This research examined the impact of attitude, behavioural intentions and actual behaviour on aircraft safety amongst by analyzing data collected from aircraft line maintenance mechanics in Hong Kong. The research used two conceptual framework models and structural equation modeling to compare two aircraft maintenance companies and was based on the theory of reasoned action and the theory of planned behaviour. It was hypothesized that attitude affects behavioural intentions and that behavioural intentions in turn affect actual behaviour; that behaviour then impacts aircraft safety. Data were collected through a questionnaire survey from 380 line maintenance mechanics in two aircraft maintenance companies located in Hong Kong. The survey produced 262 valid responses of which 129 came from company A and 133 came from company B. Principal component analysis and structural equation modeling were used to analyze the data in order to extract common factors underlying attitude and behavioural intentions, determine the relationships between the dimensions of safety attitude and behavioural intentions, and compare the differences between the two companies. Reliability and validity of the data was found to be within acceptable limits. Results indicate that there is relationship between attitude, behavioural intentions and behaviour in accordance with the theory of reasoned action and the theory of planned behaviour. The hypothesis is supported by the study’s conclusion that maintenance mechanics’ attitude will predict their behavioural intentions as well as their safety behaviour and that this will indirectly affect aircraft safety.