FlyingIron Simulations