Corrected Start up!

[Krazycolin]

Corrected START UP (Cold and dark or ready to start (from 3)





MilViz B737-200 Quick Start Procedure

1) BATTERY – ON and close cover
2) APU – START (two left clicks)
2a) If GEN1 OFF BUS lighted – GEN1 cycle (left click)
If GEN2 OFF BUS lighted – GEN2 cycle (left click)
If APU GEN OFF BUS lighted – APU GEN Left and Right ON
3) APU BLEED AIR – ON
4) ISOLATION VALVE – CLOSE (right click)
5) START VALVE ARMING – Open cover and switch ON
6) ENGINE START – Left Switch to GRD
7) When N2 reaches 22% - Left CUTOFF Lever to IDLE
Verify left ENGINE START switch returned to OFF
8) ENGINE START – Right Switch to GRD
When N2 reaches 22% - Right CUTOFF Lever to IDLE
Verify left ENGINE START switch returned to OFF
9) START VALVE ARMING – Close Cover
10) BLEED – Left and Right Engine Bleed Air Switches to ON
11) L PACK – ON
R PACK – ON
12) GASPER FAN – ON
13) ISOLATION VALVE – AUTO (left click)
14) APU BLEED AIR – OFF
15) PITOT STATIC HEAT – A and B to ON
16) YAW DAMPER – ON
17) APU – OFF
18) GEN1 and GEN2 – Cycle (left click)
19) MASTER CAUTION – Press to clear

[signmanbob]

It may surely be my error, but I thought that the isolation valve would have to be open in order for the APU bleed air to get into the circuit that starts the engines. On here it shows that the isolation valves have to be closed?

[wiltzei]

For R donk start, yes.

[signmanbob]

For R donk start, yes.

I'm sorry, I didn't understand what you are saying here

[N4GIX]

13) ISOLATION VALVE – AUTO (left click)

*Nevermind* I'll get me hat and coat now...

[mbmorgan]

13) ISOLATION VALVE – AUTO (left click)

That is wrong, wrong, wrong...

ISOLATION VALVE must be CLOSE(d).

Uh ... check step 4 where the ISOLATION VALVE is closed for engine start. You're looking at step 13 where it is set to AUTO after startup.

[N4GIX]

Uh ... check step 4 where the ISOLATION VALVE is closed for engine start. You're looking at step 13 where it is set to AUTO after startup.

*Nevermind* I'll get me hat and coat now...

[signmanbob]

13) ISOLATION VALVE – AUTO (left click)

That is wrong, wrong, wrong...

ISOLATION VALVE must be CLOSE(d).

Uh ... check step 4 where the ISOLATION VALVE is closed for engine start. You're looking at step 13 where it is set to AUTO after startup.

But according to the amplified checklist, the ISOLATION VALVE is supposed to be put to "AUTO" before starting the engines. This would make more sense to me, but it doesn't work that way with this simulation.
Also, I was able to start the engines with both PACKS turned on, which I don't believe is possible in real life.
Maybe Milviz can look a little closer at this and let me know if I'm just confused.

[mbmorgan]

But according to the amplified checklist, the ISOLATION VALVE is supposed to be put to "AUTO" before starting the engines.

I'm not sure what you mean by the "amplified checklist" ... but I can assure you that the corrected startup procedure at the top of the thread is correct for the MilViz B737-200. In step 4, the ISOLATION VALVE is closed prior to startup. This is necessary to get pressure up to the 30 psi required for a successful start. After both engines are running, in step 13 the ISOLATION VALVE is returned to AUTO.

[signmanbob]

I'm not sure what you mean by the "amplified checklist" ... but I can assure you that the corrected startup procedure at the top of the thread is correct for the MilViz B737-200. In step 4, the ISOLATION VALVE is closed prior to startup. This is necessary to get pressure up to the 30 psi required for a successful start. After both engines are running, in step 13 the ISOLATION VALVE is returned to AUTO.

