Engine Start Procedure

[Thisdale]

Normal Procedure (as it should be done):

 

F8-F5-F1 Ground crew: Connect

F8-F5-F3 Ground crew: apply air

Wait for left turbine to be above 10%

Left Engine throttle to Idle

Push left engine start for 5 seconds

Left Engine Starts

 

Doing this, will start the engine as well;

 

F8-F5-F1 Ground crew: Connect

F8-F5-F3 Ground crew: apply air

Push left engine start for 5 seconds

Wait for left turbine to be above 10%

Left Engine throttle to Idle

Left Engine starts

 

Is this normal?

Edited August 1, 2016 by BIGNEWY
TITLE

[AJaromir]

In the manual is written: Push engine start and then move the throttle.

 

Manual, page 189 (191 in page selector)

 

Left Engine Start

1. Give a command to supply air for engine motoring:

 Switch on radio communication menu |\|

 Call ground personnel |F8|

 Request air supply |F5|

 Supply air |F3|

2. Press left engine START button when the speed is 10% (mouse button or |LCtrl + LShift + C|).

3. Then set left engine throttle to IDLE position by pressing |RAlt + Home|

Edited July 31, 2016 by AJaromir

[SUI - Mustang]

IIRC pushing the engine start button lets the ingniter work for 40 seconds, so it doesn't matter too much if you press it before or after moving the throttle... But doing it according to the manual can't hurt.

[NeilWillis]

Yes, SUI - Mustang, it clearly says so in the manual. The igniters remain on for 40 seconds, so if you push the starter button early, it'll still start correctly.

 

However, the procedure says push the starter when the engine reaches 10%. So the error is in the procedure you used, not a bug in the systems modelling.

 

The reason it says 10% before pushing start is bound to be for a reason, but that cause/effect may not be modelled in the F-5E-3. It doesn't however make it a bug.

[AJaromir]

IIRC pushing the engine start button lets the ingniter work for 40 seconds, so it doesn't matter too much if you press it before or after moving the throttle... But doing it according to the manual can't hurt.

 

 

I think you should push that before moving throttle to prevent the engine from fuel flooding.

[Thisdale]

Ohh that is interesting!

 

Thanks for the clarification guys!

[Dragonares76]

But i experienced something similar, and i don't think it is normal to see the engine taking rpm when pressure is applied without pushing the start button ...

[Dragonares76]

but stop me if this is wrong, but this is pneumatic pressure plugged on the engine ? and not some kind of fan providing enough air to let the turbine windmill ...

 

I thought the operation was :

 

- plug the pneumatic pressure

- apply pressure (like the pressure in scuba gear, under pressure, but the air is not coming out until you breath)

- push the engine start button => unlocks the fan to start turning and taking rpm and sets ignition on to let the fuel burn

- Throttle to IDLE to provide fuel and effectively start the engine.

[Charly_Owl]

IRL, turning on fuel too early on jet engines usually results either in a hot start or an impressive tailpipe fire....or both...

 

Exactly. You can see it with the Huey. Lots of pretty flames (that should probably destroy the engine).

[IvanK]

IRL, turning on fuel too early on jet engines usually results either in a hot start or an impressive tailpipe fire....or both...

 

[ViFF]

but stop me if this is wrong, but this is pneumatic pressure plugged on the engine ? and not some kind of fan providing enough air to let the turbine windmill ...

 

I thought the operation was :

 

- plug the pneumatic pressure

- apply pressure (like the pressure in scuba gear, under pressure, but the air is not coming out until you breath)

- push the engine start button => unlocks the fan to start turning and taking rpm and sets ignition on to let the fuel burn

- Throttle to IDLE to provide fuel and effectively start the engine.

 

 

Stop ;)

 

It is just compressed air.

 

Here is what a typical airstart unit looks like:

 

 

and here is a combined unit that is both airstart and gpu:

 

 

Its just a big diesel engine sitting on a cart with a hose to push air, typically between 150 to 200 ppm for military engines (turbojets).

 

You connect the hose to the airplane at the proper place, start the big diesel engine and apply air.

