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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 rage (ULR) operations, offshore schedules and commuting workforces such as fly-in-fly-out (FIFO).

Sarah Booth

Sarah Booth

Research Manager

Sarah Booth is a Research Manager at Clockwork Research. A specialist in human performance in the aviation and aerospace environments, Sarah has worked with aviation operators to develop and implement Fatigue Risk Management Systems (FRMS) across multiple regulatory environments.

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

A regular speaker at both academic and industry conferences, Sarah is also a trainer, delivering to operators in the implementation of Fatigue Risk Management, as well as courses in the use of biomathematical modelling.

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 Affiliate Member of the Royal Aeronautical Society.

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.

Alexandros Kontotasios

Alexandros Kontotasios

Human Factors Specialist

Alexandros brings a unique combination of in-depth, cross-industry experience of fatigue research, psychology and human factors. His experience is supported by a solid academic background in fatigue in pilots, human factors in aviation, psychology, military psychology, and accident investigation that enables him to prepare high quality fatigue research.

Expertise and capability

  • Scientific literature reviews
  • Statistical analysis
  • Scientific safety cases
  • Fatigue Risk Management Systems implementation

Career background and experience

Alexandros is finishing a PhD at the University of Leeds (UK) exploring fatigue and performance in pilots who commute by driving and holds a BSc in Psychology, a BSc in Military Psychology, and an MSc in Human Factors in Aviation. Prior to joining Baines Simmons in 2019, Alexandros worked as a human factors psychologist for the Hellenic Air Force, where he conducted the psychological assessment of pilots, air traffic controllers, cabin crew, and train drivers, provided training on fatigue and stress management, researched fatigue and stress, and investigated accidents. He also worked as a research assistant and guest lecturer in human factors for the University of Leeds.

He is a certified accident investigator and human factors instructor, and skilled in the use of flight and driving simulation, eye-tracking, virtual reality and actigraphy for research purposes. Alexandros is a member of the European Association for Aviation Psychology, the British Psychological Society, the Chartered Institute of Ergonomics and Human Factors, and the Human Factors and Ergonomics Society – Europe Chapter. Alex is a member of the British Sleep Society

Catherine Okuboyejo

Catherine Okuboyejo


Catherine Okuboyejo is an Analyst at Clockwork Research. As a highly experienced user of the statistical programming software R, Catherine undertakes highly sophisticated analysis of large and complex datasets to extract meaningful information and visualisations from sleep, physiological and roster data, as well as surveys.

Catherine analysed data for the Trans Maldivian Airways scientific safety case that informed the implementation of their updated Individual Flight Time Specification Scheme and Fatigue Risk Management System. From, the design of data collection materials, to scoring actiwatch sleep data statistical analysis, and report writing, Catherine works to ensure data is of high quality and appropriate statistical methods are applied.

As a user of bio-mathematical fatigue models, Catherine performs sophisticated analysis in various operational environments, including airline and maritime environments, to construct key metrics for the analysis of roster-related fatigue levels and contributors to roster-related fatigue.

Catherine obtained an honours degree in Biochemistry from the University of Surrey, focusing on sleep, biological rhythms and systems biology.

Curt Graeber

Curt Graeber

Dr Curt Graeber is President of The Graeber Group, Ltd., an independent consultancy specialising in human performance and aviation safety. He retired from Boeing in 2008 as a Senior Technical Fellow, Chief Engineer for Human Factors and Director of Regional Safety Programs. He also served as Chief, Crew Operations, for the development of the 737-NG airplane series.

Previously Dr Graeber led the flight crew fatigue program at NASA’s Ames Research Center. Curt has received numerous awards from various international aerospace organizations and has authored over 100 scientific and technical articles. He is a Fellow of the Royal Aeronautical Society, the Aerospace Medical Association and the Flight Safety Foundation. He co-chaired the Flight Safety Foundation’s Ultra Long-Range Crew Alertness Initiative and led ICAO’s Fatigue Risk Management Systems (FRMS) Task Force. He chairs Air New Zealand’s Independent Alertness Advisory Panel and has worked with Clockwork as an FRMS advisor to Air France and Southwest Airlines.

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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Clockwork’s insights and experience enabled us to improve our data collection rates and their analytical skills offered invaluable insights into operational issues. It is fair to say that Clockwork has caused us to completely rethink our LOSA process, turning it into a true added-value proposition.open quote

Norman MacLeod

Human Factors Manager

Cathay Pacific Airlines

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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