Dock Not Communicating with Aircraft
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Applicable alarms (2)
DOCK_LATCH_STATUS_UNAVAILABLEDOCK_TRANSFORMS_UNAVAILABLE
Likely outcomes — click to expand
Based on 603,563 missions where this alarm fired in the last
90 days
(for DOCK_LATCH_STATUS_UNAVAILABLE) as of 2026-10-13
Grounding vs discrepancy (of 6,379 ZERP issues filed on these missions)
Top work orders
- EV2: Inspect Aircraft after Droid Left Behind (DLB) · MAINTENANCE_ACTION 633
- Inspect Droid after Droid Left Behind (DLB) · MAINTENANCE_ACTION 429
- EV3: Inspect Aircraft after Droid Left Behind (DLB) · MAINTENANCE_ACTION 338
- Reset Droid after DLB · REPAIR 294
- EV2/EV3 Diagnostics Test Without Motors · INSPECTION 272
Frequently replaced parts
| Part | P/N | Removals |
|---|---|---|
| SERVO, ASSY, UNIVERSAL, P2 | 20398 | 1,711 |
| CCW HOVER MOTOR ASSY, ZIP, P2 | 19607 | 1,459 |
| ASSY, SPOOL AND LINE, DOCKING FIN, AIRCRAFT, P2 | 48477 | 1,232 |
| CW HOVER MOTOR ASSY, ZIP, P2 | 33333 | 851 |
| OUTBOARD WING ASSY PORT(LH), DEPOP, ZIP, P2 | 24762 | 798 |
Aggregated from fleet operations and refreshed daily. Individual outcomes may vary by site and configuration.
Background
Section titled “Background”The Aircraft and Dock are not able to communicate because of a bridge software issue or a hardware issue with the pins/sockets.
Exec watchdog alarms
Section titled “Exec watchdog alarms”- DOCK_LATCH_STATUS_UNAVAILABLE
- DOCK_TRANSFORMS_UNAVAILABLE
Troubleshooting Steps
Section titled “Troubleshooting Steps”graph TD
check-the-docks-fleetwrangler-page-look{"<small><b>Step 1</b></small><br/>Question: Check the Dock’s FleetWrangler page. ..."}
proceed-to-asset-offline-troubleshootin["<small><b>Step 2</b></small><br/>Action: Proceed to Asset Offline Troubleshoo..."]
check-the-aircrafts-fleetwrangler-page{"<small><b>Step 3</b></small><br/>Question: Check the Aircraft’s FleetWrangler pa..."}
proceed-to-asset-offline-aircraft["<small><b>Step 4</b></small><br/>Action: Proceed to Asset Offline Troubleshoo..."]
inspect-the-logs-use-the-baraza-templat["<small><b>Step 5</b></small><br/>Action: Inspect the logs at the time the disc..."]
are-dock-logs-missing-at-that-time{"<small><b>Step 6</b></small><br/>Question: Are dock logs missing at that time? ..."}
do-you-see-latch-status-gaps-or-zip-presence-flipping{"<small><b>Step 7</b></small><br/>Question: Do you see /compute_a.dock_latch_sta..."}
is-the-dock-or-zip-a-repeat-offender{"<small><b>Step 8</b></small><br/>Question: Is the Dock or Zip a repeat offender ..."}
close-the-discrepancy-and-put-the-assets-back-into-service["<small><b>Step 9</b></small><br/>Action: Create and close a discrepancy agains..."]
this-indicates-that-hardware-is-causing["<small><b>Step 10</b></small><br/>Action: This indicates that hardware is causi..."]
can-you-ssh-into-the-aircraft-through-t{"<small><b>Step 11</b></small><br/>Question: Can you SSH into the Aircraft through..."}
inspect-temporary-dock-latch-status["<small><b>Step 12</b></small><br/>Action: Inspect the logs at the time the disc..."]
does-compute-a-cpu-gap-or-spike{"<small><b>Step 13</b></small><br/>Question: Look at the gap where /compute_a.doc..."}
the-hardware-allows-for-communication{{"<small><b>Step 14</b></small><br/>Escalation: The hardware allows for communication..."}}
there-could-be-a-hardware-issue-somewhe["<small><b>Step 15</b></small><br/>Action: There could be a hardware issue somew..."]
