Narrative:

1L door failed to seal; causing air return due to failed pressurization. Leveled 10;000 feet and seal did not seat. Returned to departure airport uneventfully. Found door closed; but seal not seated.

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Original NASA ASRS Text

Title: A B737 1L door seal did not seat properly and therefore the aircraft could not pressurize. The flight returned to the departure airport.

Narrative: 1L door failed to seal; causing air return due to failed pressurization. Leveled 10;000 feet and seal did not seat. Returned to departure airport uneventfully. Found door closed; but seal not seated.

Data retrieved from NASA's ASRS site as of July 2013 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.