Hyd 3 Leak

[tcas_climb 45]

Has anyone else noticed that setting the HYD SYS 3 to leak (failures menu) doesn't do anything?EDIT : That is after leaking SYS 1 and 2, is it because of the NRMPs?

[KCA9304 0]

Has anyone else noticed that setting the HYD SYS 3 to leak (failures menu) doesn't do anything?EDIT : That is after leaking SYS 1 and 2, is it because of the NRMPs?

Bryan,Just tried the scenario to see how leaks were modelled.- On a single Hydr Leak scenario, on whatever system, EDP's are switched OFF when quantity goes below 2.5 USG.This to prevent further leakage from the hydraulic lines throughout the aircraft, and preserve an amount of fluid for use during approach and landing. (leaks being small of course).What happens here on every Hydr Systems, is that the quantity keeps on decreasing untill reservoir is empty.So it's a complete reservoir leak.When handling the procedure and consulting the 'Consequence' page, there are Two Alerts remaining.LVL 2: HYD # FAIL and LVL 1: HYD # OFF.In this case (empty reservoir) the LVL 1 alert should not be there, as its consequence that the system may be used for approach and landing is not valid.Also for DUAL HYDR failures LVL1: HYD # OFF remain displayed for the empty system and is not valid.Well, now to your question on NRMP'sThat a 3rd leak can not be Activated has nothing to do with these pumps IMHO.A DUAL HYDR FAIL is giving you a very bad day already, but flying the procedure is fun nontheless.Failing the 3rd and only remaining system would 'ground' you without further pilot input required.Maybe? with 2.5 USG left in system 3 and using the ADG?? Maybe there is a change to survive.Think its prevented to have all 3 systems failed for above reasons.Also in real world this is not trained.Was nice to have a look into the system this way, thanks for putting this up.Regards,Harry

[tcas_climb 45]

hmmm thanks for the checking that for me Harry, hopefully the folks at PMDG can put in even a teency bit of input on this if necessary

[Allan Burek 3]

NRMPs dont transfer fluid, just power. It wouldnt stop a leak either.

[KCA9304 0]

NRMPs dont transfer fluid, just power. It wouldnt stop a leak either.

Thats what RMP's do as well. there has to be fluid on both sides.Regards,Harry

[tcas_climb 45]

U sure you guys arent confusing the RMP and the NRMPs? The RMPs transfer hydraulic power, and the NRMPs are supposed to trap hydraulic pressure/fluid in the event of a leak

[KCA9304 0]

U sure you guys arent confusing the RMP and the NRMPs? The RMPs transfer hydraulic power, and the NRMPs are supposed to trap hydraulic pressure/fluid in the event of a leak

Bryan,NRMP's don't trap pressure/fluid ico a leak.Their purpose is to provide an alternate source of power to the Stab Trim and Upper Rudder (NRMP 2-1) or Lower Rudder (NRMP 3-2) in case the primary system gets unpressurized. (<2000 psi)However there has to be fluid available on both sides of the NRMP for it to operate and transfer power one way.There is a shutoff valve in system 3 that isolates L&R inboard elevators and NRMP 3-2, incase fluid quantity in reservoir 3 goes below a set value. Maybe you have that one in mind. Regards,Harry