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Clockwork Research
Alexandra Holmes

Alexandra Holmes

Research Director

Dr Alexandra Holmes is Research Director at Clockwork Research, specialising in the implementation of Fatigue Risk Management (FRM) in safety critical industries. With a PhD exploring the effects of sleep loss and shift work, Alex assists operators to undertake and review scientific safety cases. Alex has over 15 years of experience in enabling operators to implement all elements of FRM, including strategy, training, promotion, risk assessment and safety assurance. Working in the aviation, oil and gas, rail and road transport industries, Alex has insight into ‘what good FRM looks like’ in different industries, cultures and regions. Alex has helped operators and regulators to manage the fatigue risk associated with ultralong range (ULR) operations, offshore schedules and commuting workforces such as fly-in-fly-out (FIFO).

Sarah Booth

Sarah Booth

Senior Manager

Sarah Booth is our Senior Manager of Fatigue Risk Management. A specialist in human performance in the aviation and aerospace environments, Sarah has worked with operators to develop and implement Fatigue Risk Management Systems (FRMS) across multiple regulatory environments, and provides scientific support to Regulators assessing FRM submissions and scientific safety cases.

Sarah specialises in the integration of key data streams into the FRMS. A highly experienced user of bio-mathematical fatigue models, Sarah develops key metrics for the analysis of roster-related-fatigue levels and roster-related fatigue contributors. Sarah also works closely with operators to implement effective, data-rich fatigue reporting systems, and to identify barriers to reporting.

In the last two years, Sarah has undertaken scientific safety cases, fatigue management diagnostics and implemented Fatigue Risk Management in some of the world’s largest airlines, as well as in the rail and maritime industries and for search and rescue helicopter operations.

Sarah obtained an honours degree in Physiological Sciences from the University of Oxford, focusing on cardiovascular physiology and immunology and a Master’s degree in Space Physiology and Health at King’s College London. Sarah is an Associate Member of the Chartered Institute of Ergonomics and Human Factors and is currently studying for a Master’s Degree in Sleep Medicine at the University of Oxford.

Cristina Ruscitto

Cristina Ruscitto

Senior Researcher

Dr Cristina Ruscitto is a Senior Researcher at Clockwork Research. She specialises in the psycho-behavioural predictors of jet lag and fatigue in the aviation sector. Her role involves a wide range of tasks, including the development of fatigue surveys and survey analysis, development of fatigue investigation process, review and recommendations of procedures, scientific study of roster patterns and the use of bio-mathematical models to conduct roster analysis.

Cristina joined Clockwork Research in April 2018, having previously completed her PhD in Health Psychology exploring the psycho-behavioural predictors of jet lag amongst long-haul cabin crew at the University of Surrey, UK. Her research examined the relationship between subjective (symptom perception) and objective (shift in melatonin acrophase) jet lag in order to provide a comprehensive account of jet lag in long-haul cabin crew. The nature of subjective jet lag was further explored in terms of how long-haul crew make sense of jet lag and how this affects their adaptation to jet lag. Finally, based on recent evidence about the circadian resetting properties of food timing, Cristina also evaluated the impact of mealtimes for reducing jet lag in long-haul crew.

Cristina’s interest in the field of jet lag and fatigue in aviation is not only academic but also personal having worked as long-haul cabin crew for 24 years. Cristina also works as a Visiting Researcher and Academic Tutor in Psychology for the University of Surrey. She is a Chartered member of the British Psychological Society and an Associate Fellow of the Higher Education Academy.

David Flower

David Flower


Strategic health leader with 30 years’ experience in high hazard, safety critical industries delivering innovative solutions to achieve business, safety and health objectives.  Global experience within the oil and gas, energy and airline industries.  Results focused with key accomplishments in the areas of leadership, fatigue management and crisis response.

