Latch Service NACKed the latch command
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Applicable alarms (1)
LATCH_SERVICE_NACKED
Likely outcomes — click to expand
Based on 0 missions where this alarm fired in the last 90 days as of 2026-10-13
Aggregated from fleet operations and refreshed daily. Individual outcomes may vary by site and configuration.
Background
Section titled “Background”When trying to actuate the latch, it may fail and give this error in Fleet Wrangler or the QR code app.
Troubleshooting Steps
Section titled “Troubleshooting Steps”graph TD
what-command-are-you-trying-to-send{"<small><b>Step 1</b></small><br/>Question: What command are you trying to send?"}
open-what-is-the-latch-service-state-in{"<small><b>Step 2</b></small><br/>Question: What is the latch_service_state in ..."}
open-retracted-safe-retracted-retained-o{{"<small><b>Step 3</b></small><br/>Escalation: This should not be possible. Escalate..."}}
open-faulted-send-a-reset-command-inste["<small><b>Step 4</b></small><br/>Action: Send a **RESET** command instead of a..."]
retract-is-there-an-aircraft-in-the-doc{"<small><b>Step 5</b></small><br/>Question: Is there an Aircraft in the Dock and ..."}
retract-on-is-the-latch-service-state-f{"<small><b>Step 6</b></small><br/>Question: Is the latch_service_state in Fleet..."}
retract-on-faulted-follow-latch-service["<small><b>Step 7</b></small><br/>Action: Follow LATCH_SERVICE_STATE_FAULTED..."]
retract-on-is-the-latch-service-state-e{"<small><b>Step 8</b></small><br/>Question: Is the latch_service_state in Fleet..."}
retract-on-empty-yes-follow-latch-servi["<small><b>Step 9</b></small><br/>Action: Follow LATCH_SERVICE_STATE_EMPTY/t..."]
retract-on-empty-yes-send-the-retract-c["<small><b>Step 10</b></small><br/>Action: Send the **RETRACT** command after th..."]
retract-on-empty-yes-if-the-issue-is-no{{"<small><b>Step 11</b></small><br/>Escalation: If the issue is not resolved, escalat..."}}
retract-on-empty-no-escalate-to-p2-dock{{"<small><b>Step 12</b></small><br/>Escalation: Escalate to P2 Dock Hardware On Call."}}
retract-off-is-the-latch-service-state{"<small><b>Step 13</b></small><br/>Question: Is the latch_service_state on Fleet..."}
retract-off-faulted-follow-latch-servic["<small><b>Step 14</b></small><br/>Action: Follow LATCH_SERVICE_STATE_FAULTED..."]
retract-off-push-on-the-center-of-the-a["<small><b>Step 15</b></small><br/>Action: Push on the center of the Aircraft un..."]
retract-off-if-not-resolved-send-an-open["<small><b>Step 16</b></small><br/>Action: If the issue is not resolved, send an..."]
retract-off-if-not-resolved-escalate-to{{"<small><b>Step 17</b></small><br/>Escalation: If the issue is not resolved, escalat..."}}
retract-no-aircraft-do-not-retract-a-do{{"<small><b>Step 18</b></small><br/>Escalation: **Do not retract a Dock with no Aircr..."}}
reset-is-the-latch-service-state-in-fle{"<small><b>Step 19</b></small><br/>Question: Is the latch_service_state in Fleet..."}
reset-faulted-this-should-not-have-caus{{"<small><b>Step 20</b></small><br/>Escalation: This should not have caused an issue...."}}
reset-something-else-reset-only-works-i["<small><b>Step 21</b></small><br/>Action: **RESET** only works if the latch is ..."]
what-command-are-you-trying-to-send -->|OPEN| open-what-is-the-latch-service-state-in
what-command-are-you-trying-to-send -->|RETRACT| retract-is-there-an-aircraft-in-the-doc
what-command-are-you-trying-to-send -->|RESET| reset-is-the-latch-service-state-in-fle
open-what-is-the-latch-service-state-in -->|RETRACTED, SAFE_RETRACTED, ...| open-retracted-safe-retracted-retained-o
open-what-is-the-latch-service-state-in -->|FAULTED| open-faulted-send-a-reset-command-inste
retract-is-there-an-aircraft-in-the-doc -->|There is an Aircraft in the...| retract-on-is-the-latch-service-state-f
retract-is-there-an-aircraft-in-the-doc -->|There is an Aircraft in the...| retract-off-is-the-latch-service-state
retract-is-there-an-aircraft-in-the-doc -->|There is no Aircraft in the...| retract-no-aircraft-do-not-retract-a-do
retract-on-is-the-latch-service-state-f -->|Yes| retract-on-faulted-follow-latch-service
retract-on-is-the-latch-service-state-f -->|No| retract-on-is-the-latch-service-state-e
retract-on-is-the-latch-service-state-e -->|Yes| retract-on-empty-yes-follow-latch-servi
retract-on-is-the-latch-service-state-e -->|No| retract-on-empty-no-escalate-to-p2-dock
retract-on-empty-yes-follow-latch-servi --> retract-on-empty-yes-send-the-retract-c
retract-on-empty-yes-send-the-retract-c --> retract-on-empty-yes-if-the-issue-is-no
retract-off-is-the-latch-service-state -->|Yes| retract-off-faulted-follow-latch-servic
retract-off-is-the-latch-service-state -->|No| retract-off-push-on-the-center-of-the-a
