HAMPTON - Poor planning and power lines caused an experimental helium balloon accident that killed two people in 2007.

The slow-motion crash killed pilot Thomas Boyland, 62, of Fort Collins, Colo., and passenger Bradley Brookhart, 37, of Littleton, Colo., Nov. 16, 2007.

Another passenger, Douglas Champlin, 59, a Clear Lake native who now lives in Albuquerque, N.M., survived the accident.

The National Transportation Safety Board recently released its final report on the crash.

It determined the probable cause was the pilot's inadequate in-flight planning which resulted in the failure to clear electrical lines. The lines were listed as a contributing factor.

Boyland was an experienced balloon pilot with a commercial rating. Both Brookhart and Champlin were certified hot-air balloon pilots.

They took off from Greeley at about 11:30 p.m. Nov. 14 and planned to fly for one or two days depending on how they were feeling and the weather.

On the afternoon of Nov. 15, the trio decided to keep flying for another night, according to the accident report.

At the time of the accident, at about 9 a.m. the following day, the crew was preparing to come down using a "stair-step" approach that would take about three or four miles to complete.

This involved dropping ballast sand and venting gas.

They spotted the power lines, and over the next three or four minutes Boyland directed Champlin to drop sand, apparently in an attempt to gain altitude.

He told Champlin to dump half a scoop, then another half scoop, then half a bag, the report states.

"When it became evident that they were going to contact the lines, the pilot instructed both passengers to get into the bottom of the gondola," the report states.

Champlin told NTSB investigators he remembered the gondola hitting the top power line and hearing an arcing sound. They were tossed around inside the basket, and the balloon became entangled in the lines.

The balloon cables then snapped, and the gondola plummeted about 60 feet to the ground.

Autopsies determined Boyland died of blunt force injuries to the chest, and Brookhart died of positional asphyxia with a neck fracture,

Contact Jeff Reinitz at (319) 291-1578 or jeff.reinitz@wcfcourier.com.