L-1011 Trainer Installation: Interbus Installation into S/O Station

L-1011 Trainer - Interbus Installation

The Lockheed L-1011 cockpit has literally hundreds of switch positions and an even larger number of annunciator lights. For the computers receiving switch data and driving the annunciator lights we use Interbus components. Interbus is a relatively old bus format but is perfect for the use on the simulator since this is a field bus system that readily works in the 24VDC domain. In a few previous postings we talked about installing Interbus Terminal stations in the Flight Engineer's (SO Station), the Overhead and the Main Instrument Panel. All the Interbus components we selected for the simulator mount onto DIN rails and will be fully field replaceable.

In order to get the DIN rails added to the simulator we are blessed to have the master of all hardware mounting, Mr. Jim Blassco, create custom mounts for the simulator. 

First we had to find a good position in the simulator's Flight Engineer station to mount the devices. We picked a spot towards the top of the station for two reasons: a) there was really a lot of space there and b) we would get good airflow over the components for cooling. 

L-1011 Flight Engineer Station - Digital I/O Bracket

Then the fun started, Jim made some custom designed brackets and introduced me to the use of an angle drill ... an amazing piece of hardware that looks like a gigantic dentist tool.

Jim Manufacturing Brackets for the L-1011 Trainer

With the brackets in place we installed the steel DIN rail (they flex a lot less than aluminum rails) and mounted the Interbus modules right onto it.

L-1011 Trainer - Digital I/O Bracket

L-1011 Trainer - Digital I/O Buildout

Every day is a step towards the finishing of this project. However, as Kevin pointed out ... in sim building a lot of the fun is actually in the journey of putting such a complex machine together. Thanks to everyone for their awesome support!

L-1011 Trainer Installation: MIP and FE Station Instrument Lighting

L-1011 Trainer: Instrument Lighting Build-Out (FE Station)

Today we continued the build-out of some of the integral instrument lighting on the FE station as well as the main instrument panel. On the FE station we connected the Engine %RPM N2 instruments as well as the Slat Monitor / Slat Position Indicator. All the instruments use 5V power and are driven from either the FE Station Lower Right Light Bus (for the %N2) and the FE Station Upper Right Light Bus (Slat Position).

During the connector installation we discovered that the FE station used for the trainer has a metal plate right behind the Slat Monitor that prevented the connector from mating correctly with the instrument. Therefore, we had to make a panel configuration change and move the Flight Engineer's Annunciator Panel into the position of the Slat Monitor and moved the Slat Monitor down.

L-1011 Trainer: FE Station Instrument Lighting and Door Annunciator

We don't think that this configuration change is going to make a significant difference to the authenticity of the L-1011 cockpit, however, one of the %RPM N2 instruments is still one of the original simulated procedures trainer instruments. Need to replace it with the real flight hardware as soon as I can find one.

L-1011 Trainer: FE Station %N2 Instrument Lighting

Last week we had started powering up the instruments on the pilot's center instrument panel. This is the place where the majority of the engine instruments are located. The instruments are split into two 5V light buses: Captain's Center Instrument Left and Captain's Center Instrument Right. The instruments that you can see illuminated in the picture below all belong to the Center Instrument Right light bus. During the initial build-out session we discovered that we did not have the right connectors for the Engine EPR instruments ... hence, we could not connect them ... we missed three Deutsch 15-S7 connectors. We now have them (those guys are hard to find and expensive) but we finally got them. So now all the instruments belonging to this light bus are connected.

L-1011 Trainer Build-Out: Main Instrument Panel Engine EPR Instrument Lighting

L-1011 Trainer Installation: Overhead and FE Station Indicator Lights Build-Out

L-1011 Trainer Installation - Indicator Buildout

L-1011 Trainer Installation - Indicator Buildout

Continued with the indicator build out today. The Indicator light as well as the Indicator Test circuits are now connected to the FCES panel as well as portions of the Hydraulic and Engine Bleed Control panel The two images above illustrate which panels got connected during the most recent installation effort.

