Simviation Forums

Hello.  My default 737 is currently sitting, cold and dark on stand at EGPD, waiting for me to open the doors and for passengers to board (yes I can see them boarding).  I've just shut down the engines as they were started when I loaded the aircraft, and I've turned off the lights and avionics switch (whatever that is).  The plane's dead.

My questions is, how do I start the thing up one phase at a time, or is the CTRL+E autostart the only way to do it?  It would be nice to be able to start it up more realistically.  I'll be upgrading to the PMDG 737 shortly once i've got everything configured and my older aircraft backed up, but I'd love to know if a full startup procedure can be done with the default 737 - I know the PMDG can.

Cheers for the help as usual and Happy Flying.

Hussein.

A real life start up procedure can not be done in the default 737.
You have several key ingredients missing, one of them is bleed air, which is provided by the APU.

The default 737 is a put to shame compared to PMDG's bird.

The default 737 is a put to shame compared to PMDG's bird.

LOL I know.  I've seen screenshots of the PMDG and it's great.  I've also got the 747 but I'm gonna do my RTW in the 737 before moving up to that - let me get used to PMDG's way of doing things.

I'm gonna have to edit my sig - I've got these great addons and it's an injustice not to let the world know about them!

Hussein.

You can start the engines seperately useing the 'overhead' switches.

Hmm thanks, I did try that before but I couldn't start it up, I'll try again though.

Cheers.

Good luck around the world.
Maybe I should do one too? In a 747 that is...  ;D

Make sure you call up the throttle window and turn the fuel switches on before you try to start otherwise your engines wont start.

Make sure you call up the throttle window and turn the fuel switches on before you try to start otherwise your engines wont start.

Or better yet, wait for the N2 to spool up or else you'll blow the engine  ;D

Thanks again guys.  Forgot about the throttles!

Cheers.

Hussein.

A&P tech here.

On most boeings, you can start the APU from the nose gear.

Here how it works on most Boeing's

APU on.
Open bleed air (this puts a big load on the APU)
Igitiors on CONT.
Pull the start switch, monitor N1 speed to 3.2% or higher but not to high to grenade the air starter but not to low or it will do a hot start and EGT limits will exceed which will call for a engine inspection.

When N1 reaches desired speed, open the fuel cutoff valve.  Engine will lightoff. when EGT rises, release starter switch and the engine will self accelerate to idle speed.

If it does not self accelerate to idle speed, it's a hung start (fire burning inside the combustion chamber but no air moving through it or the air has stalled in it.
If this happens, shut fuel off and re-do the start squence.

Observe air starter running time before doing it again, may require cooldown before re-attemping to start again.

If you open the fuel switches at 2.5 or lower N1, most likey a hot start will happen and the EGT will go past limits and this will need a shutdown and inspection.

On the 737, the autostart isn't preferred because if something goes wrong with the start squence like oil pressure not coming up or something related, it will continue to start and burn itself up!

The 777 autostart is a nice feature and is preferred, it monitors everything except the oil pressure which is the only thing needs monitoring during the autostart.  If something goes wrong other than oil pressure, it will abort start and display warning messages.

All the 777 except the GE90-115B on the 777-300ER can start 2 engines at once.
The GE90-115B is a huge engine and needs more than typical bleed air the APU can provide.

The 747-400ER can start all 4 engines at once but don't recall which engine type it was, have to ask the tech who worked on United's 747.

Allright allright...hold on here midnight.

"On most boeings, you can start the APU from the nose gear"

Huh? The APU is located far aft, you start it on the overhead panel. I'm guessing you're talking about the ground power connector, which is located close to the nose gear.

"Pull the start switch, monitor N1 speed to 3.2% or higher but not to high to grenade the air starter but not to low or it will do a hot start and EGT limits will exceed which will call for a engine inspection."

Always monitor the N2 speed when starting the engines. It's the N2 shaft that gets spooled up by the APU bleed air. It's also the N2 % that determines weither or not you have sufficient gas flow through the turbine

"On the 737, the autostart isn't preferred because if something goes wrong with the start squence like oil pressure not coming up or something related, it will continue to start and burn itself up!"

