The vocabulary of
aerospace wire safety.
Every term Lectromec uses in EWIS testing, certification, and continued-airworthiness work, defined by engineers who have spent their careers in this field. Each entry includes the technical detail, the applicable standards, and when it matters in practice.
Electrical Wiring Interconnection System
Every wire, wiring device, and combination thereof installed in any area of an aircraft for transmission of electrical energy between two or more termination points, including supporting components such as clamps, connectors, and bundle hardware.
FAA 25.1707 — System Separation Requirements
The Federal Aviation Regulation that requires EWIS to be physically separated and electrically isolated from other EWIS, aircraft systems, fluid lines, control cables, and heated equipment such that no credible failure can produce a hazardous condition.
FAA 25.1701 — EWIS Definition and Scope
The Federal Aviation Regulation that defines what an Electrical Wiring Interconnection System is and identifies the components in scope of the §25.1700 series.
SAE AS50881 — Wiring Aerospace Vehicle
The SAE aerospace standard that establishes recommended practice for the design, installation, and verification of aerospace wiring systems. Widely referenced as supporting guidance for FAA §25.1707 compliance.
SAE ARP1870A — Aerospace Electrical Bonding and Grounding
The SAE aerospace recommended practice covering electrical bonding and grounding of aerospace systems for electromagnetic compatibility and safety. Latest revision 2012.
FAA Advisory Circular 25.1701-1
The FAA Advisory Circular that provides guidance on compliance with the §25.1700 EWIS regulations, including the scope of EWIS, the EMI sources to assess, and the definition of 'independent airplane power source'.
Heavy Current Cable
Per FAA 25.1707(c), a wire or cable of 16 AWG or larger, or any conductor whose arcing failure could cause significant damage to nearby systems. Heavy current cables and their associated EWIS components must be physically separated and electrically isolated under fault conditions.
Arc Damage Modeling Tool
Lectromec's arc damage simulation tool. Simulates wire failures that produce arcing events and the subsequent damage to nearby harnesses, structure, and fuel or hydraulic lines. Used in certification packages for aerospace organizations.
Wet Arc Track Propagation
A failure mode in which a contaminating fluid lowers the surface dielectric strength of wire insulation, allowing an arc to track along the insulation and propagate from a single initial breach to multiple adjacent conductors.
Wire Bundle Derating
The reduction in allowable per-conductor current when conductors are grouped into a bundle, because heat from each conductor reduces the bundle's ability to dissipate heat from any single one. AS50881 charts 1–5 provide the standard derating curves.
Critical Clamp Marker
A visual indicator applied to an EWIS harness — typically a 50/50 marker split on each side of a clamp — that tells maintenance technicians where a clamp belongs, so a harness that shifts during access work can be returned to its designed location.
Common Cause Analysis
A systematic analysis that identifies whether a single fault, event, or environmental condition can cause the simultaneous failure of multiple components that are otherwise nominally independent. Required, in effect, by FAA 25.1707(d) and (i).
Instructions for Continued Airworthiness
The set of documents an aircraft manufacturer or STC holder provides to the operator that defines the inspections, maintenance actions, and intervals needed to keep the aircraft airworthy through its service life. EWIS items belong in the ICA.
Enhanced Zonal Analysis Program
A maintenance-program structure that drives zone-by-zone inspection of EWIS, used to ensure that age-related EWIS issues are surfaced before they create hazardous conditions.
14 terms · seed list reviewed 2026-05-14 · expanding to 60+ entries per the Lectromec GEO content roadmap.