Corby Business Academy has been given a rating of ‘requires improvement’ for the second time in two-and-a-half years by the education watchdog.
Inspectors found the school, run by the Brooke Weston Trust, had made effective progress since the start of the academic year.
But they said the quality of teaching was too inconsistent with pupil progress and attainment below average.
Secondary executive principal Anne Hill said: “The heads of school and I are pleased that interventions put into place since September 2018 have been recognised as effective.
“The inspectors are clear that corporately we have the vision and ambition to make Corby Business Academy the best that it can be.
“Our dedicated team of staff are determined to achieve that as quickly as possible.”
Inspectors graded the Gretton Road school as requires improvement in four of the five key areas with only leadership graded as good.
Lead inspector Chris Stevens said the quality of teaching was inconsistent across the school.
In his report, he said: “The quality of teaching, learning and assessment is inconsistent within and between subjects.
“Pupils across all key stages say that their enjoyment of learning is variable depending upon which teacher they have, particularly when teaching is provided by temporary staff.
“In the current school year, leaders have taken successful action to improve the quality of teaching.”
He also criticised the levels of attainment for Key Stage 4 pupils.
He said: “In 2017 and 2018, the attainment of pupils by the end of Key Stage 4 was below average across a range of subjects compared with pupils nationally.
“In 2018, there was a marked decrease in attainment compared to the previous year.
“In 2018, the progress made by pupils across a range of subjects, including English and mathematics, was below average.”
However, the report did note areas of success for the 1,091-pupil school.
Praising the school’s management, Mr Stevens said: “The recently appointed heads of school, with the strong support of the executive principal, lead with determination.
“Their ambition for rapid school improvement is having a positive impact on standards and this is improving pupils’, parents’ and carers’ confidence.”
SEN and disabled provision, pupil behaviour and sixth form leadership were also noted as improved by the inspector.
Dr Andrew Campbell, chief executive officer of the Brooke Weston Trust and former Corby Business Academy principal, said: “I would like to thank secondary executive principal Anne Hill and heads of school, Simon Underwood and Nicola Treacy, for the positive results that they have achieved so far at Corby Business Academy in their short tenure.
“Their strong leadership skills have been highlighted in this report and I have no doubt that, under their guidance and professionalism Corby Business Academy will continue to go from strength to strength.”
The school opened in 2008 and was officially opened a year later by then Prime Minister Gordon Brown.
Dr Campbell was headteacher until 2011 in a role taken on in recent years by John Henrys and Janina Taylor, who resigned for personal reasons in the summer of 2018.
Two headteachers - Nicola Treacy and Simon Underwood - and executive principal Anne Hill took the helm in September.