Hydraulic system

The hydraulic system powers the flaps, nose-wheel steering, and toe brakes from a single electrical pump (running off the left DC bus) that cycles on and off via a pressure switch. The pump engages whenever the pressure in the main accumulator falls below ca. 1350 PSI. Its characteristical sound can be heard while operating the mentioned systems.

Note

I tried different ways to make the sound quieter so it would be less annoying, so far without success. Also, I have no reference material that would let me reverse engineer the actual numbers, so the frequency of the pump actuation is only based on halfway plausible physics and the behavior of the Aerosoft models.

I will adjust it as soon as I get my hands on better reference material.

Two nitrogen-precharged accumulators retain pressure so it's available immediately on demand. The brake accumulator is isolated from the main system to keep the brakes working even if the main system loses pressure to a leak.

An emergency hand pump provides a manual backup to re-pressurize the accumulators if the electric pump fails.

Tip

If you need to manually restore hydraulic pressure, you can access the emergency hand pump via the Systems tab on the EFB.

If the pressure falls below 800-1000 PSI, expect reduced performance of the hydraulically powered systems. Flaps will extend more slowly, brakes will be less effective, and at some point in the future, the nose-wheel steering will be affected as well.

The mod's hydraulic system has been rebuilt using the sim's modern ("EX1") architecture, and updated to version 2 with the release of SU6.

Bug

I don't know how to prime the hydraulics system correctly at the beginning of a flight. Over the course of this project, I spent several days on this, but I still can't figure out how to keep the hydraulics system from draining itself during the cinematics.

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Reviewed 2026-08-18.