Well, good thing the 737 is not equipped with autostart then. Though the Engine Start switches on the 737 has an "Auto" option (replaces the OFF position), but it only provides automatic ignition to selected igniters when the engine is running

Now which company did you work at as a tech? Because they must require no training whatsoever  :-/

Start sequence for the 737NG

Battery on.
Ground power energised (ideal situation)
APU fire bottle test, looking for three greens.
Engine fire test switch to INOP/fault position. This gives test of system fault light and engine1 and 2 overheat lights.
Same switch to fire position, this illuminates the three fire handles, the master caution amber and red attention getters, and wheel well fire light. Alarm bell will also ring for as long as switch is held in position.
If all ok, then left hand wing tank inboard fuel pump on. APU start switch to on. Wait for low oil pressure light to come on and ensure that the blue Maint light does not come on. Press ground call button to alert anyone outside to APU start. Move APU start switch to start position. Hold for a couple of seconds and release. APU start sequence is automatic. APU air intake ram will go to open and APU will wind up, temperature peaking between 700 and 850 degrees C approx and then slowly decreasing to about 400 degrees C. Let APU do its thing and once the Blue APU Bus Gen light is illuminated the APU is ready to give electric power. Place either the left or the right APU Gen switch to the on position. It does not matter which one because the NG only has one APU bus. The second switch to be selected only turns off the second blue bus light, nothing more. So that pilots could convert from 400's to NG without a licence change, the major switching had to remain with the same layout. Thus the second switch has to be present, but not functional. During this switching, the ground power relay is automatically de-energised. However you can start the APU on the batteries.
At this point you can select cabin conditioning if waiting for PAX to arrive. APU bleed air on, isolation valve to open, left and right packs to auto, trim air on.
When ready to start:
Anti collision light on. Isolation valve to auto and packs to off. Make contact with ground personal. Ensure parking brake set; ask to start engine number 2. For first start of the day, select ignition switch to Right, alternating left and right for subsequent starts. Engine start switch to ground. Hold and then release. Switch is magnetically held in place.
Engine then winds up. Look for start valve open on EIS and positive oil pressure. At between 24% N2 (minimum) and 29% N2 raise full cut off lever. From this point the EEC will start the engine. Watch for starter cut out at approx 46% and start valve open on EIS going to a black box. Magnet hold will de-energise and start switch will go to off position. Monitor start; Oil pressure, N2, N1 and temp. If you think that the engine will over temp, chances are by the time your react, the EEC will have aborted the start (so it says in the manual) There are other reasons to abort, but in FS it aint gonna happen! Same procedure for engine number 1. Once started, left and right packs on, confirm 2 good engines to ground personal and ask for chocks to be removed.
If the APU is INOP, then you will require and air starter. The sequence is a little different. As the connector is on the right hand side in the forward part of the air conditioning bay, you have to start engine number 1 first. Once engine is started, request removal of air starter. Put Isolation valve to open position, select start for engine number 2 and once given the all clear advance engine number 1 to 65%. Here you are doing a cross start. Unlikely in FS, but hey, who knows?

That's it. If I have missed anything, corrections are welcome, but please don't shoot me, it is 5:30 am and I have been on shift since 9 pm, another 1 and 1/2 to go.

Matt

Edit: You can't start the APU on a 737 400 to 800 from the nose wheel well (maybe a customer option, but not on our 50+ aircraft. You can however shut it down and activate the fire suppression from the main wheel bay, aft bulkhead, right hand side.

Edit2: The only aircraft that I know of that starts on N1, is the Harrier. You wait for, as I recall to reach 4% to 7% N1 and then open the throttle to idle. Anyone have another example?

OK ok children, play nice!

I got it working! yay!  I had to hold the switches in with the mouse (well duh it makes sense as you'd have to continuously give the startup command until there was sufficient power to keep the engines running).  But at least it's better than CTRL+E.  Takes the realism up a notch.

I'm currently stuck in bed - the neuralgia in my toes is wreaking havoc with a vengence - no flying for a bit I suspect - I don't use my laptop (where I'm writing from at the mo) for FS as it's just not the same as using my desktop with the sound and other components.

Thanks again.

Hussein.

Holy Merlin matt that's some explanation!  Lookin' forward to trying it when I'm up and about again.

BTW, 04:30 here.

Hussein.

Start sequence for the 737NG.....

That pretty much covers it  ;D  ;D
some notes: Trim air is only available on the longer NG's 800/900/B2 and regarding the APU GEN switches: There are TWO switches because there are TWO bus tie brakers that supply AC transfer bus power, if I have understood it right  :)

You should be awarded with a gold star for writing such detailed and well-explained sequence. I admire your work  :) Stuff like that makes this forum so much better.