State of the L-1011 Project

My dear friends. Some of you have reached out to figure out what is going on with this project effort and I thank you for that. For now, the L-1011 project is on hold due to lack of funding. The project is not forgotten and I will from time to time attempt to continue with some work on small sets of the avionics. But until I can secure additional funding for the effort there will be not much going on. 

L-1011 Trainer Installation: NAV and COM Radio Head Integration

L-1011 Trainer NAV and COM Radio Integration

Today we finished the VHF NAV and VHF COM Radio head integration with X-Plane. Ben Klang wrote the code for the VHF NAV radios. The VHF NAV radios use a 2 of 5 encoding method and we are reading them with National Instruments DIO cards. Ben wrote a program on a small Linux box that continuously reads the values and sends them on to X-Plane via a UDP DataRef.

We also completed the VHF COM Radio integration. Here, the radios use the ARINC 429 Labels 030 with different SDI numbers to differentiate the various COM channels. For now, we integrated COM1 and COM2 to directly interface with X-Plane. Just as with the VHF NAV tuning information, the VHF COM frequencies are passed to X-Plane via the network as UDP packets.

The video below shows the operation of the VHF COM and VHF NAV radios in our L-1011 cockpit.

Avionics Bending: Mechanical Synchro Signal Producer (Part 7)

Mechanical Digital to Synchro Converter - Test Assembly

Made lots of little tweaks to the individual parts and did a test assemble of some of the components. Eventually the entire assembly will be held together by four rods. Right now, I did a test assembly of the connector plate, the stepper motor plate, the synchro transformer plate and then the section that hold the electronics. Yep, those are cable ties holding the pieces together right now; however, I did this just to double check the sizing of the spacers and to make sure that the gear mechanism lines up.

Mechanical Digital to Synchro Converter

The image below shows the basic Beagle Bone Black in the the rear section of the design. There will actually be a cape on the Beagle that will handle the Stepper motor.

Mechanical Digital to Synchro Converter - Test Assembly

The images show the center core with the Synchro Transformer not yet assembled. I will try to get some rods over the next few days and then put the entire design together and cable it.

Mechanical Digital to Synchro Converter - Test Assembly

So far I am about $86 into this effort. Really want to keep it below $100 if possible. The most expensive part, so far, was the Beagle. Maybe in future iterations I go with a RaPi, but, actually both the BBB and the RaPi are a bit of an overkill for this.

Avionics Bending: Mechanical Synchro Signal Producer (Part 6)

Mechanical Digital to Synchro Converter - Connector and Electronics Bay

I added the connector plate and the electronics bay to the design. The Beagle Bone Black (BBB) will ride in an "electronics bay" on the backside of the design. This will be located behind the synchro transmitter. For the initial design there will be daughter board on the BBB driving the stepper motor (see image below). All connectivity, except for Ethernet, will be brought in through a Tyco Circular Connector. 

Mechanical Digital to Synchro Converter - Connector and Electronics Bay

The image below show the current design from behind. I envision a case around the complete design and a DIN rail holding bracket so that the unit, or multiple units, can be attached to a DIN rail in the simulator. The 26VAC 400Hz power sill also be brought in via the Tyco circular connector.

Mechanical Digital to Synchro Converter - Connector and Electronics Bay

Here is the left hand side view of the current design iteration. 

Mechanical Digital to Synchro Converter - Connector and Electronics Bay

Over time I will probably come up with a more space optimized design. If you have any design ideas please call them out to me. 

Avionics Bending: Mechanical Synchro Signal Producer (Part 5)

Mechanical Digital to Synchro Convert

Here is the first printed and assembled version of the mechanical digital to synchro converter motor assembly. It's a pretty simply assembly and together with the stepper motor and the synchro transmitter and the optical sensor I am about $22 into the project. In the image below you can see the proposed location of the optical sensor.  Next will be to design the plate that holds the Beagle Bone to drive the stepper motor with.

Mechanical Digital to Synchro Converter

Once I get a little further with the design I will put the CAD files on grabcad and the code on github. 