L-1011 Trainer Installation - Indicator Buildout

Below is a detail of the FCES and the PFCS panels. The FCES panel indicates status of the various Flight Control computer systems. Each switchlight has either an "OFF" or "FAIL" legend.

L-1011 Trainer Installation - Indicator Buildout

L-1011 Trainer Installation - Indicator Buildout (FCES and PFCS)

L-1011 - CPT Installation at the Museum - SO Station Flood Light

L1011 Flight Engineer's Station Flood Light

Today we changed the first flood light fixture from fluorescent lighting to LED lighting. The flood light is above the Flight Engineer's station and is about 24" wide. The image above shows the Flight Engineer's station illuminated after the retrofit. 

For the retrofit I selected COOL WHITE LEDs because they are pretty close to the light that would have come from the fluorescent light bulbs. The LEDs below are standard SMD ultra bright LEDs mounted on an adhesive strip. 

Cool White LED Strip - 12VDC

The LED's can be cut just about every 2 inches (or every 3 LEDs). This makes them very flexibly for installations in the already existing flood light fixtures of the L-1011 simulator. Of course, the main advantage of using the LEDs are their durability and extremely low thermal output.

Cool White SMD LED Strip - 12VDC

The station flood light is controlled by a dimmer on the lower left hand side of the console. The image below shows the flood light at full intensity.

L-1011 Flight Engineer's Station - Flood Light Installation

The flood light fixture on top of the station has a metal strip that prevents light from spilling significantly further than the station itself.

 This contains the flood light and does not spill over to the pilot's stations or the main instrument panel.

L-1011 Flight Engineer's Station Upper Section - Flood Light 

L-1011 Flight Engineer's Station Lower Section - Flood Flight

The next flood lights to install will be above the Pilot's and First Officer's main instrument panels. The engine cluster flood light is combined with the Pilot's flood light and is controlled by the same dimmer. 

L-1011 General Aircraft Characteristics: Flight Engineers Caution and Warning Panel (25-26)

This panel provides advisory indications of abnormal conditions such as doors and openings not securely closed. Indications will remain illuminated until announced condition is corrected.

L-1011 General Aircraft Characteristics: Flight Engineers Panel (25-24)

The Flight Engineer's panel is located on the right side of the cockpit, behind the First Officer. The most important systems, such as the hydraulic, electrical and fuel systems, are located on the left side of the FE panel. Here, they are easily accessible to both the Flight Engineer and the First Officer.

System Description by Don Pierce: Nacelle/Pylon Overheat

"Don Pierce is a L-1011 Flight Test Engineer (Ship 3), then in Customer Training, then he had his own business doing maintenance training for L-1011 customers. Don is nothing but amazing in his knowledge of the L-1011. I am going to post several conversations on systems that I have had with Don over the past few weeks"

This is a topic that is part of ATA 36, Pneumatics, but does not appear on the Pneumatics panel. It has its own panel, with is at the top of the FE panel.

It is similar to Area Overheat, but also has many differences. The panel has two loop lights (A and B) per engine - at the top of the panel (not switchlights) . There are also three Loop Selector switches (one per engine) - A/BOTH/B - plus one TEST button on the panel.

Generally explained, there are two loops (A and B) per engine, located near the exhaust of a nacelle cooling vent; these are the nacelle sensors This applies to all three engines.

For the wing engines (#1 and #3), there are two more loops (A and B) near the exhaust vent for the pylon. For the center engine (#2) instead of a pylon, the engine is mounted on a "center engine support structure". This engine has three set of sensors that together qualify as the "pylon sensors". One set of loops (A and B) is located just above the engine and below the horizontal "mounting plate" for the engine. The other two sets are individual sets (A and B) mounted on a bracket to the left and to the right of the engine's pneumatic supply ducting; this is technically considered the pylon for the center engine.

If an overheat condition is sensed, the sensor will send a signal to an Overheat Control, located in the Mid Electrical Service Center (MESC), which in turn will illuminate the A and/or B light(s) on the FE panel - depending on which loop(s) send an overheat signal. At the same time the overheat controller will send a signal to close and lockout the High Pressure (HP) valve. The FE can then use the TEST switch and rotary select switch, as described for the Area Overheat system. If the FE determines it is a faulty signal, and has isolated the faulty loop, or after an overheat signal has cleared itself - the HP valve will not reopen automatically. The HP switchlight must be cycled (unlatched and then latched in) to de-energine a lockout relay, and allow the HP valve to reopen again.

