Plummeting from beacon status to special measures within a few years is rare, but not unknown. As governors know, getting the right head is crucial, but increasingly difficult, as the job itself has become the focus of a school's performance, with leaders vulnerable after any setback. Many schools fail to attract a field of strong candidates for desirable vacancies and are left either taking a chance or choosing a further period of acting headship.
Governors are also crucial. The Rev Geoff Vevers, chair of governors at the inner-city St George's primary, has been praised by Ofsted for helping his school out of special measures (page 28). Most governing bodies - unpaid volunteers - do a fantastic job, acting as a critical friend and keeping the school accountable to its neighbourhood. Some have trouble recruiting: a minority are hijacked by special interest groups.
The local authority is also crucial. A peculiarity of Dunmore is that despite the revolving door on the head's office, academic results remained good - a tribute to the professionalism of the staff. Without concrete evidence of failure, it is difficult for the authority to do much more than replace its own governors.
Dunmore seems to be an example of what can go wrong if the balance of power between heads, governors and local authorities is upset.
With good primary headship candidates increasingly rare, instability is creeping into the system. The worry is that government intentions to further diminish the role of local authorities and allow the governing bodies of some schools to be peopled by business sponsors rather than locals, might mean Dunmore becomes less of an oddity.