Aircraft Interior Sandwich Panels – 101

What Are Aircraft Interior Sandwich Panels?

Aircraft interior sandwich panels are advanced composite structural panels composed of two thin, high-strength outer face sheets bonded to a lightweight core. This multi-layer construction delivers exceptional stiffness and strength-to-weight performance, making these panels indispensable for modern aircraft interiors where weight reduction, safety, and durability are critical design priorities.
 

Why the “Sandwich” Name?

The name comes from how the panel is built, much like a sandwich, the structure consists of-

• Enclosing a lightweight core (like a filling)

• Two strong outer face sheets (like bread)

This structure dramatically increases panel stiffness without adding weight. In conventional solid materials, improving stiffness typically requires adding mass. In a sandwich panel, however, stiffness can be increased simply by adjusting core thickness, achieving superior structural efficiency with minimal weight penalty.
 

Technical Anatomy of Aircraft Interior Sandwich Panels

Aircraft interior sandwich panels are engineered using materials selected to meet strict requirements for weight reduction, structural integrity, fire safety, and passenger comfort.

Core Materials

• Nomex® (aramid paper) honeycomb – extremely lightweight, excellent fire resistance and thermal insulation, widely used in cabin ceilings, sidewalls, floor panels, and partitions.

• Alluminum honeycomb – provides higher stiffness and load-bearing capability, typically used where greater structural performance is required.

• Polymer foam cores (such as PMI and PVC) – applied in selected interior applications for insulation, vibration damping, or localized performance needs.

Face Sheets

• Glass fiber reinforced composites, typically combined with phenolic resin systems for fire, smoke, and toxicity compliance.

• Carbon fiber reinforced composites, used selectively where higher stiffness is required, while still meeting interior fire safety regulations.

• Thermoplastic composite laminates (such as glass-fiber reinforced PEI, PPS, or PEEK), increasingly adopted for improved impact resistance, manufacturability, and recyclability.

The face sheets are bonded to the core using qualified aerospace adhesives or prepreg laminate systems, forming a lightweight yet structurally efficient sandwich construction.
 

Where Are These Panels Used Inside an Aircraft?

Sandwich panels appear throughout the aircraft cabin and interior structural systems:

• Floor panels – main cabin floors and cargo deck liner panels

• Sidewalls, partitions, and bulkheads – cabin linings and structural dividers

• Ceiling and overhead panels – occupant overhead liners and service panels

• Stowage bins and galley panels – overhead storage units and galley structures

• Lavatory modules – walls, doors, and internal partitions

• Cabin monuments and class dividers – closets, separators, and privacy panels

Beyond weight savings, these panels must comply with stringent aviation safety standards. Aircraft interior sandwich panels are certified under Federal Aviation Regulation (FAR) 25.853, which governs flammability, heat release, smoke density, and, where applicable, toxicity performance for materials used inside transport-category aircraft.
 

What Makes Sandwich Panels the Preferred Choice?

Aircraft interior sandwich panels are chosen because of their quantifiable performance advantages, including:

• Exceptional strength-to-weight ratio

• High bending stiffness with minimal added mass

• Vibration damping and noise reduction

• Integrated thermal and acoustic insulation

• Long service life with low maintenance requirements

These characteristics make sandwich panels uniquely suited for the demanding operational and regulatory environment of aircraft interiors.

As aircraft programs increasingly prioritize weight efficiency, safety compliance, and lifecycle performance, aircraft interior sandwich panels continue to set the benchmark for modern cabin structures. With applications spanning floors, sidewalls, ceilings, monuments, galleys, and lavatories, these panels have become indispensable to contemporary aircraft interior design. Valued at USD 2.0 billion in 2024, the global aircraft interior sandwich panel market is projected to reach USD 2.8 billion by 2034, growing at a CAGR exceeding 2.5%, reinforcing their position as one of the most critical material systems shaping the future of aircraft interiors.