BELOW_MIN_TENSION
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Applicable alarms (1)
BELOW_MIN_TENSION
Likely outcomes — click to expand
Based on 358 missions where this alarm fired in the last 90 days as of 2026-10-13
Grounding vs discrepancy (of 8 ZERP issues filed on these missions)
Frequently replaced parts
| Part | P/N | Removals |
|---|---|---|
| WINCH, ASSY, ZIP, P2 | 24078 | 8 |
Frequently co-occurring alarms (% of the 358 missions above)
Aggregated from fleet operations and refreshed daily. Individual outcomes may vary by site and configuration.
Background
Section titled “Background”This alarm occurs during flight or package loading and indicates that the winch has detected low tension. This can indicate a line snap. We occasionally have false positives due to zip vibration, so checking for reoccurrence is recommended before escalating.
Troubleshooting Steps
Section titled “Troubleshooting Steps”graph TD
has-the-droid-been-left-behind-how-to-c{"<small><b>Step 1</b></small><br/>Question: Has the Droid been left behind? How ..."}
has-the-droid-been-left-behind-on-this{"<small><b>Step 2</b></small><br/>Question: Has the droid been left behind on thi..."}
continue-to-the-next-step-droid-left-be["<small><b>Step 3</b></small><br/>Action: Continue to the next step."]
perform-usual-maintenance-for-droid-left["<small><b>Step 4</b></small><br/>Action: Perform usual maintenance for droid l..."]
return-the-aircraft-to-service-and-obse["<small><b>Step 5</b></small><br/>Action: Return the Aircraft to service and ob..."]
link-the-issue-as-relates-to-p2p-55117["<small><b>Step 6</b></small><br/>Action: Link the issue as “Relates to” P2P-55117"]
if-the-issue-occurs-again-on-the-next-m{{"<small><b>Step 7</b></small><br/>Escalation: If the issue occurs again on the next..."}}
was-the-droid-left-behind-dlb-during-dr{"<small><b>Step 8</b></small><br/>Question: Was the Droid left behind DLB durin..."}
do-not-place-a-dlb-inspection-on-the-dr["<small><b>Step 9</b></small><br/>Action: Do not place a DLB inspection on the ..."]
raise-a-discrepancy-against-the-droid-t["<small><b>Step 10</b></small><br/>Action: Raise a discrepancy against the Droid..."]
inspect-the-droid-droid-cmm-droid-left["<small><b>Step 11</b></small><br/>Action: Inspect the Droid Droid CMM: Droid ..."]
did-the-inspection-pass{"<small><b>Step 12</b></small><br/>Question: Did the inspection pass?"}
continue-to-the-next-step-inspection-pas["<small><b>Step 13</b></small><br/>Action: Continue to the next step."]
if-there-is-a-clear-root-cause-perform{{"<small><b>Step 14</b></small><br/>Escalation: If there is a clear root cause, perfo..."}}
reset-the-aircraft-umm-5-5-1-e-reset-zi["<small><b>Step 15</b></small><br/>Action: Reset the Aircraft UMM 5.5.1.e Rese..."]
has-the-droid-been-left-behind-how-to-c -->|Yes| continue-to-the-next-step-droid-left-be
has-the-droid-been-left-behind-how-to-c -->|No| return-the-aircraft-to-service-and-obse
has-the-droid-been-left-behind-on-this -->|Yes| perform-usual-maintenance-for-droid-left
has-the-droid-been-left-behind-on-this -->|No| return-the-aircraft-to-service-and-obse
continue-to-the-next-step-droid-left-be --> was-the-droid-left-behind-dlb-during-dr
return-the-aircraft-to-service-and-obse --> link-the-issue-as-relates-to-p2p-55117
link-the-issue-as-relates-to-p2p-55117 --> if-the-issue-occurs-again-on-the-next-m
was-the-droid-left-behind-dlb-during-dr -->|Yes| do-not-place-a-dlb-inspection-on-the-dr
was-the-droid-left-behind-dlb-during-dr -->|No| raise-a-discrepancy-against-the-droid-t
do-not-place-a-dlb-inspection-on-the-dr --> reset-the-aircraft-umm-5-5-1-e-reset-zi
raise-a-discrepancy-against-the-droid-t --> inspect-the-droid-droid-cmm-droid-left
inspect-the-droid-droid-cmm-droid-left --> did-the-inspection-pass
did-the-inspection-pass -->|Yes| continue-to-the-next-step-inspection-pas
did-the-inspection-pass -->|No| if-there-is-a-clear-root-cause-perform
continue-to-the-next-step-inspection-pas --> reset-the-aircraft-umm-5-5-1-e-reset-zi
style has-the-droid-been-left-behind-how-to-c fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style has-the-droid-been-left-behind-on-this fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style continue-to-the-next-step-droid-left-be fill:#dcfce7,stroke:#22c55e,color:#14532d
style perform-usual-maintenance-for-droid-left fill:#dcfce7,stroke:#22c55e,color:#14532d
style return-the-aircraft-to-service-and-obse fill:#dcfce7,stroke:#22c55e,color:#14532d
style link-the-issue-as-relates-to-p2p-55117 fill:#dcfce7,stroke:#22c55e,color:#14532d
style if-the-issue-occurs-again-on-the-next-m fill:#fef3c7,stroke:#f59e0b,color:#78350f
style was-the-droid-left-behind-dlb-during-dr fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style do-not-place-a-dlb-inspection-on-the-dr fill:#dcfce7,stroke:#22c55e,color:#14532d
style raise-a-discrepancy-against-the-droid-t fill:#dcfce7,stroke:#22c55e,color:#14532d
style inspect-the-droid-droid-cmm-droid-left fill:#dcfce7,stroke:#22c55e,color:#14532d
style did-the-inspection-pass fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style continue-to-the-next-step-inspection-pas fill:#dcfce7,stroke:#22c55e,color:#14532d
style if-there-is-a-clear-root-cause-perform fill:#fef3c7,stroke:#f59e0b,color:#78350f
style reset-the-aircraft-umm-5-5-1-e-reset-zi fill:#dcfce7,stroke:#22c55e,color:#14532d Hover or focus a block to preview it. Select the block to keep the preview open.
1 question >=2026.09
Has the Droid been left behind? How to Check if Droid is Left Behind.
2 question 2026.03
Has the droid been left behind on this flight? Follow this guide: How to Check if Droid is Left Behind.
3 action >=2026.09
Continue to the next step.
4 action 2026.03
Perform usual maintenance for droid left behind. This alarm can be safely ignored – it’s expected in this case since the line has been cut
5 action
Return the Aircraft to service and observe whether the same issue occurs on the next flight.
6 action
Link the issue as “Relates to” P2P-55117
7 escalation
If the issue occurs again on the next mission, stop flying the Aircraft and escalate to P2 Droid Controls On Call. The Aircraft will likely need maintenance.
8 question >=2026.09
Was the Droid left behind (DLB) during Drone Loading (formally known as Ground Loading)?
9 action >=2026.09
Do not place a DLB inspection on the Droid.
Continue to the next step.
Continue to the next step.
10 action >=2026.09
Raise a discrepancy against the Droid that was left behind.
11 action >=2026.09
Inspect the Droid (Droid CMM: Droid Left Behind Inspection).
12 question >=2026.09
Did the inspection pass?
13 action >=2026.09
Continue to the next step.
14 escalation >=2026.09
If there is a clear root cause, perform applicable maintenance if required. Otherwise, escalate to P2 Droid Autonomy On Call.
15 action >=2026.09
Reset the Aircraft (UMM 5.5.1.e Reset Zip After Droid Left Behind).
Resolution note
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