I've learned how to add altitude to the AP route (ABCD@24000), and the route is showing it; ""FL24". However, once in the takeoff pattern under AP control, the altitude increases at a snails pace taking 300 or 400 (estimate) to get above FL20. I haven't been able to locate a VVI to tell what it's using, but the artifical horizon is usually at the 7 or 8 degree position. To reach FL, I have to alternate between overspeeding and forcing a steep VS climb, back to WNAV when speed drops close to stall, and repeat.
When flying commercially (passenger), I don't remember waiting an hour until "we're at cruising alt of xx" mentioned and that the climbing alt was much steeper than apparent in FlighGear (although, that's difficult to tell as my tuccas is firmly set into my recliner ).
I've tried various aircraft and they all behave the same way, and even tried putting a cruising altitude off FL25,FL30 or FL40 on the first waypoint hoping it would force the AP to do it's best to reach that. I saw somewhere in the documentation someone has added an "A" or "B"?? to the rout planner altitude to instruct the AP to reach that waypoint at or above, or at or below - the letter was ignored so either I misunderstood, that feature doesn't work on the aircraft I tried it on and/or it's in a different version.
Any ideas on what I'm missing?