Meaning
Controlled fluid pressure applied through multi-point lifting cylinders restores structural alignment in heavy airframe assemblies that have experienced positional sag. Tooling crews perform hydraulic jacking realignment to correct spatial distortion before installing critical internal wing frames and floor structures. This operation governs elevation datums and structural contour symmetry across large metallic and composite airframe sections.
The process stops applying once temporary support loads transfer completely onto permanent structural frames and floor ties.
Pressure Synchronization
Proportional control valves regulate hydraulic fluid delivery across independent jack locations to maintain uniform lift rates. Load cell sensors feed force measurements back to a central controller, preventing localized stress concentration in airframe skins. Synchronized movement prevents structural twisting during heavy assembly elevation adjustments.
Deflection Correction
Structural deformation measurements dictate localized hydraulic pressure values across active lifting points. Metrology targets monitored by laser trackers provide closed-loop positional feedback during elevation operations. Operators increase cylinder stroke lengths in discrete increments until internal reference frames return to engineering drawing coordinates.
Precision shims secure load points once target elevations meet specification tolerances, enabling cylinder pressure release. Inspection logs capture pre-jack and post-jack dimensional scans to confirm structural compliance before permanent fastening.
Safety Protocol
Pressure relief valves protect structural pick-up points from unexpected hydraulic pressure spikes during operation. Mechanical locking collars on jack cylinders prevent structural collapse if fluid pressure fails unexpectedly. Handover logs document total applied forces and duration to track structural strain history.
