ckovoor

Engine Autostart Switch on GE model (PMDG House)

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Hi everyone,

This is a screenshot of the Engine Start Panel on my GE model (PMDG House livery) 747-400v3 (QOTSII):

36146553300_e8758db9ff_o.jpg

I was under the impression that all GE models would have a (momentary with annuntiator) Autostart Switch, in the area I have circled..

Could someone please clarify.

Thanks,

Chakko.

(FSX SP2 Win7x64)

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3 minutes ago, ckovoor said:

Hi everyone,

This is a screenshot of the Engine Start Panel on my GE model (PMDG House livery) 747-400v3 (QOTSII):

https://farm5.staticflickr.com/4400/36146553300_e8758db9ff_o.jpg

I was under the impression that all GE models would have a (momentary with annuntiator) Autostart Switch, in the area I have circled..

Could someone please clarify.

Thanks,

Chakko.

(FSX SP2 Win7x64)

Autostart is an option which can be activated in the FMC

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Dear Chris,

Thank you for your prompt response to my query. It is as you say......I believe you must know this simulation like the back of your hand......:ohmy::biggrin:

Thanks again,

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This option is usually a customer (Airline) request during manufacturing. If you have downloaded an Airline livery that comes with an accurate INI file this auto start option may have been removed as that airline chose not to have it installed.

However as PMDG777 said all is not lost just active it from within the FMC.

Iceman

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I thank you, @PMDG777 and @Iceman2 for your explanations.

What I found puzzling about this 'customer option', at least as depicted in the PMDG version in my screenshot, is that the AUTO selector (SINGLE/BOTH) remains even after the momentary AUTOSTART switch is removed.

Anyway, after activating the option via the FMC, all is well as far as I am concerned. :biggrin:

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The AUTO SINGLE/BOTH selector relates to auto ignition, not the autostart system. 

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Amazing what people would learn and be able to enjoy if they simply opened the Intro Manual...

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4 minutes ago, scandinavian13 said:

Amazing what people would learn and be able to enjoy if they simply opened the Intro Manual...

I sometimes wonder if it's not obvious enough (hint of sarcasm, it is obvious but not to everyone). Maybe a shortcut to the intro should be placed on the desktop by the installer and automatically open it when installation is complete?

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If you turn off the autoswitch button and attempt to do an autostart (Fuel cocks open) will the aircraft hotstart?

Not sure if this can even be modeled in fsx/p3d..? Does a hotstart require a programmed failure to be entered?

I read about a Thai crew who did this a few years ago and managed to trash all four engines by accident, all because they didn't check the switch was on and then stupidly did not intervene when the EGT started rocketing up.

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8 hours ago, paradoxbox said:

If you turn off the autoswitch button and attempt to do an autostart (Fuel cocks open) will the aircraft hotstart?

Nope, but it'll start super slowly and otherwise perform like garbage until it stabilizes.

8 hours ago, paradoxbox said:

Not sure if this can even be modeled in fsx/p3d..? Does a hotstart require a programmed failure to be entered?

Not modeled, I don't believe. There's a list of every single failure that spans a number of pages in the Intro Manual. Have a look.

8 hours ago, paradoxbox said:

I read about a Thai crew who did this a few years ago and managed to trash all four engines by accident, all because they didn't check the switch was on and then stupidly did not intervene when the EGT started rocketing up.

Things can definitely go south quickly. From what I recall, the APU is rated to start all 4 simultaneously. I find it incredibly brave that some operators will try that.

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22 hours ago, scandinavian13 said:

Nope, but it'll start super slowly and otherwise perform like garbage until it stabilizes.

That's very interesting. You learn something new every day.

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Quote

Things can definitely go south quickly. From what I recall, the APU is rated to start all 4 simultaneously. I find it incredibly brave that some operators will try that.

For the record... only 3 engines were trashed. However, Thai doesn't start all 4 engines simultaneously. They start (or used to start) them in pairs, but I can't recall how they trashed 3 engines (but, as I recall, they did seem to start the engines fairly fast in succession). As a pushback engineer, we are supposed to monitor the engines during the push for tailpipe fires, but it gets harder if two engines are started at once (especially if engines on opposite wings are started at the same time... e.g. like Atlas).

Somehow one engine survived. I was working at the airport that day, but fortunately, Thai wasn't my responsibility that day.

The ignition switch affects how many igniters (spark plugs) are used for engine start (there are two igniters per engine). Normally (in single), the EEC (engine electronic control unit) selects a single igniter for start on the ground, but next time it starts that same engine on the ground, it will use the other igniter. In BOTH, both igniters are used for ground start.

The Autostart switch is not momentary. It's alternate action.

Cheers

JHW

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4 hours ago, Qavion2 said:

The Autostart switch is not momentary. It's alternate action.

Thank you for this clarification, @Qavion2 ....... I am familiar with Alternate Action. However, I do have a question about whether this Autostart switch is, on the basis of its electromechanical design, momentary contact (physically non-latching or springs back to non-depressed location on release of pressure) or maintained contact (physically latches into a depressed position when pressed on).

Interestingly, I had the same confusion with nomenclature while building an AFCAS+EFIS for my (Digital Aviation) Fokker 100, which might be of interest:

Pushbutton switches on EFIS and AFCAS

Thank you!

 

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The autostart switch is alternate action. The switch stays in or out as selected on or off. None of the switches with a mechanical position indicator are momentary action.

If it is mechanically alternate action it doesn't make any sense for it to be electrically momentary. Momentary action is used for things like reset switches and where other logic can turn the system on or off.

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