Quote from Hangar45 Admin on December 14, 2017, 8:59 am

(Original thread started on 05-05-13 by Marco Lamanna)

Does anyone know how to use the fuel pump switches? I can't find anything related to them in the checklists. I use the checklist found on this site: [url]http://freechecklists.net/simchecklists.asp[/url]

When should they be switched on and off?

 

(Posted by Ron Rollo on 05-06-13)

Hey Marco, you are talking about the transfer and standby switches. In normal flight, you don't have to do anything with them at all. However, if you have to shut an engine down, you might need to transfer fuel from one wing to the other to maintain balance. When I built my flight box over five years ago, I was able to use FS offsets to get it to work. So it can be done without a whole lot of effort.

 

Just last week I started wiring up my Engine Start panel (with fuel switches). Hopefully at the end of this week I will have it completely working and I can answer this question in more detail for you.

 

(Posted by Alan Norris on 05-06-13)

Marco, I think you are referring to the Left and Right Standby switches on the Engine Start panel. Here's the relevant information.

 

If you have your Engine Start switches and the LEDs in both switches programmed correctly, the LEDs in the Left Fuel Standby and left Engine Start switches will illuminate [b]ON[/b] after the Left Engine Start switch is pressed and will stay on for about 10 seconds until the engine is running and then both LEDs will extinguish.

 

In flight if you see an imbalance between the left and right wing fuel tanks you can press the cross flow switch (its LED -- a horizontal bar will illuminate) and then press either the left or right Fuel Standby pump switch (and its LED will illuminate ON) to transfer fuel from one tank to the other e.g. if there is more fuel in the left tank than the right, then press the left standby pump switch to transfer fuel to the right wing tank.

 

(Posted by Marco Lamanna on 05-06-13)

Thanks for your answers. So I need the Fuel Pump just to balance the fuel tanks. Is it right?

 

Reading your posts I found some imprecision in my "startup panel logic". When I press Left Start switch, I lights up the LED "Left Start" (through FSUIPC offset) and nothing more. I understand that also the Left Fuel Pump LED must be light up? And then, when the engine is running both LEDs will turn off automatically? Is this the right procedure?

 

(Posted by Alan Norris on 05-06-13)

Yes the fuel pumps are only used in flight to transfer from left wing tank to right wing tank. The standby pumps come on as the engines are started and shut off when the engines are running as the main pumps that are driven off the engine gearbox take over. I'm not at my sim PC right now so I don't know what the various settings are. Later on this morning I'll post the correct offsets. You won't need a SIOC script to do it as it's all done with offsets.

 

(Posted by Eric Tomlin on 05-06-13)

Marco, remember that the Fuel system is totally managed by a computer in regards to engine starting for the LJ45. The only thing you need to do is 1) place the fuel levers in the "Run" range and then press the start switch for the desired engine. The Standby Pump is activated automatically in the sim aircraft. If you want to replicate that action, then simply program then L/R Fuel Standby lights to indicated ON during the start process. They should extinguish when the starter turns itself off at about 21.5% N1.

 

(Posted by Marco Lamanna on 05-06-13)

Hi Eric, but FSUIPC does not control these events, according to the state of the sim? I expect that the left start LED lights off automatically and so the fuel pump LEDs. Is this not true? I have to put this logic in my SIOC code? Or maybe I am using wrong offsets. Thanks for your support.

 

(Posted by Alan Norris on 05-06-13)

Here are the offsets for the left and right engine start and fuel pump switches and LEDs. I'm programming in InterfaceIT so don't know how to do this in FSUIPC but I'm sure you can figure it out.

 

Both of these offsets go to each of the switch functions.

 

Start Switch:

Down for ON

Offset Left Engine 0892, Right Engine 092A

Offset Type: L & R Engines: Word

Operation: L & R Engines: Set value then zero

Value: L & R Engines: 1

Sleep: L & R Engines: 18000

 

Generator:

Down for ON

Offset Left Engine 3B78, Right Engine 3AB8

Offset Type: L & R Engines: Longword

Operation: L & R Engines: Set value

Value: L & R Engines: 1

 

Engine Start Switch LED

Offset: Left Engine: 0892 , Right Engine: 092A

Offset Type: Byte

Operation: Value - on

Value On: 1

 

Fuel Standby Switch LEDs

Offset: Left Engine: 0892, Right Engine: 092A

Offset Type: L & R Engines: Word

Action: L & R Engines: Value On

Value On: L & R Engines: 1

 

Hope this helps. I haven't programmed the L & R Fuel switches yet. If you are using the FDS board and Interface IT let me know and I'll let you know how to set it up.

 

(Posted by Marco Lamanna on 05-06-13)

Thanks for your info. I've just checked my offset and the ones for the engine are the same but the LED light doesn't turn off automatically. I have to press it a second time and also in the default FSX panel it works the same way. Perhaps the Learjet45 model is not so accurate as the real one. Maybe I have to model by myself in SIOC.

 

About the fuel pumps, the offsets are the same as the engine offsets, is this correct?

 

(Posted by Alan Norris on 05-06-13)

Marco. are you using the FDS board to connect your hardware and InterfaceIT to program it? If not then you need to find out how to program the offset in FSUIPC (or your SIOC script) for the engine start switch and engine start switch ON LED.

 

It's important to use the correct offset type with a Setvalue then zero with a sleep time. This ensures that when the switch is turned on the LED is also turned on but goes off after the sleep time is reached. The value of 18000 results in about 10 seconds (not sure how that is calculated -- maybe Eric can chime in).

 

If you download the FSUIPC SDK package there is a very useful program in it called FS Interrogate. When you run it it will connect to FSX and display all of the offset values and offset types used. If you click on the first column heading for Offsets then scroll down until you find offset 0892 (the left engine start function) it will tell you all about that offset.

 

(Posted by Marco Lamanna on 05-06-13)

No, I'm using an Opencockpit USBOutput to drive LED and a standard keyboard to send input signal. I tried to light off Left start Led after engine running but I'm not sure it is the right way because it does not work.

 

- I press the Left Start button:

- In SIOC Code I get Offset 0892 with value = 1 and light on the led and then set a delay function to write offset 0892 with the value of 0 after 15 seconds...

- After 15 secs the Left Start button is released but a second later it is pushed again (by itself, I don't know why...)

 

I think there is something wrong in SIOC code but I cannot get it to work.

 

UPDATE:

Just to give a solution to this thread, I finally I found a solution (I don't know if it is the right one) for my startup procedure.

 

Using SIOC, when I press the Left Start Button I light up the Left Start Led and the left pump LED. Then, when the "combustion flag" is set after 5 seconds I turn off the left start and left pump led and I light up the Left Gen LED. I don't know if this last step is the right one. Before I used a switch to get the left generator ON.

 

What do you think about this:

https://youtu.be/hAx0FZn-b94