The B737 Classic Project

[RojanTrojan]

Hi Morten, Jan and crew.

I subscribed to your IXEG YouTube page and there was a new video on there on the 1st of November, but it seems to have dissappeared now. The thumbnail looked great though! :-) What we have seen so far looks absolutely marvellous.

With X-plane 10 around the corner (and looking incredible) will some of the new technology that has been brought to this version be used for the 737 classic? If i remember correctly your product was going to be for soley for XP10. Is it likely you guys will be given a beta copy to test?

Keep up the fantastic work, gents!

Cheers

Rhydian

[Litjan]

Hello Rhydian, hello Meshboy,

the video you saw there briefly was tagged "public" wrongly. It was actually a movie of a nasty autopilot bug that killed many virtual passengers .

I am happy to say that the autopilot is steadily improving, though, and only kills me once in a while now.

To do a demonstration about the electrical system would be very boring - not a whole lot of switches to move, and the effect would be limited to some caution lights and flags coming on and corresponding instruments going offline. We have a debugging tool that lists all the busses and wether they are powered or not. You´d need to lay the electrical diagram on the side while watching to understand what is going on. Geeky stuff!

I will add bits about the electrical system into the other systems-video, though. For example, I can unpower a transfer bus by disconnecting it´s AC power source and moving the bus transfer switch to OFF, then try to start an engine without the corresponding igniter system powered. Now THAT is showbusiness!

Can´t say too much about IXEG and XP10, except that yes, the IXEG 737 will be a XP10 product. My personal guess is that we won´t release before XP10 is declared "final", though (out of the Release Candidate state).

Jan

[Morten XPFW]

I'll just add that we offcourse are making a custom autopilot which is about 50 times more advanced

than the default one, CWS modes etc..

[RojanTrojan]

Thanks for the update Jan & Morten. Sorry to hear about those virtual passengers . It's good to see a X-plane add-on being made with such complex systems programming.

Cheers

Rhydian

[meshboy]

i need a fix before the weekend.

a new screenshot pretty please...

[Litjan]

i need a fix before the weekend.

a new screenshot pretty please...

Sorry, I am too busy playing Battlefield3 this weekend! If you want to help, come online and be my target so I can get to level 50 faster .

But the development team put the basic cockpit shell back in and I have a couple days off after this weekend, so hopefully we can whip up a small movie during that time.

Recently we finished a couple more small systems. Window and pitot heat (including test modes, of course), wing- and engine thermal anti-ice and the firewarning panel. Also the gear lever (including the famous "off" position) with it´s lights.

Jan

[Simmo W]

Sorry, I am too busy playing Battlefield3 this weekend! If you want to help, come online and be my target so I can get to level 50 faster .

That is the best, funniest response I've seen for ages Jan!

Then there's COD 'testing' next I'm sure..

[RojanTrojan]

Sorry, I am too busy playing Battlefield3 this weekend! If you want to help, come online and be my target so I can get to level 50 faster .

But the development team put the basic cockpit shell back in and I have a couple days off after this weekend, so hopefully we can whip up a small movie during that time.

Recently we finished a couple more small systems. Window and pitot heat (including test modes, of course), wing- and engine thermal anti-ice and the firewarning panel. Also the gear lever (including the famous "off" position) with it´s lights.

Jan

I think I'll pass on being a 'target' Jan. Out of interest, and if you don't mind me asking in between killing terrorists, with the anti-ice system is there something that could be simulated graphically within X-plane? Such as Ice build up on the windows and the window heat dissipating it etc etc.. Is that something that can be achieved?

Thanks (ducks for cover)

Rhydian

[Litjan]

I think I'll pass on being a 'target' Jan. Out of interest, and if you don't mind me asking in between killing terrorists, with the anti-ice system is there something that could be simulated graphically within X-plane? Such as Ice build up on the windows and the window heat dissipating it etc etc.. Is that something that can be achieved?

Thanks (ducks for cover)

Rhydian

We are thinking about adding some effect...just don´t want it to be cheesy or unrealistic. Austin´s "window icing" is very basic - if it is ON then there is no ice, if it is OFF then there will be ice under what he considers to be icing condition. Real life works a bit different (as usual).

The 737´s window heat is always on during flight, as a matter of fact you need to turn it on at least 10 mins prior departure. This is both to avoid ice buildup and fogging, but also and most importantly to make the windows flexible so they can withstand a bird-strike.

BUT there is still some ice building up on the windows if you are in moderate to severe icing conditions - just around the edges, not really impairing the vision too much.

So, yes, I think we will have some icing effect - just don´t expect to "toggle" the switches to get rid of it. They are always on.

The anti-ice for wings and engines works a bit differently, but that is another story.

