L-1011 Trainer Installation: Switch (Digital) Input Modules

Interbus Input Module Preparation

Cables, Cables and more Cables. The next few weeks are going to be filled with lots of postings on the digital cabling process of the L-1011 Trainer at the museum. The digital cabling connects all of the hundreds of trainer switches and lights to the computers. Today, I started building out the first of many digital input modules for the simulator. As described in a few earlier postings, I will be using a PLC system based on Interbus for the switch input and for the annunciator and switch light output on the L-1011 trainer.

interbus 8-bit Switch Input

Each of the digital input (DI) modules has 32 inputs that are arranged in 8 channels + 1 GND signal per group. The image above shows the 8 digital input lines that will be coming from switches. Each cable represents a bit and together each connector represents one Byte of information on the Interbus. 

L-1011 Procedure: APU and Air Conditioning Startup

When the simulator is powered up and the EXT POWER switch located on the simulator power control panel is in the ON position the simulator emulates the behavior of the aircraft sitting on the ground with external power connected to it.

The next step will be to start the APU. The APU will be started by the Flight Engineer with the following procedure:

If external power is not in use, but the green AVAIL light is illuminated, actuate the external power switch. This will provide AC and DC power to the simulator systems.

Note: If external power does not turned on in the simulator, turn the battery switch ON . This will provide power to the simulated Ground Control Unit (GCU) and the DC standby bus. Once external power is on the simulator, it will be able to power the GCU through the DC standby bus.

Prior to starting the APU, check the fire detection system for the APU and engines.

1.  Detector loop selectors ....... BOTH

2.  Detector loop lights .. EXTINGUISHED

3.  Press A & B Test buttons simultaneously and check:

• Waring bell is on (press cutout to silence)
• A and B loop lights illuminated 
• Master fire warning lights on glare shield illuminated 
• Fire Pull handles illuminated 
• FIRE DET LOOP annunciator light on Caution and Warning Panel

APU START PROCEDURE

From Lockheed L-1011 Flight Training Manual

1. Select DC meter to BAT and AC meter to APU. Check that the BATTERY CONDITION light on the APU panel is not illuminated.

2. Position the APU master power switch to ON. (OBSERVE: Primary emergency shutoff fuel valve opens. AUTO FIRE SHUTDOWN ARMED light on APU panel illuminates.

3. IF external AC power is available, turn on #2 fuel tank pump.

4. Position the Bleed Air Mode switch on the APU Panel to MIN MODE.

5. APU Bleed Air S/O switch unlatched and OPEN light extinguishes.

6. Press the Start switch until the DOORS IN TRANSIT light illuminates. (OBSERVE: DOORS IN TRANSIT light cycle as the engine inlet and APU compartment ejector doors open).

After pressing Start, monitor the following:

• DONT LOAD light and APU GEN OIL PRESS light (on the electrical panel) illuminated after DOORS IN TRANSIT light extinguished. 
• While the APU RPM and APU TGT are increasing, check the Battery volts and amps. If either is low the simulator is presenting you with an abnormal APU start. 
• When APU RPM and APU TGT have stabilized in the green range, with the DONT LOAD light extinguished, check that the APU generator field flow bar is illuminated, generator oil PRESS light extinguished, and generator volts and frequency are normal 

      Voltage = 117 +/-2, Frequency = 401 +/-2Hz

• Check APU generator KW load. 81KW max, but normal around 40-50KW with system on.
• DC ammeter indicates normal battery charging. 

Preparing for APU Air

From Lockheed L-1011 Flight Training Manual

1. Aft fuselage ISLN and both crossbreed valves are latched in.

2. Pack Flow Control valve switches unlatched (closed). When Pack Flow Control valve switches 2 and 3 are unlatched, their hot air valves should be unlatched at the same time. 

