Showing posts with label Oil Temperature Indicator. Show all posts
Showing posts with label Oil Temperature Indicator. Show all posts

Thursday, September 2, 2010

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.

Saturday, February 6, 2010

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.