Avionics Bending: Mechanical Synchro Signal Producer (Part 4)

Mechanical Digital to Synchro Assembly

Here is the first design draft of the mechanical digital to synchro converter. The stepper motor on the bottom turns the Synchro Transmitter on the top of the design. The gear ration between the NEMA 17 motor and the Synchro should allow for very fine adjustment of the Synchro. The next rendering shows the the top plate and the Synchro Transmitter removed.

Mechanical Digital to Synchro Assembly

The picture below shows the assembly with the holder on the left hand side for the optical zero detection.

Mechanical Digital to Synchro Assembly

Another view of the prototype assembly from below. Here you can see the cutout for the NEMA 17 motor.

Mechanical Digital to Synchro Assembly

The entire assembly will be 3D printable. I will print the first prototype in PLA and then see how rigid the design is. The next step will be to add the design for the Beagle Bone Black holder and the 400Hz 26VAC  connections into the design.

Mechanical Digital to Synchro Assembly

Avionics Bending: Mechanical Synchro Signal Producer (Part 3)

L-1011 Project - Mechanical Synchro Converter

Modeled the motor and synchro components to go into the design. Here is how I currently envision the device to work .... it's actually quite simple. Above is a block diagram of initial idea for the device.

Let's take an example of the Airspeed indicator:

1. The device initializes by rotating the assembly until Zero Detection is reached. We have now stablished the starting point. 
2. Indicated Airspeed (IAS) is sent from X-Plane via UDP across the Ethernet to the Beagle Bone Black (BBB). 
3. The BBB translates the airspeed into angular information around the airspeed indicator dial. 
4. The BBB instructs the Stepper Motor Controller to move a computed number of steps forward or backwards. 
5. The linked Synchro Transmitter takes a 26V 400Hz input sources and creates the 3 Phase Synchro output needed by the L-1011 Airspeed Indicator. 

Avionics Bending: Mechanical Synchro Signal Producer (Part 2)

Mechanical Digital to Synchro Converter - Modular Mounting Plate Back

Mechanical Digital to Synchro Converter - Modular Mounting Plate Front

Working on the design of the motor mounting plate for the Stepper and the Synchro. This modular plate should accommodate a single stepper motor and a single Synchro Control Transmitter. The modular motor holder. I am also working on an alternate design that can accommodate the Coarse and Fine CTX for Altitude encoding. 

Once getting closer to a more practical design of the holder I will make it available as an Open Hardware project. 

Avionics Bending: Mechanical Synchro Signal Producer (Part 1)

Components for the initial Synchro Transmitter Controller

Today, I am embarking on a project to build a mechanical Digital to Synchro converter. Digital to Synchro converters are, of course, available in the form of very very expensive solid state devices form companies like DDC or other. However, for the L-1011 project I don't have the financial resources to purchase several of these devices to address all of my synchro signal needs. If you remember, synchro transmitters produce a 3 phase signal that is created form a single 400Hz 26V AC reference signal. The 3 phase shifted signals encode the angle of the synchro shaft. This technology has been around for a very long time and was, and in many cases still is, the standard for transmitting shaft angle between components.

For example, on the L-1011 the airspeed indicator and the mach number are both transmitted form the transducers to the cockpit instruments as 3 phase synchro signals. If you want to read more about Synchro Transmitter, like the ones I will be using to build this first prototype with, you can read about them here.

To build this first prototype idea I will create a mechanism for a stepper motor to drive a synchro transmitter. I will print the components using my Makerbot 3D printer and since none of the components need too much rigidity for the initial testing I will print them in PLA. I will use a Be able Bone Black as a way to drive the stepper motor and to read the Zero point on the Synchro. My initial idea is to zero the synch by using an indexer on the synchro gear.

PLA printed Synchro Gear with Indexer

The plan is to read the index with an optical switch.

I picked a NEMA 17 stepper motor not because they are needed to drive a tiny little synchro ... they are really an overkill and rather large ... but because I bought 50 of them for close to nothing on eBay.

