Fuselage - Boeing Material Specification (BMS) 8-39 Flexible Urethane Foam - Inspection / Modification / Replacement
- Published
- Effective
- Deadline
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Affected operators must complete all required inspections, modifications, and replacements within 72 months of the AD's effective date, September 12, 2018. They should follow the Boeing Special Attention Service Bulletins specified in the AD for detailed procedures. Operators should also prepare for potential on-condition actions if BMS 8-39 foam is found during inspections.
Summary
The Federal Aviation Administration's Airworthiness Directive 2018-16-06 addresses certain Boeing Model 747 series airplanes, including the 747-100, -200, -300, -400, 747SP, 747SR, and 747-8 series. This directive focuses on inspecting, modifying, and replacing Boeing Material Specification (BMS) 8-39 flexible urethane foam used in fuselage floor panel assemblies and power drive unit cover assemblies. The AD aims to mitigate fire risks associated with the degradation of this foam material.
What changed
This new Airworthiness Directive requires operators to inspect for BMS 8-39 flexible urethane foam insulation in specified airplane areas, perform on-condition corrective actions, modify certain dripshields, and replace BMS 8-39 foam strips with BMS 8-371 foam strips on certain dripshields. It introduces these requirements to address additional areas where the foam was found during prior inspections and to reduce the risk of uncontrolled fire.
Why it matters
This AD is critical for aviation professionals because degraded BMS 8-39 foam poses a fire hazard that could lead to loss of airplane control. Operators, maintenance, and compliance teams must ensure inspections and modifications are completed to maintain aircraft safety and regulatory compliance. Failure to comply could result in increased fire risk in areas not covered by existing fire detection or protection systems.
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