Airworthiness

An Introduction to Aircraft Certification and Operations

Filippo De Florio

• Publisher: Butterworth-Heinemann
• Year: 2016
• ISBN:
  9780081009406
• Edition: 3
• Topic: Technik & Maschinenbau
• Subtopic: Luft- & Raumfahrttechnik

Airworthiness: An Introduction to Aircraft Certification and Operations, Third Edition, once again proves to be a valuable, user-friendly reference guide for certification engineers engaged in professional training and practical work in regulatory agencies and aircraft engineering companies. The discussions reflect the recent changes in the EASA-FAA regulations and also include the concepts of flight safety and airworthiness; the ICAO and civil aviation authorities; airworthiness requirements; type certifications and the type-certification process; production of products, parts, and appliances; certifications of airworthiness; and rules for spaceworthiness.

Since publication of the second edition, airworthiness regulation and certification around the world have gone through significant changes. For example, EASA structure has completely changed, FAA rules are no longer applicable, substantial changes have been made in the international airworthiness regulations and certification procedures, and unmanned aircraft have evolved technically and operationally. The changes in airworthiness regulations in the last five years have been striking, changing the way in which we look at airworthiness and certification processes around the world.

• Includes updates throughout to reflect changes to the airworthiness regulations of the two most influential ruling authorities—EASA and FAA
• Includes an update on remotely piloted air systems as well as space vehicles
• Provides guidelines to shape a comprehensive 'certification map' including comparisons, explanations, and backgrounds of institutions and processes
• Features a new chapter "Certificates of Airworthiness and Permits to Fly" that provides an overall description of the requirements governing the certificates of airworthiness

Chapter 1

Flight Safety

Abstract

Everything in this book is related to the safety of flights. In this chapter we focus on its definition, explaining the three conventional flight safety factors: person, environment, and machine. A more detailed analysis of these factors can be found in Chapter 10 (10.9 Safety Management System (SMS)).

Keywords

Environment; Factors; Machine; Safety; Training

 

Safety is a concept generally ingrained in the human mind. The word safety has many definitions depending on the context. In general sense, the official Merriam-Webster definition of the word is ‘The condition of being safe from undergoing or causing hurt, injury, or loss’.

The ICAO¹ offers a definition for safety more pertinent to aviation as ‘The state in which risks associated with aviation activities, related to, or in direct support of the operation of aircraft, are reduced and controlled to an acceptable level’.

Another good definition is ‘Safety is the freedom from those conditions that can cause death, injury, occupational illness, damage to or loss of equipment or property, or damage to the environment’.²

Safety is something related to all human activities and, therefore, every civil society is organised (or should be organised) to guarantee public safety in relation to one’s own or others’ activities. This is certainly a moral obligation, and it is also a practical requirement because accidents causing damage to persons and properties have either social or economic costs. This is also the reason why human activities that could cause damage to persons and properties are controlled by national states through regulations.

1.1. Flight Safety Factors

We will specifically deal with safety related to aeronautical activities with methods for safety assessment in relation to the certification of aircraft systems. We start now by considering what we have defined as the main conventional flight safety factors: the person, the environment, and the machine.

(1) Person is intended here as an active part of the flight operations; we then consider flight and ground crew members, air traffic controllers, and others. Clearly it is important to be able to rely on very skilled people to avoid errors that cause accidents or catastrophes in flight operations. It is then of paramount importance to place these people in a legislative and organised context to guarantee a suitable level of professional training, updating of techniques and procedures, and psychological and physical fitness. National states entrust special public institutions with the responsibility for such obligations.

(2) The environment covers all the external factors that can have an influence on the flying of an aircraft. This includes meteorological conditions, traffic situations, communications, aerodromes, and so on. It is equally important to avoid situations that could jeopardise the aircraft itself. Then we should consider correct meteorological information, rules for the vertical and horizontal separation of the aircraft, suitable aerodromes, and so on.

Figure 1.1 Flight safety represented as three links in a chain.

(3) The machine does not require a definition, but it is easy to understand the importance of a good project, sound construction, and efficiency in relation to the operations to be carried out. Also, in this case, national states entrust special public bodies with the responsibility of assuring that the project, the construction, and the operating instructions comply with flight safety.

An important point regarding these safety factors is that they act in series and not in parallel. They can be seen as three links of a chain representing flight safety (Fig. 1.1).

The failure of a single link is sufficient for an accident to happen. A pilot’s error can put the best aircraft in jeopardy, and the best pilot cannot compensate for a serious failure in an aircraft. Accident reports offer countless examples of this; however, accidents are often caused by a combination of factors that could involve all these safety factors. Nevertheless the accident always begins with the failure of one of the above-mentioned links.

1.1.1. The Machine

In this book, we deal specifically with one of these safety factors: the machine.

We explain design rules, the people who make them, those who make the oversight from design to construction and operations and who is responsible for the organisation of manufacturers and air operators.

We must consider in any case that the machine factor is strictly interlinked with the other two factors. The design of the machine, must consider the environment in all of the forms connected with the expected operations: air pressure and temperature, gusts, icing and lightning protection, air traffic communications, etc.

Certainly it is of paramount importance to remember that the machine is operated by persons in flight and on the ground. In the last few years, we have seen fatal accidents caused by insufficient crew management: pilots incapable of controlling efficient aircraft with just one system failure and incapable of deciding what to do efficiently.

In these cases, it is easy to blame the pilots, but the true question is the relationship between person and machine: are the pilots sufficiently trained to the complexity of modern automated aircraft? Are the machines designed to make training easier? Should the pilots be capable, like in the past, to control manually a modern commercial aircraft? These and other questions are still being carefully considered by authorities and air operators.

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¹ International Civil Aviation Organisation Annex 19.

² U.S. Title 48 of Federal Acquisition Regulation System (Chapter 18).

Chapter 2

Airworthiness

Abstract

Airworthiness is a fundamental element of aviation safety. This chapter offers a definition of airworthiness in addition to a summary of the development of its related concepts.

Keywords

Allowable limits; Safe conditions; UAS; Unmanned

2.1. Definition of Airworthiness

A definition of ‘airworthiness’ can be found in an Italian RAI-ENAC Technical Regulations text: ‘For an aircraft, or aircraft part, (airworthiness) is the possession of the necessary requirements for flying in safe conditions, within allowable limits’. In this definition, three key elements deserve particular consideration: safe conditions, possession of the necessary requirements, and allowable limits.

(1) We can take for granted the meaning of safe conditions relating to the normal course and satisfactory conclusion of the flight. According to one definition we have seen, ‘safety is the freedom from those conditions that can cause death, injury or illness, damage to/loss of equipment or property, or damage to the environment’.

(2) Possession of the necessary requirements means that the aircraft, or any of its parts, is designed and built according to the studied and tested criteria, to fly in safe conditions, as mentioned above. Regulations are intended to promote safety by eliminating or mitigating conditions that can cause death, injury, or damage. These regulations are established by the airworthiness authorities appointed by each...