L-1011 Procedure: Preflight Check - Fuel System, Fuel Control Amplifier, Fuel Used and Engine Oil Panel

From Lockheed L-1011 Flight Training Manual

Fuel Panel

• Verify refueling is complete and the REFUEL POWER ON switch legend is extinguished. 
• Test the fuel quantity system. Check that fuel quantity indicators and digital readouts drive towards FULL. The 2L and 2R INBD LOW quantity lights illuminate, and FUEL SYSTEM annunciator light on the CAWP is illuminated. 
• Latch in one pump switch on 2L or 2R thank, and open all three cross feed valve. This provides full pressure to all engines in preparation for start. 
• All amber lights should be extinguished, and all tank valve and cross feed valve switchlight flow bars illuminated, as well as one tank pump switch flow bar in 2L or 2R tank. 

Fuel Dump Panel 

• All light are extinguished.

Fuel Control Amplifier

• Switches should be unlatched and guarded and OVRD legend extinguished. 

Engine Fuel Used Panel

• Turn the test knob on each indicator and observe the fuel flow indicators drive to 10,000 pph, and the Fuel Used indicators increase at that rate. Fuel Used indicators are then reset by the Fuel Used Reset switch on the Fuel System panel. 

Engine Oil Panel

• Check all FILER PRESSURE lights extinguished. 
• Test the pressure gauges with the PRESS IND test switch. Oil pressure indicators go to the 9 o'clock position. 
• The (3) three oil temperature gauges should indicate approximately the same, depending on time since engine shutdown. 
• Oil quantity should be adequate for the flight (normally 15 - 20 US quarts)

Avionics Bending: Engine Oil Pressure Indicator

L-1011 Engine Oil Pressure - Smiths' Ltd.

The Engine Oil Pressure indicators used on the Lockheed L-1011 are made by Smiths. All in all there are three of these, one for each engine. They have a range from 0 to 100 psi in increments of 5 psi. Pressure range markings are red from 0 to 35 psi, yellow from 35 to 40 psi and green from 40 to 100 psi.

The three indicators have a common test switch on the panel (not shown in this posting). The test switch will drive the indicators to about 22 psi.

To indicate pressure the instrument would send a 400Hz SIN and COSIN signal to a sensor. The oil pressure presses down on a piston that then moves a coil that sends back a phase shifted signal to the instrument. The phase difference between the 400Hz reference signal and the signal produced by the sensor is then indicated as the pressure on the front of the instrument.

The image below shows a simulated phase shifted signal that outputs the 55 psi you see in the image at the top of this posting. The phase shift can be somewhat reproduced with a digital potentiometer, however, a much more elegant way would be with a resolver or a Digtial to Synchro Converter. The video at the bottom of the posting shows the instrument in action receiving a number of different wave offsets.

L-1011 Engine Oil Pressure Indicator - Phase Offset

Here is the schematic and pinout for the L-1011 Engine Pressure Indicator made by Smith Ltd.:

Avionics Bending: Engine Oil Quantity Indicator

L-1011 Engine Oil Quantity

The Engine Oil Quantity used on the Lockheed L-1011 is a General Electric 8DJ173 LWD1 and is a relatively simple instrument. It takes 115V 400Hz power. The instrument has a BITE test button on the lower left front. The test switch drives the indicator needle to 10.5 Quart. You can see operation of the instrument in the short demonstration video below.

On the real aircraft the instrument acts as the power source for the oil quantity probe. The instrument outputs 6.5VDC which can then be run through a digital 10K potentiometer to simulate the oil level probe. 

Below is the schematic and pinout for the Instrument from the L-1011 Training manual:

Engine Oil Quantity - Pinout and Schematic

System Description by Don Pierce: Engine Status and Engine Oil

ENGINE STATUS Panel:

The top row of indicators are the N2 indicators, showing N2 speed. They are round dial instruments on all L-1011s, even though some planes have vertical tape instruments for N1 and N3. It is normal for the FE to call out beginning of N2 rotation during the engine start process.


The second row if indicators are the Vibration Monitor Indicators. They read from 0 to 5 units of vibration. Each indicator has a BITE button which will drive that respective indicator to approximately 4.0 units, verifying indicator operation. Also. each indicator has an amber light that illuminates about about half-scale (2.5 units) At the same time a light will illuminate on the pilots' caution and warning panel. The reading of the light varies - it might be ENG VIB/FLTR PRESS or ENGINE/APU STATUS.

Below the indicators are a series of test-related switches. The TEST push-button switch is used to test the signal conditioner (located in the MESC) and all three indicators. Pressing and holding the switch will cause all three indicators to read approximately 4.0 units; the amber lights will illuminate when the needles of the indicators pass about 2.5 units. When the switch is release, the indicator will return to 0 units (assuming the engine is not running) but the light remains "on", if the needles had passed 3.0 units when the needle was "rising". To extinguish the lights, the TEST switch must be pressed a second time (briefly).

The A and B latching switchlights provide the capability to select either of the two vibration pickups. When both switchlights are unlatched, both pickups are sampled, every 0.5 second. Note: the reading for the switchlights may be FAN and TRUB - for an earlier configuration; location of the vibration transducers will also vary. The ON light is switchlight position.

The four-position rotary switch is a "filter selector". When the switch is at the NORM (normal) position, the rotor frequency being monitored is the frequency range of all three rotating assemblies. When the other three rotary switch positions are selected, the frequency range is of one of the three rotors being monitored: LOW is the LP shaft (N1), MED is the IP shaft (N2) and HIGH is the HP shaft (N3). Note: The level of vibration being seen depends on the "age" of the engine.


ENGINE OIL Panel:

The engine oil QUANTITY indicators have a units display that varies from airline to airline; the quantity also varies, depending on type of engine.

Below the QUANTITY indicators are three oil TEMP indicators, in °C. All six of these indicators each have a small BITE button that is used to test the respective indicator. Faceplate light access for all six indicators is via the front of the indicator. All six instruments are made by General Electric.

Next are three oil PRESS (pressure) gages, manufactured by Smiths Industries. The range of the gage is 0 to 100 psi, in increments of 5 psi. The range is red from 0 to 35 psi, then yellow from 35 to 40, and green from 40 to 100 psi. The three pressure gages have a single, common TEST switchlight. There are three OIL PRESS ENG (x) lights on the pilots' caution and warning panel, which illuminate when the associated engine's oil pressure is too low.

The three amber FILTER PRESSURE lights illuminate to show an excessive pressure drop across either the associated oil pressure filter or the associated fine oil scavenge filter. At the same time, the ENG VIB/FLTR PRESS light on the caution and warning panel will illuminate. This light was also discussed (above) along with Engine Vibration.

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