Endurance and Thrassian flight

At Thrassian race level 4, the class gains 1 turn of flight; however, there is the limitation that the character can fly 60 rounds (1 turn) before becoming fatigued.

The proficiency Endurance states that the character is nearly tireless, and does not need to rest every 6 turns (of travel).

How do these two mix, if at all? If I treat this flight ability as effectively 6 times as tiring as marching, then it lines up - rest after 1 turn of flying, or rest after 6 turns of marching. Endurance allows you to skip the rest without penalty; would that mean that a Thrassian 4 with Endurance could fly for 8 turns without penalty? Or is the 1 turn of flight a hard limit? What is the maximum flight distance at +0 CON? At +3?

I have not developed rules for how Endurance and Thrassian Flight would interact. Let's try to!

An adventurer normally can move for 5 turns of every 6, for 8 hours per day, without penalty. An adventurer with Endurance can move for 6 turns out of every 6, for 8 hours per day. This means that a character with Endurance can move *continuously* for (48/6) 8 times as long as a character without the proficiency.

Since we know that a Thrassian can fly 1 turn continously before Endurance, we can conclude he can fly 8 turns continuously with Endurance.

We know that the character with Endurance's continuous movement (48 turns of movement) equals the movement of an entire day. We can conclude that 8 turns of continuous movement therefore constitutes an entire's day's movement.

For that to be the case, in an 8 hour day, for a Thrassian without Endurance, then the Thrassian must only be able to fly for 1 turn out of every hour (1 turn, then rest 5 turns; multiplied by 8 hours/day to get 8 turns of flying per day).

So that suggests:

- Without Endurance a Thrassian can fly for 1 turn, then has to rest 5 turns.

- With Endurance, a Thrassian can fly for 8 turns, then has to rest 5 turns.