FS2004 Boeing 747 Classic

[arwasairl]

Tape gauges for the JT9D and the CF6-50 have been implemented, though it is in NWA's layout. A KSSU cockpit will come at some point once I can get better references for the individual gauges the consortium used, as I don't know the model numbers or the manufacturers of those gauges.

 

[arwasairl]

The LTN-72 has now been implemented. This is the base model LTN-72 with no RNAV capabilities (no DME updating) and no triple mixing, so for those especially long flights you will have a lot of drift over time.

Every single feature including each data display's page, AUTO/MAN/RMT switch, and some quirks of the 72-3 program (for example, unable to key waypoints 0 to 1 when 0 is in the waypoint thumbwheel selector. It needs to be out of 0 for a track change to occur).

The physics are slightly different on the LTN too. The Delco CIV-A has a carouseling 4-gimbal platform to reduce Schuler oscillations, whereas the Litton unit has wander-azimuth mechanization with G1200 DTG (dry tuned-rotor gyro) and A1000 accelerometers. This means that the gyro platform is not slaved to polar north like the Carousel and it does not have any issues navigating the poles. Under the hood the behavior of both INSs are different though in practice there isn't meaningful amount of differences other than the CDUs themselves.

I may consider the LTN-72R, which added DME/DME updating, but the newer LTN models had the alphanumeric keys with an internal navigation database that held around 100 waypoints. Although the actual panel and code itself isn't the problem, acquiring database data is a big problem, as I asked Navigraph if they could provide support for the project in their navigation updater program but they did not give me any response even after a month and 3 replies

So unless I figure out a solution, maybe provide a tool to convert your own data into the proper navigation data like Aerowinx's Navburo (though with this you will have to provide your own AIRAC data as I don't have any), systems like the LTN-72RH or the LTN-92 or CMC FMS/Honeywell FMS will not be implemented in the future.

 

[arwasairl]

I decided to move from systems to some more visual things. The 747 now has ground services, though at the moment I only got the pushback tug and its associated features.

I should note that this is not an object that is tied to the external model, it is a separate BGL scenery object that the module hooks into FS9's BGL opcodes to drive vehicle animations and have animation states. Something that the newer FSX added with SimObjects and SimConnect, but neither of which are available to us in FS9.

This is a similar approach to what Aerosoft's AES did (their BGL objects looked to be older FS5 SCASM objects), but it relied on VistaMare's Core module to hook and serve the opcode hooks and IDs. Regardless, the same idea behind the BGL opcode hooks as well as an RPN expression interpreter used to create XML code for creating ground vehicle object states have been implemented.

I will say there is one major upside to my system compared to AES, and that is that there is no need for "credits", the ground vehicles are placed by first reading all the installed scenery's AFCAD files and indexing them in a cache file (similar to how GSX does it). This works for both default and add-on scenery provided that the add-on scenery's AFCAD is in good quality. Pushback tug directions are precalculated via the Dubins path, and I went through a lot of lengths to create a good algorithm that wouldn't cause the pushback tug to jackknife its towbar constantly with the aircraft.

Currently, there are no people models yet but I have found a way to implement vertex deformation animations in FS9, it requires hooking the vertex rendering pipeline every frame and its not as clean or as elegant as a solution as FSX's native skin system would be. The vertex animations in FS9 can only be done by exporting pre-baked vertex deformation and normals information beforehand from a 3d software and storing them as data for the module to use to control vertex animations. I have hopes that this system will allow us to have good looking ground crew animations instead of robotic movements.

There is only one downside to this system, and that it directly conflicts with AES. Because both me and ViMa's modules hook the same offsets, I anticipate there being quite a lot of instabilities. Therefore AES must be disabled or uninstalled to use the ground services feature. The rest of the aircraft however does not depend on this and will work fine with or without AES installed.

I should also note that my ground service system is not a replacement for AES. It only supports the 747, and only supports airports with GATE_HEAVY. Other aircraft are simply not supported and the ground service feature does nothing on aircraft that isn't the 747. Adding support for other aircraft is quite a big task and looks to be like an entirely new project.

 

[shamrock77]

I haven't checked in on this project for a while and, holy moly, I cannot believe the progress that has been made and how much the original scope has been expanded. Absolutely outstanding work @arwasairl.

