Your question is at the heart of much very careful research. It is a great question because it is core to the understanding of social insects-- how they use castes to perform complex and differing behaviors. Bee practice "temporal polyethisim" -- a mouthful phrase to describe different jobs at different life stages-- as distinct from ant species which have castes that are fixed at birth.
Researchers date the beginning of orientation flights to Day 5-7 after emergence (about halfway through the "house bee" phase). Younger bees are not fully mature on emergence, and don't have the flight muscles for sustained flight, specifically special mitochondria to power the immense energy demands of the wings. See: http://www.sciencedirect.com/science/article/pii/0012160663900265
Bee have a "juvenile hormone" that changes in concentration over the adult lifespan and affects development of the phases. See: http://link.springer.com/article/10.1007/BF00300679
Researchers have taken "naive" bees (raised trapped in an observation hive) and studied the learning that occurs on the first flight-- down to the formation of brain synapses from a single flight. See: http://www.sciencedirect.com/science/article/pii/0006899382909775
The foremost researcher of orientation flights is Elizabeth A. Capaldi --- she has published several papers -- one where they track the individual bee path with harmonic radar. See: http://www.nature.com/nature/journal/v403/n6769/pdf/403537a0.pdf
What she learned is the bee track on a narrow sector in a particular flight, but make multiple learning flights to build a full mental map of the hive location.
She reports that bees spend about the same time on each learning flight, but begin with very slow hovering flights, and at the end of the learning period fly very quickly for longer distances. Her bee made their first orientation flight over various days -- ranging from day 4 to day 14 (mean was day 6.2 s.e. 0.29). The number of learning flights ranged from 1 to 18 with a mean of 5.6 (s.e. 0.18). The mean length of the flights was 331 seconds s.e. 59 .