The school made famous by TV series Educating Yorkshire has been found to require improvement in its latest Ofsted inspection.
The report into Thornhill Community Academy near Dewsbury says GCSE results are lower than they should be - especially in English and maths.
Inspectors say leaders did not react quickly enough to allow pupils to meet the requirements of more academic courses and end of year exams following Government reforms.
However the report also says the outgoing head teacher Jonny Mitchell and senior leadership team have established a positive culture for learning in classrooms and the school. And its says pupils’ spiritual, social, moral and cultural development is good and prepares them well for life in modern Britain.
Commenting on the report Mr Mitchell said: “The report is a fair reflection of the 2014 results and everything else is geared around that.
“The prospects for improvement in this summer’s results are more than good and the academy is resolutely committed to making the necessary improvements.
“There are many strengths reflected in the report, and we firmly believe the 2014 results are a blip and will be an isolated occurrence.”
Thornhill Community Academy was made famous by the Educating Yorkshire documentary series on Channel 4 which turned Mr Mitchell and several other teachers and pupils into household names in 2013.
The programme was watched by an audience of more than four million people and it won a series of television awards.
The new Ofsted report praised the work of the school’s governing body for ensuring the making of a television programme “was well managed and that the interests of students and staff were protected.” It also says that money made from staff speaking at conferences or subsequent television shows on the back of the series have been donated to charity.
Last summer Thornhill saw its GCSE results fall sharply with the level of pupils achieving five good A* to Cs including English and maths drop from above 50 per cent to 17 per cent.
When league tables were published in January Mr Mitchell said the real figure should have been higher as some pupils’ results were not included. This was because their first attempt was only in an English Literature exam and did not include an English language element - meaning it did not count toward the school’s league table score.
And when the same pupils then sat a combined literature and language GCSE this was not included either as it was classed as their second attempt.
“If they had been included our figure would have been 47 per cent which is still down on last year but more in line with the national picture,” Mr Mitchell said at the time.