Narrative:

I departed the airport for a pleasure flight. The flight was estimated to be 2 hours and I topped off with fuel for a 4 hour endurance. No flight plan was filed. I fly over this area frequently and navigated by ground reference. I first flew northwest to the western edge of a mountain range; then traveled east along the southern face of these mountains. My plan was to continue to fly along the mountain range to the east; and then south to land. While transitioning between the two ranges; I switched fuel tanks; and the engine immediately quit running. I switched back to the previous tank; turned on the boost pump and increased the mixture. The prop was wind milling. I waited for a few seconds for the engine to restart. When it did not restart; I pumped the throttle a few times. This was not successful and the prop stopped. I initiated my forced landing procedure at this point while turning over the engine with the key for another 20 seconds or so. I decided on the freeway. The landing was uneventful. The plane was removed from the freeway by a flatbed truck. The engine was restarted and a number of tests were done to isolate the cause of failure; but none could be found. I used a stretch of open road to take off and return. My mechanic told me that I should always turn on the boost pump when switching tanks in a low wing. I am making this part of my normal procedure; as well as only switching tanks when within glide of an airport; whenever possible.

Related reports:

Google
 

Original NASA ASRS Text

Title: An experimental aircraft pilot reported switching fuel tanks which caused the engine to quit and made a forced landing.

Narrative: I departed the airport for a pleasure flight. The flight was estimated to be 2 hours and I topped off with fuel for a 4 hour endurance. No flight plan was filed. I fly over this area frequently and navigated by ground reference. I first flew northwest to the western edge of a mountain range; then traveled east along the southern face of these mountains. My plan was to continue to fly along the mountain range to the east; and then south to land. While transitioning between the two ranges; I switched fuel tanks; and the engine immediately quit running. I switched back to the previous tank; turned on the boost pump and increased the mixture. The prop was wind milling. I waited for a few seconds for the engine to restart. When it did not restart; I pumped the throttle a few times. This was not successful and the prop stopped. I initiated my forced landing procedure at this point while turning over the engine with the key for another 20 seconds or so. I decided on the freeway. The landing was uneventful. The plane was removed from the freeway by a flatbed truck. The engine was restarted and a number of tests were done to isolate the cause of failure; but none could be found. I used a stretch of open road to take off and return. My mechanic told me that I should always turn on the boost pump when switching tanks in a low wing. I am making this part of my normal procedure; as well as only switching tanks when within glide of an airport; whenever possible.

Data retrieved from NASA's ASRS site 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.