Narrative:

Morning flight in a hot air balloon. Arrived at launch field after sunrise. The launch field is an empty field approximately 1 mi south of hillsborough, nc. Hillsborough is almost 1/2 way between raleigh and greensboro on I-40. I had a duats WX briefing showing 700 ft measured ceiling, 5 mi visibility and fog at rdu. Gso was reporting clear below 12000 ft and 7 mi visibility. Both airports had less than 2 degree spread in temperature/dewpoint. When we arrived at the launch field, the sky was clear, no fog or clouds. We set up and prepped the balloon. The launch procedure took approximately 15 mins. Upon launch, I realized that the area had fogged in. AGL height was only 20 or 30 ft, I was climbing at 200 FPM. I tried to abort takeoff and land, but was approaching trees and power lines. I climbed above the fog layer, which was approximately 100-200 ft thick, to an altitude of 1000 ft AGL. After 30 mins the fog had dissipated and I landed safely. No damage to the aircraft or property on the ground and nobody was hurt. In retrospect, I should have paid closer attention to the temperature/dewpoint spread. Also, I should have been more aware of the changing conditions as I prepared for launch.

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Original NASA ASRS Text

Title: A HOT AIR BALLOON PLT TOOK OFF IN IMC CONDITIONS, THEN CLBED TO ON TOP.

Narrative: MORNING FLT IN A HOT AIR BALLOON. ARRIVED AT LAUNCH FIELD AFTER SUNRISE. THE LAUNCH FIELD IS AN EMPTY FIELD APPROX 1 MI S OF HILLSBOROUGH, NC. HILLSBOROUGH IS ALMOST 1/2 WAY BTWN RALEIGH AND GREENSBORO ON I-40. I HAD A DUATS WX BRIEFING SHOWING 700 FT MEASURED CEILING, 5 MI VISIBILITY AND FOG AT RDU. GSO WAS RPTING CLR BELOW 12000 FT AND 7 MI VISIBILITY. BOTH ARPTS HAD LESS THAN 2 DEG SPREAD IN TEMP/DEWPOINT. WHEN WE ARRIVED AT THE LAUNCH FIELD, THE SKY WAS CLR, NO FOG OR CLOUDS. WE SET UP AND PREPPED THE BALLOON. THE LAUNCH PROC TOOK APPROX 15 MINS. UPON LAUNCH, I REALIZED THAT THE AREA HAD FOGGED IN. AGL HEIGHT WAS ONLY 20 OR 30 FT, I WAS CLBING AT 200 FPM. I TRIED TO ABORT TKOF AND LAND, BUT WAS APCHING TREES AND PWR LINES. I CLBED ABOVE THE FOG LAYER, WHICH WAS APPROX 100-200 FT THICK, TO AN ALT OF 1000 FT AGL. AFTER 30 MINS THE FOG HAD DISSIPATED AND I LANDED SAFELY. NO DAMAGE TO THE ACFT OR PROPERTY ON THE GND AND NOBODY WAS HURT. IN RETROSPECT, I SHOULD HAVE PAID CLOSER ATTN TO THE TEMP/DEWPOINT SPREAD. ALSO, I SHOULD HAVE BEEN MORE AWARE OF THE CHANGING CONDITIONS AS I PREPARED FOR LAUNCH.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.