Select Committee on Science and Technology Written Evidence

Memorandum by the Boeing Company

  Boeing is pleased to submit evidence to the Science and Technology Committee in support of its inquiry into the progress made in the aircraft cabin environment since issuing its Air Travel and Health Report in 2000. This response includes a discussion of cabin environment features on current Boeing production aircraft, enhanced cabin environment features on new products, and ongoing standards and research activities within which Boeing is engaged.


  Boeing is the world's leading aerospace company and the largest manufacturer of commercial jetliners and military aircraft, with capabilities in rotorcraft, electronic and defence systems, missiles, satellites, launch vehicles and advanced information and communication systems. Our reach extends to customers in 145 countries around the world, and we are the number one US exporter in terms of sales. Headquartered in Chicago, Illinois, USA, Boeing employs more than 153,000 people in more than 67 countries.

  Boeing has a long standing relationship with the UK dating back almost 70 years and today the UK remains a critically important market for the company, as a supplier base and a source for technology partners. Boeing's annual spend in the aerospace industry supports thousands of jobs around the UK, in the process generating intellectual property and facilitating exports.

  Boeing sources more from the UK than from any other country in the world, except the USA. In 2005, the company bought more than $1 billion of services and materials from around 300 UK suppliers. There are currently more than 600 Boeing UK employees, in locations from Glasgow to Dorset.


  Boeing Commercial Airplanes (BCA) is the world leader in commercial aviation because of its complete focus on airplane operators and the passengers they serve. Boeing products and services deliver superior design, efficiency and support to airline customers and allow passengers to fly where they want to go, when they want to go. By working together with supplier partners from around the world, Boeing has delivered more than 15,000 airplanes to customers worldwide including airlines, leasing companies, governments and private firms.

  Boeing Commercial Airplanes is headquartered in Renton, Washington, under the leadership of President and Chief Executive Officer Scott Carson. It is organised into three primary business units—787 Program, Airplane Programs and Commercial Aviation Services—as well as providing Airplane Trading services.


  Cabin environment features on current Boeing production aircraft include:

  HEPA filtration for recirculated cabin air is basic equipment on all Boeing production aircraft. These filters capture 99.97% of particles 0.3 microns in diameter. For aircraft application, the most penetrating particle size is in the range of 0.1 to 0.2 microns. Capture efficiency exceeds 99.97% for particles larger than 0.3 microns and smaller than 0.1 microns. HEPA filters are an effective means to prevent the spread of airborne bacteria or viruses via the air distribution system.

  Ozone converters for outside air are basic equipment on the Boeing 777 and 747-400 Freighter aircraft, and are optional equipment on the Boeing 737 and 747-400 Passenger aircraft. Ozone concentrations in the atmosphere vary with altitude, latitude, and season. Thus, the need for ozone converters is dependent on the time of year and routes the aircraft will operate.

  Since 2000, design improvement packages to reduce flight deck noise have been implemented on the Boeing 737 and 747-400. Additional improvements were made to the 737 to reduce aft cabin noise levels.

  Total ventilation rate results in an air change rate of 20-30 times per hour (compared with an air change rate of 4-10 times per hour in a typical building). The high air change rate in the cabin facilitates rapid removal of airborne particulate matter.

  Personal air outlets (PAOs) are basic equipment on the Boeing 737, and are optional equipment on the 747 and 777 aircraft. PAOs provide an effective means for passengers to control their personal environment.

  Boeing has worked, and continues to work, with leading university and industry researchers to better understand the multiple factors that influence comfort and health-related symptoms experienced by passengers and crew in aircraft cabins. We are dedicated to expanding our knowledge, as well as improving our products. We continue to conduct research on cabin environment multiple factors that affect passenger and crew comfort.

  Enhanced cabin environment features on the Boeing 787 will include HEPA filtration for recirculated cabin air and will remain basic equipment for all new products.

