MIXED/WINCH_HARDWARE_FAULT
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Applicable alarms (2)
MIXED_HARDWARE_FAULTWINCH_HARDWARE_FAULT
Likely outcomes — click to expand
Based on 36 missions where this alarm fired in the last
90 days
(for MIXED_HARDWARE_FAULT) as of 2026-10-13
Grounding vs discrepancy (of 74 ZERP issues filed on these missions)
Top work orders
- Perform Software Update on Aircraft · MAINTENANCE_ACTION 30
- EV2: Replace Aft Motor Assembly on Aircraft · MAINTENANCE_ACTION 30
- EV2/EV3 Perform Preflight Without Motors · INSPECTION 22
- EV2: Mixed Hardware Fault Troubleshooting · TROUBLESHOOTING 18
- EV2: Replace Mixed Motor on Aircraft Aft Motor Assembly · MAINTENANCE_ACTION 18
Frequently replaced parts
| Part | P/N | Removals |
|---|---|---|
| AFT MOTOR ASSY, ZIP, P2 | 23548 | 210 |
| MIXED MOTOR ASSY, ZIP, P2 | 25263 | 126 |
| BATTERY ASSY, ZIP, P2 | 27158 | 28 |
| PCBA, COATED, TAIL NODE, PRE-EV2, ZIP, P2 | 29407 | 21 |
| CCW HOVER MOTOR ASSY, ZIP, P2 | 19607 | 20 |
Frequently co-occurring alarms (% of the 36 missions above)
Aggregated from fleet operations and refreshed daily. Individual outcomes may vary by site and configuration.
There was an overcurrent at the mixed motor or winch load switch, which likely indicates a short or damage on the distro, motor, or somewhere in between. This may be indicative of a serious problem. The goal of these troubleshooting steps is to try to identify where the potential damage is, swap the damaged component, or escalate to engineering for further steps.
Troubleshooting Steps
Section titled “Troubleshooting Steps”graph TD
disconnect-the-battery-from-the-aircraf["<small><b>Step 1</b></small><br/>Action: Disconnect the battery from the Aircr..."]
is-the-fault-related-to-a-winch-mot{"<small><b>Step 2</b></small><br/>Question: Is the fault related to a winch motor..."}
confirm-the-mixed-motor-rotor-core["<small><b>Step 3</b></small><br/>Action: Confirm the mixed motor rotor core ha..."]
use-a-multimeter-to-measure-resistance["<small><b>Step 4</b></small><br/>Action: Use a multimeter to measure resistanc..."]
follow-the-instructions-below-based-on{"<small><b>Step 5</b></small><br/>Question: Follow the instructions below based o..."}
inspect-the-faulting-busbar["<small><b>Step 6</b></small><br/>Action: Inspect only the busbar associated wi..."]
escalate-to-p2-powertrain-on-call{{"<small><b>Step 7</b></small><br/>Escalation: Escalate to Powertrain On Call."}}
follow-the-instructions-below-based-on-2{"<small><b>Step 8</b></small><br/>Question: Follow the instructions below based o..."}
document-the-damage-and-share-on-the-in["<small><b>Step 9</b></small><br/>Action: Document the damage and share on the ..."]
replace-the-busbar-poor-bolted["<small><b>Step 10</b></small><br/>Action: Replace the busbar."]
run-a-health-check-on-the-aircraft-poor["<small><b>Step 11</b></small><br/>Action: Run a health check on the Aircraft."]
document-the-damage-and-share-on-the-2["<small><b>Step 12</b></small><br/>Action: Document the damage and share on the ..."]
replace-the-busbar-damaged["<small><b>Step 13</b></small><br/>Action: Replace the busbar."]
run-a-health-check-on-the-aircraft-dama["<small><b>Step 14</b></small><br/>Action: Run a health check on the Aircraft."]
