Let's say I'm on Vatsim flying at 250kts and the controller just wants me to reduce speed to say 220kts - What would be the correct way of doing this while still following the VNAV/LNAV path.

I've noticed that pressing the SPEED button on the MCP doesn't seem to control the auto throttle very well and often causes the speed to drop or increase wildly.

 

Have you tried the Speed INV button? It works the same as the Altitude one - just press it and it brings up your current speed, and then you can set it at what you need.

Let's say I'm on Vatsim flying at 250kts and the controller just wants me to reduce speed to say 220kts - What would be the correct way of doing this while still following the VNAV/LNAV path.

 

At this point you are done with all the science, smoke & mirrors that VNAV & ECONnomy flying provides - VNAV is a wonderful & strategic tool but by the time ATC starts barking specific ALTitudes & SPeeDs at you its time for your grey matter to shift up a gear into a more 'tactical' mode.

 

With the AP engaged you'll find direct interaction with the MCP easier to handle than "heads down button punching" on the CDU...it also helps to maintain your Situational Awareness.

 

FLCH is the tool - get the Speedbrake out too (if necessary) because you cannot go down & slow down (very easily) at the same time.

 

V/S is useful to get the throttles away from the Idle Stop towards the last 1000ft of a FLCH descent & can create a nice smooth transition from an FLCH idle descent into a 'power on' level flight segment (if that is what ATC require) or a nice subtle CDA onto the glideslope.

Thanks Steve that's exactly what I was unsure about and explained it very well.

Just wanted to let you know that have now understood how to fly the aircraft and have had a few flights with no issues whatsoever. Thanks to all for the great info and help provided.