This "behind the scenes" look really does highlight how incredibly complex developing for the sim is. At this point it's transitioned into aviation art - you should be extremely proud of the work that's gone into it.

All the best, going forward!

 

[edetroit]

Adding support for other aircraft is quite a big task and looks to be like an entirely new project.

Cooooeee! That would be very interesting!

Regards

Ed

 

[Jon_aus]

The LTN-72 has now been implemented. This is the base model LTN-72 with no RNAV capabilities (no DME updating) and no triple mixing, so for those especially long flights you will have a lot of drift over time.

Every single feature including each data display's page, AUTO/MAN/RMT switch, and some quirks of the 72-3 program (for example, unable to key waypoints 0 to 1 when 0 is in the waypoint thumbwheel selector. It needs to be out of 0 for a track change to occur).

I may consider the LTN-72R, which added DME/DME updating,

Amazing stuff. Love using the Civa INS so this looks great!


This means no updating via a VOR? I could be wrong as I believe the LTN-72 COULD be updated if flying VOR-VOR and using the known lat/long position of the radio beacons when overflying them. Rather then the CIva DME/DME position update. Just wondering if that will be implemented?

 

[arwasairl]

Amazing stuff. Love using the Civa INS so this looks great!


This means no updating via a VOR? I could be wrong as I believe the LTN-72 COULD be updated if flying VOR-VOR and using the known lat/long position of the radio beacons when overflying them. Rather then the CIva DME/DME position update. Just wondering if that will be implemented?

This was already implemented, however the assumption that it could be updated with just a VOR is a bit misconstrued, because this is not an automatic update like the CIVA had or the newer RNAV version. You the pilot would have to push HOLD to freeze the data display then manually insert the position you think the plane is at once you determine you are over a VORTAC fix.

The accuracy is obviously not as good as CIVA's updating, as you the pilot are responsible for timing exactly when to hold and enter the position data. If you enter it too late your plane will be slightly forward of your actual position, though due to decimal truncation on the data display it is not as meaningful of a difference. It is also worth noting that the 747's actual DME distance display (not the input source) does not update constantly and has a lag, thereby increasing possible drifts.

But by the conventions of how the LTN is updated, technically you can update it using any kind of fix. Whether it be an airport, or a landmark, or a celestial star, as long as you had some kind of equipment or way to tell exactly where you are and input the positions at the exact right time.

The reason why I said there is "no updating" is because this manual update procedure does not qualify the LTN-72 as an RNAV5 device. The CIVA INS is an RNAV5 device due to its DME/DME updating feature, but the LTN-72 is not due to this. The 72R added abilities to make it RNAV5 compliant.

Hence why I don't consider it true updating. It is kind of like saying you know where you're at by walking 100 steps because you roughly know your stride length. It is not an accurate measurement by any means but it will get you close enough.

I should also note that the LTN-72 also does not even have triple mixing. So each unit will have its own drift values that do not converge like the CIVA's does.

 

[Jon_aus]

This was already implemented, however the assumption that it could be updated with just a VOR is a bit misconstrued, because this is not an automatic update like the CIVA had or the newer RNAV version. You the pilot would have to push HOLD to freeze the data display then manually insert the position you think the plane is at once you determine you are over a VORTAC fix.

Does sound fun though and very realistic.

I should also note that the LTN-72 also does not even have triple mixing. So each unit will have its own drift values that do not converge like the CIVA's does.

I did read somewhere that the 3rd unit could be used as a go between for INS-1 and INS-2 if they differed greatly in positions.

This will make Atlantic flights or other long over water flights much more fun. Exciting!

 

[Tim Collins]

I can only remember one occasion when I had to use manual updating on the LTN72. Outbound from LGW-MCO we were concerned about the drift of one unit and did a manual update over the Brest VOR (BZH). It worked well enough and we continued on to the ocean. Our later 742s had GPS updating for the INS using the later LTN92 system, but in those early days (early for me, not for the 747!) I used to carry a hand-held Lowrance GPS just in case - a legacy from my C130 days. I still have that device!