  Ozone converters for outside air will be basic equipment for the Boeing 787, as well as the 747-8 Passenger and Freighter aircraft. These aircraft will fly polar routes at high altitudes, thus increasing risk for exposure to high atmospheric ozone concentrations.

  Gaseous air purification system for recirculated cabin air will be basic equipment on the Boeing 787. This system removes gaseous contaminants, odors and irritants. Research at the International Center for Indoor Environment and Energy at the Technical University of Denmark (DTU) demonstrated that the use of gaseous filtration results in a reduction of symptoms commonly reported by passengers and crew. This includes some dryness symptoms typically associated with low humidity and irritation of the respiratory tract.[57]

  The ventilation system controls on the Boeing 787 will allow the outside air ventilation rate to be adjusted per flight based on passenger loading. This capability reduces fuel burn, and maintains higher relative humidity in the cabin. The research conducted at DTU demonstrated that the combination of increased humidity and gaseous purification provide preferred cabin air quality.

  Maximum cabin pressure altitude will be set at 6,000 feet on the Boeing 787. Research at the Oklahoma State University Center for Health Services demonstrated a reduction in cerebral/respiratory symptoms and muscular discomfort after three to five hours of exposure to a pressure altitude of 6,000 feet compared with exposure to a pressure altitude of 8,000 feet.[58]

  The Boeing 787 will have a no-bleed architecture for the outside air supply to the cabin. This architecture eliminates the risk of engine oil decomposition products from being introduced in the cabin supply air in the rare event of a failed engine compressor seal. In addition, this architecture improves fuel efficiency, thus reducing fuel burn and associated engine emissions.

  Personal air outlets will be basic equipment on the Boeing 787. This includes nozzles at passenger seats, at attendant workstations in the galleys, and at attendant seats.

  The Boeing 787 will feature an advanced flight control system. The system can detect and react to vertical gusts associated with light and moderate turbulence. The reduction in vertical aircraft displacement will reduce the number of occupants who experience motion sickness.

  Boeing has set aggressive cabin noise level targets for the 787. Targeted noise levels are less than existing in-service aircraft.

  Boeing continues to support and is actively engaged in standards and research activities, including the following:

  American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) Standard 161P for Air Quality within Commercial Aircraft.

  ASHRAE Research Project 1262. This project includes cabin environmental measurements, and collection of passenger and crew subjective responses, on over 160 commercial airline flights. The research will examine the link between aircraft cabin air and other factors to comfort and health related symptoms experienced by passengers and crew members.

  Federal Aviation Administration (FAA), Center of Excellence (COE), Aircraft Cabin Environment Research (ACER) Team. Established in 2004, the FAA COE ACER Team[59] is engaged in the several research activities, including:

    —    impacts of ozone in passenger cabins;

    —    exposure and risks of pesticides in aircraft cabins;

    —    impacts of reduced pressure in aircraft cabins;

    —    bleed air contamination incidents;

    —    development of CFD tools to simulate contaminant transport in aircraft cabins;

    —    evaluation of environmental air quality (EAQ) and chemical/biological sensors; and

    —    evaluation of technologies for aircraft decontamination.

  In summary, the Boeing Company is committed to providing a safe, healthy and comfortable cabin environment for passengers and airline crews.


  Boeing is committed to maintaining high standards in the provision of cabin environment features on all its commercial airliners. Boeing is also constantly developing new ways of improving the cabin environment and enhancing the passenger experiences. Many innovative features aimed at improving the cabin environment can be seen on the Boeing 787, such as increased cabin humidity, higher cabin pressure and gaseous air purification systems.

18 June 2007

57   Reference: P Strom-Tejsen, et al "Effects of Gas Phase Adsorption Air Purification on Passengers and Cabin Crew in Simulated 11-hour Flights", Proceedings of Healthy Buildings 2006. Back

58   Technical paper due for publication in June 2007. Back

59 Back

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