Narrative:

I was flying a J-3 cub which I have approximately 30 hours in. The weather was excellent but winds were forecast to be increasing to 10-15 KTS with gusts to 20 KTS. I departed a grass strip with variable winds I would estimate gusting to 10 KTS. I wanted to practice crosswind landings in a tail wheel plane. I performed 5 crosswind landings at the grass strip with no problems. I then did some sightseeing on my way to ZZZ. Winds at ZZZ were stronger with automated weather (VFR only) reporting winds 280 degrees at 10 KTS gusting to 15 KTS. I landed on runway 23 with no problems but the winds appeared stronger and the windsock was changing directions indicating runway 5 may be the better choice. I departed runway 23; crossed mid field; and entered a downwind for runway 5. I set up for a crosswind landing on runway 5 by crabbing and then while on short final slipping. I touched down on the left main and tail wheel followed by the right main. I was just left of the centerline on touchdown. Everything appeared fine but as the plane slowed; it yawed hard to the left. It occurred so suddenly that it caught me by surprise. I went full right rudder and believe I applied both brakes. I could hear a tire squeal but I exited the left side of the runway onto some grass. This grass section leads down a slight hill and I was convinced that if I went down this the plane would nose over and I would strike the propeller. I then inputted full left rudder to continue the yaw to the left and bring the nose around and avoid going down the hill. This was successful and the nose of the plane was now perpendicular to the runway and I was moving slowly. Not wanting to get stuck in the grass; I advanced the throttle and taxied back onto the runway. After the incident; I taxied to the FBO and the plane handled fine. I stopped the plane and a mechanic came out and both of us checked the plane for damage and found none. I was not injured in this incident. With a crosswind from the left when the plane yawed left; it caught me by surprise. I would have expected the wind to push me off the right side of the runway. Speaking with the owner of the plane later; he advised that in that location there are gusts that come off the adjacent hill. He surmised that a gust struck the rudder while the plane was slowing and weathervaned it to the left. He advised the proper technique would have been to anticipate this and apply right brake as it began to yaw. Lesson learned; and I have a new respect for all the old-time tail wheel pilots.

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Original NASA ASRS Text

Title: Piper J3 Cub pilot practicing crosswind landings has runway excursion during landing roll out. Aircraft is taxied back to the ramp and inspected where no damage is found.

Narrative: I was flying a J-3 Cub which I have approximately 30 hours in. The weather was excellent but winds were forecast to be increasing to 10-15 KTS with gusts to 20 KTS. I departed a grass strip with variable winds I would estimate gusting to 10 KTS. I wanted to practice crosswind landings in a tail wheel plane. I performed 5 crosswind landings at the grass strip with no problems. I then did some sightseeing on my way to ZZZ. Winds at ZZZ were stronger with automated weather (VFR only) reporting winds 280 degrees at 10 KTS gusting to 15 KTS. I landed on Runway 23 with no problems but the winds appeared stronger and the windsock was changing directions indicating Runway 5 may be the better choice. I departed Runway 23; crossed mid field; and entered a downwind for Runway 5. I set up for a crosswind landing on Runway 5 by crabbing and then while on short final slipping. I touched down on the left main and tail wheel followed by the right main. I was just left of the centerline on touchdown. Everything appeared fine but as the plane slowed; it yawed hard to the left. It occurred so suddenly that it caught me by surprise. I went full right rudder and believe I applied both brakes. I could hear a tire squeal but I exited the left side of the runway onto some grass. This grass section leads down a slight hill and I was convinced that if I went down this the plane would nose over and I would strike the propeller. I then inputted full left rudder to continue the yaw to the left and bring the nose around and avoid going down the hill. This was successful and the nose of the plane was now perpendicular to the runway and I was moving slowly. Not wanting to get stuck in the grass; I advanced the throttle and taxied back onto the runway. After the incident; I taxied to the FBO and the plane handled fine. I stopped the plane and a Mechanic came out and both of us checked the plane for damage and found none. I was not injured in this incident. With a crosswind from the left when the plane yawed left; it caught me by surprise. I would have expected the wind to push me off the right side of the runway. Speaking with the owner of the plane later; he advised that in that location there are gusts that come off the adjacent hill. He surmised that a gust struck the rudder while the plane was slowing and weathervaned it to the left. He advised the proper technique would have been to anticipate this and apply right brake as it began to yaw. Lesson learned; and I have a new respect for all the old-time tail wheel pilots.

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.