I would very much like to make this an Open Hardware project and would like to invite you to participate in it. I am drawing the components in Autodesk Fusion 360. Please send an e-mail to curdzechmeister@gmail.com and I will add you to the Fusion 360 project.

L-1011 Trainer Installation: Flight Director Integration Tests

L-1011 Flight Director Integration Tests

The ADIs in the L-1011 simulator incorporate Flight Director (FD) bars for Pitch, Roll and Yaw. Today I worked on moving Flight Director information from X-Plane to the ADIs. To do so, I am using ARNIC 429 Label 170, 171 and 172. The Flight Director bus is a slow speed bus and FD information is passed to the ADI at 12.5Kbps. For the first few tests tonight I focused on the roll and pitch data. X-Plane actually does not have Flight Director data for guided yaw, however, that information can be derived from a number of other X-Plane data points.

The video below is a short demo of a Flight Director guided roll to the left to heading 225 and then we see a flight director guided roll-out at the target heading. Watch the HSI and the ADI in particular:

p.s. Ignore the erratic Localizer indicator on the ADI, it's only getting test data.

Avionics Bending: End-To-End Test of the ADI, HSI, VSI and ALT with X-Plane

L-1011 Trainer Installation - X-Plane to ARINC End-To-End Test

Today Jim and myself reached another important millstone with the L-1011 project. We performed a complete end-to-end test of the ARINC 429 compatible primary flight instruments. This now finally tests all of the components in the loop for both the Captain's as well as the F/O station. The instruments tested today are:

• Altimeter (ALT)
• Vertical Speed Indicator (VSI)
• Attitude Director Indicator (ADI)
• Horizontal Situation Indicator

All in all we are transmitting 46 ARINC 429 labels over 8 discrete transmit buses. 4 of the buses are 100Kbps buses and 4 are 12.5Kbps buses. Of the four 12.5Kbps buses two are standard ARINC 429 buses and two are ARINC 575 compatible buses (so no SSM information on the label word). The video below is a short demonstration of flying the L-1011 sim in a very basic mode with no trim and only basic functions enabled, again, the test if for the ARINC instruments and not for the A/D conversion of the control inputs. 

In addition to the ARINC and X-Plane end-to-end tests we also installed the left hand side audio side panel. 

L-1011 Left Hand Side - Audio Side Panel

L-1011 Trainer Installation: Captain's and F/O ARINC 429 Instrument Tests

We are slowly ramping up the number of ARINC 429 labels sent as test data to the simulator instruments. The test data set has now enlarged from 26 to 48 labels sent over a total of 6 different buses; 3 buses on the Captain's side and 3 buses on the F/O side. Both sides will receive different data sets just as they would on the actual aircraft, this way we will be able to simulate complete subsystem failures. The video above show generic test data being sent to the Capt ARINC 429 instruments as well as to the F/Os instruments. 

L-1011 Trainer Installation: ARCIN 429 for Altimeter and Audio Side Panel

L-1011 Altimeter ARINC 429 Integration Tests

Today Jim Blasco and myself worked on doing ARINC 429 label integration tests with the Altimeter. The Altimeter uses Label 204 and due to the fact that it uses a slightly different variant of a ARINC 429 compatible protocol it has to run on it's own bus. The 204 Label for the Altimeter uses a 32bit word that does not have a SSM field or Parity Bit.

The short demo video bellows shows data being sent to the ADI, HSI, VSI and ALT.  The next steps will be to send actual simulator from X-Plane to the instruments. 

Besides the tests with the Altimeter we also installed the first of two audio side panels. The L-1011 Cockpit Procedure Trainer did not come with these side panels and we got them from an actual (British Airways) L-1011. The audio side panels provide the hookups for the headset (boom and headset) as well as a connector for the hand microphone. The side panel also has room to store the headset in.

