An area critical to safety in an organisation is the perceived and actual culture. National Air Traffic Services (NATS) work closely with large safety-critical industries including various aviation companies to enable them to identify strengths and vulnerabilities with the aim of improving safe practice. NATS have developed a simple free downloadable self-assessment App that individuals can use to assess their own culture perception in their organisation. The App has 16 questions arranged in four domains but to our knowledge it has not been used to date in healthcare. As part of the initiatives to improve staff culture, we evaluated operating theatre colleagues' safety perception in our large acute NHS Trust in a pilot study using the NATS safety App. Staff downloaded the App to their smart device before completing it. Responses were sent anonymously through the App and collated by NATS. A total of 146 colleagues downloaded and completed the questionnaire. One hundred and seventeen staff (80%) felt encouraged to report safety concerns, but 86% (n=126) confirmed a lack of available support from healthcare managers. Only 43% of respondents (n=63) would find it easy to challenge colleagues if they observed unsafe behaviour. This pilot study has identified positive indicators of an evolving NHS safety culture, and some concerns about speaking up, support, and challenging colleagues without fear. These issues are known to occur across healthcare. Further work is needed in the NHS to provide a supportive environment to improve patient safety, and lower hierarchy in surgical teams.