Aircraft Maintenance Reliability. Basics & other questions
An article by our Guest Blogger and Senior Reliability Trainer Rustom D. Sutaria of Avia Intelligence.
What is reliability?
- It is the characteristic of an item, component, system or aircraft expressed by the probability that it will perform a required function in a stated environment for a stated period.
- Where aviation is concerned: RELIABLILITY = DEPENDABILITY = STABLILITY
- COMPONENTS, SYSTEMS or AIRCRAFT are:
- RELIABLE if they follow an expected law or behaviour (i.e. they function in the way they are designed)
- UNRELIABLE – if they depart from the expected law or behaviour (i.e. they DO NOT function in the way they were designed)
- Reliability is also a function of probability of performing without failure.
What are the elements of Reliability?
What do reliability engineers and departments have to deal with?
- The accumulation of relevant aircraft/component maintenance data (Hours / Cycles / Failure modes / etc.)
- The study, evaluation and life cycle management of this data;
- Drawing conclusions & recommendation designed to manage the effectiveness of aircraft maintenance programme.
How is reliability typically measured or demonstrated?
Often measured as:
- ONE minus probability of failure;
- A measure of ‘Availability’
Is maintainability an important function of reliability?
- Maintainability is intrinsically linked to Reliability…. like an old married couple!!!
- Lack of maintenance programme effectiveness = loss of maintainability = loss of reliability.
Reliability Programme – Checklist:
Do you have the following reliability programme features or do you have the answers to these questions?
What information should reliability be reporting on?
- Indicators of the level of effectiveness of your Aircraft Maintenance Programme
- Pilot Reports (PIREPS)
- Engine Performance / In Flight Shut Downs
- Technical Interruptions / Delays
- Unscheduled Removals
- Etc., as required by the operator & their regulator.
Other questions regarding reliability that need to be answered:
- How is your reliability programme administered?
- How do you manage competency within your reliability framework?
- Are your reliability procedures delivering good results, or are they ineffective?
- How do you manage external information sources?
- Is your reliability data being applied effectively in support of the management of continuing airworthiness?
- How you your procedures manage check findings in context of reliability?
- Does your system of reliability manage repetitive defects in an effective manner?
- What is in place regarding the evaluation, review and change of the reliability programme?
- Do you have an alerting system that graphically demonstrates increasing rate of failure?
If you would like to arrange an EASA Compliant Reliability Training Course please email: office@sassofia.com or see www.sassofia.com for more details of how SAS may help you.