L-1011 Audio Side-Panel Installation

L-1011 Trainer Installation: ARINC 429 Mixed Data Rate Tests

L1011 Trainer - ARINC 429 Mixed Label and Bus Speed Test

Now that the 429 cabling is complete I have stated with mixed data rate testing for the ADI, the HSI and the VSI. Between the three instruments I am sending a total of 24 different labels on both 100Kbps (HS) and 12.5Kbps (LS). The bus setup for the instruments shown in the video below is as follows:

• CAPTHS1 (Captain's ARINC 429 High Speed Bus 1)
• CAPTLS1 (Captain's ARINC 429 Low Speed Bus 1)
• CAPTLS2 (Captain's ARINC 429 Low Speed Bus 2)

and

• FOHS1 (F/O ARINC 429 High Speed Bus 1 as instrument alternate source)
• FOLS1 (F/O ARINC 429 Low Speed Bus 1 as instrument alternate source)

L-1011 Trainer Installation: ARINC 429 Cabling Complete

We have reached another millstone with the L-1011 project. All of the cabling is complete for the ARINC 429 compatible devices. To test the correct installation of the cables and to make sure that there are no problems with the type of cable that we are using in the simulator we ran some tests by sending test data to the left hand side (captain's) ADI and HSI. Here is a short video showing ARINC 429 high speed and low speed data being transmitted to both instruments cabled to the same high speed and low speed bus.

Cable Type Used: AWG 24 2 Conductor Shielded

Over the next two weeks we will start sending all ARINC 429 labels needed for the simulator over a total of 16 TX and 16 RX lines. The instruments used in the L-1011 simulator that are ARINC 429 compatible are:

1. Attitude Direction Indicator (ADI)
2. Horizontal Situation Indicator (HSI)
3. Altimeter (ALT)
4. Vertical Speed Indicator (VSI)
5. Traffic and Collision Alert System (TCAS)
6. VHF Communication Radio Controller
7. ATC Transponder Controller

Ultimately we would like to replace the current RDMIs with ARINC 429 compatible ones. 

Avionics Bending: Honeywell VSI/TRA

Honeywell VSI/TRA Display from TCAS-2000 System on the L-1011

Many of the L-1011's got upgraded with TCAS during their service time. The most commonly installed TCAS system on the L-1011 is the Honeywell TCAS-2000. I recently got my hands on a pair of Honeywell 4067644 VSI/TRA displays. The displays are vintage 1990s and will make the L-1011 simulator a lot more authentic, and, they are a lot of fun to work with. They take ARINC 429 input for both the VSI data as well as the TACAS data. The image above shows the VSI/TRA without any data sent to it, therefore, it indicates both TCAS and VSI as FAIL.

Here is a short demo of the VSI/TRA receiving Vertical Speed data from the ARINC 429 Primary bus

From: Honeywell TCAS-2000 Installation Manual

The VSI/TRA display runs off 115V 400Hz power and can take both ARINC 429 data as well as ARINC 575 ADC data. The 575 stuff is purely analog so not so interesting for working with the flight simulator, but the ARINC 429 stuff comes in very handy. Also, the VSI/TRA comes in a 41pin as well as a 55pin version. The ones that I have are the 41 pin version; and, here is the pinout for the 41pin VSI/TRA:

