August 20, 20187 yr Hi all, I simulated an APU bleed inop event. So I connected the air starter, to get some air, via the fs actions menu and got no duct pressure. Config: PACKS both OFF, Isolation valve OPEN. Something I missed? Edited August 20, 20187 yr by 30K Cheers Henrik K. IT Student, future ATPL holder, Freight forwarder air cargo and thx to COVID no longer a Ramp Agent at EDDL/DUS+ | FS2Crew Beta tester (&Voice Actor) for the FSlabs and UGCX Sim: Prepar3d V4.5 Rig: CPU R7-5800X | RAM: 32GB DDR4-3000 | GPU: GTX 3080 | TFT: DELL 3840x1600
August 20, 20187 yr FCOM SP.7.5 the first thing I noticed is your APU bleed is open. Perhaps that is where your air is going? Dan Downs KCRP
August 20, 20187 yr Author The screenshot was taken before having a look into the FCOM to be sure I do it right. I closed it later on. I actually tried every combination and I never got the pressure. Cheers Henrik K. IT Student, future ATPL holder, Freight forwarder air cargo and thx to COVID no longer a Ramp Agent at EDDL/DUS+ | FS2Crew Beta tester (&Voice Actor) for the FSlabs and UGCX Sim: Prepar3d V4.5 Rig: CPU R7-5800X | RAM: 32GB DDR4-3000 | GPU: GTX 3080 | TFT: DELL 3840x1600
August 20, 20187 yr Author Okay, I restarted the sim and tried it again and it worked. I have no clue what exactly was the problem. Btw. it worked with APU bleed on and off. Cheers Henrik K. IT Student, future ATPL holder, Freight forwarder air cargo and thx to COVID no longer a Ramp Agent at EDDL/DUS+ | FS2Crew Beta tester (&Voice Actor) for the FSlabs and UGCX Sim: Prepar3d V4.5 Rig: CPU R7-5800X | RAM: 32GB DDR4-3000 | GPU: GTX 3080 | TFT: DELL 3840x1600
August 21, 20187 yr There's a non return valve and a pressure controlling valve also in the APU bleed duct. This is why the APU bleed switch position doesn't affect plenum pressure. On the -4/8/900 these is a large mix manifold under the fuselage. The bottom of this manifold is where the ground conditioned air flap valve is positioned. the high pressure air also goes into the ducts. As long as the pack valve switches are off, there should be enough pressure to start the engines. Normally the checklists call for starting the No2 engine from Air Starter unit, then disconnect it. Connect generator, disconnect GPU, and finally push onto centreline to prepare for crossbleed start of No1. It's frankly a pain in the word not allowed- be nice to your APU! At 55'c degrees in deepest rural Turkey.... it is essential to keep your cool in every way! Mark Harris. Aged 54. P3D, & DCS mostly. DofReality P6 platform partially customised and waiting for parts. Brunner CLS-E Yoke and Pedals. Winwing HOTAS and Cougar MFDS. Scan 3XS Laptop i9-9900K 3.6ghz, 64GB DDR4, RTX2080. B737NG Pilot. Ex Q400, BAe146, ATP and Flying Instructor in the dim and distant past! SEP renewed and back at the coal face flying folk on the much deserved holidays!
August 22, 20187 yr Author 14 hours ago, MarkJHarris said: There's a non return valve and a pressure controlling valve also in the APU bleed duct. This is why the APU bleed switch position doesn't affect plenum pressure. On the -4/8/900 these is a large mix manifold under the fuselage. The bottom of this manifold is where the ground conditioned air flap valve is positioned. the high pressure air also goes into the ducts. As long as the pack valve switches are off, there should be enough pressure to start the engines. Normally the checklists call for starting the No2 engine from Air Starter unit, then disconnect it. Connect generator, disconnect GPU, and finally push onto centreline to prepare for crossbleed start of No1. It's frankly a pain in the word not allowed- be nice to your APU! At 55'c degrees in deepest rural Turkey.... it is essential to keep your cool in every way! Thanks, I asked one of the tech guys at our airport. Said the same. When I am a wing walker for a cross bleed start and required air starter, we use the start sequence 2 then 1. Depends on the position though. Cheers Henrik K. IT Student, future ATPL holder, Freight forwarder air cargo and thx to COVID no longer a Ramp Agent at EDDL/DUS+ | FS2Crew Beta tester (&Voice Actor) for the FSlabs and UGCX Sim: Prepar3d V4.5 Rig: CPU R7-5800X | RAM: 32GB DDR4-3000 | GPU: GTX 3080 | TFT: DELL 3840x1600
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