For Area Overheat, no valve closed automatically. For Nacelle/Pylon Overheat, the HP valve does close automatically.

For Area Overheat, there is only one Loop Select switch, which means all nine channels will be monitoring the same loop(s). For Nacelle/Pylon Overheat, there are three loop select switches, so each engine can be set as desired.

Avionics Bending: Cabin Vertical Speed Indicator (Analysis)

There are a number of different configurations of the Cabin Pressuizaiton control panel for the Lockheed L-1011. Most L-1011's had a combination instrument that would show cabin pressure and cabin altitude (similar to what you would find on the overhead of Boeing 737 panel). However, versions of the L-1011 had a discrete VSI, Pressure Differential and Cabin Altitude instrument .... very much like the Boeing 747. The pressurization panel that I have happens to be one that takes all 3 instruments. Today, we are going to look inside the fully analog CABIN VERTICAL SPEED Insrument.

Top View: The inside of the instrument is dominated by the large copper disk that flexes under different air pressure and controls the needle. Air will either enter the instrument at a fixed rate or leave it at a fixed rate ... hence, the differential will show the cabin climb or descent in thousands of feet per minute.

Original Flight Hardware: Engine Status Panel

The flight engineer station on the Lockheed L-1011 is home to a number of engine panels. A few days ago I showed you the ENGINE OIL panel. In today's posting we are taking a look at the ENGINE STATUS panel. There are actually a total of 3 panels that specifically deal with engine information, they are: ENGINE STATUS, ENGINE OIL and ENGINE FUEL.

The panel is home to the following instruments for the number 1, 2 and 3 engines.

• %N2 Stage RPM
• Engine Vibration

The Engine Status panel has a number of selector switches, a rotary switch and a test button (as seen in the image above). The TEST button is a momentary switch that will drive all the indicators towards zero for testing. The PICKUP SELECTION switches decide if FAN (A) or TURB (B) vibration will be indicated on the VIB instruments. The rotary switch sets the sensitivity of the vibration indicators from NORM, LOW, MED to HIGH.


Panel Location

Avionics Bending: Indicator Oil Temperature (Analysis)

There are number of temperature gauges in the Lockheed L-1011 cockpit. The three engine oil temperature gauges and the fuel temperature gauge are built the same way. The ECS temperature gauges are different. The gauges are basically synchros. At instrument shown in this posting was made by General Electric Corporation (GE) to Lockheed specifications.


Typical for this instrument is the way the instrument casing is mounted. There are three screws on the back of the instrument holding the core to the shell with 3 mounting clips.



Top View. What is interesting with this type of instrument is that the circuit boards are an integral structural component of the entire instrument. The boards have the back plate with the connector mounted on one side the instrument head mounted on the other. Also, note the use of flexible printed circuits as a replacement for hookup wires.


Right hand side view


Bottom View

Left hand side view

Just as the engine instruments from the main instrument panel cluster, the temperature gauges also have small post lights in the top left and top right corners. There is a test switch that can be used to test the instrument. Pressing the test switch will drive the needle to zero.


There is a large round transformer that would be used for transformation of the 115V 400Hz 1 Phase input signal.

Original Flight Hardware: Engine Oil

The Engine Oil panel is part of the lower flight engineer panel on the Lockheed L-1011. The panel has 3 discrete indicator clusters for Engine Oil Quantity, Engine Oil Temperature and Engine Oil Pressure. Directly below the oil pressure gauge is an annuciator that illuminates when oil pressure across the filter falls below a certain level.

The PRESS IND TEST switch drives the pressure gauges to zero which tests free indicator movement.

At the time of the posting of this blog entry, I am actually still missing 5 of the 9 instruments. They will come with time. (The picture on top of the posting is a composite picture .. need to be truthful about that).



Panel Location