The airplane was climbing in the direction of thunderstorms vaulting across northeast Indiana when an air traffic controller radioed the pilots to recommend a course change toward smoother air.

Normally such advice would be heeded, but the purpose of the storm-chasing flight was to test a new type of onboard radar that major airlines will purchase for thousands of new aircraft to comfortably maneuver around storms while saving fuel, improving on-time arrivals and substantially reducing encounters with ­turbulence.

So the Honeywell Aerospace flight crew kept flying toward the storms, explaining to the controller that the mission was to take the ­Convair 580 to the edges of the worst weather, vividly displayed in yellow and red on the cockpit screen, and skirt it for a while until weaving a path through pockets of calm air. It was all outlined by a new 3-D weather radar system made by Honeywell called IntuVue.

Airlines are eager to expand technology to combat weather-related delays. Federal officials say delays have totaled the equivalent of more than 106 days at Chicago's two airports through the first half of this year and cost the industry billions annually nationwide.

The new generation of weather radar, manufactured in separate versions by Honeywell and its competitor Rockwell Collins Inc., is designed to reduce those delays with their ability to scan for trouble across the sky hundreds of miles ahead of the plane.

Choppy air sometimes sneaks up on crews because weather detectors in the nose of planes miss volatile air on the flight path. That's often because older weather ­systems scan only a narrow radar beam.

"One of the things this new radar does a better job of is helping pilots interpret distant weather possibly sooner, which definitely could save you some time and fuel and potentially increase safety by making a decision sooner on circumnavigating a nasty thunderstorm," said Southwest Airlines Capt. Bill Lusk.

About 2,000 planes at more than 70 different airlines worldwide are outfitted with IntuVue, with about 2,500 more on order. □