Hello Mike,
The "Amplified Checklist" is the checklist that comes with the Milviz manuals, under "Normal Procedures" and explains the actions of the regular checklist, but in detail.
I'm only trying to get this straight.
I know that the procedure that is above works with the Milviz 737. That's not my question.
The Milviz 737 is absolutely fantastic and I love it, but I believe that they got the pressurization system wrong.
I don't believe there is a lot of difference between the pressurization system in a 737NG and an early 737-200c. The panels look almost the same in both aircraft.
Yet in the NGX, the sequence for setting up the pressurization system for startup, would be to start the APU, put the ISOLATION VALVE in AUTO or OPEN, and shut off the PACKS. This would give you the needed pressure to start the engines, while getting APU pressure to both sides of the ducting system to start both the left and right engine.
With the Milviz 737, you are starting the APU, closing the ISOLATION VALVE, closing the PACKS, then starting the engines.
Following this sequence, if I just go ahead and leave the PACKS open, as long as the ISOLATION VALVE is closed, I can still start the engines on the Milviz 737.
Problem is that, I don't think this is the way the real aircraft is set up.
Try to leave your PACKS open and start the NGX. You cannot do it. Try to close the ISOLATION VALVE in the NGX, with the APU running, and start the engines. They will not start.
If the ISOLATION VALVE separates the left and right bleed air systems, how can you start both engines with it closed?

Below is a schematic of the bleed air system on an NG. I believe it is similar on the early 737s. If the ISOLATION VALVE is closed, no APU bleed air can get to the right side to start the right engine. The reverse is true if using Ground Power. The pressure from the Ground Power unit cannot get to the left side engine, with the ISOLATION VALVE closed. Also there is no way that you can start the engines with the PACKS open, since the APU could not fill the whole duct system and still have enough pressure to start the engines.
Last night, I was able to start the engines with the PACKS open on the Milviz 737.
Again, I'm not being cridical, since the fact is that I love this Milviz simulation. I just want to understand what is going on and why I have to close the ISOLATION VALVE in order to start the engines on this 737, and put them in AUTO or OPEN (with the PACKS closed), to start the engines on the NGX.
http://www.b737.org.uk/pneumatics.htm




Below is from a forum conversation http://www.airliners.net/aviation-forum ... ain/78025/

From the AFM (Flight Manual)
Air Conditioning Considerations During Hot weather Conditions

With an operating APU and high ambient temperatures and/or heavy passenger loads, it is desireable to start #2 engine first. This allows the right pack to be operated while starting #1 engine using the APU.

Note: After #2 engine has stabilized, reposition the ISOLATION VALVE switch to CLOSED, and place the R PACK switch to ON.
--------------------------------------------------------------------
...do you happen to know if the BLEED AIR switches are left in the ON position at all times even prior to start the engines or they are flipped to ON only once the respective engine is running?

Normally left ON.

...if the switches are in ON and the PACKS are in ON, is the isolation valve open during startup?

Yes. Packs are turned OFF for engine start = Isol.Valve opens.

[Krazycolin]

Being fixed now and will be released shortly.

[N4GIX]

It has been corrected now to start up per the "amplified checklist." While developing the logic I inadvertently found myself studying the "abnormal checklist" which requires that the ISO VALVE be set to "OPEN.

QED.

[signmanbob]

That's great Bill! I can just imagine that creating such a super complex simulation like this 737-200 can be mind-numbing with all of the manuals and procedures that have to be read and absorbed, then, not to mention all of the coding and making things play nice together.
I want you to know that I am thrilled with my purchase of this Milviz 737, and only brought this up because I was getting confused by it and wanted to help if I had really found a problem.
You guys at Milviz did a stand-up job of creating this beautiful aircraft, not only with the visual model, both inside and out, but with the outstanding FDE and systems.
When I fly this aircraft, I feel like I'm really flying a 737-200. It is gripping and exciting.
I am seeing a lot of good comments about it over on Avsim and just want to congratulate Milviz on this real "home-run" simulation.
When you guys announce a release, you always have my attention

[Jettrader]

I'm not sure what you mean by the "amplified checklist" ... but I can assure you that the corrected startup procedure at the top of the thread is correct for the MilViz B737-200. In step 4, the ISOLATION VALVE is closed prior to startup. This is necessary to get pressure up to the 30 psi required for a successful start. After both engines are running, in step 13 the ISOLATION VALVE is returned to AUTO.

