CLOCK_ERROR_IS_HIGH
Applicable alarms (4)
Likely outcomes — click to expand
Based on 682,060 missions where this alarm fired in the last
90 days
(for INACCURATE_CLOCK_REFERENCE) as of 2026-10-13
Grounding vs discrepancy (of 4,741 ZERP issues filed on these missions)
Top work orders
- EV2: Inspect Aircraft after Droid Left Behind (DLB) · MAINTENANCE_ACTION 345
- Inspect Droid after Droid Left Behind (DLB) · MAINTENANCE_ACTION 255
- ZCO-2026-06-11 M5 Connector Bracket Retrofit (FRCO-252 / SB-2026-020 / HIT-171) · UPGRADE_RETROFIT 109
- EV2: Replace Aft Motor Assembly on Aircraft · MAINTENANCE_ACTION 88
- EV2: Displace and Reinstall Hover Motor on Aircraft · MAINTENANCE_ACTION 80
Frequently replaced parts
| Part | P/N | Removals |
|---|---|---|
| SERVO, ASSY, UNIVERSAL, P2 | 20398 | 1,470 |
| CW/CCW HOVER MOTOR ASSY, ZIP, P2 | 19607 | 1,195 |
| WING ASM FULL, TRIAX, AL, STRBRD(RH), ZIP, P2 | 25266 | 828 |
| TRIAX WING ASM, PORT(LH), DEPOP, ZIP, P2 | 24762 | 828 |
| TAIL, STBD, ZIP, P2 | 21840 | 770 |
Aggregated from fleet operations and refreshed daily. Individual outcomes may vary by site and configuration.
Background
Section titled “Background”The system has a high clock error, meaning it is poorly synchronized. The inputs to the system clock are GNSS, cell, and the wired dock connection. This alarm has no behavioral impact.
Troubleshooting Steps
Section titled “Troubleshooting Steps”graph TD
has-the-system-been-powered-on-within-t{"<small><b>Step 1</b></small><br/>Question: Has the system been powered on within..."}
wait-10-minutes-did-the-alarm-clear{"<small><b>Step 2</b></small><br/>Question: Wait 10 minutes. Did the alarm clear?"}
the-aircraft-can-return-to-service["<small><b>Step 3</b></small><br/>Action: The Aircraft can return to service."]
inspect-the-gnss-antenna-for-steps-see{"<small><b>Step 4</b></small><br/>Question: Inspect the GNSS antenna. For steps, ..."}
replace-the-antenna-for-steps-see["<small><b>Step 5</b></small><br/>Action: Replace the antenna. For steps, see: ..."]
power-cycle-the-aircraft-for-steps-see{"<small><b>Step 6</b></small><br/>Question: Power cycle the Aircraft. For steps, ..."}
return-the-aircraft-to-service("<small><b>Step 7</b></small><br/>Reference: Return the Aircraft to Service.")
escalate-to-embedded-linux-oncall{{"<small><b>Step 8</b></small><br/>Escalation: Escalate to P2 Embedded Linux On Call."}}
has-the-system-been-powered-on-within-t -->|Yes| wait-10-minutes-did-the-alarm-clear
has-the-system-been-powered-on-within-t -->|No| inspect-the-gnss-antenna-for-steps-see
wait-10-minutes-did-the-alarm-clear -->|Yes| the-aircraft-can-return-to-service
wait-10-minutes-did-the-alarm-clear -->|No| inspect-the-gnss-antenna-for-steps-see
inspect-the-gnss-antenna-for-steps-see -->|Yes| replace-the-antenna-for-steps-see
inspect-the-gnss-antenna-for-steps-see -->|No| power-cycle-the-aircraft-for-steps-see
power-cycle-the-aircraft-for-steps-see -->|Yes| return-the-aircraft-to-service
power-cycle-the-aircraft-for-steps-see -->|No| escalate-to-embedded-linux-oncall
style has-the-system-been-powered-on-within-t fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style wait-10-minutes-did-the-alarm-clear fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style the-aircraft-can-return-to-service fill:#dcfce7,stroke:#22c55e,color:#14532d
style inspect-the-gnss-antenna-for-steps-see fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style replace-the-antenna-for-steps-see fill:#dcfce7,stroke:#22c55e,color:#14532d
style power-cycle-the-aircraft-for-steps-see fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style return-the-aircraft-to-service fill:#f3e8ff,stroke:#a855f7,color:#581c87
style escalate-to-embedded-linux-oncall fill:#fef3c7,stroke:#f59e0b,color:#78350f Hover or focus a block to preview it. Select the block to keep the preview open.
- UMM: Remove Aft GNSS Antenna
- UMM: Install Aft GNSS Antenna.
Resolution note
This plaintext block is ready to paste into the Resolution Note field on the ZERP issue you're working. The permalink below gives engineering review access to the full step-by-step timeline including any back-navigation; share it if the case needs a deeper look.
Permalink:
Session is too large to fit in a URL. Use Download session JSON to share the timeline out-of-band.
Did this guide help you get unblocked?
Open suggestions
There are no open suggestions.
Open pull requests
There are no open pull requests.