Plane passengers bumped to lighten load

Heat lessens planes’ capacity to climb

Persistent hot weather in Southwest Colorado has forced American Eagle, US Airways and United Airlines to decrease passenger loads on certain flights leaving the Durango-La Plata County Airport recently.

Ten people on Sunday night and six Monday night were bumped from their seats and shuttled to Albuquerque to be booked on larger aircraft, said David Galus, owner of Buck Horn Limousine Service. Several other passengers returned to Durango until a later flight could be found.

All diverted passengers were volunteers and received ticket or cash vouchers from their respective airlines.

“If you aren’t in a hurry to get somewhere, these can be a good deal,” said Ron Dent, director of aviation at the airport.

Low air density is to blame for the complications.

Hot temperatures, among other atmospheric conditions, make the air thinner, raising what is called “density altitude.”

Durango-La Plata County Airport sits at 6,685 feet above sea level, but with temperatures exceeding 90 degrees, conditions are mimicking those in Leadville, about 3,250 feet higher in elevation.

“The plane thinks it’s taking off at 10,000 feet,” Dent said.

When density altitude is higher than physical altitude, it becomes more arduous for a plane to take off. Diminished power production in the engine slows runway acceleration, the wings don’t give as much lift, and the plane climbs at a slower pace.

As a result, some aircraft require a lighter weight load – fewer passengers – to operate safely. Alternatively, airlines can reconfigure their schedules so planes depart during cooler hours of the day.

Upcoming fleet changes could limit the need for diverted passengers.

Dent said the airport is expecting a new assortment of planes for its United flights in late August: 700-series regional jets built by Canadair and a Bombardier Q-400 turboprop. They carry 25 more passengers than existing jets and are not as weight-restrictive when it comes to heat.

Dent said the airlines are taking “every measure” to prevent diversions, but are left with few options given the scorching weather and full flights during tourist season.

Integrating the revamped fleet should help.

“They are more efficient, have more seats and are better performers under hot and high conditions. With the new mix of aircraft, I think we’ll be all right,” he said.

Until then, passenger diversions remain a possibility as long as the heat lingers.

Following in the footsteps of a warm winter and spring, June temperatures in the county have consistently stayed 5 to 10 degrees above average.

lgroskopf@durangoherald.com

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