Airlines' efficiency set to soar

HONOLULU— Airlines next month will be able to reduce flight time and save fuel on flights across the Pacific Ocean by using satellite-based data communications to file new flight plans electronically while en route.

The Federal Aviation Administration has tested the procedure, known as Dynamic Aircraft Route Planning (DARP), on the Sydney-to-Los Angeles route, which is flown mostly by Qantas of Australia and United Airlines. Next month the FAA will roll out DARP to multiple sectors of airspace that the FAA controls over the Pacific, said Ron Morgan, the FAA's director of air traffic.

Morgan, speaking at the Armed Forces Communications and Electronics Association's annual TechNet Asia-Pacific '98 Conference and Exposition this month, said the FAA will use DARP to give pilots updated route information based on new weather forecasts about three hours after takeoff.

Weather is a key factor in planning flights over the Pacific, where wind can affect a plane's speed by 23 mph. DARP will enable pilots to change course quickly so they can fly the most fuel- and time-efficient route.

R. Randall Park, assistant air traffic manager at the FAA's Oakland Center in California, said the satellite data link that the FAA uses for DARP offers greater reliability and speed of delivery than the high-frequency (HF) voice communications used to control most of the world's trans-oceanic flights. The data link is provided by ARINC Inc., a communications provider owned by a consortium of major airlines.

Technical problems with HF often limit communications with aircraft operating south of the equator to once every 45 minutes, Park said. Aircraft equipped with satellite receivers do not suffer from the same problem. Furthermore, Park said, it takes seven minutes to deliver a message to or from an aircraft via HF, while it only takes one minute for that same message to travel over the satellite data link.

"Even if you save a few minutes [of flight time], that is not trivial," said Mohammad Wasique, program manger for value-added services at ARINC. "In the pre-DARP age, once a flight plan is filed, [pilots] fly that flight plan."

DARP is an important step toward free flight, which will let pilots choose the best route, speed and altitude for a particular flight, Wasique said. "This is a step in the right direction," he said. "For free flight to be a reality, these concepts have to be proven and implemented beyond any doubt."

Morgan added that the satellite-based data communications ensure greater accuracy than voice communications for transmitting route changes because the data link feeds new latitude and longitude headings directly into the aircraft computer, avoiding the possibility of the pilot writing down a wrong number.