Hydraulic Pressure

[Guest N5KT]

Hi all,This is my first messsage in this forum after months of reading and learning a lot from all of you.Yesterday I was showing the sim (737NG Series) to a retired 737-200 and DC-9 Captain. He was amazed with the high quality of the sim, in fact he is going to buy the software as he wants to update his knowledge of many of the systems he never used when he was active. He also pointed out the simplicity of the modern cockpits when compared with his old DC-9 full of switches everywhere.We spent 8 hours simulating different situations, profiles, etc,..the same he did in his training courses at Boeing headquarters long time ago.To make this story short, we found a situation we did not know how to resolve:After landing, airplane shut-off with flaps 30 down. As there were no hydraulic pressure to move the flaps up, we did the following:- turn on the APU, - checked the hydraulic panel. Electric Hyd Pumps 1 and 2: ON Lights off- Checked EICAS: Hydraulics indications: Hyd Pressure OKSo it seemed that we had hydraulic pressure but we were not able to get the flaps up.We only got the flaps up with engine on again.It could be because of:1. Wrong procedure2. APU hyd pressure not modeled. Only modeled engine hyd pressure3. Something is wrong with my airplane in my computer.Any ideas.Many thanks for your help.Scott

[Mats_J 2]

Scott,I think your suggestion no. 2 is the correct one. I don't think the hydraulic systems are modelled for the APU.By the way. Have you shown your retired buddy the freeware DC-9 panel from Stellan Hilmerby at www.hilmerby.com I think he will be impressed. Stellan used to be a niner captain at SAS. He is now on the A330/A340.Hope it helps,

[zubart 5]

>Hi all,>>This is my first messsage in this forum after months of>reading and learning a lot from all of you.>>Yesterday I was showing the sim (737NG Series) to a retired>737-200 and DC-9 Captain. He was amazed with the high quality>of the sim, in fact he is going to buy the software as he>wants to update his knowledge of many of the systems he never>used when he was active. He also pointed out the simplicity of>the modern cockpits when compared with his old DC-9 full of>switches everywhere.>>We spent 8 hours simulating different situations, profiles,>etc,..the same he did in his training courses at Boeing>headquarters long time ago.>>To make this story short, we found a situation we did not know>how to resolve:>>After landing, airplane shut-off with flaps 30 down. As there>were no hydraulic pressure to move the flaps up, we did the>following:>>- turn on the APU, >- checked the hydraulic panel. Electric Hyd Pumps 1 and 2: ON >Lights off>- Checked EICAS: Hydraulics indications: Hyd Pressure OK>>So it seemed that we had hydraulic pressure but we were not>able to get the flaps up.>>We only got the flaps up with engine on again.>>It could be because of:>>1. Wrong procedure>>2. APU hyd pressure not modeled. Only modeled engine hyd>pressure>>3. Something is wrong with my airplane in my computer.>>>Any ideas.>Many thanks for your help.>>ScottScott,With the engines off, the ELECTRIC HYD PUMPS should be able to move the flaps on the ground. The ENGINE DRIVEN HYDRAULIC PUMPS only produce hydrualic pressure if the engines are running. It's probably just not modeled in the PMDG airplane.The APU doesn't provide any hydraulic pressure. The APU only provides bleed air and electrics.Floyd

[Guest N5KT]

Mats, Floyd,Many thanks for your prompt answers. That was what we thought, that maybe the electric hydraulic pumps were noy implemented. Well, we can

[victorlima01 2]

hehe, nice tactic. I think I'll give the PMDG 737 package to my uncle who's a captain for the triple seven and see if he'll let me ride up at least on the F/O's chair next time I go up with him.best regards, Victorhttp://www.precisionmanuals.com/images/forum/800driver.jpg