request-an-inspection-of-the-dock-pins["<small><b>Step 16</b></small><br/>Action: Complete the Dock pin inspection wor..."]
are-all-four-4-pins-in-the-dock-fin-hat{"<small><b>Step 17</b></small><br/>Question: Are all four 4 pins in the Dock fin..."}
are-any-dock-fin-pins-damaged{"<small><b>Step 18</b></small><br/>Question: Check the Dock fin hat pins for physi..."}
re-secure-dock-fin-pins-before-measurement["<small><b>Step 19</b></small><br/>Action: Re-seat and secure any loose Dock fin..."]
measure-resistance-between-dock-comms-p{"<small><b>Step 20</b></small><br/>Question: **Turn off the breaker for the associ..."}
create-latch-swap-work-order["<small><b>Step 21</b></small><br/>Action: Create a work order for a latch swap...."]
are-all-four-sockets-in-the-zip-fin-pre{"<small><b>Step 22</b></small><br/>Question: Use Work Order Template 1095: Aircr..."}
are-the-lamella-contacts-present-and-undamaged{"<small><b>Step 23</b></small><br/>Question: Inspect the lamella contacts in the A..."}
this-docking-fin-needs-to-be-replaced["<small><b>Step 24</b></small><br/>Action: This docking fin needs to be replaced..."]
remove-the-upper-foam-from-the-aircraft{"<small><b>Step 25</b></small><br/>Question: Remove the upper foam from the Aircra..."}
add-torque-stripe-and-continue["<small><b>Step 26</b></small><br/>Action: Add torque stripe and continue to the..."]
this-might-be-the-issue{"<small><b>Step 27</b></small><br/>Question: This *might* be the issue. Re-seat an..."}
the-aircraft-and-dock-may-return-to-serv["<small><b>Step 28</b></small><br/>Action: The Aircraft and Dock may return to s..."]
unplug-the-docking-fin-comms-m5-connect{"<small><b>Step 29</b></small><br/>Question: Unplug the docking fin comms M5 conne..."}
this-docking-fin-needs-to-be-replaced-2["<small><b>Step 30</b></small><br/>Action: This docking fin needs to be replaced..."]
is-either-the-aircraft-or-the-dock-a-re{"<small><b>Step 31</b></small><br/>Question: Is either the Aircraft or the Dock a ..."}
this-is-a-2026-22-specific-bug["<small><b>Step 32</b></small><br/>Action: This is a 2026.22 specific bug that c..."]
if-the-aircraft-inspections-nominal-dis{{"<small><b>Step 33</b></small><br/>Escalation: If the Aircraft inspections in the pr..."}}
if-the-dock-inspections-nominal-control{{"<small><b>Step 34</b></small><br/>Escalation: If the Dock inspections in the previo..."}}
does-the-aircraft-work-with-a-different{"<small><b>Step 35</b></small><br/>Question: Does the Aircraft work with a differe..."}
points-to-a-dock-problem-with-a-dock-co["<small><b>Step 36</b></small><br/>Action: Points to a Dock problem with a Dock ..."]
