Select Committee on Science and Technology Fifth Report



2.1 Few destinations anywhere on earth are now more than one or two flights away. Both business and leisure are shaped by the ready availability of affordable air transport. Enormous numbers take advantage of this. Annually, the world's airlines carry a staggering total of approaching some two billion passengers[4]. At any one moment, about half a million people world-wide are flying in commercial aircraft (p 288).

2.2 Such mass travel has developed only over the last forty years. Indeed, powered heavier than air flight was widely dismissed as impossible only a century ago. Orville Wright proved doubters wrong in 1903 with a flight of 196 feet, or barely two-thirds the wingspan of the largest modern airliners. With the military stimulus of the troubled 20th century, aircraft were developed rapidly thereafter.

2.3 Purposeful civil aviation arrived in the 1920s, best marked in the United Kingdom by the formation of Imperial Airways in 1924. During the 1930s, a world-wide network of commercial routes was developed. Air travel was, however, the preserve of those who were both wealthy and determined: the early flights from London to Australia took twelve days and involved up to five changes of aircraft with over forty re-fuelling stops.

2.4 Civil aviation came of age only in the 1950s with the widespread introduction of longer range jet aircraft. Thanks to pressurised cabins, these could fly high enough - 26,000-42,000[5] feet[6] - to avoid the bulk of weather disturbances and to use fuel more efficiently. Additional design and technical improvements have brought yet more efficient aircraft, facilitating the mass market for air travel that exists today. Some outline indications of the growth of UK air travel over the last twenty years and its nature today are set out in Box 1[7].

Box 1

The growth and nature of UK air travel

During the last twenty years:

•  Passenger numbers have more than trebled (being 2.5 times greater for domestic flights and 3.5 times greater for international travel)

•  Among international travellers, business passengers have doubled and leisure passengers have quadrupled

•  Female business passengers have doubled to 20% of the total, while female leisure travellers have remained at just over half the total

At present:

•  Nine out of ten passengers travel internationally, although only one in ten travels outside the EU

•  85% of business travellers are in the age range 25-54, compared to 55% of leisure travellers

•  Nearly one in ten leisure travellers is aged under 15 years old while another one in ten is aged more than 65

•  Nearly three quarters of leisure and a third of business passengers travel on charter or discount economy class tickets

•  Nearly all business passengers are in socio-economic groups A-C1 while a quarter of leisure travellers are in groups C2-E

Source: Calculated by the Parliamentary Office of Science and Technology from data in annual issues of Transport Statistics, Great Britain, The Stationery Office; and Passengers at Gatwick, Heathrow and Manchester Airports in 1998 (CAP703), CAA, November 1999

2.5 Development seems bound to continue. There is no sign of any abatement in the growing appetite for air travel. The International Air Transport Association (IATA) predicts continuing air traffic growth at 5-6% annually, twice the rate of general economic growth[8]. Over the next twenty years, The Department of the Environment, Transport and the Regions (DETR) forecasts UK-origin passenger numbers to double[9] and Airbus Industrie predicts a trebling of global traffic[10].

2.6 The technology will also change. For example, Airbus Industrie announced the long-range 600+ seat A3XX aircraft during the course of this Inquiry. They also forecast[11] that, over the next twenty years, aircraft seating more than 400 passengers would increase from one in a hundred to one in five of all passenger aircraft and that mid-range aircraft seating 100-175 passengers would fall from just over half to about a third of the total.


2.7 As explored in this Report, the aircraft cabin has a number of unusual features, and the combination of these makes for a unique environment. There is now a much larger number and, in terms of age and state of health, wider range of people travelling by air - and thus exposed to that unique environment - than thirty or forty years ago. Our concern was that arrangements to safeguard passenger and crew health might not have been keeping pace with, on the one hand, the changing nature of air travel and travellers and, on the other, improving knowledge of links between health and environmental factors. All this was reinforced by growing public concern in the press and elsewhere.


2.8 The Inquiry was conducted by Sub-Committee II, which also prepared this Report. The Sub-Committee membership and declaration of interests are set out in Appendix 1. Our Specialist Adviser was Dr D Michael Davies, a consultant in occupational and environmental medicine, with special experience of passenger and crew health[12]. We are grateful for his assistance in considering the many medical and technical questions that arose during the Inquiry.


