Airlines Use Low-Altitude Flights to Ease Delays

D A L L A S, Aug. 23, 2000 -- In a travel season rife with late arrivals and

canceled flights, several airlines have begun flying at lower

altitudes, trading fuel efficiency for on-time arrivals.

The FAA more than a year ago gave airlines approval to operatesome short flights—up to 500 miles—at between 8,000 feet and23,000 feet. But airlines had resisted until recently becauseflying through denser air at lower altitudes burns more fuel.

But with thousands of flight delays drawing the ire of travelersand the eye of federal regulators, more airlines are turning tothis quick fix.

New Task Force

After meeting with airline, union and airport executives Monday,Transportation Secretary Rodney Slater announced the formation of atask force to monitor airline service.

The Federal Aviation Administration reported more than 44,000flight delays in July alone, and that was an improvement from June.Delays have been attributed to increased numbers of peopletraveling, bad weather and—at least for one airline—labordisagreements.

Another contributing factor: some 670 million Americans will flythis year, up 20 million from a year ago and an increase that istaxing the system and could not have been foreseen, Slater said.

Low-altitude routes are not as congested as the high-altitudeones, allowing planes to travel faster. The less-busy flight pathsalso enable planes to get off the ground more quickly instead ofhaving to wait in line to be cleared for takeoff, said FAAspokesman Paul Turk.

In addition, planes flying low-altitude routes spend less timeclimbing to cruising altitude and descending for a landing.

Routes Tested

Standard cruising altitude for jetliners is between 33,000 and39,000 feet.

Northwest Airlines, TWA, Delta, Continental and US Airwaystested the routes in some cities this spring. At Chicago’s busyO’Hare International Airport, United Airlines began rerouting somedeparting planes to underused, lower-altitude flight paths in June.

And Fort Worth-based American Airlines could begin the lowflights this week, pending approval of a memorandum ofunderstanding with the FAA, American Airlines spokesman John Hotardsaid.

At United, between 30 and 40 LAADR flights take off from O’Haredaily, saving an average of two minutes on the ground and about 10in the air, spokesman Joe Hopkins said. And the airline isconsidering adding up to 30 more.

“If you multiply that out over 365 days ... that couldpotentially be a very significant savings,” Hopkins said.

Northwest, which started flying low-altitude flights out ofDetroit and Minneapolis in March, has noticed a big difference intaxi-out times at those airports, said Lorne Cass, director offlight dispatch.

On-time arrivals were up 33 percent in July, compared with June,in part because of the procedure, he said.

Lower-altitude flights do raise some concerns of increasedturbulence because of air currents interacting with the ground,said Michael Barr, director of aviation safety at the University ofSouthern California and a former Air Force fighter pilot.

Dangerous Situations Icing conditions tend to be worse at lower altitudes, and apilot trying to navigate a thunderstorm may be under it instead ofabove it, he said. Some pilots also worry about bringing big jetsdown into skies reserved for general aviation aircraft not equippedwith transponders that relay critical plane-location information.

But low flights are generally kept above 18,000 feet.

“LAADR flights aren’t down in the weeds with the two-seaters,”Turk said.

Furthermore, an onboard computer system known as TCAS, forTraffic Collision Avoidance System, allows commercial planes tomonitor the air space around them and avoid collisions.

Turk and others said adequate separation between planes atcruising altitudes is five nautical miles from nose to tail and1,000 to 2,000 feet vertically, forming a pocket of airspace thatshould be breached only during ascent and descent.

And while low flights may relieve congestion, experts say theonly real long-term solution is to build more airports.

“The flights are a stopgap measure for a system that was neverdesigned to deal with this much traffic,” said Darryl Jenkins,executive director of the Aviation Institute at The GeorgeWashington University.