3. Pack Auto/MNL switches latched in --> AUTO illuminated 

4. Ground control switch latched in and legend not illuminated. 

5. Aircraft zone air trim switches latched in and not illuminated. 

6. Zone temperature control to 12 o'clock position. 

Accepting APU Bleed Air

From Lockheed L-1011 Flight Training Manual

1. Latch in APU Bleed Air S/O switch and observe the OPEN legend illumination.

2. Observe bleed air pressure on the engine duct pressure indicators.

3. Latch int he No. 2 pack flow control valve and its hot wire valves.

4. Turn the APU Mode Selector to Normal.

Avionics Bending: Making Cables for the Simulator

Finished Deutsch Connector with Strain Relieve

Since a lot of time the last few weeks has gone into making cables for the instruments and panels of the L-1011 trainer at the museum I thought it would be fun to show you how I make these cables. By the way, there are pretty strict standards on how to makes cables used on actual aircraft and the cables that I make somewhat loosely follow them, however, you should not consider this a guid on how to make cables used on actual aircraft.

Many of the connectors that we use on the simulator came out of actual airplanes. Every now and then you can get a friendly scrapper to cut off the cable ends for you right before the aircraft is scrapped. This is how we ended up with many connectors looking like this:

Tools 

Here are the tools that I use for making cables.

To get the old cables and pins out of the connectors you will need an extraction tool. Extraction tools come in all forms and shapes and are somewhat specific to the connector manufacturer. On circular avionics connectors the most common pin size is RED. The extraction tool below is metal and little more durable, but there are also plastic tools that only cost a few cents and do the job well .... if you are not planning on doing hundreds or pins. By the way, Clay Young from Precession Electronics here in Atlanta showed me a cool trick; when you dip the extraction tool into alcohol prior to using it it will grip to the pin better.

Insertion/Extraction Tool 

Jim just recently found a lot of tools for the museum and they have been a huge help. To put pins back onto the ends of your cables you will need some sort of a crimp tool that can be used with the pins used on circular connectors. Again, there are different crimp tools for different manufacturers. The most common crimp tool is show below and is made by Daniels Corporation and is called the M22520/1-01. The tool that we have at the museum has a turret head on it that can crimp three different sizes (green, red and blue)

Daniels Crimp Tool M22520/1-01 with Turret Head

The pin is inserted on the other side of the turret and then crimped by applying lots and lots of ponds via an easy to operate ratcheting grip.

SETP 1: Pull out the unused pins with the extraction tool.

Keep the pins! They will come in handy when you are making cables. By the way, when these connectors are being built for use on actual aircraft, all pin positions are filled with pins ... regardless of having a cable attached to it or not. These "unused" pins can be re-used in the simulator which then cuts down on the cost. 

STEP 2: Make the cable

Using the Crimp tool, I am now crimping one of the spare pins onto the AWG 22 cable and insert it into the correct location in the connector

STEP 3: Strain and Vibration Relieve of the Cable

If you don't strain relieve the cables on the backside of the connector you risk that, over time, the cable inside of the connector might break off from the pin. This can happen quite easily if you have a lot of strain on the cable, or, if the weight of a cable bundle pulls on a single cable in the connector. Therefore, always build a strain relieve for the cable. 

I use the back-shell clamps that fit the Deutsch and Amphenol connectors to do so. In order for the back-shell not to clamp down on the actual wires, or, as is the case with most connectors, the cable bundle is too small for the clamp to secure the cables I use 3M Temflex Rubber Splicing tape. 

Temflex tape is a thick rubber tape that is not adhesive. It is perfect to wrap around the cables and build a plug with allow the back-shell clamp can clamp down on.

Once in place, the Temflex tape absorbs all strain and vibration that the cables might exert on the pins. 

And this is how I make cables :)

L-1011 Trainer Installation: INU CDU Power-Up

L-1011 Trainer: INU Display Unit #1

The Litton INU display units are terminal units, often referred to as a Central Display Unit (CDU), that use a variant of the ARINC 429 standard to display information and read character input. A few months ago I started writing software for these INU CDU units. Today we installed three of these units in the L-1011 simulator. Typically L-1011 routes across the Atlantic would have had 3 of these units installed, and this is what we are simulating here.

