PAN-FSR-2091-057

Fault Description

No fault. This FSR was auto-generated by the Vector Fleet preventive-maintenance scheduler when PAN-DRN-02 logged its 200th flight hour since the previous airframe service (PAN-FSR-2091-031, completed 2091-03-04). SOP PAN-ENG-022 (Vector Drone Airframe Service) mandates a full airframe inspection, rotor assembly teardown, and avionics baseline verification at 200-hour intervals. PAN-DRN-02 was removed from the mission-ready roster at 18:00 on 2091-05-28 and transferred to the Vector maintenance bay.

Root Cause Analysis

Not applicable — scheduled preventive maintenance. No corrective action required.

Work Performed

J. Park and T. Lim attended the Vector maintenance bay on 2091-05-29 at 06:00 local. Work performed under SOP PAN-ENG-022:

1. Airframe structural inspection. Full visual and NDT (eddy-current) inspection of the carbon-fibre airframe. No delamination, impact damage, or fastener loosening detected. Airframe stress indicators (strain-gauge telemetry review for the previous 200 hours) confirmed all loading within the design envelope. Landing-gear pivot bushings measured within wear tolerance; no replacement required.

2. Rotor assembly teardown. All four rotor assemblies removed, disassembled, cleaned, and inspected. Motor bearings checked with a vibration analyser — rotor 3 (starboard aft) measured 0.18 mm/s RMS, approaching the 0.20 mm/s replacement threshold. Bearings on rotor 3 replaced proactively. Rotors 1, 2, and 4 measured between 0.06 and 0.11 mm/s RMS — well within specification. All rotor blades inspected for edge erosion and leading-edge coating integrity; no replacement required. Assemblies re-torqued to specification and re-installed.

3. Propulsion system test. Ground-run test at 25%, 50%, 75%, and 100% thrust. All four rotors confirmed balanced within ±0.3% of target RPM at each power setting. Current draw, temperature rise, and vibration signature all nominal.

4. Avionics firmware baseline. Flight controller, navigation module, and communications suite verified at firmware baseline v6.1.4 (current fleet standard). Encrypted telemetry link to the Watch Floor confirmed operational. GPS/INS alignment test passed. No firmware update required — PAN-DRN-02 was already at baseline.

5. Sensor payload inspection. Electro-optical/infrared (EO/IR) camera gimbal cleaned and functionally tested through full range of motion. Image quality confirmed against calibration target. Gimbal bearing backlash measured at 0.004° — within the 0.01° specification.

6. Return to service. PAN-DRN-02 completed a 45-minute post-maintenance check flight at 14:30 local. All parameters nominal. Asset returned to mission-ready roster at 16:00.

Parts Consumed

1x motor bearing set, rotor assembly (P/N VF-RB-04) — drawn from Vector maintenance bay stores for proactive replacement of rotor 3 bearings. Stock level remains above minimum-on-hand threshold; no automatic reorder triggered.

Sign-off Chain

Service performed by: J. Park, Vector Fleet Technician & T. Lim, Vector Fleet Technician — 2091-05-29

Check flight performed by: J. Park — 2091-05-29

Report closed by: Dae-Jung Park, Lead Engineer (Vector Program) — 2091-05-29

Post-Action Notes

The proactive replacement of rotor 3 bearings at 0.18 mm/s RMS (below the 0.20 mm/s threshold) is consistent with fleet policy: bearings approaching threshold at a scheduled service interval are replaced rather than run to the next 200-hour cycle. The removed bearings will be returned to the manufacturer for failure-analysis trending as part of the fleet reliability programme. PAN-DRN-02 has now completed 6 consecutive 200-hour service cycles without a corrective-maintenance event — the best reliability record in the surveillance-class fleet.