iniBuilds Tristar Airliner Development Update

[mattY]

Welcome to our next Tristar Airliner dev update! In our initial dev update, we introduced the TriStar project and outlined the core philosophy guiding its development, we wanted to achieve a deeply authentic recreation, built around period-correct systems, flexible navigation workflows, and a visual standard that reflects both the aircraft’s character and decades of service life. We went over how elements such as the triple INS, Performance Management System, and multiple navigation configurations define the TriStar’s unique operational identity, alongside an early look at the extensive art, sound, and performance foundations already in place. If you have yet to read that dev update, you can do so here: December Aircraft Dev Update ✍️

With the foundation for the project having been established in the December update, development has since progressed and is now set for the final blocks to be placed. The focus has shifted from defining what the TriStar is, to now refining how it behaves, how its systems interact, how it flies under automation and manual control, and how its characteristic design choices influence the overall experience in day-to-day operations. Today's dev update will begin to pull those ideas together, taking a closer look at the aircraft’s core systems, flight modelling, audio environment, and visual detail as they reach maturity and progress toward a complete TriStar Airliner.

✈️Flight Model
At the heart of the TriStar’s performance are its three Rolls-Royce RB211-524 turbofan engines, recreated with a strong focus on physical accuracy and real-world behaviour. Thrust generation and power management are driven by authentic EPR logic, with carefully tuned engine inertia and spool characteristics that reflect the RB211’s distinctive response profile. Acceleration limits, transient behaviour, and power changes all follow realistic constraints, ensuring the aircraft feels appropriately deliberate and smooth across all phases of flight. From idle-to-takeoff power transitions to subtle thrust adjustments in cruise and approach, the engine simulation plays a central role in defining the TriStar’s character.  🔊

🛬Flight Handling and Aerodynamics
The TriStar’s handling qualities are captured through a high-fidelity flight model that reflects the aircraft’s reputation for stability, smoothness, and refined wide-body characteristics. Particular attention has been paid to approach and landing behaviour, where the aircraft truly distinguishes itself. Direct Lift Control (DLC) is fully simulated, utilising the TriStar’s signature spoiler-to-pitch coupling to provide precise glidepath control without excessive pitch changes. This system allows for fine vertical path adjustments during approach, delivering the stable, confidence-inspiring handling that made the L-1011 so well regarded by flight crews. 🛩️

🧠Systems - Automatic Flight Control System (AFCS)
The TriStar’s advanced Automatic Flight Control System is fully simulated, faithfully reproducing the aircraft’s sophisticated automation philosophy. The system supports full CAT IIIB autoland capability, complete with accurate flare logic, de-rotation behaviour, and rollout control. An integrated auto-throttle system works in close coordination with the Performance Management System and navigation logic, providing period-authentic automation that balances pilot authority with advanced system assistance. Lateral and vertical modes, along with capture and intercept behaviour, are modelled to reflect real-world logic and limitations, highlighting just how advanced the TriStar’s automation was for its era.⚙️

🔧Systems - Hydraulic, Pneumatic, and Electrical Systems
All primary aircraft systems are fully modelled. The hydraulic system is recreated in full, including its three independent circuits and their associated redundancy logic. The pneumatic system simulates bleed air behaviour, pack operation, engine starting, and cabin pressurisation. The electrical system is equally detailed, featuring complete AC and DC architecture with essential buses, load-transfer behaviour, and accurate power-management logic.


 
⛽Systems - Fuel Management 
The fuel system is recreated with its authentic tank layout and transfer logic, including cross-feed and automatic transfer behaviour. It also models the TriStar’s characteristic trim changes as fuel moves throughout the aircraft. All operations are carried out through a fully simulated Flight Engineer station, reflecting real-world procedures and workload in manual and automatic modes.
 
🌡️Systems - Environmental Control and Pressurisation
The environmental control system features TriStar-specific pack behaviour and fully modelled zoned cabin temperature control. Pressurisation operates in both automatic and standby modes, each behaving as it would on the real aircraft. The system also includes realistic reversion patterns and accurate environmental responses, reflecting the aircraft’s unique design and operational philosophy.
 