  • Developed and implemented a Fatigue Management Policy and process for BP’s global upstream business.  The supporting material comprised a template local policy document, risk assessment tool, and an on-line risk-based overtime authorisation process.  Also
  • Developed Group Guides on Fatigue Management providing recommendations for the establishment of fatigue risk management systems across all BP assets.
  • Developed a bow-tie fatigue risk assessment to enable the necessary risk mitigations to be visualised using the accepted company risk management tool.
  • Led the development of a suite of self-directed sleep and fatigue e-learning training modules with course assessment.
  • Managed scientific studies of sleep, alertness, and fatigue in offshore workers in the North Sea and gas-field workers in Oman.
  • International Association of Oil and Gas Producers and the International Petroleum Industry Environmental Conservation Association (IOGP/IPIECA) Fatigue Task Force Chair. Led the development of numerous guides, ultimately leading to publication of IOGP Report 626 Managing Fatigue in the Workplace comprising a comprehensive suite of practical guides https://www.iogp.org/managing-fatigue-in-the-workplace/
  • Led a task force comprising scientists and physicians from the Royal College of Physicians Edinburgh, Harvard University, Université Paris Descartes, Paris and Keil Centre, Australia to develop a fatigue guide for physicians at the request of the Royal College of Physicians, London.
  • Member of the American College of Occupational and Environmental Medicine (ACOEM) President’s Task Force on Fatigue and co-author of the Guidance Statement on ‘Fatigue Risk Management in the Workplace’ https://acoem.org/Guidance-and-Position-Statements/Guidance-and-Position-Statements/Fatigue-Risk-Management-in-the-Workplace.
  • Steering Group Member and participant in the Flight Safety Foundation/Boeing/Airbus Industrie Ultra Long-Range Workshops which provided a framework for airlines to work with their national regulators to introduce ultra long haul passenger services https://flightsafety.org/asw-article/in-it-for-the-ultra-long-haul/.
  • Member of the airline transport group contributing to the US Department of Transportation Operator Fatigue Management handbook.
  • Working with British Airways’ Flight Operations, Cabin Services and Human Resources, the National Aeronautics and Space Administration (NASA), Université Paris Descartes and Airbus Industrie, developed an industry leading Alertness Management programme for flight and cabin crew. The programme included training of all crew members and the creation of fatigue management advice cards to assist the flight and cabin crew member to manage their sleep and light exposure to improve alertness.

Al Gallacher

Al has spent 43 years in aviation: 20 of them as a fighter pilot in the Royal Air Force (RAF) and 23 years with a major Hong Kong airline, retiring as a Senior Captain on the BOEING 777.

He held several instructional positions in the RAF, on the Jaguar and Tornado, and was an Air Combat Instructor on the Phantom in the United States Air Force.  He was a senior supervisor of flying in both air forces and was also a Flight Safety Officer in the RAF.  He was a staff officer in the UK MOD, working with the Civil Service, research Scientists and UK industry.

Throughout his commercial career, Al experienced exposure to fatigue on most of his duties, which involved mainly the Command of Long Haul flights between Europe and Hong Kong.  He investigated, and implemented, techniques to mitigate the effects and risks of fatigue both to himself and the wider crew community.  At his earliest opportunity, he joined the Airline’s FRMS Committee.  Al is committed to using his experience to improve the life and health of all who are exposed to the effects of fatigue and to reduce the risk to the organisations who employ them.

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We have been working closely with Clockwork since 2013. They have been instrumental in the airline successfully setting up an effective fatigue programme, through an in-depth analysis of the airlines operations and produced excellent training materials to improve the crew understanding of fatigue. The staff at Clockwork are extremely knowledgeable and professional, making it easy to achieve good results in reducing the risks associated with fatigue in our very complex environment.open quote

Russel Ellis

Director, Operations Control

Air Astana

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We embarked on a complex project with Clockwork and the team at Clockwork were receptive to our ideas and made sure they immersed themselves in our own company culture. This relationship building gave us the ability to give open and honest feedback from both parties which resulted in an excellent programme that our cabin crew could use that was appropriate to their roles and easy to relate to.open quote

Matt Whipp

Manager SEP, Security & AvMed Training

Virgin Atlantic Airways

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Luxair has built a strong link to Clockwork over the past years. Not only did they help us to develop successful fatigue surveys with our cabin and cockpit crews but they also played a major role in the development of our fatigue reporting, our FRMS training and the analysis of our scheduling practices. Clockwork's staff were always open to our ideas/thoughts and with their professionalism and dedication helped us achieve our goal of mitigating fatigue related risks through our SMS.open quote

Pascal Kremer

Safety Manager