Air Travel

ADVERTISEMENT

Air travel fuel efficiency has improved in the last 30 years more than threefold, and since 2000 fuel conservation in the airlines has improved by almost 25 percent. The U.S. passenger fleet has made even better strides when measured in revenue passenger miles (RPM), which equals one fare-paying passenger carried one mile. The U.S. RPM per gallon of fuel has more than doubled since 1978. Passenger and freight airlines made this remarkable progress in fuel efficiency by using the following methods:

Engineers design advanced transit systems to meet the particular needs of a city and its surrounding communities. The goal of advanced transit is to speed travelers to their destinations with superior efficiency. Future advanced transit projects will include safe routes for pedestrians, bicycles, and motor scooters, and they will provide electricity for recharging electric-powered vehicles during the workday.

1. single-engine taxiing
2. selective engine shutdown on ground delays
3. better weight distribution
4. cruising longer at higher altitudes
5. shorter, steeper approaches to cruising altitude

Aircraft engineers may always struggle to simultaneously solve fuel efficiency and emissions because high-altitude flights give better fuel efficiency, but slower aircraft cruising at lower altitudes emit less CO2. Airline industry engineers, nevertheless, have other opportunities that can complement each other for reaching better overall efficiency, such as the following:

1. improved navigation and weather forecasting systems to calculate most efficient routes
2. fuel-efficient engines and aircraft
3. winglets to reduce air drag and reduce fuel use 3–5 percent
4. new paints to reduce heat absorption, which requires extra energy for cooling
5. airport power hookups rather than use of onboard auxiliary power when at the gate
6. innovations in current kerosene-type jet fuel that comes from crude oil
7. aircraft innovations to reduce noise pollution

Redesigned hubs (a centralized heavy-traffic airport) and better flight scheduling should also reduce resource waste. For instance, a typical airport may run the following operations in a single day: (1) jet fuel arrives by pipeline or truck to a storage site; (2) airport hydrant system distributes fuel to the terminals; (3) hoses carry the fuel from the terminal hookup to individual planes; and (4) refueling trucks carry fuel to remote terminals. These systems work well enough, but newer designs will extract savings by relying less on trucks or by changing an airport’s capacity to fuel more airplanes from a single fuel tank. Airports have
already changed configurations to allow more planes to land and take off without ground delays, which saves fuel on the ground and in the air. The Air Transport Association of America has stated its view on fuel efficiency: “Beyond the numerous, diverse, successful measures that U.S. airlines have taken and continue to explore to conserve fuel, the
single biggest advance in fuel conservation, and emissions reduction, will come from reform of the U.S. air traffic control system, which continues to rely on 1950s technology and procedures.” Clearly, the airline industry has a broad horizon of opportunities for improving society’s use of natural resources.