L-1011 Flight Controls: Surface Hydraulic Systems (27-10)

The L-1011 has four (4) hydraulic systems that operate the individual surfaces. Hydraulic pressure is provided as follows:

• The Number 1 Engine drives the A hydraulic system.
• The Number 2 Engine drives the B and C hydraulic systems.
• The Number 3 Engine drives the D hydraulic system. 

The Rudder receives hydraulic pressure from three different systems: A, B and C
The Stabilizer receives hydraulic pressure from all four hydraulic systems: A, B, C, and D

The Ailerons are driven by different hydraulic systems depending on their location along the wing:

Inboard Ailerons us 3 systems. On the left hand side they use systems A, B and C and on the right hand side they use systems B, C and D. For the outboard ailerons on the left hand side we use system A and B and on the right hand side systems B and D.

The Flaps and Slats are powered by two systems: A and C

The hydraulic systems for the Spoilers are rather diverse:

• No.1 Spoiler Limiter System - B system.
• No.2 and 3 Spoiler Limiter System - D system.

Left Wing

• No. 1, 4 and 6 Spoiler - B system
• No. 2 Spoiler - A system
• No. 3, 4 and 5 Spoiler - C system

Right Wing

• No. 1, 4 and 6 Spoiler - B system
• No. 2 Spoiler - D system 
• No. 3 and 5 Spoiler - C system

Note that the No. 2 spoilers are the odd power sources relating to their wing engines.