does-a-different-aircraft-work-on-the-d{"<small><b>Step 37</b></small><br/>Question: Does a different Aircraft work on the..."}
if-the-aircraft-inspections-nominal-esc{{"<small><b>Step 38</b></small><br/>Escalation: If the Aircraft inspections in the pr..."}}
escalate-to-p2-ee-on-call-for-help-debu{{"<small><b>Step 39</b></small><br/>Escalation: Escalate to P2 EE On Call for help de..."}}
check-the-docks-fleetwrangler-page-look -->|Yes| proceed-to-asset-offline-troubleshootin
check-the-docks-fleetwrangler-page-look -->|No| check-the-aircrafts-fleetwrangler-page
check-the-aircrafts-fleetwrangler-page -->|Yes| proceed-to-asset-offline-aircraft
check-the-aircrafts-fleetwrangler-page -->|No| inspect-the-logs-use-the-baraza-templat
inspect-the-logs-use-the-baraza-templat --> are-dock-logs-missing-at-that-time
are-dock-logs-missing-at-that-time -->|Yes| close-the-discrepancy-and-put-the-assets-back-into-service
are-dock-logs-missing-at-that-time -->|No| do-you-see-latch-status-gaps-or-zip-presence-flipping
do-you-see-latch-status-gaps-or-zip-presence-flipping -->|Yes| is-the-dock-or-zip-a-repeat-offender
do-you-see-latch-status-gaps-or-zip-presence-flipping -->|No| can-you-ssh-into-the-aircraft-through-t
is-the-dock-or-zip-a-repeat-offender -->|No| close-the-discrepancy-and-put-the-assets-back-into-service
is-the-dock-or-zip-a-repeat-offender -->|Yes| this-indicates-that-hardware-is-causing
this-indicates-that-hardware-is-causing --> request-an-inspection-of-the-dock-pins
can-you-ssh-into-the-aircraft-through-t -->|Yes| inspect-temporary-dock-latch-status
can-you-ssh-into-the-aircraft-through-t -->|No| there-could-be-a-hardware-issue-somewhe
can-you-ssh-into-the-aircraft-through-t -->|Not applicable| there-could-be-a-hardware-issue-somewhe
inspect-temporary-dock-latch-status --> does-compute-a-cpu-gap-or-spike
does-compute-a-cpu-gap-or-spike -->|Yes| this-is-a-2026-22-specific-bug
does-compute-a-cpu-gap-or-spike -->|No| the-hardware-allows-for-communication
there-could-be-a-hardware-issue-somewhe --> request-an-inspection-of-the-dock-pins
request-an-inspection-of-the-dock-pins --> are-all-four-4-pins-in-the-dock-fin-hat
are-all-four-4-pins-in-the-dock-fin-hat -->|Yes| measure-resistance-between-dock-comms-p
are-all-four-4-pins-in-the-dock-fin-hat -->|No — one or more pins are m...| are-any-dock-fin-pins-damaged
are-all-four-4-pins-in-the-dock-fin-hat -->|No — one or more pins are v...| create-latch-swap-work-order
are-any-dock-fin-pins-damaged -->|Yes| create-latch-swap-work-order
are-any-dock-fin-pins-damaged -->|No| re-secure-dock-fin-pins-before-measurement
re-secure-dock-fin-pins-before-measurement --> measure-resistance-between-dock-comms-p
measure-resistance-between-dock-comms-p -->|Yes| are-all-four-sockets-in-the-zip-fin-pre
measure-resistance-between-dock-comms-p -->|No| create-latch-swap-work-order
are-all-four-sockets-in-the-zip-fin-pre -->|Yes| are-the-lamella-contacts-present-and-undamaged
are-all-four-sockets-in-the-zip-fin-pre -->|No| this-docking-fin-needs-to-be-replaced
are-the-lamella-contacts-present-and-undamaged -->|Yes| remove-the-upper-foam-from-the-aircraft
are-the-lamella-contacts-present-and-undamaged -->|No| this-docking-fin-needs-to-be-replaced
remove-the-upper-foam-from-the-aircraft -->|Yes, the M5 connector is ti...| unplug-the-docking-fin-comms-m5-connect
remove-the-upper-foam-from-the-aircraft -->|The M5 connector seems tigh...| add-torque-stripe-and-continue
remove-the-upper-foam-from-the-aircraft -->|The M5 connector is not tig...| this-might-be-the-issue
add-torque-stripe-and-continue --> unplug-the-docking-fin-comms-m5-connect
this-might-be-the-issue -->|YES| the-aircraft-and-dock-may-return-to-serv
this-might-be-the-issue -->|NO| unplug-the-docking-fin-comms-m5-connect
unplug-the-docking-fin-comms-m5-connect -->|Yes| is-either-the-aircraft-or-the-dock-a-re
unplug-the-docking-fin-comms-m5-connect -->|No| this-docking-fin-needs-to-be-replaced-2
is-either-the-aircraft-or-the-dock-a-re -->|Yes, the Aircraft| if-the-aircraft-inspections-nominal-dis
is-either-the-aircraft-or-the-dock-a-re -->|Yes, the Dock| if-the-dock-inspections-nominal-control
is-either-the-aircraft-or-the-dock-a-re -->|Both aircraft and dock| if-the-dock-inspections-nominal-control
is-either-the-aircraft-or-the-dock-a-re -->|No| does-the-aircraft-work-with-a-different
does-the-aircraft-work-with-a-different -->|Yes| points-to-a-dock-problem-with-a-dock-co