2.9 Against the background set out above, our general objectives for the Inquiry were as follows:

    (a)  to establish current knowledge (and any gaps) about the health implications of the commercial aircraft cabin environment;

    (b)  to examine the extent to which that knowledge informs

      (i)  the present national and international regulatory arrangements;
      (ii)  other design matters at the discretion of aircraft manufacturers and airlines;
      (iii)  maintenance arrangements;
      (iv)  guidance to passengers and crew; and
      (v)  public concern about these issues;

    (c)  to explore the effectiveness of the present regulatory structures and other arrangements; and

    (d)  to make recommendations as necessary.

2.10 To gather material for our purposes, the call for evidence reproduced in Appendix 2 was issued in March 2000. To help keep the focus on what has, as expected, turned out to be a complex area, three topics were explicitly excluded from the Inquiry. These were:

    (a)  general air safety and in-cabin physical safety (including "air rage") which were considered by the House of Commons Select Committee on the Environment, Transport and Regional Affairs in 1999[13];

    (b)  military and private aviation; and

    (c)  the environmental effects of air travel.


2.11 We received a large volume of evidence from a wide range of sources, listed in Appendix 3. We are grateful to all of those concerned for their help in clarifying the issues. The written evidence was complemented by oral evidence received at eight public hearings in May and June 2000. The oral evidence and most of the written evidence is published in Volume II of this Report.

2.12 As noted in paragraph 2.7, our concerns were echoed by concerns among the wider public. Among our written evidence were many letters from individuals about their particular experiences, as summarised in Appendix 4. While this material is not statistically representative, it does lend colour and immediacy to the more technical submissions received.

2.13 To help us prepare for reviewing the technical evidence that was to be received, some of us visited British Airways Maintenance, Cardiff (BAMC) in April 2000 to see at first hand the mechanisms for controlling environmental conditions in the aircraft cabin. A note of that visit is in Appendix 5. We are grateful to all those involved for providing a helpful introduction to the topic.

2.14 As part of a wider examination of air safety questions, an Australian Senate Committee has inquired into complaints about cabin air quality in the BAe 146 aircraft. Its Report[14] was published on 12 October 2000, and we have been able to take account of its findings in our Report.


2.15 Chapter 1 of this Report gives an overview of our findings. They flow from our consideration of a wide variety of inter-related medical, technical and other matters. The rest of this Report is structured to provide a guide through all that detailed material, as below. In each case we rehearse the issues that arise, often prompted by complaints we have received; discuss these in the light of the views of expert witnesses, regulators and the air travel industry; and set out our own views.

  • To clarify the general background, Chapter 3 describes the regulatory structures and outlines the way they bear on the health of passengers and crew.
  • As the majority of representations we received concerned the quality of cabin air, Chapter 4 considers the elements of healthy air for passengers and crew.
  • Given those respiratory and other needs, Chapter 5 discusses the practical provision of a healthy cabin atmosphere.
  • Turning to what we consider to be the main medical concern, Chapter 6 discusses deep vein thrombosis (DVT) together with associated issues of seating, stress and the scope for harmful interaction between aspects of the cabin environment.
  • In Chapter 7, we deal with the other significant medical matters arising from the Inquiry, namely: the transmission of infection; the effects of the cabin environment on vulnerable individuals; and the handling of in-flight medical emergencies
  • Chapter 8 discusses a variety of wider issues needing to be addressed, in particular the availability of information.
  • In Chapter 9, we then draw together a number of inter-related strands with some concluding broad-ranging points.


2.16 The abbreviations and technical terms used in this Report are generally explained only the first time they are used. For convenience, they are all listed in Appendix 6.

4   The 1997 Annual Report of the Council of the International Civil Aviation Organisation noted a global total of some 1.5 billion passengers for that year, and estimated that 2 billion passengers would be carried annually by 2005. Back

5   50,000-60,000 feet for Concorde. Back

6   Throughout this Report, we follow the aviation industry's standard use of a variety of non-metric and metric units. Back

7   We discuss the limited availability of these sorts of data in paragraph 8.20. Back

8 Back

9 Back

10   Global Market Forecast 2000-2019, Airbus Industrie, July 2000.  Back

11   ibid. Back

12   Fuller details are in Appendix 1. Back

13   Aviation Safety, 4th Report, Session 1999-2000, HC Paper 275. Back

14   Air Safety and Cabin Air Quality in the BAe 146 Aircraft, report by the Australian Senate Rural and Regional Affairs and Transport References Committee, October 2000, ISBN 0 642 71093 7. Back

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