👨‍✈️Systems - Flight Engineer Station
The TriStar’s Flight Engineer station is fully interactive. All major systems—hydraulics, electrics, fuel, pneumatic, and environmental—can be managed exactly as on the real aircraft. True-to-life flows and operating procedures guide every action, and the station provides fully functional system monitoring and control for an authentic three-crew experience. 🎛️
An automatic operation mode is also provided where these tasks are handled by an AI-driven Flight Engineer. This can be toggled at any time through our unique PFP (Paper Flight Bag) interface.



🗺️Navigation & Autoflight Philosophy
From the beginning of development, our navigation concept was divided into three stages: 

• RADNAV only 
• INS only 
• INS + PMS (to provide VNAV) — originally planned for a later update. 

As we are now shipping all three aircraft variants from day one, we broadened the philosophy to support everyone: from casual flyers taking their first steps into classic airliners to the most dedicated purists who want to operate the aircraft exactly as it was. 

The objective became simple: maximum flexibility while preserving visual authenticity. As such, a navigation mode selector has been added to the "PFB", allowing you to define how the aircraft is operated. These options include:

• RADNAV
• INS
• GPS
• INS + GPS.

Each option will provide you with a different experience, from a more modern approach to airliner navigation, all the way to the original navigation methods used on this aircraft. To keep system logic aligned with each operating philosophy, systems such as the PMS (and therefore advanced VNAV capability) is available only when an INS-based option is selected. Alternatively, you can select pure RADNAV or GPS-only, which disables the PMS. This method allows you to tailor the experience of the Tristar to your own preference. 🎯 

🛰️AFCS Lateral Modes & GPS Integration 

One of the most delicate challenges during development has been introducing GPS capability without compromising cockpit authenticity. 

The AFCS panel already provides the real-world lateral modes: 

• ILS
• LOC
• VOR
• INS
• BC 

And that is the crucial point — there is no dedicated GPS button on the real unit. 

While some early aircraft iterations experimented with additional switching, these were not representative of operational service and were later abandoned. Adding a permanent GPS pushbutton or fictional mode would therefore mean creating something that never truly existed. 

Which lead to our solution, we allow the "PFB" to determine the navigation source, which means that when a pilot selects GPS-only operation, the aircraft will replace the INS label on the AFCS with GPS. 

From the cockpit, the workflow feels entirely natural — the same button, in the same location, operated in the same way. Behind the scenes, lateral guidance is now provided by the Garmin GNS 530 rather than the inertial system. 

This means different things for different pilots: newcomers & casual flyers can enjoy straightforward, modern GPS navigation with minimal learning curve, making it easy to jump in and fly; INS and procedural users will see no change to the standard operation - simply select INS in the "PFB" and the aircraft will behave like originally designed; and for everyone, the cockpit experience will remain coherent, believable and true to the real aircraft.

📥INS Route Imports 
Planned since early development, we are also implementing the ability to import routes created via SimBrief or through the simulator’s own EFB directly into the INS. 

This will dramatically reduce pre-flight workload while preserving the depth and procedural nature of inertial navigation — perfect for experienced crews who want realism without lengthy manual entry. 📋

📘Paper Flight Bag
As we briefly mentioned above, the TriStar introduces our new period-authentic "Paper Flight Bag", a vintage-inspired alternative to the modern EFB found in other iniBuilds aircraft. Designed to match the era and atmosphere of the L-1011, the PFP provides a tactile, analogue-style interface while still delivering the full suite of essential features simmers expect. Performance calculations, aircraft configuration tools, loading and fuel management, navigation references, and system controls (such as the automated Flight Engineer) are all accessible, offering both immersion and convenience without compromising capability.

🎨Exterior Art
The TriStar’s exterior has been brought to life with a strong emphasis on mechanical accuracy and dynamic behaviour. Control surface animations follow real-world sequencing and logic, ensuring that every movement reflects how the aircraft operates in service. This includes correct spoiler lift behaviour during  operation, realistic flap actuation timing and geometry, and accurate landing gear compression responses during taxi, braking, and touchdown. These details work together to ensure the aircraft not only looks correct, but behaves correctly during all phases of flight.