does-the-aircraft-work-with-a-different -->|No| does-a-different-aircraft-work-on-the-d
does-a-different-aircraft-work-on-the-d -->|Yes| if-the-aircraft-inspections-nominal-esc
does-a-different-aircraft-work-on-the-d -->|No| escalate-to-p2-ee-on-call-for-help-debu
style check-the-docks-fleetwrangler-page-look fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style proceed-to-asset-offline-troubleshootin fill:#dcfce7,stroke:#22c55e,color:#14532d
style check-the-aircrafts-fleetwrangler-page fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style proceed-to-asset-offline-aircraft fill:#dcfce7,stroke:#22c55e,color:#14532d
style inspect-the-logs-use-the-baraza-templat fill:#dcfce7,stroke:#22c55e,color:#14532d
style are-dock-logs-missing-at-that-time fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style do-you-see-latch-status-gaps-or-zip-presence-flipping fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style is-the-dock-or-zip-a-repeat-offender fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style close-the-discrepancy-and-put-the-assets-back-into-service fill:#dcfce7,stroke:#22c55e,color:#14532d
style this-indicates-that-hardware-is-causing fill:#dcfce7,stroke:#22c55e,color:#14532d
style can-you-ssh-into-the-aircraft-through-t fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style inspect-temporary-dock-latch-status fill:#dcfce7,stroke:#22c55e,color:#14532d
style does-compute-a-cpu-gap-or-spike fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
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style are-all-four-sockets-in-the-zip-fin-pre fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
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style escalate-to-p2-ee-on-call-for-help-debu fill:#fef3c7,stroke:#f59e0b,color:#78350f Hover or focus a block to preview it. Select the block to keep the preview open.
1 question
Check the Dock’s FleetWrangler page. Look at the status at the top of the page. Is the Dock offline?
2 action
Proceed to Asset Offline Troubleshooting Landing Page to triage why the Dock is offline.
3 question
Check the Aircraft’s FleetWrangler page. Look at the status at the top of the page. Is the Aircraft offline?
4 action
Proceed to Asset Offline Troubleshooting Landing Page to check why the Aircraft is offline.
5 action
Inspect the logs at the time the discrepancy was set. Use the Baraza template "Dock Zip Flakey Comms".
6 question
Are dock logs missing at that time? (This would indicate a transient power outage to the Dock.)
7 question
Do you see
/compute_a.dock_latch_status.latch_service_state has irregular gaps longer than 1 second? Do you see that the /dock.zip_presence_detection_unfiltered signal frequently is flipping true/false multiple times per second? 8 question
Is the Dock or Zip a repeat offender (i.e. has the asset had multiple discrepancies set against it for comms issues)?
9 action
Create and close a discrepancy against the dock with the title "Dock Not Communicating with Aircraft" to track repeat offenders. Close the original discrepancy and put the assets back into service.
10 action
This indicates that hardware is causing flakey comms. It could be on the Zip or Dock side.
11 question
Can you SSH into the Aircraft through the Dock? If this is an EV3 Aircraft where SSH-through-Dock is not supported, choose "Not applicable" and continue with the hardware inspection.
12 action
Inspect the logs at the time the discrepancy was set. Use the Baraza template Temporary Dock Latch Status Unavailable Bug. Add 20 seconds of padding after.
13 question
Look at the gap where
/compute_a.dock_latch_status is not published. Does /compute_a.global_resource_monitor.cpu also not get published OR spike to >93%? 14 escalation
The hardware allows for communication. There is a software issue with the Aircraft to Dock bridge service.
Escalate to P2 Dock Embedded On Call.
Escalate to P2 Dock Embedded On Call.
15 action
There could be a hardware issue somewhere in the chain between the Aircraft Distro and the Dock Controller.
Continue to the next step.
Continue to the next step.
16 action
Complete the Dock pin inspection (work order below) AND the Aircraft socket inspection (work order in a later step) and any resulting maintenance actions before returning EITHER asset to the field. Start with the Dock pin inspection below.