J1-1	VS +DC REF	ARINC 575
J1-2	VS DC RATE	ARINC 575
J1-3	VS -DC REF	ARINC 575
J1-4	Primary VS (HI)	ARINC 565
J1-6	Primary VS (LO)	ARINC 565
J1-5	VS 26 VAC Ref (Hi)	ARINC 565
J1-7	Not Used
J1-21	Not Used
J1-8	VSI Valid Flag	ARINC 575/565
J1-9	5V Lamp Dimming (LO)
J1-10	5V Lamp Dimming (HI)
J1-11	TCAS TA/RA (B)	ARINC 429
J1-26	TCAS TA/RA (A)	ARINC 429
J1-12	VS No 1 (B)	ARINC 429
J1-27	VS No 1 (A)	ARINC 429
J1-13	Not Used
J1-14	VS No 2 (B)	ARINC 429
K1-30	VS No 2 (A)	ARINC 429
J1-15	Config Common
J1-16	VS 26 VAC Ref (C)
J1-17	CS3	Configuration Bit
J1-18	PTM Common
J1-19	PTM PWR Out -15VDC
J1-20	PTM PWR Out +15VDC
J1-22	Chassis Ground
J1-23	115VAC 400Hz (C)
J1-24	Remote Light Sensor (LO)
J1-25	Remote Light Sensor (HI)
J1-28	Not Used
J1-29	RA Valid Out
J1-31	Source Select In
J1-32	CS0	Configuration Bit
J1-33	CS1	Configuration Bit
J1-34	CS2	Configuration Bit
J1-35	CS4	Configuration Bit
J1-36	CS5	Configuration Bit
J1-37	CS6	Configuration Bit
J1-38	CS7	Configuration Bit
J1-39	DC Ground
J1-40	115VAC 400Hz (H)
J1-41	CS8	Configuration Bit

The Vertical Speed input label for the VS 1 and VS 2 sources is Label 212.

Avionics Bending: Audio Panel Integration for the L-1011 Trainer

Tim Joransen and myself discussed how to do realistic audio panel integration for the simulator. So, to use a Virtual Air Traffic Control System (in our case VatSIM) we are currently thinking about using XSquawkbox.

To make the cockpit experience as realistic as possible from an audio perspective we need to have a number of discrete audio channels that can be fed into and received from the 4 audio panels in the cockpit. What and where are the four audio panels?

1. Captain's Audio Selector Panel on the aft center console
2. First Officer's Audio Selector Panel on the aft center console
3. Second Officer's Audio Selector Panel on the lower Flight Engineer's Console
4. Observer Audio Selector Panel to the left of the observer's seat

L-1011 Audio Selector Panel Locations - From Delta Pilot's Reference

Most audio panels made by Gables Engineering have a very similar pin configuration. And allow for a number of external components to be connected. For the L-1011 project, here are the external elements that connect to each audio selector panel:

• Headset (All Stations)
• Boom Microphone (part of the headset) (All Stations)
• Oxygen Mask Microphone  (All Stations)
• Hand Microphone (Captain, F/O and S/O only)
• Overhead Speaker (Captain and F/O only)
• Yoke R/T and INT Switch (Captain and F/O Only)

Here are the different audio channels that need to be fed to the Audio Select Panel to make the simulation as realistic as possible:

1. VHF COM 1 Audio (xsquawkbox)
2. VHF COM 2 Audio (xsquawkbox)
3. VHF COM 3 Audio (xsquawkbox)
4. HF COM 1 Audio (tbd)
5. HF COM 2 Audio (tbd)
6. VOR 1 Audio (xplane via plugin)
7. VOR 2 Audio (xplane via plugin)
8. ADF 1 Audio (xplane via plugin)
9. ADF 2 Audio (xplane via plugin)
10. Marker Beacon (xplane via plugin)
11. Ground Proximity Warning (xplane via plugin) 
12. Interphone (within the simulator)

The audio panel also routes the microphones for each of the audio stations to the respective channels. For the simulator here is the proposed mapping:

1. VHF COM 1 Microphone (to xsquawkbox)
2. VHF COM 2 Microphone (to xsquawkbox)
3. VHF COM 3 Microphone (to xsquawkbox)
4. HF COM 1 Audio (tbd)
5. HF COM 2 Audio (tbd)
6. Voice Recorder Output (tbd)
7. Interphone (within the simulator)

Of course there is still the Passenger Address (PA) system that would be, of course, part of the L-1011 however, for the purpose of building the simulator we will not worry too much about the PA system. We will not integrate the PA into the audio panel, however, the L-1011 has a Passenger Address panel on the overhead panel and we might consider connecting that. 

