The plural 'Weyrleaders' typically refers to the Weyrwoman as well as the Weyrleader, though in some contexts it may refer to a council of Weyrleaders, a conference among the military leaders of the Weyrs.
The domestic head of the Weyr is the Weyrwoman, the rider of the ranking gold queen in the Weyr. If the Weyrwoman dies, or if her dragon ceases to mate due to old age or serious injury, the rider of the next gold to rise to mate will take the position. Though she & her gold are called 'senior pair' they are senior in rank, not necessarily in age or in experience.
The Weyrwoman is in charge of all matters that pertain to housing, food, the raising of children living in the Weyr, training, organization & discipline of the support staff of the Weyr, as well as the day-to-day living requirements of the dragons & their riders. The Weyrwoman is also a diplomatic ambassador, responsible for relations to other Weyrs, Holds & the Crafthalls. Most of her duties are administrative, delegating responsibilities to her Headwoman or junior gold riders.
The Headwoman is the Weyrwoman's primary assistant. The Headwoman is responsible for implementing the Weyrwoman's orders regarding management of the Lower Caverns, where the bulk of the support staff live & work. She is in charge of the cook staff, the cleaning staff, maintenance staff & the Fostering staff. She wields a great deal of power inside of the Weyr.
Retired gold riders often remain in the Weyr as an assistant or advisor to the Weyrwoman. They are sometimes designated to represent the Weyrwoman in the Weyrwoman's absence.
Junior gold riders are also assistants to the Weyrwoman. All dragons will obey the orders of a queen, unless they contradict the orders of the senior gold. Because of this, all gold riders must act as leaders. The junior gold riders are typically assigned to record keeping, lower-level diplomatic duties, training gold weyrling pairs & fostering teenage girls who are likely to rise to a leadership position within the Weyr. This provides them with important experience for future leadership positions, as each junior pair has the chance to become Weyrwoman on very short notice.
The military side of the Weyr is headed by the Weyrleader. Weyrleadership is determined by the mating flights of the senior queen. The rider of whichever bronze catches (mates with) her becomes the Weyrleader. The Weyrleader is in charge of making sure that the fighting wings are up to strength & well trained. He also determines the strategy for thread fighting. The turnover of Weyrleadership varies greatly.
One of the most important ranks in the Weyr, below the Weyrleaders & Wingleaders, is that of the Weyrlingmaster. He is in charge of the training & discipline of the young dragon pairs known as weyrlings. While under his care, weyrlings learn everything from basic dragon husbandry to advanced thread fighting techniques. The Weyrlingmaster must be appointed by the Weyrleaders. The Weyrlingmaster must have a good deal of experience, & thick skin, because as many as 25% of all Weyrlings can die before the end of their training. Weyrlingmasters are usually bronze riders, though highly respected & very senior brown or blue riders are sometimes assigned to the position.
Leadership is determined through chance. The first gold dragon to rise to mate after the previous Weyrwoman's gold dragon has died or ceased to mate becomes Weyrwoman; the rider of the bronze dragon that catches that dragon becomes Weyrleader. This system can (and has) produce inept or otherwise unsatisfactory leadership. There is no way to remove a bad Weyrwoman & the only way to replace a Weyrleader is for a different bronze to fly the Weyrwoman's gold dragon. During an Interval, it may be as long as a decade between mating flights.
When a new Weyr is opened the first among the newly assigned gold dragons to rise to mate becomes the first Senior gold at that Weyr & the rider of the bronze that catches her is the new Weyrleader. Often when the golds are assigned to the Weyr they assign only a single gold at first, to ensure the chosen leadership, or they wait until the chosen gold rider's dragon is about to rise to mate to assign golds to the new Weyr.
A retiring Weyrwoman may choose her successor by timing her retirement to occur just before her chosen successor's dragon is about to rise to mate. However, this may not be possible if her choice of successor is not going to rise to mate in a reasonable amount of time. A Weyrwoman who fails to retire in a reasonable amount of time after her gold has failed to rise to mate may be forced to step down by force of the junior gold riders, the bronze riders and/or the weyrfolk. This method of choosing a successor is also no guarantee of a quality replacement, as the Weyrwoman herself may choose her successor based on cronyism, personal bias against an otherwise capable gold rider or on poorly thought-out criteria.
