What is the difference between Airworthiness and Quality? Where do Quality and Airworthiness begin? We know they have no end. I shall attempt to put these questions into perspective from the operator's point of view, but first of all we have to try and understand our meanings of these words. Today, with the intense competition within the air transport industry, it is important that we ask the question 'How do we assess the quality standards being achieved and what do we require from an air operator's organisation as a whole?' The first and unimpeachable quality characteristics must be safety. Secondly, the airline passenger expects to reach his/her destination at the proper times published in the timetables. Regularity and punctuality thus become other important quality characteristics we must recognise. Thirdly, we must ensure that the passenger wants to fly on our aircraft and therefore, aircraft presentation is yet a further characteristic we must consider. All this sounds well from the user's viewpoint. However, not only have modern jet aircraft become complex systems, but so also have the maintenance systems that go with them. We must accept that the existing inspection programmes are based on a weighting of the classification of the effects of failure on the aircraft and also accept that the objective of a maintenance organisation is primarily to prevent deterioration of the quality of the design. How do we achieve these standards using a quality organisation to support work being done by a Maintenance and Overhaul organisation? Somehow we have to develop a coordinated system embracing all the resources within the organisation to enable aircraft maintenance to be completed to both regulatory authority and specific company requirements and standards in respect of the most significant item of safety through to the aesthetic standards of passenger accommodation. Having understood what we require from a quality standpoint we now have to try and ascertain whether or not airworthiness requirements are met and therefore the meaning of airworthiness has to be established. This will show if the approach to good airworthiness and good quality are compatible. Asking the man in the street what he understands by the word airworthiness he would immediately reply that it was ensuring that aircraft are 'safe to fly'. The Oxford Dictionary seems to support this view by defining it as 'fit to fly'. Another reference book defines it as 'in fit condition for safe flying'. So it appears to the customers we serve that it means 'safe' — the aircraft is safe to fly. One very interesting point is that there are only a few people in the aircraft industry who really know what it means. As engineers, we ourselves also believe that the word only has a connotation with safety to fly. The legislation which surrounds us does not give us any guidance. In fact you have to look extremely hard to find the word mentioned at all. The certifications made by engineers, be it either a Certification of Maintenance or a Certification of Compliance, do not mention airworthiness and furthermore the Air Navigation Orders covering them do not refer to it. We do have, however, a Certificate of Airworthiness, but what does that mean? Article 8 of the Air Navigation Order states that the Regulatory Authority has to be satisfied that the aircraft is fit to fly having regard to:— "(a) The design, construction, workmanship and materials of the aircraft (including in particular any engines fitted therein) and of any equipment carried in the aircraft which it considers necessary for the airworthiness of the aircraft; and (b) The results of flying trials and such other tests of the aircraft as it may require:" It further states:— "A certificate of airworthiness issued in respect of an aircraft shall cease to be in force:— (a) If the aircraft, or such of its equipment as is necessary for the airworthiness of the aircraft is overhauled, repaired or modified, or if any part of the aircraft or of such equipment is removed or replaced, otherwise than in a manner and with material of a type approved by the Authority either generally or in relation to a class of aircraft or to the particular aircraft; or