If you are in the UK then there is a law, it is AN 47.
The corporate management of all approved maintenance organisations are required to review this Airworthiness Notice and implement suitable policies and procedures to make all maintenance staff aware of them. The requirements of Articles 18(7) and 18(8) of the Air Navigation Order (2005) as amended, in addition to an understanding of the requirements placed upon the UK CAA within Part 66.B.500, fall on those who
certify the completion of maintenance. The guidance material contained in this Airworthiness Notice is equally applicable to all non-licensed personnel engaged in aircraft maintenance tasks and in principle should be adopted throughout the aviation industry as a code of practice. Organisations shall also take note of items in paragraph 3 which require their participation in the areas concerned.
3 Guidance
3.1 Fitness In most professions there is a duty of care by the individual to assess their own fitness to carry out professional duties. This has been a legal requirement for some time for doctors, flight crew members and air traffic controllers. Licensed aircraft maintenance engineers are also now required by law to take a similar professional attitude.
Cases of subtle physical or mental illness may not always be apparent to the individual but as engineers often work as a member of a team any sub-standard performance or unusual behaviour should be quickly noticed by colleagues or supervisors who should notify management so that appropriate support and counselling action can be taken. In particular, a decrease in mental fitness in many cases may be related to stress from within the working environment or to the personal circumstances of the
individual. Instances of aggressive behaviour, vagueness and slippage of personal standards (cleanliness, appearance etc.) may be indicative of more serious mental issues. Such issues may bring into question the ability of the individual to be trusted or to maintain the necessary levels of concentration to take appropriate decisions on airworthiness matters.
3.2 Fatigue Tiredness and fatigue can adversely affect performance. Excessive hours of duty and shift working, particularly with multiple shift periods or additional overtime, can lead to problems. Whilst the safety management aspects of these matters are being addressed through the UK Operators Technical Group individuals should be fully aware of the dangers of impaired performance due to these factors and of their personal responsibilities.
3.3 Stress Everyone is subject to various stresses in their life and work. Stress can often be stimulating and beneficial but prolonged exposure to chronic stress (high levels or differing stress factors) can produce strain and cause performance to suffer allowing mistakes to occur.
Stress factors can be varied, physical – e.g. heat, cold, humidity, noise, vibration; they can be due to ill-health or worries about possible ill-health; from problems outside the workplace – e.g. bereavements, domestic upsets, financial or legal difficulties. A stress problem can manifest itself by signs of irritability, forgetfulness, sickness absence, mistakes, or alcohol or drug abuse. Management have a duty to identify individuals who may be suffering from stress and to minimise workplace stresses.
Individual cases can be helped by sympathetic and skilful counselling which allows a return to effective work and licensed duties.
Been there, done it and used it. (HKAR's are the same as UK)