If a Weyrleader dies in office, the Wingleaders rule by committee until the Weyrwoman's gold rises to mate.
Wingleaders & Wingseconds are chosen through merit, though only bronze riders are considered for Wingleader & only bronze & brown riders for Wingsecond.
New Wingleaders are selected by The Weyrleader, advised by existing Wingleaders.
Wingseconds are chosen by the Wingleader from among his wingriders, though with permission he might be able to recruit a promising rider from another Wing.
The capacity of a Weyr varies from 300—600 dragons. However, during a Pass the dragonriders' duties leave little time for any other activity, so each Weyr has a large support staff that can number into the thousands. The residents of weyrs are known as weyrfolk.
@Dragonriders — living in weyrs (lower case w, or the individual cavern where a single dragon & his/her rider lives), usually in the cliff faces in Northern Weyrs.
Weyrlings — young, immature @Dragons & their riders. Young dragons generally fly for the first time at about one Turn (year) & train with the Weyrling Wing until mature enough to join a Fighting Wing, usually between 1 1/2 to 2 Turns. Weyrling dragon riders may not join a Wing until age 16, no matter how mature their dragon. Weyrling riders who have completed training but are not yet Turned 16 are often assigned messenger or sentry duties until they come of age. They do not have adult level rank/status until they have been accepted into a Fighting Wing.
Lower Caverns staff — Often, but not always, the Candidates who fail to Impress a dragon, or those who have run away from home to live in the more liberal, accepting atmosphere of the Weyr. Lower Cavern staff are often the grown children of dragon riders. This includes cooks, servers, cleaning staff for common areas, those who care for the beasts that will feed the dragons, & many others. Lower Caverns workers socialize & interact just as all other residents. They are led & organized by a headwoman, who is usually ranked just under the weyrleaders in authority.
Weyrbrats — The children who are born in the Weyr are called (affectionately) Weyrbrats. Weyrbrats may be the children of @Dragonriders, Lower Cavern staff or Crafters. Every Weyrbrat has the right to become a Candidate & stand for Impression at age 12. The entire weyr aids in caring for children & are matched with teachers most suited to their personality & distinct skills.
Candidates — Young people who are given the opportunity to become a @Dragonrider. They are chosen through Search, where a sensitive dragon, usually a blue or green, seeks mentally sensitive boys & girls who are of the correct temperament to match minds with a dragon hatchling. Usually those searched are young males, aged 12 — 18, although older girls (aged 16-22) are sometimes searched if there is a gold egg available. With the addition of any Weyrbrat aged 12-18, the Searched are familiarized with the eggs & are present when the eggs hatch. The Hatchlings choose, or Impress, a Candidate who suits his or her temperamental and/or other (still unknown) needs. The minimum age of the Candidates is decided by the Weyrleaders & may be changed according to the Weyr's needs. If there is a greater need for older more responsible riders, the age may be pushed back, if there is a lack of Candidates, the age may be lowered. The minimum age may also be changed depending on whether Pern is experiencing Fall or Pass. The youngest anyone has Impressed a dragon is aged 10 (F'nor), the oldest seems to be in their early twenties. Whether or not female Candidates are allowed on the Hatching Grounds if there is no gold egg is unknown, but it can be speculated this may be allowed in more progressive, or liberal, Weyrs.
Craftsmen — assigned to the Weyr by their Craft, Craftsmen serve the @Dragonriders & support staff as they would serve any Hold. The position is usually a high prestige assignment, & they are autonomous from Weyr structure. However, some craftmen gain their position at a Weyr by being Searched & proficient in their craft discipline, at which point they are appointed by their Mastercrafter as the official representative.
For @Dragonriders, social & Wing status are completely dependent on the color of their dragon. This is due to the natural/instinctual social structure of the @Dragons themselves, a legacy of their @Fire-Lizard ancestors. Gold & bronze dragons & their riders are at the top of the social/military structure. Brown dragons & their riders have the most flexibility & can achieve rank nearly equal to bronze dragons or fall to lower ranks, according to ability & personal preferences of the Riders. Blue & green dragons & their riders are at the bottom of the social & military hierarchy, the dragons because they will obey gold & bronze (and sometimes brown) dragons generally without question, their riders tend to have matching 'follower' personalities & are usually content to do so. Even the lowest ranked adult dragonrider is equivalent in rank to a senior journeyman in a craft.