Jan

[YYZatcboy]

Yeah. Don't turn the wing anti ice on when you are over 23000 ft or you depressurize the cabin. (Pilots have told me that they have never in their career turned on the wing anti ice on in flight )

[davidngr]

Yeah. Don't turn the wing anti ice on when you are over 23000 ft or you depressurize the cabin. (Pilots have told me that they have never in their career turned on the wing anti ice on in flight )

Why does it lead to depressurize the cabin?

[Litjan]

Well, I think we are mixing up some things here.

First, we turn on wing-anti-ice all the time during flights. Whenever you go through clouds that have suitable moisture (temperature/droplet size) ice will form on the leading edges. You then turn on the wing-anti-ice to heat the leading edges, this will shed the ice. You could theoretically turn on the wing-anti-ice even before accumulating the ice - but this leads to a bigger performance penalty and also entails the danger of droplet running back over the warm leading edges and refreezing further back on the wing. Thats why we use the anti-ice more like a de-ice...

The other part of the problem is the rather large pneumatic demand that the wing-anti-ice system places on the air system. A lot of air is routed from the corresponding manifold side to the leading edge. There are certain limitations going along with this - for example you are not supposed to run the system of the APU - it would just overload its capability to create bleed pressure.

It is however not a problem to run the wing-anti-ice AND engine-anti-ice while both engines are running at a decent RPM and/or at lower altitudes. There will still be enough pressure left to drive the pressurization.

I think you might run into trouble if you want to drive all of this at 37000 feet and idle power (just starting the descent, for example) - but then again there would be no need for wing-anti-ice up there. Ice will usually only form with TAT´s of about -20 to +3 C or so.

There are many more ramifications of the system during degraded operation - for example during engine fire. You will close the isolation valve to avoid smoke and fumes from the damaged engine to enter the airconditioning - but then you would have no pressure for the wing-anti-ice on the damaged side -> asymetrical anti-ice -> bad!

Also if using the APU to pressurize the cabin (possible up to 25.000 feet) after a "no bleeds" takeoff you can´t use the wing-anti-ice. So if performing such a take-off in icing conditions with an engine failure could get you into trouble really quick. Nursing the aircraft across that mountain ridge - can´t turn on the bleeds because you need all the power to get across the terrain - ice forming on the wings because you can´t use the APU to power the wing-anti-ice...

Jan

Edited November 21, 2011 by Litjan

[YYZatcboy]

My Airline (Granted we fly NG's now, so they may well be different) only turns on the Engine anti Ice when passing through visible moisture. Turning on Wing Anti Ice above (IIRC) 23000 feet diverts so much bleed air to the leading edge that there is not enough left to maintain pressurization in the cabin. (Or So MCC, and the pilots have told me)

[Litjan]

My Airline (Granted we fly NG's now, so they may well be different) only turns on the Engine anti Ice when passing through visible moisture. Turning on Wing Anti Ice above (IIRC) 23000 feet diverts so much bleed air to the leading edge that there is not enough left to maintain pressurization in the cabin. (Or So MCC, and the pilots have told me)

Same here for the engine-anti-ice. The rule is visible moisture and temperatures between +10C TAT and -40C SAT. During descent there is no lower temperature limit.

When I say "we turn wing-anti-ice on all the time" I use a misleading phase, sorry. I do not literally mean that it runs the whole time. During the winter I use it about every second flight, in the summer much less if at all. This was just to emphasize that I find it hard to believe that some pilots have never turned it on in their whole career...well, maybe if they fly in the Southwest US or Africa or the tropics it wouldn´t surprise me.

I am not aware of a hard limitation on wing-anti-ice as far as altitude goes. There is a caution note that says: Use of wing-anti-ice above approx. FL350 may cause bleed trip off and possible loss of cabin pressure...

Jan

[YYZatcboy]

It could well be a difference between the Classics and the NG's. And the MCC guys could have been oversimplifying it. I will look in the FOM to see if there is anything in there about it. The pilots were positive about not turning it on in flight in the NG though.

[Litjan]

Hmm - what use for the wing-anti-ice do they have then? Or is it because they never encounter icing conditions?

Maybe it is different on the NG. I have heard that the A380 has no wing-anti-ice at all - supposedly its leading edge is shaped in a way to make it impossible for ice to accumulate. Also the 747-400 I flew could not turn on the wing-anti-ice when the leading edge slats were extended. So I guess there are different configurations possible.

Jan

[Litjan]

Finally got around making that video I promised you .

http://www.youtube.com/user/IXEG1

Enjoy,

Jan

[FlorianR]

somebody pinch me! first the xp10 demo, and now this . By the way, words cannot describe the detail you put into this, fantastic work!

