A 13-page report into Highfield Leadership Academy outlined a number of areas where improvement is needed, and where inspectors from Osted were impressed.
The education watchdog has placed the school, in Highfield Road, South Shore, in special measures and said improvement is needed immediately.
Summary of the key findings for parents and pupils (all from Ofsted's report, which is due out on Friday)
* Pupils make inadequate progress in many subjects. Leaders, including trustees and governors, have been unable to improve the school quickly enough. As a result, the quality of education falls far short of being acceptable.
* Leaders and trust representatives have an overgenerous view of the school's effectiveness.
* Arrangements to safeguard pupils are ineffective. Some pupils do not feel safe.
* Many pupils report their teachers do not tackle bullying effectively. Some pupils report they witness homophobic discrimination.
* The use of offensive language by pupils in the corridor is commonplace. Some pupils show a lack of respect for each other and staff.
* Pupils' behaviour disrupts learning. Disruption from some pupils mean many classrooms are disorderly. Some pupils ignore instructions from staff.
* Temporary staff do not receive adequate help to plan learning or manage pupils' behaviour effectively.
* Despite teachers' efforts, much time during learning is not used effectively. Many pupils do not focus well on their learning.
* Many teachers do not use assessment information effectively to plan learning.
* Some teachers have low expectations of pupils' behaviour. They do not use the school's systems effectively to challenge pupils' poor behaviour.
* Some pupils have gaps in their learning. They do not have sufficient knowledge to make the progress of which they are capable.
* Pupils' progress at key stage is among the worst in the country. Pupils have underachieved significantly in most subjects, including English and mathematics.
* Provisional information for 2018 shows the progress made by disadvantaged pupils, the most able pupils, and boys, is exceptionally poor. Pupils with special education needs and/or disabilities (SEND) also underachieve.
* Some pupils expressed concerns about the negative effect that leaders' recent changes to the curriculum will have on their choices when they leave the school.
* Although pupils' attendance has improved, almost one quarter of disadvantaged pupils continue to be absent from school regularly.
* Many pupils arrive at school late. Also, many pupils do not arrive punctually at their lessons.
The school was found to have the following strengths:
* Leaders and trust representatives have a strong sense of moral purpose. They have faced substantial obstacles and have worked tenaciously to overcome these.
* Many pupils at the school want to do well and they are polite and friendly.