Beyond primary animations, a range of secondary visual effects add a subtle but important sense of life to the aircraft. Wing flex responds naturally to aerodynamic loading, engine vibration is visible through the airframe, and heat shimmer behind the wing-mounted RB211 engines reacts dynamically to power settings and environmental conditions. Together, these elements help convey the mass, power, and presence of the TriStar in motion.

💺Interior Art
The cockpit represents a complete and faithful recreation of the L-1011-500 flight deck, encompassing the Captain and First Officer stations alongside the full Flight Engineer station. High-resolution materials and carefully crafted textures capture the distinct mix of metals, plastics, and fabrics found throughout the real aircraft. Brushed aluminium panels, worn labels, accumulated dust, faded markings, scratches, and panel paint degradation all contribute to a cockpit that feels lived-in and authentic, reflecting decades of service rather than a factory-fresh appearance. 🕰️

Wear and tear has been applied with restraint and purpose. Frequently used switches and controls show polished metal surfaces, high-traffic areas exhibit chipped paint, and recessed sections display realistic grime build-up. These details are informed directly by real-world references, ensuring the aircraft feels aged in a believable and consistent way rather than artificially distressed.



Every instrument, control, and Flight Engineer component is fully modelled within the limits of the underlying systems simulation. Knobs, switches, circuit breakers, and annunciators are positioned precisely using real measurements and photographic reference, aided by a camera-matching workflow during 3D development. Cockpit visibility is further enhanced through accurate reflective behaviour on glareshield materials and windows, combined with baked ambient occlusion and light maps that respond naturally to shadows, instrument backlighting, and changing external light conditions.



We hope to showcase more areas of the cockpit and showcase the cabin very soon as we polish and refine the texture sets to our ideal result in our continued development updates.
 
💡Lighting, Cockpit and External
Although we were unable to obtain our own bespoke lighting references for the TriStar, the lighting environment has been carefully developed using physically based intensity values and averaged colour reproduction derived from extensive photographic and video reference material. The goal has been to achieve lighting that feels believable and functional rather than exaggerated, ensuring consistency with the aircraft’s era while still taking full advantage of Microsoft Flight Simulator 2024’s lighting capabilities.

Cockpit lighting includes fully adjustable integral panel backlighting, instrument illumination, pedestal flood lighting, dedicated Flight Engineer station lighting, and overhead flood lights. Each lighting source behaves as expected during transitions between bright exterior conditions and low-light night operations, allowing the cockpit environment to adapt naturally as ambient lighting changes. Particular care has been taken to balance readability with atmosphere, preserving clear instrument visibility without washing out surface detail or texture work.

Exterior lighting has been equally refined. Landing lights, taxi lights, wing illumination, beacons, strobes, and navigation lights are all tuned to behave correctly across a wide range of environmental conditions. These light sources interact dynamically with fog, cloud density, precipitation, and reflective surfaces, ensuring the aircraft remains visually grounded within the surrounding environment. Whether taxiing in low visibility or penetrating cloud on approach at night, the TriStar’s lighting behaves in a manner consistent with real-world expectations.



🖌️Liveries
At release and for future updates, we plan to include a range of our high quality ‘3D decal’ liveries representing airlines that operated the L-1011-500 including the registration of Delta, British Airways, Air Transat, LTU, Pan Am and United amongst many others.
Each livery is created using correct brand colours, layout references and aircraft-specific markings – with the MSFS recommended 3D decal method for ultimate performance and quality when viewed close in first person. ✈️

🛬Closing remarks
To close out, we hope that this dev update has provided some useful information for you! Development is now entering its final stages, and while what you’ve seen here represents a substantial portion of the aircraft, there is still more to share. We will be releasing another update prior to launch, diving even deeper into additional features, refinements, and areas of the aircraft that we cannot wait to show you.

We are incredibly grateful for the continued enthusiasm, feedback, and patience from our community throughout. The TriStar is a special aircraft, and it has been a privilege to recreate it with the depth and respect it deserves. ❤️

We cannot wait for you to get your hands on the TriStar Airliner and experience this iconic wide-body for yourselves. ✈️✨

iniBuilds Team ❤️