How should wire bundles be routed relative to the aircraft rib structure?

How should wire bundles be routed relative to the aircraft rib structure?

• A. Wrap bundles around components tightly
• B. Route bundles along the fuselage exterior
• C. Keep bundles circular around fittings
• D. Bundle angles at parallel or right angles to the aircraft rib structure

Answer: (D)

Routing wire bundles with bends that are parallel to or at right angles to the aircraft rib structure keeps the wiring aligned with the airframe's flex and spacing. When you bend and route in these orientations, the bundle moves with the ribs rather than fighting against their motion, which minimizes bending stress on the insulation, reduces the risk of abrasion at rib edges, and helps maintain consistent clearance from fittings and hardware. This approach also makes inspection and maintenance easier because the harness follows predictable lines along the rib grid and doesn’t create sharp pinch points or snag hazards. Avoid tight wraps around components, routing along the exterior, or circling fittings, as those practices increase wear, exposure to damage, and interference with other systems. Always ensure bend radii are appropriate for the conductor size and insulation to further protect against fatigue.

Routing wire bundles with bends that are parallel to or at right angles to the aircraft rib structure keeps the wiring aligned with the airframe's flex and spacing. When you bend and route in these orientations, the bundle moves with the ribs rather than fighting against their motion, which minimizes bending stress on the insulation, reduces the risk of abrasion at rib edges, and helps maintain consistent clearance from fittings and hardware. This approach also makes inspection and maintenance easier because the harness follows predictable lines along the rib grid and doesn’t create sharp pinch points or snag hazards. Avoid tight wraps around components, routing along the exterior, or circling fittings, as those practices increase wear, exposure to damage, and interference with other systems. Always ensure bend radii are appropriate for the conductor size and insulation to further protect against fatigue.