Use Work Order Template #1094: Latch pin inspection for the Dock pin inspection.
Use Work Order Template #1094: Latch pin inspection for the Dock pin inspection.
17 question
Are all four (4) pins in the Dock fin hat present, secured, and undamaged?
18 question
Check the Dock fin hat pins for physical damage. Are any pins damaged?
19 action
Re-seat and secure any loose Dock fin hat pins before proceeding. Ensure all four pins are fully seated and secured.
20 question
Turn off the breaker for the associated Dock before measuring resistance. Using a multimeter, measure the resistance between the two Dock comms pins.
Does it measure ~2kOhms?
Does it measure ~2kOhms?
21 action
Create a work order for a latch swap. Create an ISS ticket, link it to the Dock discrepancy, and return the failed latch hardware to the Dock hardware returns owner.
22 question
Use Work Order Template #1095: Aircraft socket inspection for the Aircraft socket inspection.
Are all four sockets in the zip fin present and secured? None should be loose.
Are all four sockets in the zip fin present and secured? None should be loose.
23 question
Inspect the lamella contacts in the Aircraft sockets. Are the lamella contacts present, undamaged, and free of contamination?
24 action
This docking fin needs to be replaced.
Create a discrepancy against the Aircraft.
Create a work order to replace the docking fin.
The issue should be resolved after the docking fin has been replaced. Send the broken docking fin to the Aviary
Create a discrepancy against the Aircraft.
Create a work order to replace the docking fin.
The issue should be resolved after the docking fin has been replaced. Send the broken docking fin to the Aviary
25 question
Remove the upper foam from the Aircraft (see UMM Chapter 53: Remove Upper Foam). Is the M5 connector from the docking fin to the distro tight and is the torque stripe is present?
26 action
Add torque stripe and continue to the next step.
27 question
This might be the issue.
Re-seat and tighten the M5 connector (hand tight + 1/8 turn by needle nose pliers).
Add torque stripe.
Place the Aircraft back into the Dock. Is the Dock communicating with the Aircraft?
Re-seat and tighten the M5 connector (hand tight + 1/8 turn by needle nose pliers).
Add torque stripe.
Place the Aircraft back into the Dock. Is the Dock communicating with the Aircraft?
28 action
The Aircraft and Dock may return to service.
29 question
Unplug the docking fin comms M5 connector from the distro.
Is there continuity from each comms socket to the end of the M5 connector?
Is there continuity from each comms socket to the end of the M5 connector?
30 action
This docking fin needs to be replaced.
Create a discrepancy against the Aircraft.
Create a work order to replace the docking fin.
The issue should be resolved after the docking fin has been replaced. Send the broken docking fin to the Aviary
Create a discrepancy against the Aircraft.
Create a work order to replace the docking fin.
The issue should be resolved after the docking fin has been replaced. Send the broken docking fin to the Aviary
31 question
Is either the Aircraft or the Dock a repeat offender (several issues within 1 week) with no comms?
32 action
This is a 2026.22 specific bug that can be ignored. It is fixed in 2026.22.1. Close this discrepancy.
33 escalation
If the Aircraft inspections in the previous steps were nominal, it is likely a Distro issue.
Escalate to P2 Firmware Platform On Call.
Escalate to P2 Firmware Platform On Call.
34 escalation
If the Dock inspections in the previous steps were nominal, it is likely a Dock controller issue.
Escalate to P2 Dock Hardware On Call.
In the scenario that both Aircraft and Dock are repeat offenders, mention this in the escalation.
Escalate to P2 Dock Hardware On Call.
In the scenario that both Aircraft and Dock are repeat offenders, mention this in the escalation.
35 question
Does the Aircraft work with a different Dock?
36 action
Points to a Dock problem with a Dock controller issue. If the latch inspections performed in a previous step were nominal, create a work order for a Dock controller swap, link an ISS ticket, and return the failed Dock controller hardware to the Dock hardware returns owner.
37 question
Does a different Aircraft work on the Dock?
38 escalation
If the Aircraft inspections in the previous steps were nominal, it is likely a Distro issue.
Escalate to P2 Firmware Platform On Call.
Escalate to P2 Firmware Platform On Call.
39 escalation
Escalate to P2 EE On Call for help debugging the electrical connection.
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