[meshboy]

Wooow! This stuff is incredible!

I fint this project even more exciting than x-plane 10!

without this bird any simulation is useless, i want study sim aircrafts like this! =)

And here are some questions to the captain Jan.

1, In real life, what are the consequences of wrong data input of the IRS? does the ILS and everything else fail?

2, What is transition altitude? Is it the altitude where you set Standard Barometer so all aircraft are at the same level? Or has it to do with air navigation and communication?

3, Fuel pumps, why are there four pump switches? There are only two engines on the 737?

[Litjan]

Wooow! This stuff is incredible!

I fint this project even more exciting than x-plane 10!

without this bird any simulation is useless, i want study sim aircrafts like this! =)

And here are some questions to the captain Jan.

1, In real life, what are the consequences of wrong data input of the IRS? does the ILS and everything else fail?

2, What is transition altitude? Is it the altitude where you set Standard Barometer so all aircraft are at the same level? Or has it to do with air navigation and communication?

3, Fuel pumps, why are there four pump switches? There are only two engines on the 737?

Glad you like it.

1. It depends. You will get a warning of the IRS if the position you put in differs too much from the original position before last shutdown. The IRS can also catch a latitude input error if it is big enough (it "feels" the earth rotate underneath during alignment). A wrong longitude input will not be caught initially - but soon the FMC will warn you, because the IRS position does not match the data from the automatically scanning DME´s and the GPS. Also you will not see the route you put in on the map. The ILS and VOR receivers are independent of the position, you can use them even with the IRS not aligned (but the FMC uses those signals to update it´s position).

The whole thing is complicated and we took a little liberty with it in our model. You can not ultimately put in the wrong position - it will keep rejecting it until you put in one that is reasonibly close to the "real one". This way we don´t have to maintain an "offset" latitude and run our own navigational model in relation to that. Note that the IRS´s WILL drift over time in our model, the indicated position will become more inaccurate.

The aircraft´s position will stay accurate (as in real life) as long as the GPS and radio updating works (which it usually does).

2.) Transition altitude is the altitude above which you set 1013.2hPa on the altimeter, so all aircraft fly at the same reference (flight-level). Below that you would fly the local altimeter setting (QNH), so you are always at the same altitude referenced to sea level.

3.) There are 6 fuel pumps altogether (plus a scavenge pump, which we also model). Each tank has two pumps for redundancy and also to always supply fuel in case of high attitudes (where all the fuel would run backwards or forwards). One pump is enough to supply fuel for full power. If all pumps fail the engines keep running on "suction feed" - so don´t expect them to flame out when you turn off the fuel pumps! (Can´t wait for the bug-reports on this one ;-) ) . Thrust degradation might occur at high power settings/altitudes.

Jan

Edited November 25, 2011 by Litjan

[meshboy]

Ah, cool thank you very much.

I think your lesson by video is maybe more fun than actualy flying in x-plane.

You should release a dvd with 1-2 hour of explanation of the 737 when its ready and charge 40$ or something.

I would buy it from day one!

[Dozer]

This is amazing. I'm definitely one of the 0.9% (I suppose claiming to be part of "the 1%" is not a good idea nowadays). I'm completely enthralled by this. Hopefully by the time it's released I'll have had a well-paying job long enough to be able to pay for an XP-10 capable computer that will do this justice.

A thought occurred to me while watching that video - pretending the APU had failed and there was an entry against it in the logbook. Why not also simulate the logbook? External software to generate a scenario, a back-history for the aircraft you're taking over, including a smattering of minor failures and degraded equipment. You'd load the aircraft and the aircraft presents you with a logbook telling you what's not working today.

Given that you're modelling everything in such fine detail, are you also including the facility to fail specific elements? (edit: and the facility for elements to wear out or break down individually and mysteriously).

A model like this would be a great basis for a flight simulator simulator - an aircraft that behaves like the training simulator rather than the real aircraft, where a thousand things break every minute and the objective is to stress-test the flight crew...

Edited November 25, 2011 by Dozer

[davidngr]

Amazing job....Speechless again....

[meshboy]

by the look of the last video, all systems in the overhead panel seems to be pretty much complete.

What is left that only has a small percentage completion.

how far are you guys on autopilot and fmc?

can you insert a flightplan and use LNAV,VNAV etc?

With the X-Plane 10 demo proving to be this great i hope you tune the inside cockpit with cool lighting and stuff that is for x-Plane 10. =)

[Morten XPFW]

Our website is now up

http://www.ixeg.net/

It contains a blog, gallery and other information which will be update on a regular basis.

You can also ask questions on the commenting system there and get in contact with the

rest of the team.

We will offcourse still keep you updated here in the forums as well.

M