 

[Jon00]

I can only remember one occasion when I had to use manual updating on the LTN72. Outbound from LGW-MCO we were concerned about the drift of one unit and did a manual update over the Brest VOR (BZH). It worked well enough and we continued on to the ocean. Our later 742s had GPS updating for the INS using the later LTN92 system, but in those early days (early for me, not for the 747!) I used to carry a hand-held Lowrance GPS just in case - a legacy from my C130 days. I still have that device!

Wow, you really brought back some memories! Ever since handheld GPS units became available on the consumer market, my father has always carried one with him.
The real revolution came with the models that had 5 or more channels.
I remember that with a Garmin from the mid-90s, it would take quite a few minutes for it to figure out his location.

 

[Tim Collins]

Wow, you really brought back some memories! Ever since handheld GPS units became available on the consumer market, my father has always carried one with him.
The real revolution came with the models that had 5 or more channels.
I remember that with a Garmin from the mid-90s, it would take quite a few minutes for it to figure out his location.

Yes, I'd had one of some sort or other since shortly after the Falklands conflict. The Lowrance was a 12-channel device, I think - one of the first - and worked pretty well, though entering waypoints (only 10 available) was a bit of a chore. The battery life wasn't great either, so I used to leave it plugged in to a power point on the flight deck. While I can't say it ever rescued a poor navigation situation, it was good to have an independent confirmation of where we were when using the old LTN72s on the ocean. The 92 completely resolved those issues.

 

[Jon_aus]

I think its said it could be 1 nm per hour drift? So a flight over the Atlantic around 7-8 nm?

 

[Tim Collins]

I think its said it could be 1 nm per hour drift? So a flight over the Atlantic around 7-8 nm?

It was typically about half that, though with three of them the position error really wasn't that bad as they used the 'voting' system to eliminate the worst unit. Coming off the Atlantic we updated the position using VOR/DME so by the time we coasted in we were as accurate as any system could be at that time. Bearing in mind that a few years earlier on the C130 I'd been crossing the Atlantic using Loran C and astro navigation (well, not me strictly - the navigator!), later supplemented by Omega, and the triple Litton 72 setup was revolutionary! I then went on to the Airbus A340 (300 and 600) and navigation ceased to be an issue at all.

 

[Jon00]

Yes, I'd had one of some sort or other since shortly after the Falklands conflict. The Lowrance was a 12-channel device, I think - one of the first - and worked pretty well, though entering waypoints (only 10 available) was a bit of a chore. The battery life wasn't great either, so I used to leave it plugged in to a power point on the flight deck. While I can't say it ever rescued a poor navigation situation, it was good to have an independent confirmation of where we were when using the old LTN72s on the ocean. The 92 completely resolved those issues.

My father starting flying on the C-119, and he used to tell me that on one of his first long-haul trips, he flew to Central Africa.
As I recall, once they moved past North Africa, the LORAN signals were no longer available, so they had to rely on celestial navigation.
In Africa especially during that period there was no formal airspace structure; you would file a flight plan, but it was essentially useless. Instead, while in flight, you would make radio calls announcing your altitude and speed and hoping that any nearby aircraft might hear you.

 

[Tim Collins]

The lack of a formal airway structure was very much the case right up to the 1980s in some parts of Africa, and even now we have an air-to-air frequency where we announce level changes and positions to other traffic as in much of Africa ATC is still procedural, not based on a radar or SSR picture. There are similar frequencies in other parts of the world (like the North Atlantic) but they are mainly for passing on useful information like email addresses for selfies! Edit: such as this one, taken of my aircraft by a USAF EC135.

 

[Jon_aus]

Nice update. Thanks .

 

[Jon00]

The lack of a formal airway structure was very much the case right up to the 1980s in some parts of Africa, and even now we have an air-to-air frequency where we announce level changes and positions to other traffic as in much of Africa ATC is still procedural, not based on a radar or SSR picture. There are similar frequencies in other parts of the world (like the North Atlantic) but they are mainly for passing on useful information like email addresses for selfies! Edit: such as this one, taken of my aircraft by a USAF EC135.

After certain unpleasant events in Central Africa, he would no longer fly in an "official" flights.
He spent a few years flying the C-130H, but following some internal disagreements, he was assigned to the NATO E-3, where he eventually concluded his military career.
P.S.
Was it true that the A340-600 would flex/bend during takeoff?

 

[Tim Collins]

Was it true that the A340-600 would flex/bend during takeoff?

Yes, quite significantly.