FAA Aviation Mechanic Airframe (AMA)Airframe StructuresMedium

A technician is recovering a fabric-covered aircraft using a synthetic fabric covering process approved under a supplemental type certificate. Which practice is required to remain in compliance during this process?

  1. AApplying any FAA-approved dope system interchangeably between different STC processes
  2. BFollowing the specific manufacturer's process steps and approved materials exactly as documented
  3. CUsing cellulose nitrate dope regardless of the fabric manufacturer's instructions
  4. DSubstituting materials from a different manufacturer's process as long as strength is similar
Show answer & explanation

Correct answer: B. Following the specific manufacturer's process steps and approved materials exactly as documented

When recovering an aircraft under a fabric STC (such as Ceconite or Poly-Fiber), the technician must follow that specific manufacturer's approved process and materials exactly, since STC approval covers the complete process as a system, not individual components. Mixing materials or steps from different STC processes voids the approval.

Why the other options are wrong

  • A. Dope systems are approved as part of a specific process and are not interchangeable between different STCs.
  • C. Cellulose nitrate dope may not be compatible with all synthetic fabric STC processes.
  • D. Substituting materials from another process voids the STC approval even if strength seems similar.

Fabric Covering STC Process

An FAA-approved fabric covering process (e.g., Ceconite, Poly-Fiber, Stits) that must be followed in its entirety, using only the specified materials and procedures.

  • STC approval covers the entire process, not individual materials
  • Mixing processes/materials voids the approval
  • Common systems include Ceconite, Poly-Fiber, and Stits

Memory trick: 'One STC, one recipe—no substitutions allowed.'

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