Tony Kingston and Jean Riley took four days last week to inspect Gilsland primary in Cumbria, a tiny grant-maintained school with only 30 pupils and a sublime view of Hadrian's Wall.
They were tired from planning, observing lessons and talking to the head, teachers and local residents when they departed last Thursday night for their homes in Yorkshire.
They are among the first batch of additional inspectors recruited by OFSTED to overcome its backlog of primary and special school inspections. "I am learning a huge amount," said Mr Kingston, 45, head of Tadcaster primary in North Yorkshire, who is on secondment for one year.
"I have discovered it is not only schools that go through a period of anxiety before the inspection. So do the inspectors. You have to be sure you have got it right. Being a member of an inspection team is a very serious business. "
Last week's visit to Gilsland was the first time the pair had undertaken an inspection without the guiding hand of one of Her Majesty's Inspectors. Mr Kingston led the four-person team. Later this month Mrs Riley, 48, gets the chance to lead an inspection of another primary school.
Both heads praised the training they received from HMI, which focused on planning and managing an inspection, and included training in making judgments within the inspection framework and communicating verbally and in writing.
The two heads trained and conducted two supervised training inspections together. "It's been superb working closely with another colleague and we have a very considerable understanding of schools now because of the depth we have gone to in our inspections," said Mrs Riley, who is head of a tiny village school in Horton-in-Ribblesdale in North Yorkshire.
Watching other teachers teach had been useful and sometimes moving, she added, because of the high quality.
Both heads applied for the AI jobs for reasons of professional development. Mrs Riley said she wanted to make inspection less of an ordeal for schools. At the end of her year on secondment she expects to return to her school. "I have missed teaching considerably since July," she said. "I would be a much better head on my return. I have a much deeper understanding of organisation, management, dealing with people and sensitivity."
Urging teachers not to be frightened of inspections, she said inspectors were on teachers' sides. "Inspectors are trying to make the schools show themselves in as good a light as possible. We have spent many hours looking for the good practice."
Had they seen anything lousy? Mr Kingston declined to comment. "We have seen weaknesses, but there are weaknesses too in our own schools," said Mrs Riley.
Gilsland's head Richard West was confident his school would come out of the process well. For him, the beauty of the AI team was that the inspectors were heads who understood the agonies schools suffer during inspections. The team kept Mr West informed of what they were doing and where the school stood.