Hello donnlass,
Every airline has slightly different procedures but, in general, the pilots will "trade off" sectors. I can only speak for the airlines that I have flown for, but here are a couple of the limitations imposed on crew:
1. The captain will always do the first takeoff of the day, except where the crew flew the aircraft the day before and both pilots know its condition.
2. The captain will handle all landings onto ice.
3. The captain will handle all takeoffs and landings when low visibility operations are in effect.
3. Co-pilots are restricted to crosswind components of 10 knots until they have accumulated 25 hours on type. (Note: at this point the ban is lifted and it becomes captains discretion whether to allow the co-pilot to land in higher crosswinds).
There are others, but they all revolve around the same theme that if it's considered a higher risk, the captain will conduct the takeoff and/or landing.
Also, for long haul flights it is possible that the flying pilots will trade off during the flight. For example, the captain will do the takeoff, while the first officer will do the landing.
That's all from the airline world. From the bush world, where you are landing on floats or skis, the first officer may never get to takeoff or land until they have considerable time on the aircraft (1,000 hours or more) due to the inherent risks of landing on shallow rivers, the open arctic tundra, or similar locales.
I hope this answers your question!
Last edited by +TSRA; 24th Mar 2013 at 14:30.
Reason: Spelling and grammar