Airframe Systems & Structural Maintenance Flashcards

An aircraft uses a power-boost hydraulic flight control system. How does it differ from a full-power hydraulic system?

Answer: Power-boost allows the pilot to feel aerodynamic loads through the control surface; full-power does not

In a power-boost system, hydraulic pressure assists but does not completely replace pilot effort, allowing aerodynamic feedback; in a full-power system, the pilot has no direct aerodynamic feel.

When a sheet metal repair uses a splice plate to restore strength to a cut or damaged stringer, the splice plate must:

Answer: Have a cross-sectional area equal to or greater than the original stringer and extend past the damage by the required edge distance

A splice plate must restore the original cross-sectional area and be long enough to develop full load through the required number of fasteners past the damaged area.

The purpose of a 'joggle' in a sheet metal part is to:

Answer: Allow two overlapping sheets to lie in the same plane where they join a common surface

A joggle is an offset bend in a structural member that allows two parts to overlap while keeping their outer surfaces flush and in the same plane.

Which rivet is used when access is available to only one side of the structure?

Answer: Blind rivet (such as a Cherry or Bulb-Tite)

Blind rivets are specifically designed to be installed from one side only, making them necessary when the back side of the structure is inaccessible.

During a weight and balance check after a major structural repair, you find the CG is at the forward limit. What does this indicate?

Answer: The repair added weight forward of the CG datum or removed aft weight

A CG at the forward limit after a repair means net weight was added forward of the datum or removed from aft stations, shifting the balance point forward.

When inspecting a pressurized fuselage, fatigue cracks most commonly originate at:

Answer: Window and door cutouts, fastener holes, and areas of stress concentration

Stress concentrations at fastener holes, window frames, and door cutouts create the highest cyclic stress levels during pressurization cycles, making them the most common fatigue crack initiation sites.

What is the purpose of the 'cleco' fastener used during sheet metal assembly?

Answer: A temporary clamp that holds parts in alignment while rivets are installed

Clecos are spring-loaded temporary fasteners that hold sheet metal parts in precise alignment during assembly until permanent rivets are installed.