High altitude flight planning

I'm a piston single pilot, so completely foreign to the world of high
altitude flight. I'm mostly asking this to add some realism to flight
simulator and VATSIM flights.

I was wondering what the procedure is for planning a flight on jet
airways. Do you file direct to the nearest fix or navaid that's a
waypoint on a jet airway? Or do you need to file to a jet airway fix
that is far enough away to reach FL180 before reaching the fix?

I noticed that some routes on fltplan.com contain both Victor and Jet
airways. If you receive a route like that, are you actually restricted
to remaining below FL180 while on the victor airways?

For example, fltplan.com suggests a route of NELIE CMK J75 MXE V378
BAL for KBOS-KBWI.

I know practically, for this routes, the victor airway would be
replaced by radar vectoring, so the question is moot, but for flying
on VATSIM or simulating NORDO, would a pilot be expected to descend
below FL180 before reaching the victor airway on this route?

-- Joshua Levinson, February 26, 2010

Answers

In brief, the transition altitude is a non-event for a few reasons:

- Most jets hit FL180 pretty quickly, given they have climb rates of at least 3000'/min

ATC is vectoring you up anyway, so they know how far / fast you are going. If you are climbing too slowly for traffic, they will give you a sidestep vector. If you're NORDO in the climb, you must follow the assigned route, and non-NORDO traffic will be vectored around you.

In the case of NORDO, for descent planning, you'll have to descend before hitting the Victor airway anyway, as descents can start easily 100 nm away. So in your example, a NORDO Jet pilot would likely have to descend below FL180 by MXE in any case.

It gets more interesting internationally where the flight levels start significantly lower, like FL040.

-- David Wihl, March 31, 2010