Hydraulic power, on the Lockheed L-1011, is used for operation of the flight controls, landing gear, nose gear steering and main gear brakes. The power is furnished by four separate hydraulic systems. The image below shows the Hydraulic System as I have re-assembled today (1/3/2010) - the instruments for the A and the B system are still missing.
The four hydraulic systems are designated as A, B, C and D. Which can be seen in the picture below.
Systems A and D are normally pressurized by single hydraulic pumps driven by engine #1 and engine #3 respectively. Additionally, they can be pressurized by systems B and C thru Power Transfer Unites (PTUs), however, there is no fluid transfer from one system to the other.
System B and C are normally pressurized by respective hydraulic pumps driven by engine #2. The pressurization systems are:
- A1 .. pump driven by engine #1
- B1 .. pump driven by engine #2
- B2 .. pump driven by ATM
- B3 .. pump driven by AC motor
- C1 .. pump driven by engine #2
- C2 .. pump driven by ATM
- C3 .. pump driven by AC motor
- D1 .. pump driven by engine #3
- B-A .. pressurization by PTU
- C-D .. pressurization by PTU
The image above shows the alternative pressurization methods for system B and C which are: RAM Air Turbine (RAT) and the two AC powered electrical pumps.
The image below shows the two Air Turbine Motor systems that can further be used to augment the pressurization of the B and C hydraulic systems. The ATMs are driven by bleed air from the pneumatic system and can be engaged automatically, manually or disabled. There is a separate lubrication reservoir for each ATM with an annunciator showing HI TEMP and/or LO PR for the lubricant.
The rotary switch for the ATM is in a locked position when in the OFF position. The ATM system has an over-speed test position called "OVSP TEST". Turbine RPM can be read from the RPM instrument.
In the image below, the red line indicates the primary system operation for the "C" hydraulic system as driven by the ENG2 hydraulic pump. The orange line indicates the alternate fluid path through the ATM that allows to C system to be pressurized via the pneumatic system. The blue line shows the primary system operation for the "D" hydraulic system as driven by the ENG3 hydraulic pump. The purple line indicates the alternate system pressurization via the Pressure Transfer Unit (C-D) from the "C" hydraulic system.
Below the third methods of pressurizing the "B" and "C" hydraulic systems. The red line shows "B" system pressurization via the RAM Air Turbine (RAT) and the orange line shows "B" system pressurization via the B3 AC Electric pump. The blue line shows system "D" pressurization via the D3 AC Electric pump. Of course, both systems again are able to pressurize the "A" (via the B-A PTU) system as well as the "D" (via the C-D PTU) system.
Panel Location
No comments:
Post a Comment