 

The whole engine assembly starts turning over including all the stages.

 

Then you would typically press the start switch before moving the throttle from cutoff to idle, as the start switch would typically launch an ignition process that is usually controlled by an electronic device responsible for the way the igniter will behave during the engine start. Moving the throttle from "OFF" to "IDLE" introduces the fuel into the start process.

 

Cheers!

[Dragonares76]

Ok fine thanks for the infos ^^

[Mizzy]

where can I get the manual ?

[Art-J]

Dragonares, just to make sure You've got the correct impression of how the things work - the air supply ViFF wrote about doesn't blow the engine compressor or turbine directly, but goes into an air starter - a small turbine with a planetary reduction gear, which meshes with the engine accessory gearbox - THAT makes the engine spool up. So it's almost like fuel-powered APUs You know from other modules, but with air (from external source) being used instead.

[Dragonares76]

Yep I got it but thanks, it helps me to understand better ^^

 

Yeah in fact I tought really it was like scuba gear => under pressure until you breath

So I tought it was => under pressure until you press the start button ...

 

But I understand now how it works and that the start button only activate ignition

[randomTOTEN]

This might be helpful understanding how the engine is being started.

 

[ame]

[/ame]

 

 

Most aircraft have a valve before the air turbine starter. When a start button or knob is pressed, the valve opens which allows compressed air into the starter and turns the engine. The Tiger is different in that there is no such valve.. as soon as the start "huffer" cart applies compressed air the starter spins the engine. The only thing the start button does is turn on the igniters for 40 seconds. Fuel is introduced by moving the throttle from OFF to IDLE.

Edited August 8, 2016 by randomTOTEN

[randomTOTEN]

As there's no start valve on the F-5 engine, why doesn't the starter continue to run after the the external air has been disconnected as it's now being driven by the engine?

The engine start valve has nothing to do with disconnecting the starter from it's physical connection with the engine. The only thing the start valve does is block compressed air (from an outside source) from entering the starter. The F-5 starter doesn't need to have a start valve close after the engine start is complete, the pilot commands the ground crew to turn off the start cart. This removes the air supply from the air turbine starter. The F-5 has two separate start cart connections; one for each engine.

 

Your question about the starter being turned by the engine is a different matter, unrelated to the compressed air supply.

 

[ame]

[/ame]

[r4y30n]

Whoops, missed the other replies

Edited August 9, 2016 by r4y30n
Whoops, missed the other replies

[LeCuvier]

Using the "Throttle OFF" switches in the TM Warthog throttle

 

I was wondering why I could not start the engines, until I realized that it wants to see a distinct switch from Throttle Off to Idle; something I haven't experienced on any of my earlier modules. Now I didn't feel like sacrificing precious HOTAS switches but wanted to use the "invisible" 'Throttle Off' switches in the TM Warthog HOTAS throttle. This required a little customization in the file "Throttle - HOTAS Warthog.lua" under "...\Mods\aircraft\F-5E\Input\F-5E\Joystick". Here are the added lines in the file (in the "Throttle Quadrant" section):

--added 2 lines HWF 29AUG2016
{down = iCommandLeftEngineStop, up = iCommandLeftEngineStart, name = _('Throttle (Left) - 2-Pos OFF/IDLE'), category = _('Throttle Quadrant')},
{down = iCommandRightEngineStop, up = iCommandRightEngineStart, name = _('Throttle (Right) - 2-Pos OFF/IDLE'), category = _('Throttle Quadrant')},

This creates two new lines in the controls binding tool:

Throttle (Left) - 2-Pos OFF/IDLE (which I bound to JOY_BTN30) and

Throttle (Right) - 2-Pos OFF/IDLE (which I bound to JOY_BTN29)

Works fine and uses the natural behaviour of the throttle.

PS:

1. I use OvGME to ensure I don't lose my mods in an update.

The somewhat older JSGME would work as well.

2. Should also work with other throttles that have built-in Off/Idle switches (different button numbers of course)

3. In my throttle the contact closes in the "Off" position. If in your throttle it closes in the "Idle" position, the words "up" and "down" need to swap positions.

