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The B737 Classic Project


Morten XPFW

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A little glimpse into our debug screen as we refine the electrical system.   When the APU is started,  the APU starter uses the battery and induces a really heavy load to the battery.  Anybody care to guess what happens to the battery and the annunciator lights attached to the battery bus during the APU start?

 

post-5-0-91980900-1354567034_thumb.jpg

 

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Anybody care to guess what happens to the battery and the annunciator lights attached to the battery bus during the APU start?


The correct answer is that the battery explodes and the lights gets in to "disco mode"

Please let me know if you ixeg team has some questions, i am happy to answer.!
Hahaha

Of course the highest system simulation in sim history should be freeware!
Hahaha again
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A little glimpse into our debug screen as we refine the electrical system.   When the APU is started,  the APU starter uses the battery and induces a really heavy load to the battery.  Anybody care to guess what happens to the battery and the annunciator lights attached to the battery bus during the APU start?

 

attachicon.gifvoltages.jpg

 

Battery volts drop, low voltage lights come on? Battery heats up, battery draws high recharging current for the next 30 minutes or so, and if the recharging current does anything except decrease after generators come online, there is a problem with the batteries and something urgent must be done.

 

That's a lot of buses! They're not tied in that screenshot. The aircraft I'm working on has about twelve, but that's because for some reason there's 7 (or 8) separate AC buses at varying voltages, phases, and levels of essentialness. I have no idea what 'A phase' and 'C phase' AC power is, the manual takes it for granted the reader will know, there's no mention of a B phase. I'm assuming it's single-phase and 3-phase AC and hoping that textbook will explain.

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  • 2 weeks later...

Hey guys.  Jan has done another video showing some more details of the electrical system, which is pretty much ready to go.  We have 17 electrical busses powered, we have equipment tied to each of these busses so when a bus goes down, things dependent on that bus go down.  We have modeled generator heating and cooling, taking into account ambient temperatures and heat transfer coefficients, DC battery drain and voltage drops under heavy load, galley power, ground service bus with attendants switch, even coffee maker and hot air ovens.  We have filament fadein/fadeout so the lights don't just pop on instantly.  Momentary generator disconnects on switching power sources (you'll see lights flicker during this process) Warning annunciators are tied to their appropriate recall system..and lights dependent on voltage dim under voltage drops. 

 

Seems like a lot of detail but the coolest thing  of all is you just let it run and it looks and feels real.  No funny needle jumping, no instant on lights, it just all seems normal.  Another video to follow shortly where Jan flies a simple pattern around Nice.

 

-TomK

 

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  • 2 weeks later...

 

I think I remember Jan saying that it would be released in max. 6 month "from now". That was in September 2012.

Is that timeframe still valid?

 

 

We really don't know when.  We know when we would LIKE to have it out, but our experience over the last 2.25 years has shown that you never know what comes down the way.   Sometime in the first half of 2013 is desired by the team and that's really all we can say.    We are very much committed to not cutting corners and providing a complete product.   Work continues regularly however.  I am nearly finished with the exterior and maybe in the next four weeks we can put up some screenshots....I'll work towards that milestone.

 

Tom K

Laminar / IXEG

Edited by tkyler
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Posted the Nice circuit video on the Avsim X-plane general discussion forum the other day. Superb work guys, really really superb. I'm sure the IXEG 737 will win over many hearts and minds. 

 

Thanks - I was wondering why the views on it splurged ahead like they did!

 

And thanks for everyone´s nice remarks - we are humans and definitely cherish the appreciation. Just like a soccer team plays better when they get cheered on by the homecrowd ;-)

 

Jan

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Thank you cyrille.  I am "keep going" right now, working on the last few parts of the exterior model even today (sans landing gear).  We should be providing some in flight exterior screenshots in the upcoming weeks.

 

Tom K

*Gasp* The exterior is almost done! Cannot wait for the screenshots.... 

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OK, I thought this is cool and worth posting.   We just got around to tying in the reversers to the hydraulics.  There are 3 hydraulic sources:  Engine power, Electric pump and a standby pump...each pump weaker than the next.  Well how fast the reversers deploy is tied to how much hydraulic power is going into them.  So the reversers will deploy nice and fast with the engine pumps.   Not so fast with the electric pumps...and just downright slow with the standby pump.   So lets say you have one systems down...the 'A' system on the left side.   In this case, the left reverser won't deploy...not good on landing (sort of...the standby pump cuts on automatically under certain conditions but I'm making a point :).  You CAN; however, turn on the standby pump and  use that to deploy the A reverser, BUT it will take a bit longer than the B (right) side so on touchdown, you'll have a bit of asymmetric thrust as you deploy the reversers until the slow reverser opens up fully....but only if you advance the throttles though.  You could "pull into reverse"...wait a few extra seconds to let the slower side deploy, THEN crank back on the reverse throttle.  If the standby system has to power both sides, then the extension time is doubly long.....almost such that you won't get significant reverse thrust till you're a good ways down the runway.    You can play with the hydraulic switches, turn pumps on and off and see the reversers deploy at different rates.    When I was testing it, I deployed the reversers, turned off system A....commanded the reversers closed and sat there for about 30 seconds staring at the reverser lock annunciator waiting for the other one to close before I realized I hadn't turned on the standby pump.  very cool!

 

Tom K

Laminar / IXEG

Edited by tkyler
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This is the sort of stuff that happens when you model systems at a nice low level...all sorts of subtle nuances start popping up for "free" in terms of developer time.

 

Great job.

 

I recall having something similar happen when we were first testing PilotEdge's radio system...we had a pilot drop down too low while he was too far from the transmitter that was in use (our fault for not swapping him to a frequency with a more local transmitter). We low two way comms with the pilot but noticed an aircraft flying at a much higher altitude not too far away. We asked that pilot to hop over to the lost pilot's frequency and relay a message to contact Oakland Center on freq xxx.xx, and then to return to this freq after the relay was done. The pilot said he'd give it a shot. Low and behold, we get a message 20 seconds later from the lost pilot on the right frequency. Even I was shocked after that one.

 

When you model a system after the real thing, all sorts of neat stuff just happens as a result.

Edited by Keith Smith
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