What ever I tried to keep plane flying in solid IFR condition,main tank full  and left/right no fuel. I cannot cross feed from main tank. I lost all three engines and crashed.

Why I cannot manage the cross feed?What is the proper cross feed procedure?
I need help.
Thnaks
Sanal

There are 3 tanks on the 727. None of them are mains since there are no aux tanks. The hydraulic fluid in the 727 is fuel cooled. The 727 has "A" system hydraulic cooling in tank #3. The "B" system hydraulic fluid is cooled in fuel tank #1.  The tanks should never be drained or the hydraulic fluid could overheat. If tank #2 has more than #1 and #3 then you crossfeed from tank #2 until all 3 tanks are equal then set the fuel system up to feed tank to engine. Fuel tanks 1&3 should never have more than #2.

The procedure to setup a crossfeed from tank 2 to engines 1&3 is...

Continuos ignition: ON
Boost pumps Tank 2: Foward/AFT ON
Crossfeed valves: OPEN
Blue Valve In Trasit Lights ON then OFF
Boost Pumps Tanks 1 & 3: OFF
Boost pump low pressure lights: Illuminated
Fuel Flow Guages: CHECK
EPR Gauges: CHECK
Continuos ignition: OFF

Maybe you are operating the fuel shutoff valves? They should always be "open" and never touched in flight unles there is an emergency!

Here is the panel setup for crossfeed....

If the fuel shutoff valves are closed that's an instant flameout. They should never be operated unlesss required by an emergency checklist.

In the real 727 you would never run into a situation where the #1 & #3 boost pumps were on and the tanks were empty (hopefully).

Maybe the CS simulation is setup that fuel will not crossfeed from tank #2 to engines #1 & #3 with the boost pumps on. It could be a software issue, But the 727 should never be operated in that configuration.

Update:

I made a test flight and followed your Crossfeed procedure. CS-727-100X crossfeed worked perfect.

I will advise CS support that your Crosfeed Procedure  should be put in  manual.
Thanks.again

Sanal