AMS-S-8802E is a fuel-resistant sealing compound for integrated fuel tanks and fuel cell cavities.

AMS-S-8802E is a fuel-resistant sealing compound for integrated fuel tanks and fuel cell cavities.

The “AMS-S-8802E Fuel-resistant sealing compound for integrated fuel tanks and fuel cell cavities” standard, developed by the Society of Automotive Engineers (SAE), describes two-component, fuel-resistant polysulfide synthetic rubber compounds that cure at room temperature.

AMS-S-8802E is a fuel-resistant sealing compound for integrated fuel tanks and fuel cell cavities.

These sealing materials are primarily used for sealing and repairing integrated fuel tanks and fuel cell cavities in aircraft, as well as other areas exposed to aviation fuels, oils, lubricants, water, and weather conditions. They provide high adhesion, flexibility, and long-term durability in harsh aviation environments.

The SAE AMS-S-8802E standard, focusing on sealing compounds for aviation fuel tanks and critical applications, replaces the earlier MIL-S-8802 standard while maintaining technical continuity.

The basic characteristics of this standard are as follows:

  • Basic chemistry: Polysulfide synthetic rubber (two-component system: base and curing agent).
  • Curing: Curing at room temperature creates a flexible, durable rubber with excellent elastomeric properties.
  • Temperature range: Continuous use between -54 degrees and +121 degrees; some formulations allow for shorter periods at higher temperatures.
  • Fuel and chemical resistance: Exceptional resistance to aviation fuels (including jet fuel), hydraulic fluids, and other chemicals.
  • Applications: Corner sealing, joint sealing, fastener sealing, aerodynamic smoothing, and cabin pressure sealing.

The AMS-S-8802E standard classifies materials by Type (curing agent) and Class (application method and viscosity/service life).

  • Types:
    • Type 1: Dichromate cured (generally preferred in dry climates as it cures independently of humidity).
    • Type 2: Manganese dioxide cured (most common in modern aviation due to performance and environmental considerations).
  • Classes:
    • Class A: For brush or spray application (low viscosity).
    • Class B: For extrusion gun or spatula application (thixotropic, non-sagging).
    • Class C: For sealing joint surfaces (thin film applications).

Dashed numbers (e.g., B-2, B-1/2) indicate the working/application life in hours (e.g., -2 means approximately 2 hours of working time before it becomes too viscous to be effectively applied).

Integrated fuel tanks in modern aircraft (e.g., wings and fuselage sections) are structural and must remain leak-proof under extreme conditions: vibration, thermal cycling, pressure changes, and continuous fuel exposure. The AMS-S-8802E standard specifies that sealing materials ensure structural integrity, prevent fuel leaks (creating fire and safety risks), and reduce maintenance costs. They are widely specified in commercial, military, and general aviation programs.

The latest revision (E) of this standard includes updated test methods, quality requirements, and technical descriptions. Previous revisions were based on the MIL-S-8802F standard. Manufacturers should always verify the latest revision and the list of qualified products for specific applications.

Sealants conforming to the AMS-S-8802E standard are two-component compounds requiring appropriate mixing ratios. Shelf life is generally limited (typically 6-9 months for unopened kits), and while cured material is durable, uncured components should be used according to the manufacturer's safety data sheet.

This standard remains a cornerstone of aerospace sealing technology, balancing performance, reliability, and manufacturability in one of the industry's most critical applications.

In short, the SAE AMS-S-8802E standard defines performance requirements for sealants that must withstand aviation fuels, lubricants, weather conditions, and extreme operating temperatures while maintaining adhesion and flexibility. Primarily derived from military sealant requirements, this standard is widely used in both military and commercial aviation manufacturing and maintenance programs.

This standard covers temperature-resistant sealing compounds designed for:

  • Integrated fuel tanks located in aircraft wings and fuselage structures.
  • Fuel cell cavities
  • Sealing joints exposed to the following:
    • Aviation fuel
    • Hydraulic fluids
    • lubricating oils
    • Humidity and exposure to weather conditions
    • Pressure differences
    • Thermal cycle

These sealants are typically supplied as two-component compounds that chemically harden after mixing. The primary aim is for a sealant to be able to provide the following:

  • Prevent fuel leakage
  • To maintain structural seal integrity.
  • To resist deterioration over long service periods.
  • Strong adhesion to aerospace metals and coatings.

The basic material and performance criteria of the AMS-S-8802E standard are as follows:

  • Adhesion: Sealants must adhere strongly to common aviation substrates such as:
    • Aluminum alloys
    • Stainless steel
    • Titanium
    • Primed or coated aircraft surfaces

High adhesion is critical because vibration, thermal expansion, and pressure changes can continuously stress the sealed joints.

  • Fuel resistance: The material must withstand prolonged exposure to the following:
    • Jet fuels
    • Aviation fuel
    • Synthetic lubricants

The tests assess the following:

    • Swelling resistance
    • Softening resistance
    • Weight change after immersion

This prevents seal failure after continuous fuel contact.

  • Temperature resistance: Sealants conforming to this standard should perform over a wide range of temperatures, typically including:
    • Low temperature flexibility for high altitude conditions.
    • High temperature resistance near engines or heated structures.

Typical aviation environments involve rapid thermal cycling, so cracking or brittleness is unacceptable.

  • Flexibility and elastic recovery: The cured compound must remain flexible to accommodate:
    • Structural movement
    • Vibration loads
    • Expansion/contraction cycles

Rigid materials will not crack under aircraft operating loads.

  • Curing characteristics: Standard controls include:
    • Mixing ratio
    • Application consistency
    • Service life (application period)
    • Curing time

This facilitates maintenance in both production and field repair environments.

The AMS-S-8802E standard includes the following tests:

  • Adhesion strength
  • Peel resistance
  • Hardness
  • Low temperature flexibility
  • Liquid immersion resistance
  • Application features
  • Curing verification

These tests simulate realistic aviation service conditions.

In conclusion, the SAE AMS-S-8802E standard is a fundamental aerospace sealing standard that regulates high-performance polysulfide sealants for fuel containment and structural sealing. By standardizing adhesion, chemical resistance, temperature stability, and durability, it helps aircraft manufacturers and maintenance organizations ensure the safe and leak-free operation of fuel systems under demanding aviation conditions.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services compliant with the AMS-S-8802E standard.

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