Hello Mike,
The "Amplified Checklist" is the checklist that comes with the Milviz manuals, under "Normal Procedures" and explains the actions of the regular checklist, but in detail.
I'm only trying to get this straight.
I know that the procedure that is above works with the Milviz 737. That's not my question.
The Milviz 737 is absolutely fantastic and I love it, but I believe that they got the pressurization system wrong.
I don't believe there is a lot of difference between the pressurization system in a 737NG and an early 737-200c. The panels look almost the same in both aircraft.
Yet in the NGX, the sequence for setting up the pressurization system for startup, would be to start the APU, put the ISOLATION VALVE in AUTO or OPEN, and shut off the PACKS. This would give you the needed pressure to start the engines, while getting APU pressure to both sides of the ducting system to start both the left and right engine.
With the Milviz 737, you are starting the APU, closing the ISOLATION VALVE, closing the PACKS, then starting the engines.
Following this sequence, if I just go ahead and leave the PACKS open, as long as the ISOLATION VALVE is closed, I can still start the engines on the Milviz 737.
Problem is that, I don't think this is the way the real aircraft is set up.
Try to leave your PACKS open and start the NGX. You cannot do it. Try to close the ISOLATION VALVE in the NGX, with the APU running, and start the engines. They will not start.
If the ISOLATION VALVE separates the left and right bleed air systems, how can you start both engines with it closed?

Below is a schematic of the bleed air system on an NG. I believe it is similar on the early 737s. If the ISOLATION VALVE is closed, no APU bleed air can get to the right side to start the right engine. The reverse is true if using Ground Power. The pressure from the Ground Power unit cannot get to the left side engine, with the ISOLATION VALVE closed. Also there is no way that you can start the engines with the PACKS open, since the APU could not fill the whole duct system and still have enough pressure to start the engines.
Last night, I was able to start the engines with the PACKS open on the Milviz 737.
Again, I'm not being cridical, since the fact is that I love this Milviz simulation. I just want to understand what is going on and why I have to close the ISOLATION VALVE in order to start the engines on this 737, and put them in AUTO or OPEN (with the PACKS closed), to start the engines on the NGX.
http://www.b737.org.uk/pneumatics.htm




Below is from a forum conversation http://www.airliners.net/aviation-forum ... ain/78025/

From the AFM (Flight Manual)
Air Conditioning Considerations During Hot weather Conditions

With an operating APU and high ambient temperatures and/or heavy passenger loads, it is desireable to start #2 engine first. This allows the right pack to be operated while starting #1 engine using the APU.

Note: After #2 engine has stabilized, reposition the ISOLATION VALVE switch to CLOSED, and place the R PACK switch to ON.
--------------------------------------------------------------------
...do you happen to know if the BLEED AIR switches are left in the ON position at all times even prior to start the engines or they are flipped to ON only once the respective engine is running?

Normally left ON.

...if the switches are in ON and the PACKS are in ON, is the isolation valve open during startup?

Yes. Packs are turned OFF for engine start = Isol.Valve opens.

Actually there is a difference - I discussed this a few months ago in the CaptainSim Forum (as you could only start their 732 with the PACKS ON) and then asked Westjet Pilot, who now flies the NG but has experience on the old 732. As far as I now have heard from many sources, the pressurization system of the older 737-200 is different from the NG variants and startup procedure differs in some ways

[signmanbob]

Actually there is a difference - I discussed this a few months ago in the CaptainSim Forum (as you could only start their 732 with the PACKS ON) and then asked Westjet Pilot, who now flies the NG but has experience on the old 732. As far as I now have heard from many sources, the pressurization system of the older 737-200 is different from the NG variants and startup procedure differs in some ways

I'm sure that it is different, but the main concept is the same. The ISOLATION VALVE is used to separate the left bleed air duct system from the right, similar to the way that the fuel cross over valve works with the fuel system.
If the ISOLATION VALVE is closed, bleed air from the APU cannot reach the right engine starter, and bleed air from the ground unit, if that was used, couldn't reach the left engine starter.
On any 737, the ISOLATION VALVE has to be in AUTO or OPEN position, in order to start both engines, unless you start the left first, then close the ISOLATION VALVE, while opening the left PACK, to cool the passengers, and then start the left engine.