escalate-to-p2-powertrain-on-call-2{{"<small><b>Step 15</b></small><br/>Escalation: Escalate to Powertrain On Call."}}
disconnect-the-battery-from-the-aircraf --> is-the-fault-related-to-a-winch-mot
is-the-fault-related-to-a-winch-mot -->|Winch| use-a-multimeter-to-measure-resistance
is-the-fault-related-to-a-winch-mot -->|Mixed| confirm-the-mixed-motor-rotor-core
confirm-the-mixed-motor-rotor-core --> use-a-multimeter-to-measure-resistance
use-a-multimeter-to-measure-resistance --> follow-the-instructions-below-based-on
follow-the-instructions-below-based-on -->|Measurement was LESS than 6...| inspect-the-faulting-busbar
follow-the-instructions-below-based-on -->|Measurement was BETWEEN 60–...| escalate-to-p2-powertrain-on-call
inspect-the-faulting-busbar --> follow-the-instructions-below-based-on-2
follow-the-instructions-below-based-on-2 -->|There is evidence of a poor...| document-the-damage-and-share-on-the-in
follow-the-instructions-below-based-on-2 -->|There is evidence of a dama...| document-the-damage-and-share-on-the-2
follow-the-instructions-below-based-on-2 -->|No loose connections or obv...| escalate-to-p2-powertrain-on-call-2
document-the-damage-and-share-on-the-in --> replace-the-busbar-poor-bolted
replace-the-busbar-poor-bolted --> run-a-health-check-on-the-aircraft-poor
document-the-damage-and-share-on-the-2 --> replace-the-busbar-damaged
replace-the-busbar-damaged --> run-a-health-check-on-the-aircraft-dama
style disconnect-the-battery-from-the-aircraf fill:#dcfce7,stroke:#22c55e,color:#14532d
style is-the-fault-related-to-a-winch-mot fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style confirm-the-mixed-motor-rotor-core fill:#dcfce7,stroke:#22c55e,color:#14532d
style use-a-multimeter-to-measure-resistance fill:#dcfce7,stroke:#22c55e,color:#14532d
style follow-the-instructions-below-based-on fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style inspect-the-faulting-busbar fill:#dcfce7,stroke:#22c55e,color:#14532d
style escalate-to-p2-powertrain-on-call fill:#fef3c7,stroke:#f59e0b,color:#78350f
style follow-the-instructions-below-based-on-2 fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style document-the-damage-and-share-on-the-in fill:#dcfce7,stroke:#22c55e,color:#14532d
style replace-the-busbar-poor-bolted fill:#dcfce7,stroke:#22c55e,color:#14532d
style run-a-health-check-on-the-aircraft-poor fill:#dcfce7,stroke:#22c55e,color:#14532d
style document-the-damage-and-share-on-the-2 fill:#dcfce7,stroke:#22c55e,color:#14532d
style replace-the-busbar-damaged fill:#dcfce7,stroke:#22c55e,color:#14532d
style run-a-health-check-on-the-aircraft-dama fill:#dcfce7,stroke:#22c55e,color:#14532d
style escalate-to-p2-powertrain-on-call-2 fill:#fef3c7,stroke:#f59e0b,color:#78350f Hover or focus a block to preview it. Select the block to keep the preview open.
1 action
Disconnect the battery from the Aircraft.
3 action
Confirm the mixed motor rotor core has not slipped by following Mixed Rotor Slip Suspected.
If no rotor has slipped proceed to the next step.
If a rotor slip has been detected, add a work order to Replace the AMA on the Aircraft, and then continue to the next step to also check busbar resistance.
If no rotor has slipped proceed to the next step.
If a rotor slip has been detected, add a work order to Replace the AMA on the Aircraft, and then continue to the next step to also check busbar resistance.
4 action
Use a multimeter to measure resistance between the
[positive motor busbar contact] and the [negative motor busbar contact on the Distro]. Use the red lead on the positive contact and the black lead on the negative. Record the value of the resistance. 5 question
Follow the instructions below based on the recorded measurement:
6 action
Inspect only the busbar associated with the alarm (winch or mixed motor) for loose bolts, shorting connections/contacts, or damage.
7 escalation
Escalate to Powertrain On Call.
8 question
Follow the instructions below based on the inspection results:
10 action
Replace the busbar.
11 action
Run a health check on the Aircraft.
13 action
Replace the busbar.
14 action
Run a health check on the Aircraft.
15 escalation
Escalate to Powertrain On Call.
Resolution note
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