FlyingIron Simulations has posted another update, this time detailing the systems inside their F-117 Nighthawk.

Through a couple of posts on the x-plane.org forum, Dan goes into depth about some of the systems that has been accomplished, and what there is still to do.

The Inertial Navigation System (INS) and Control Display Unit (CDU) is one such focus, as Dan describes the system briefly:

"The INS is a fully automatic, self-contained, space-stable system which consists of the Inertial Measurement Unit (IMU), Interface Electronics Unit, Weapons System Computer (N-WSC) and the Control Display Unit (CDU). The INS continuously computes the following navigation data for use by the pilot and aircraft avionics:

• Present Position
• Attitude (3 Axis)
• Ground Speed
• Ground Track
• Heading (True & Magnetic)
• Wind Vector
• Altitude
• Time to Go
• ETA
• Distance to WP
• Desired Track

"The INS can store 94 waypoints (which are entered via Lat/Long and elevation) as well as 188 offset points for weapons delivery. Moreover, waypoints 95-99 can be used to store spontaneous Mark Points, to mark the aircraft's current position as a waypoint.

"The primary purpose of the INS is to provide navigation to a predetermined target with sufficient accuracy to allow target acquisition via the Infrared (IRADS) system. It is also works in conjunction with the Autopilot system to provide full flight-plan autopilot capabilities and hands free flying."

He goes on to state that the documentation they have of the INS is very detailed and will allow the team to develop it with "some significant depth."

For the INS, the INS alignment procedures/update buttons, alternate power modes and offset points still need to be modelled.

FlyingIron Simulations will implement extra features to improve the user experience inside of X-Plane for the INS:

• Pilots will be able to Load/Save/Import a flight-plan into the INS system with ease - any flight plan that can be imported into the default X-plane FMC will also work with our INS simulation. All waypoints will be automatically converted to Lat/Long Coordinates.
• Users will be able to adjust Lat/Long Entry via the MDI Screens and controls. As you can see, by default the entry mode is decimal. The user will have the option to cycle between DMS & Decimal Waypoint entry.
• We will *likely* include a plugin that converts traditional flight-plans (ie with Named Waypoints, ICAO codes etc) into Lat/Long Coordinate Waypoints that the user can then enter into the CDU. This will allow pilots to fly their favourite routes without needing to lookup Lat/Long Coordinates every time.

In the next post, he goes forth to demonstrate the MDI Primary Flight Displays' functionalities. The MDI screens on the left and right are identical, displaying an assortment of information, and utilises twenty buttons around them.

"Each MDI has 8 different Display pages, which are grouped into 2 sets: The HSD set & VSD set.

"The Horizontal Situational Display (HSD) is primarily used for navigation, and also includes several subpages: The Status Page, Stores Management Page, Maintenance Display and the Tactical Plot Display. The Vertical Situation Display (VSD) acts more like a roll-ball, and includes several of it's own sub-pages: A basic Test Screen, SMS Page, and the VSD Page itself."

The image below shows the VSD page in default mode, and below that, is the VSD in alternate mode (Pitch/Ladder):

Other pages include:

• Test: A simple test page that displays some warnings‍
• Status: Displays the status of key aircraft systems, revealing any system failures or BIT failures.‍
• SMS: Used for communication between pilots/ground crew‍
• Stores Management: Used for weapons selection & settings input‍
• Tactical Plot: This is essentially your moving map page/ Tactical Overview. Displays the Flight Plan and overlays any known Targets/threats.‍
• Maintenance: Used by Ground-crew/Maintenance crew only.

Again, the documentation is thorough, although it lacks around the stores management pages and tactical plot display page. They will use the F/A018 Hornet to create the best estimate of how those pages work. Details on how they will improve the user experience was also shared for the MDI:

• The Maintenance Page has no real function in X-plane, and will therefore be converted to a 'Settings' Page. This will work similarly to how we have done our 'VR/GUI Panel' in past aircraft. It will allow the user to change flight options (such as Lat/Long entry mode) without breaking immersion.
• The status page will be adjusted slightly from it's real-world functionality to be more useful in X-plane
• We will likely include an additional 'Checklist' page, with dynamic colours to indicate checklist progression.

"The MDI systems are huge and very in-depth, hence why this update is sparse on information. I will post more detailed updates on each page as I get time."

Dan says the next update will be on the HUD and Up-Front Controller (UFC), and is expected in the next week. Keep up-to-date with development on the forum thread here.

Last week, some screenshots of the modelling and texturing of the cockpit were posted, which you can check out below: