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Guest frazer

3 system-bugs

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Guest frazer

Hi everybody!I have three bugs to report in the systems of the B737NG.First one is the pneumatic-system. You can't have both enginge bleed-air-valves and apu bleed-air-valve open and start the engine. In the real aircraft, the bleed-vales doens't open until the engine is stabilized after start.Number two is the Level Change mode on the AP. If you fly in LVL CH-mode with the A/T disengaged, the aircraft will behave very strange if you reduce the thrust below about 88% of N1. This is not the behavior of the real aircraft, since many pilots flying the NG likes to do their climbs this way.And last, if you fly with the AP in either VS-mode or ALT HOLD-mode with manual throttle (no A/T). If you then reduce the thrust to a setting where the aircraft can not maintain either the set VS or the set ALT, the AP should enter reversion mode. But the AP in the PMDG doens't do this.That's three bugs I've found lately, for your information.I guess there will not be another update for the 737NG, but you may want to think about these bugs in the future releases.Regards,Daniel

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Guest tmetzinger

>Hi everybody!>>I have three bugs to report in the systems of the B737NG.>>First one is the pneumatic-system. You can't have both enginge>bleed-air-valves and apu bleed-air-valve open and start the>engine. In the real aircraft, the bleed-vales doens't open>until the engine is stabilized after start.>>Number two is the Level Change mode on the AP. If you fly in>LVL CH-mode with the A/T disengaged, the aircraft will behave>very strange if you reduce the thrust below about 88% of N1.>This is not the behavior of the real aircraft, since many>pilots flying the NG likes to do their climbs this way.>>And last, if you fly with the AP in either VS-mode or ALT>HOLD-mode with manual throttle (no A/T). If you then reduce>the thrust to a setting where the aircraft can not maintain>either the set VS or the set ALT, the AP should enter>reversion mode. But the AP in the PMDG doens't do this.>>That's three bugs I've found lately, for your information.Daniel - you're correct about the first (more a limit in flight sim which doesn't model the pneumatics at all), half correct on the second,- it behaves this way in climb only), and I'm curious what you mean by "reversion mode" in the third - revert to what?

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Guest frazer

>Daniel - you're correct about the first (more a limit in>flight sim which doesn't model the pneumatics at all), half>correct on the second,- it behaves this way in climb only),>and I'm curious what you mean by "reversion mode" in the third>- revert to what?It's called reversion mode when the AP has to revert to LVL CH-mode due to that it's unable to keep the speed with the current vertical mode (VS or ALT HOLD). You can ask any other pilot on the NG, and he/she will know what I mean by "reversion mode".

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>You can't have both enginge bleed-air-valves and apu bleed-air-valve open and start the engine. In the real aircraft, the bleed-valves doesn't open until the engine is stabilized after start.This is correct, but I see no bug in PMDG. How do you know the bleed valves are open/closed?Cheers.Ian.

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Guest navneet_cxp

Like Ian said,I tried out and "TESTED" the PMDG NGs and found that the 1st two were bugs but the third one was not.It did revert to the FL CH mode after the AP could not maintain the speed and altitute.-NavneetFS 2004 Version 9.1AMD Athlon 64 3000+ATI Radeon 9600 128MB - Anti-Aliasing 6x512MB DDR400 Kingston RAMWestern Digital 30 GB - Seagate 8.4 GBHp CD12 CDRW - Pioneer DVD ROMLG Flatron 775FT 17' MonitorCreative SBLive! X-Gamer 5.1Creative Inspire 5.1 5200Windows XP Pro SP2 v.2180Microsoft Sidewinder Precision Pro 2Logitech Cordless Optical Mousehttp://www.hifisim.com/images/as2004proudsupporter.jpghttp://www.avsim.com/pss/phoenix.jpghttp://www.precisionmanuals.com/images/forum/747400.jpg-|http://www.precisionmanuals.com|-http://www.cpavirtual.org/Delta/images/deltaVirtual.gif

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>Like Ian said,I tried out and "TESTED" the PMDG NGs and found that the 1st two were bugs Whoah there.... I think you've misunderstood me. I didn't say there were any bugs in PMDG's pneumatic system. I just said that it's true that you can't have engine valves and the APU valve open for starting (or at least it will be harder to start the engine).Switch position does not necessarily indicate valve position. Just because a switch is on, it doesn't mean the respective valve is open. During start, valves open/close automatically to enable the bleed air to go to the starter motor and not into the engine core. If you can show me (in PMDG) that the engine bleed valves aren't closing automatically during start, then there is a bug. If not, there is NOT a bug. Thanks.Cheers.Ian R>

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Daniel,Regarding the 3rd one : The flight director pitch mode does indeed revert to "stall protection" mode which yes is something like level change with the exception that speed target can be variable. It is a bit more complicated that simple level change. This mode and protection is based on angle of attack related target speed corrections as per AOM. If AT is OFF you have to manually "floor" the throttle though.Try AT ON, ALT HLD at say 5000 ft (any will do) and set speed to something silly low (100 ?). See what happens then. Best,Vangelis


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Precision Manuals Development Group

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Guest navneet_cxp

>>Like Ian said,>I tried out and "TESTED" the PMDG NGs and found that the 1st>two were bugs >>Whoah there.... I think you've misunderstood me. I didn't say>there were any bugs in PMDG's pneumatic system. I just said>that it's true that you can't have engine valves and the APU>valve open for starting (or at least it will be harder to>start the engine).>>Switch position does not necessarily indicate valve position.>Just because a switch is on, it doesn't mean the respective>valve is open. During start, valves open/close automatically>to enable the bleed air to go to the starter motor and not>into the engine core. If you can show me (in PMDG) that the>engine bleed valves aren't closing automatically during start,>then there is a bug. If not, there is NOT a bug. >>Thanks.>Cheers.>Ian R>Yeah Ian,Thats what i meant.I didn't mean that those were "bugs".Cheers,-NavneetFS 2004 Version 9.1AMD Athlon 64 3000+ATI Radeon 9600 128MB - Anti-Aliasing 6x512MB DDR400 Kingston RAMWestern Digital 30 GB - Seagate 8.4 GBHp CD12 CDRW - Pioneer DVD ROMLG Flatron 775FT 17' MonitorCreative SBLive! X-Gamer 5.1Creative Inspire 5.1 5200Windows XP Pro SP2 v.2180Microsoft Sidewinder Precision Pro 2Logitech Cordless Optical Mousehttp://www.hifisim.com/images/as2004proudsupporter.jpghttp://www.avsim.com/pss/phoenix.jpghttp://www.precisionmanuals.com/images/forum/747400.jpg-|http://www.precisionmanuals.com|-http://www.cpavirtual.org/Delta/images/deltaVirtual.gif

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Guest canyonblue737

>First one is the pneumatic-system. You can't have both enginge>bleed-air-valves and apu bleed-air-valve open and start the>engine. In the real aircraft, the bleed-vales doens't open>until the engine is stabilized after start.switch position has nothing to do with the actual position of the bleed. it is normal and common in the real aircraft to have the engine bleed and APU switches all in the open position. where are you seeing that the actual engine bleed valves aren't remaining closed during the start? looks normal to me...>Number two is the Level Change mode on the AP. If you fly in>LVL CH-mode with the A/T disengaged, the aircraft will behave>very strange if you reduce the thrust below about 88% of N1.>This is not the behavior of the real aircraft, since many>pilots flying the NG likes to do their climbs this way.i think i have seen this because i was doing the santa ana cutback procedure where for noise abatment we take a ton of power off a 1000 AGL and LVL would command unacceptable pitches.>And last, if you fly with the AP in either VS-mode or ALT>HOLD-mode with manual throttle (no A/T). If you then reduce>the thrust to a setting where the aircraft can not maintain>either the set VS or the set ALT, the AP should enter>reversion mode. But the AP in the PMDG doens't do this.it worked for me.

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Guest canyonblue737

to a tiny bug: the wheel well fire light illuminates even when no AC source (engine or APU gens, or external power) are applied and the fire test switch is pushed. it should not illuminate until AC power is applied.

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Guest frazer

>switch position has nothing to do with the actual position of>the bleed. it is normal and common in the real aircraft to>have the engine bleed and APU switches all in the open>position. where are you seeing that the actual engine bleed>valves aren't remaining closed during the start? looks normal>to me...But can you start the engines with all three bleed-valve-switches in the open position?I can't, but I can in the real aircraft. This is what I ment, sorry if I wasn't clear in my first post.

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Guest yylie1

Harlow everyone, I have been flying the PMDG B737NG with an increased fuel tank. I used the repaint and called it my own BBJ. The only flaw that i really found irritating about the PMDG 737NGs are the missing PLIs in the PFD. It is missing in both versions of the PFD. IN the 777 style one and in the SouthWest config as well. Is there any patch soon to correct this? I believe that other people have asked this in the forum before as well and nothing has been done about it so far due to claims on concentrating all "efforts" on the B747-400. I always pretend and tell myself that there is a PLI symbol generator failure whenever i fly the B737s. I see that there is a patch out for the PMDG B1900C but the new patch for the PMDG B737NGs havent come out in quite a while already.Regards,Melissa

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Guest tmetzinger

What are PLIs?

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