Just with any of other ARINC 429 compatible instrument in the simulator, we are hoping to drive the Litton LTN-72RLs with the SIM429-11 interfaces.

L-1011 Trainer: INU Display Unit #3

L-1011 Trainer Installation: AC an DC Standby Power from Battery

L-1011 Trainer: AC and DC STBY Power from Battery

Finished the L-1011 AC Standby (STBY) and DC STBY power fail-over to the on-board Battery yesterday evening. On the actual aircraft, once transferred to Battery power, the standby buses are alive for about 30 minutes before the Battery is depleted.

Normally, the DC STBY bus receives powered from the DC Essential bus and the AC STBY bus is powered by the AC Essential bus. The AC and DC STBY bus are the last resort to keep the aircraft operational in case of a complete loss of primary electrical systems. If the respective Essential power busses fail, the STBY busses are switched to the on-board Battery. AC power is created form the on-board Battery via a DC to 115V/400Hz Inverter. Watch the short demonstration video below and you will see the system in action.

L-1011 Trainer Installation: Deep in the Cabling Trenches

L-1011 MIP Cabling

The last few sessions working on the Lockheed L-1011 trainer at the museum have been very deep in the cabling trenches of the main instrument panel (MIP). Cabling takes a lot of patients and it is not particularly fast work either.  In the image above and below you can see some of the new cable bundles introduced into the MIP on both the Captain's and the First Officers side. All this cabling is being done in preparation for the simulator being outfitted with the Ethernet based SIM429-11 ARINC interfaces.

L-1011 MIP Cabling

Saturday I also installed the second of 3 Ethernet switches into the simulator. This 5 port 10/100T switch will connect the SIM429 interfaces to the computer.

L-1011 Trainer - Forward Ethernet Switch

L-1011 Trainer Installation: Ethernet and Interbus Cabling

L-1011 Trainer - Ethernet

Today was one of those "got a lot done .. but have little to show" kind of installation days. Today I installed Ethernet cabling into the simulator for both the instrumentation control as well as the simulation computer network. In the diagram below you can see the different cables installed into the simulator for both of the main data systems; Ethernet and Interbus:

L-1011 Trainer: Interbus and Ethernet Cabling

All cables are built to custom length, so it took a while to get them all laced in, cut and ends crimped on them. All Ethernet connections are now point to point tested from the simulator computers to the switches. The Interbus tests are to follow.

Simulation Platform - Network Tests

L-1011 Simulator System Architecture

L-1011 System Architecture 

Had a good conversation with Premek Truksa today and realized that I had not blogged about the revised computer and interface architecture for the L-1011 sim. Well, as they always say in engineering and innovation ... "the first idea is always wrong". With that in mind, over the last few months the systems architecture of the L-1011 sim has changed a few times and as we work through iterations of the model it gets more and more refined. As you can see in the high-level topology drawing above, as of today, October 2013, we are planning on running the L-1011 simulator with the following components:

1. Three Apple OSX systems running the visual rendering engines and one running the core physics and systems engine. These three systems (depicted in blue) will be tied together by a dedicated 1Gbit Ethernet network. 
2. The OSX systems running the physics model will also connect to the primary systems network through a second ethernet connection. This will be a 10/100T Ethernet network and all components in the physical simulator will be controlled via this network link. 
3. The systems network connects a series of ARINC 429 interfaces that will receive and deliver information directly to the physics engine or will send and receive data from a Linux system that handles analog input and output.
4. Besides the ARINC 429 interfaces there will also an interface (or a set of) that can produce tachometer signals for engine instruments. 
5. Lastly, all of the analog switch and annunciator I/O will be handled via INTERBUS. The INTERBUS master is the Analog System Linux server. 

For now, this is the systems architecture we are building towards. It could, of course change over time. 

