IFR enroute planning

[uncertifiedpilot]

Hello,

1) I'm new to flying in the flight levels. Is there generally anything different to using high enroute IFR charts compared to low enroute ones for flight planning? Seems the exact same thing to me, but I am not quite sure.

2) Must planned IFR (low/high) routes always follow depicted airways? I guess not. If not, I'm not sure when planning to fly 'off-airways/direct' is generally accepted or considered appropriate by ATC (ie. not resulting in amended IFR route clearance).

Thanks!

Tim

[frantzy]

Not sure why nobody has replied to your reasonable questions so I will give it a try. Most of my RW experience is in the US but some outside.

In the US for flight levels, it is usually not necessary to plan a route entirely on airways. More important is a logical SID to get out and a logical STAR to get in. Between those fixes, dispatchers will optimize for winds and weather and overall efficiency, and using SIMBRIEF you may see different options filed and cleared in the past few days. Sometimes (N/S routes on the West Coast for example) there are very convenient J- or Q- airways along your route. But other times (N/S thru the Midwest, say) you plot a zigzag route on airways you can usually straighten it out by going direct between some VORs for example.

Busy routes may have Preferred Routes published that are more or less required, but thats’s the same in low altitudes.

In some countries (like China) flights maybe required to stay on airways more often.

Mike

[FDXDave]

Just a quick note on high routes and low. A few observations. high Enroute charts have the high altitude blue stamps frequencies. And you would look for Jetways to fly on instead of Victor airways. Victors are primarily for anything under class A , under Fl180. And when possible you would want to file a Jetway (J222) inbetween A SID&STAR. other times a victor airway can be used on a flight plan intending to climb above FL180 is when you are expected to be under 180 during those phases of flight. So you depart an airport you use a victor to climb on or descend on if lacking a procedure. For short trips above 180 i sometimes use victor airways but only file the VOR wp's. Sometimes i file the victor airways above 180 and most of the time its acceptable. I'm just an armchair pilot. So I'm likely wrong on some of these things. But i figured I'd try to help too.
Dave