He wrote: “The governing body have asked Mrs Debby Lipkin, who has been working as consultant headteacher for the past few weeks, to take on the role of executive headteacher.
“Mrs Lipkin will lead the school and work in partnership with Mr Simon Appleman in his role as headteacher.
Mr Woolf added: “These are interim appointments, and will be in place until August 2017, whilst we undertake a wide ranging search for the highest calibre leaders.
“Mrs Lipkin and Mr Appleman will work with an expanded Senior Leadership Team to continue to drive the school forward.”
The school was knocked by a critical Ofsted report two years ago after an unexpected inspection.
Having been rated as an "outstanding school" in 2009, it dropped two inspection grades to a school "requiring improvement".
Mr Miller described the Ofsted report as "not an accurate reflection of the school we know".
A follow-up inspector's visit a few months later recorded that the school's leadership had acted "resolutely" to make improvements.
It noted that the local authority had contracted an unnamed "independent school improvement adviser" to work with JFS.
With around 2,000 pupils JFS, in Kenton, north-west London, is Europe's biggest Jewish school.
