MOTOR_FREEWHEELING_TEMPORARILY
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Applicable alarms (1)
MOTOR_FREEWHEELING_TEMPORARILY
Likely outcomes — click to expand
Based on 54,929 missions where this alarm fired in the last 90 days as of 2026-10-13
Grounding vs discrepancy (of 625 ZERP issues filed on these missions)
Top work orders
- EV2: Inspect Aircraft after Droid Left Behind (DLB) · MAINTENANCE_ACTION 46
- EV2/EV3 Diagnostics Test Without Motors · INSPECTION 36
- EV2: Replace Aft Motor Assembly on Aircraft · MAINTENANCE_ACTION 32
- Reset Droid after DLB · REPAIR 31
- EV3: Inspect Aircraft after Droid Left Behind (DLB) · MAINTENANCE_ACTION 30
Frequently replaced parts
| Part | P/N | Removals |
|---|---|---|
| AFT MOTOR ASSY, PRE-EV2, ZIP, P2 | 23548 | 232 |
| SERVO, ASSY, UNIVERSAL, P2 | 20398 | 215 |
| CCW HOVER MOTOR ASSY, ZIP, P2 | 19607 | 166 |
| WING ASM FULL, TRIAX, NO DAA, STRBRD(RH), ZIP, P2 | 25266 | 135 |
| WING PORT, ZIP, P2 | 24762 | 135 |
Frequently co-occurring alarms (% of the 54,929 missions above)
Aggregated from fleet operations and refreshed daily. Individual outcomes may vary by site and configuration.
Background
Section titled “Background”This alarm can be raised by any motor in the Aircraft or the Zip. The root cause could be, but isn’t necessarily in, any of the following:
- Zip Battery
- Bus Bars
- Zip Distribution Board
- Zip Network
- Motors
We’ll use feedback on the occurrence of these issues to provide diagnostic indicators for the common underlying issues.
Troubleshooting Steps
Section titled “Troubleshooting Steps”graph TD
check-compute-flight-arming-2026-15["<small><b>Step 1</b></small><br/>Telemetry: Check if both Compute A and Compute B..."]
was-the-alarm-driven-by-a-fault-injec{"<small><b>Step 2</b></small><br/>Question: Was the alarm driven by a fault-injec..."}
send-a-reboot-mission-and-return-the-zip-to-service["<small><b>Step 3</b></small><br/>Action: Send a reboot mission, then reattempt..."]
did-the-mission-fail-with-flight-disarmed-again{"<small><b>Step 4</b></small><br/>Question: Did the mission fail again in the exa..."}
return-the-zip-to-service("<small><b>Step 5</b></small><br/>Reference: Return the Zip to service.")
follow-the-relevant-active-guide("<small><b>Step 6</b></small><br/>Reference: Follow the troubleshooting guide for ...")
escalate-to-zip-exec-on-call{{"<small><b>Step 7</b></small><br/>Escalation: Escalate to P2 Exec On Call."}}
document-the-fault-injection-as-the-c("<small><b>Step 8</b></small><br/>Reference: Document the fault injection as the c...")
escalate-to-motors-on-call{{"<small><b>Step 9</b></small><br/>Escalation: Escalate to P2 Firmware Motors On Call."}}
check-compute-flight-arming-2026-15 -->|Yes, flight is armed| was-the-alarm-driven-by-a-fault-injec
check-compute-flight-arming-2026-15 -->|No, Compute B stops request...| send-a-reboot-mission-and-return-the-zip-to-service
check-compute-flight-arming-2026-15 -->|No, flight is disarmed for ...| escalate-to-zip-exec-on-call
was-the-alarm-driven-by-a-fault-injec -->|Yes| document-the-fault-injection-as-the-c
was-the-alarm-driven-by-a-fault-injec -->|No| escalate-to-motors-on-call
send-a-reboot-mission-and-return-the-zip-to-service --> did-the-mission-fail-with-flight-disarmed-again
did-the-mission-fail-with-flight-disarmed-again -->|Yes| escalate-to-zip-exec-on-call
did-the-mission-fail-with-flight-disarmed-again -->|No, flight arms and the iss...| return-the-zip-to-service
did-the-mission-fail-with-flight-disarmed-again -->|No, a different alarm or fa...| follow-the-relevant-active-guide
style was-the-alarm-driven-by-a-fault-injec fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style send-a-reboot-mission-and-return-the-zip-to-service fill:#dcfce7,stroke:#22c55e,color:#14532d
style did-the-mission-fail-with-flight-disarmed-again fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style return-the-zip-to-service fill:#f3e8ff,stroke:#a855f7,color:#581c87
style follow-the-relevant-active-guide fill:#f3e8ff,stroke:#a855f7,color:#581c87
style escalate-to-zip-exec-on-call fill:#fef3c7,stroke:#f59e0b,color:#78350f
style document-the-fault-injection-as-the-c fill:#f3e8ff,stroke:#a855f7,color:#581c87
style escalate-to-motors-on-call fill:#fef3c7,stroke:#f59e0b,color:#78350f Hover or focus a block to preview it. Select the block to keep the preview open.
1 telemetry >=2026.15,<2026.22
Check if both Compute A and Compute B have requested flight arming. Is flight armed?
Flight armed example:
Compute B stops requesting flight arming example:
Flight armed example:
Compute B stops requesting flight arming example:
Enter the mission identifier above to load the plot.
2 question
Was the alarm driven by a fault-injection test?
3 action >=2026.15,<2026.22
Send a reboot mission, then reattempt the mission.
4 question >=2026.15,<2026.22
Did the mission fail again in the exact same way with flight still disarmed?
5 reference >=2026.15,<2026.22
Return the Zip to service.
6 reference >=2026.15,<2026.22
Follow the troubleshooting guide for the active alarm or failed mission.
7 escalation >=2026.15,<2026.22
Escalate to P2 Exec On Call.
8 reference
Document the fault injection as the cause. No escalation is needed.
9 escalation
Escalate to P2 Firmware Motors On Call.
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:
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