EASA AD US-2021-02-14
Fuel - Side of Body Slot - Inspection
Summary
Federal Register Volume 86, Number 34 (February 23, 2021) is a final rule airworthiness directive issued by the FAA addressing certain Boeing 737-600, -700, -700C, -800, -900, and -900ER series airplanes. The directive mandates inspection of the side of body (SOB) slot for insufficient sealant due to unclear production drawing instructions, which could lead to fuel leaks and potential fire hazards. It requires a general visual inspection and corrective actions to ensure safety.
What Changed
This new airworthiness directive introduces a requirement for a general visual inspection of the SOB slot sealant on specified Boeing 737 models. It references the latest Boeing Multi Operator Message MOM-MOM-20-0049-01B(R4) for inspection procedures and clarifies acceptance criteria, inspection areas, and corrective actions. The directive also addresses comments from industry stakeholders and confirms that installation of certain winglets does not affect compliance.
Why It Matters
This directive is critical for aviation professionals to prevent fuel leaks into the air distribution mix bay, which could cause fire, explosion, or fuel vapor inhalation risks. Operators and maintenance organizations must ensure compliance to maintain aircraft airworthiness and passenger safety. Clear inspection criteria and updated service information help reduce the risk of incorrect inspections and repairs.
What To Do
Operators of affected Boeing 737-600, -700, -700C, -800, -900, and -900ER airplanes must perform a general visual inspection of the SOB slot sealant by March 30, 2021, following Boeing Multi Operator Message MOM-MOM-20-0049-01B(R4). Any insufficient sealant found must be corrected according to the service instructions. Stakeholders should obtain the referenced service information and coordinate with the FAA for any compliance time extension requests.
Your fleet's weekly compliance brief
AI-summarized regulatory changes, compliance deadlines, and action items — filtered to your aircraft, every Monday.
AI-generated summary from official EASA source document. Always verify against the original.