They are chosen by the Weyrleader and his Wingleaders
They are older rider, that has good skills to teach the new dragon's and riders how to care for their charges, making sure, they had meat ready, to be cut up into morsels, many times a day, till, and then three times a day, till they had their fangs grown in then twice a week, hunting their own food.
Make their first Fighting Straps, harness, and other needed stuff.
Sean Connell would say that we need every dragon, they are reason that we are surviving on Pern. To each dragonpair,/
Caution pleases me much more than agility", "Don't be clever "You've never been here before. Hasn't F'neldril drilled into your skull to air space landing as well as taking off?"
Firestone / flamethrowers
How to chose the right type of firestone, and bag it, how much is issued to a pair.
Firestone aka Flamestone
The older once tossing firestone sacks, back and forth, 
Search Dragon / Rider Pair
Loss of dragon, rider, or pair both
No matter how often they were cautioned by the Weyrlingmaster and Weyrleader, weyrlings inexplicably disappeared and the older dragons grieved. The casualties were such a waste of the Weyr's resources Like unnamed weyrling at Benden Weyr. Sean Connell, felt the loss during training, the worst.
- F'neldril - Sixth Pass - Fort Weyr
- C'gan - Ninth Pass - Benden Weyr
- T'mar - Second Interval - Fort Weyr
- Kindan / K'din Third Pass - Telgar Weyr Far Western Continent
- The Chronicles of Pern: First Fall
- The Red Star / Dragonseye
- Moreta: Dragonlady of Pern
- Nerilka's Story
- ↑ http://www.audible.com/pd/Sci-Fi-Fantasy/Dragonheart-Audiobook/B002V02WEE
- ↑ http://www.audible.com/pd/Sci-Fi-Fantasy/Dragonseye-Audiobook/B002VA9XQ4/ref=a_series_c2_13_saTtl?ie=UTF8&pf_rd_r=1S6EAC2DMAD3E3EGKA5K&pf_rd_m=A2ZO8JX97D5MN9&pf_rd_t=101&pf_rd_i=series-detail&pf_rd_p=1374482202&pf_rd_s=center-2
- ↑ http://www.audible.com/pd/Sci-Fi-Fantasy/Moreta-Audiobook/B002V0KHV4/ref=a_series_c2_7_saTtl?ie=UTF8&pf_rd_r=0NT7HC42CR5W3HTX5CG4&pf_rd_m=A2ZO8JX97D5MN9&pf_rd_t=101&pf_rd_i=series-detail&pf_rd_p=1374482202&pf_rd_s=center-2