[Justin Case]

LeCuvier, i think this function is implemented already. Because this is how it works for me, I can't remember the name for this bind in the options right now.

Great job though :)

[nomdeplume]

^ I think the bindings I use are called:

 

Throttle (Left) - OFF/IDLE

Throttle (Right) - OFF/IDLE

 

There are also separate OFF and IDLE bindings, but the OFF/IDLE are obviously intended for switches (i.e. the 'button' is held down).

[LeCuvier]

LeCuvier, i think this function is implemented already. Because this is how it works for me, I can't remember the name for this bind in the options right now.

Great job though :)

Well you and Nomdeplume made me believe that I had re-invented the wheel again (and I do that sometimes); so I did some tests. First the short: at the end, I went back to my newly invented wheel.

Now the long. I tried different bindings. I only mention the 'Left' ones below because I'm lazy:

1. 'Throttle (Left) - OFF' to JOY_BTN30: Doesn't work at all.

2. 'Throttle (Left) - IDLE': to JOY_BTN30: Works for engine start, but does not cut the engine when I pull the lever back to the "Off" position.

3. 'Throttle (Left) - OFF/IDLE' to JOY_BTN30: Works only if I start with the throttle in "Idle" position, then pull it back to "Off" and then push it to "Idle" again.

I could live with scenario 2. or 3. if there was nothing else. But I prefer my new wheel. I start with the throttle in "Off", then request air and then push & hold the start button and push the theottle to "Idle" before hitting the "Start" button.

And when (should say "if") I have landed safely and returned to my parking spot, I stop the boost pumps and pull the throttle back to "Off" which cuts the engines. Now if you can do this "natural cycle" all without customization and without using keyboard combinations, I'd be interested.

Edited August 30, 2016 by LeCuvier

[LeCuvier]

^ I think the bindings I use are called:

 

Throttle (Left) - OFF/IDLE

Throttle (Right) - OFF/IDLE

 

There are also separate OFF and IDLE bindings, but the OFF/IDLE are obviously intended for switches (i.e. the 'button' is held down).

nomdeplume, I guess you use pushbuttons on your HOTAS?

I don't want to use any of the "visible" switches; just the built-in switch in my throttle that closes when the throttle is in the "Idle" position.

[nomdeplume]

nomdeplume, I guess you use pushbuttons on your HOTAS?

I don't want to use any of the "visible" switches; just the built-in switch in my throttle that closes when the throttle is in the "Idle" position.

No, I use the TM Warthog, the throttle off position activates (and holds down) a DirectX button (as far as the game/any software is concerned).

 

I start with the throttle in "Off", then request air and then push & hold the start button and push the theottle to "Idle" before hitting the "Start" button.

I'm a little confused about this part, particularly the "push and hold the start button ... before hitting the start button". :)

 

The whole thing with having to move the throttle into the off position before the game will recognise it's in the off position is just par for the course. You might be able to avoid that with the 'sync controls at startup' option or whatever it's called, but when I tried that it didn't seem to make things appreciably easier. Basically, DCS doesn't scan for button states at startup so doesn't know the button is down until it receives a button press event.

 

So, I just plonk the throttles into the off position when I first get in the cockpit as part of my standard routine, same with resetting the zoom to normal level.

 

Your lines seem to be functionally the same as the existing ones, so I'm not sure why/how you're avoiding having to let DCS know your throttles are already in the off position.

[LeCuvier]

I'm a little confused about this part, particularly the "push and hold the start button ... before hitting the start button". :)

 

Sorry, I didn't proof-read enough. Should have read simply:

"I start with the throttle in "Off", then request air and then push & hold the start button and push the throttle to "Idle".

 

You use what I defined as "scenario 3." and there's nothing wrong with that at all. I have the throttle in "Off" before the mission starts, and my solution ensures that the program recognizes the change to "Idle" without having seen a change to "Off" first. I'm a retired engineer and notorious perfectionist :)

PS: I have the "Synchronize Cockpit Controls...." enabled and it works most of the time but not always. But it always works if I forgot to set my "Drag Chute" switch to OFF before mission starts. Makes great takeoffs.