Hot air balloon pilot reports encountering fog approaching from the east and quickly descends to min...

Narrative:

While at a balloon event we were to do a fly-in task towards the balloon field. The event went on a weather hold for a while and it was later decided that the weather had cleared enough for us to go out and find a site to fly from that would put us over the target on the launch field. I went south of the field a few miles and found a home where I could fly out of their front yard. The weather was quite clear with at least 3 miles visibility on my take-off and no clouds overhead. I headed west for the first 500 ft of altitude and then turned towards the north above that height. As I was heading to the north; I noticed some low level fog moving in from the east/northeast and I immediately went down to a lower altitude to hug the treetops until I found a clear field to land in. My visibility had dropped to about a mile or a little better upon my landing. After I landed; I received a call from a fellow pilot on the launch field asking me if I had flown; and if so; was I on the ground. I informed him that I was flying until I saw the fog moving in. I landed at the first opportunity I had. I was just south of the heavier fog and never felt I was in any personal danger. I had no intention of flying in or near fog that morning; it just moved in unexpectedly from a distant storm area.

Original NASA ASRS Text

Title: Hot Air Balloon pilot reports encountering fog approaching from the east and quickly descends to minimum altitude and lands in the first available landing space. Visibility had dropped to about a mile at the time of landing.

Narrative: While at a balloon event we were to do a fly-in task towards the balloon field. The event went on a weather hold for a while and it was later decided that the weather had cleared enough for us to go out and find a site to fly from that would put us over the target on the launch field. I went south of the field a few miles and found a home where I could fly out of their front yard. The weather was quite clear with at least 3 miles visibility on my take-off and no clouds overhead. I headed west for the first 500 FT of altitude and then turned towards the north above that height. As I was heading to the north; I noticed some low level fog moving in from the east/northeast and I immediately went down to a lower altitude to hug the treetops until I found a clear field to land in. My visibility had dropped to about a mile or a little better upon my landing. After I landed; I received a call from a fellow pilot on the launch field asking me if I had flown; and if so; was I on the ground. I informed him that I was flying until I saw the fog moving in. I landed at the first opportunity I had. I was just south of the heavier fog and never felt I was in any personal danger. I had no intention of flying in or near fog that morning; it just moved in unexpectedly from a distant storm area.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	910317
Time
Date	201009
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Aircraft 1
Make Model Name	Balloon
Operating Under FAR Part	Part 91
Flight Phase	Landing
Route In Use	Visual Approach
Flight Plan	VFR
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial Flight Crew Lighter-Than-Air
Experience	Flight Crew Last 90 Days 5 Flight Crew Total 534.2 Flight Crew Type 534.2
Events
Anomaly	Deviation - Procedural FAR Inflight Event / Encounter VFR In IMC Inflight Event / Encounter Weather / Turbulence

Hot air balloon pilot reports encountering fog approaching from the east and quickly descends to minimum altitude and lands in the first available landing space. Visibility had dropped to about a mile at the time of landing.