L-1011 Trainer Installation: Flight Station Bus Failure

L-1011 Trainer: Flight Station Bus Failure 

The FLT STA BUS FAIL lights are located on the Electrical System panel of the L-1011 S/O station. The lights illuminate amber when power is lost to the Flight Station Bus segment of the respective AC Load Bus.

The ELECTRICAL SYSTEM annunciator also illuminates on the Pilot's Annunciator Panel, however, this part has not yet been implemented. Below is a short video that demonstrates the Flight Station Bus failure and how it occurs independent form the Load Bus.

L-1011 Trainer Installation: Battery and Standby DC Power Transfer

L-1011 Trainer - Battery ON Indicator

The Lockheed L-1011 power system has a very high degree of redundancy and fail over capabilities. Looking at the L-1011 schematics and talking to people who flew and worked on the L-1011 all say that it was really hard loosing power on the L-1011 due to the very well designed AC and DC power distribution systems on-board.

First thing we did today was to connect the Battery ON/OFF switch on the S/O Console as well as the associated annunciator. Here is an excerpt from Delta's L-1011 Pilot Reference Manual explaining the Battery switch as well as the associated annunciator:

from: Delta Airlines L-1011 Pilot's Reference Manual p.Electrical.20

L-1011 Trainer - Battery Flow Indicator

There are also a number of Standby and Essential Bus Fault indicators. While we did not complete the build out for this system fully, we have as of today implemented the DC power fail over systems. Below is a short video illustrating how the DC fail over systems work:

from Delta Airline L-1011 Pilot's Reference Manual page.Electrical-16

L-1011 Trainer - BUS 3 Failure and Essential AC Failure

L-1011 Trainer Installation: SFENA HSI Installation Preparation and ARINC 429 Bus Integration

For the ARINC 429 integration of the L-1011 trainer at the museum we will be using bus interfaces made by V1 Avionics. For the integration testing V1 Avionics used the museum's L-1011 HSIs and ADIs. The video below shows the instrument preparation and testing prior to installation into the L-1011 trainer. The L-1011 sim will use the following ARINC 429 capable instruments:

1. Attitude Director/Indicator (ADI)
2. Horizontal Situation Indicator (HSI)
3. Altimeter (ALT)
4. Vertical Speed Indicator (VSI)
5. Inertial Navigation Unit Display (INU CDU)
6. Datalink Display Unit (DU)
7. Performance Management Unit (PMU)
8. Communication Radio Faces (COM1/COM2/COM3)
9. ATC Transponder (ATC)

L-1011 Trainer Installation: Research

The last few days we have been doing a lot of research on the instrumentation cabling. The WDM, which are all the wiring diagrams and schematics for the L-1011, that Paul Talbott found for the museum a few months ago is on Microfiche. Microfiche is not a very common format any longer because most documentation today is supplied as PDF files on CD-ROMs, DVDs or are simply downloaded. So a big obstacle was having a Microfiche reader. Clay Young, from Aero Maintenance Group - Precision Electronics here in Atlanta, is letting the museum borrow a Microfiche reader for the next few weeks. This is going to help a lot because it allows us a quick deep dive into the cockpit instrumentation schematics. Thank you Clay!

The microfiche frames are organized by ATA and come in these neat books.

The drawings are the WDM drawings furnished by Lockheed to Delta Airlines in the 1980s and are perfect for our project.

History: Delta Airline's 2001 Farewell to the L-1011

Today is the 40th anniversary of Delta placing the Lockheed L-1011 into service. A moment to celebrate.

Delta Airlines retired its fleet of Lockheed L-1011 after 28 years of service on July 31st 2001. The L-1011 had been the backbone of Delta's international business and many people had grown immensely attached to this beautiful aircraft. So when Delta retired the L-1011 this video was produced by Delta Airlines Video Services as a tribute the L-1011 an its long history with Delta Airlines. This farewell video is a beautiful tribute to the most amazing aircraft ever built .... enjoy!

The video above is © Delta Airlines / Delta Airlines Video Services, 2001