L-1011 Trainer Installation: S/O Console and Center Panel Power-Up - Continued

L-1011 F/O Audio Panel and SELCAL Panel Installation

The power up of our L-1011 panels continues. Jim and myself powered up a total of 4 additional panels and also installed the necessary cable bundles for the instruments. Today we powered up the F/O side audio panel, the SELCAL panel located on the aft center console (see below). Currently the Captain's side and the F/O side audio panels are different. The F/O panel is actually just a placeholder for now; it will be replaced with an audio panel identical to the Captain's next week.

L-1011 SELCAL and F/O Audio Panel

We further powered up the Cabin Pressurization module on the upper Second Officer console as well as the APU Control panel located on the lower S/O console (see below). 

L-1011 Pressure Control and APU Control Panels

The Lockheed L-1011 Cabin Pressure Control panel is a really neat instrument. It has two large windows with a tape behind them for adjustments. The window on the left hand side sets the Flight Altitude and the one on the right sets the barometric pressure (see below).

L-1011 Cabin Pressure Control Panel

Besides the panel light up, Jim started preparing the Pilot's and First Officer's side consoles for the installation of the audio connectors. The side console holds connectors for the headset an headset-boom microphone; a handheld microphone and the audio connectors for the oxygen masks.

Jim Blasco working on the F/O side audio connectors.

L-1011 Trainer Installation: 75% Panel Light-Up Milestone

L-1011 Panel Lighting

Today we celebrate reaching the 75% panel light-up milestone! Jim and myself also worked on installing more bus bars for the panel lighting. Currently we have a few more panels on the pilot's overhead panel to light up as well as a few panels on the Flight Engineers station. Most of the remaining 25% of panel lighting are the circuit breaker panels. Once this is complete, all the of the instrument lighting, panel lighting, flood lighting, instrument digital, instrument analog and flight control analog cabling is in place. Then we will get really deep into the phase where it's mostly software between the cabled components and the simulator platform.  

L-1011 Flight Engineer Station

Here are a few more pictures of the current state of the simulator panel lighting:

L-1011 Project - Panel Lighting

L-1011 Trainer Installation - Overhead Panel Lighting

L-1011 Project - Panel Lighting 

L-1011 Flight Engineer Console ... 2/3 Panel illumination complete. 

L-1011 Trainer Installation: Audio Panel and Dual ADF Head Power Up

This evening I ran the cabling for the first audio selector panel as well as the dual ADF panel. Both are located on the aft center console. The audio selector requires a lot of cables due to the fact that each of the audio channels has its own cable. The two remaining components that are not powered up yet on the aft console are the weather radar selector and the first officer's audio panel.

L-1011 Trainer Installation: Light Plate Power-Up - Continuation

L-1011 Center Console - Light Plate Power-Up

Today was a busy sim building day. Jim Blasco and myself mounted the 5VDC 120A power supply we talked about in the last posting into the simulator and cabled the supply to the circuit breaker boards. While this sounds like a pretty tribal task, it actually took us several hours to it it all into place.

Certain groups of light plates as well as in some cases single light plates have their own circuit breakers. For example, the aft center console light plates are split over to different circuit breakers located on the CB2 panel.

Below shows the first F/E station light plate that is now permanently cabled in; it is the light plate for the Electrical System panel.

L-1011 Electrical System Panel - Light Plate

L-1011 Trainer Installation: Initial Light Plate Power-Up

L-1011 Light Plate Power-Up

I finally got my hands on a nice and compact 5VDC 120A power supply for the instrument panel light plates. Almost every panel in the Lockheed L-1011 cockpit has a backlit light plate that illuminates the legend on the plate. The power for the Light plates is 5VDC. Due to the fact that there are so many of them and that they use incandescent bulbs we needed a supply that can output a lot of Amps for the 5V required. Today we tested the power supply with 4 panels on the overhead panel: We powers up the Captains Windshield Wiper panel, the Exterior Lights panel on the eyebrow and the Interior Light panel also located on the eyebrow. Some of the light plates need some of the bulbs replaced, but, that's to be expected when dealing with 40 year old flight hardware.

The plan is to have all over the overhead and center console light plates powered up over the coming weekend.