retract-off-push-on-the-center-of-the-a --> retract-off-if-not-resolved-send-an-open
retract-off-if-not-resolved-send-an-open --> retract-off-if-not-resolved-escalate-to
reset-is-the-latch-service-state-in-fle -->|FAULTED| reset-faulted-this-should-not-have-caus
reset-is-the-latch-service-state-in-fle -->|Something else| reset-something-else-reset-only-works-i
style what-command-are-you-trying-to-send fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style open-what-is-the-latch-service-state-in fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style open-retracted-safe-retracted-retained-o fill:#fef3c7,stroke:#f59e0b,color:#78350f
style open-faulted-send-a-reset-command-inste fill:#dcfce7,stroke:#22c55e,color:#14532d
style retract-is-there-an-aircraft-in-the-doc fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style retract-on-is-the-latch-service-state-f fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style retract-on-faulted-follow-latch-service fill:#dcfce7,stroke:#22c55e,color:#14532d
style retract-on-is-the-latch-service-state-e fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style retract-on-empty-yes-follow-latch-servi fill:#dcfce7,stroke:#22c55e,color:#14532d
style retract-on-empty-yes-send-the-retract-c fill:#dcfce7,stroke:#22c55e,color:#14532d
style retract-on-empty-yes-if-the-issue-is-no fill:#fef3c7,stroke:#f59e0b,color:#78350f
style retract-on-empty-no-escalate-to-p2-dock fill:#fef3c7,stroke:#f59e0b,color:#78350f
style retract-off-is-the-latch-service-state fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style retract-off-faulted-follow-latch-servic fill:#dcfce7,stroke:#22c55e,color:#14532d
style retract-off-push-on-the-center-of-the-a fill:#dcfce7,stroke:#22c55e,color:#14532d
style retract-off-if-not-resolved-send-an-open fill:#dcfce7,stroke:#22c55e,color:#14532d
style retract-off-if-not-resolved-escalate-to fill:#fef3c7,stroke:#f59e0b,color:#78350f
style retract-no-aircraft-do-not-retract-a-do fill:#fef3c7,stroke:#f59e0b,color:#78350f
style reset-is-the-latch-service-state-in-fle fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style reset-faulted-this-should-not-have-caus fill:#fef3c7,stroke:#f59e0b,color:#78350f
style reset-something-else-reset-only-works-i fill:#dcfce7,stroke:#22c55e,color:#14532d Hover or focus a block to preview it. Select the block to keep the preview open.
1 question
What command are you trying to send?
2 question
What is the
latch_service_state in Fleet Wrangler? 3 escalation
This should not be possible.
Escalate to P2 Dock Embedded On Call.
Escalate to P2 Dock Embedded On Call.
4 action
Send a RESET command instead of an OPEN command. See Reset Dock Latch.
5 question
Is there an Aircraft in the Dock and is it powered on?
6 question
Is the
latch_service_state in Fleet Wrangler FAULTED? 7 action
Follow LATCH_SERVICE_STATE_FAULTED.
8 question
Is the
latch_service_state in Fleet Wrangler EMPTY? 9 action
Follow LATCH_SERVICE_STATE_EMPTY
NOTE: Push on the center of the Aircraft until the second latch jaw closes.
NOTE: Push on the center of the Aircraft until the second latch jaw closes.
10 action
Send the RETRACT command after the
latch_service_state is RETAINED. 11 escalation
If the issue is not resolved, escalate to P2 Dock Hardware On Call.
12 escalation
Escalate to P2 Dock Hardware On Call.
13 question
Is the
latch_service_state on Fleet Wrangler FAULTED? 14 action
Follow LATCH_SERVICE_STATE_FAULTED.
15 action
Push on the center of the Aircraft until the second latch jaw closes.
1. Listen for a click of the latch jaws.
2. Try sending another RETRACT command after giving the Aircraft a solid push.
1. Listen for a click of the latch jaws.
2. Try sending another RETRACT command after giving the Aircraft a solid push.
16 action
If the issue is not resolved, send an OPEN command via QR code and re-insert the Aircraft into the Dock.
17 escalation
If the issue is not resolved, escalate to P2 Dock Hardware On Call.
18 escalation
Do not retract a Dock with no Aircraft in it.
If you feel that there really is an issue, escalate to P2 Dock Embedded On Call.
If you feel that there really is an issue, escalate to P2 Dock Embedded On Call.
19 question
Is the
latch_service_state in Fleet Wrangler FAULTED or something else? 20 escalation
This should not have caused an issue.
Escalate to P2 Dock Embedded On Call.
Escalate to P2 Dock Embedded On Call.
21 action
RESET only works if the latch is faulted.
1. If you are trying to open the latch, send an OPEN command.
2. If the issue is not resolved, escalate to P2 Dock Embedded On Call.
1. If you are trying to open the latch, send an OPEN command.
2. If the issue is not resolved, escalate to P2 Dock Embedded On Call.
Resolution note
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