C2_EXTENDED_LOSS
Viewing this guide for
Applicable alarms (3)
C2_EXTENDED_LOSS0x00100349ZIP_EXECUTIVE_V4_C2_UNAVAILABLE
Likely outcomes — click to expand
Based on 11,499 missions where this alarm fired in the last
90 days
(for C2_EXTENDED_LOSS) as of 2026-10-13
Grounding vs discrepancy (of 121 ZERP issues filed on these missions)
Top work orders
- EV3: Inspect Aircraft after Droid Left Behind (DLB) · MAINTENANCE_ACTION 19
Frequently replaced parts
| Part | P/N | Removals |
|---|---|---|
| ASSY, SPOOL AND LINE, DOCKING FIN, AIRCRAFT, P2 | 48477 | 61 |
| PREPPED HOVER HARNESSING, STBD, ZIP, P2 | 0117583 | 32 |
| SERVO, ASSY, UNIVERSAL, P2 | 20398 | 23 |
| T800 CW HOVER PROPELLER, ZIP, P2 | 31101 | 20 |
| CCW HOVER PROPELLER BLADE, ZIP, P2 | 29857 | 20 |
Frequently co-occurring alarms (% of the 11,499 missions above)
Aggregated from fleet operations and refreshed daily. Individual outcomes may vary by site and configuration.
Background
Section titled “Background”C2_EXTENDED_LOSS occurs when the Aircraft loses command and control communication with the cloud for an extended period. Based on validator analysis, there are three primary failure modes:
ZIP_EXECUTIVE_V4_C2_UNAVAILABLE occurs when the Aircraft cannot acquire C2 before takeoff, and it may trigger before C2_EXTENDED_LOSS is set.
- Cell Coverage Loss: Complete loss of cellular coverage from the cell modem not having a connection (due to a weak/nonexistent cell signal or other issues) will result in a loss of all Zip to Cloud comms.
- Cloud Communications Loss: Where the Zip is unable to successfully complete a Zip to Cloud request (i.e send all cloudbound messages and receive Zipbound messages as a response) for varied reasons (could include weak cell signal, DNS issues, or issues within the comms agent channel or comms server)
- Controller Heartbeat Loss: Cloud software issues where comms agent channels appear healthy but the link between the Zip and Controller is interrupted
This alarm may cause a DockASAP or mission failure depending on flight phase and duration.
C2 Loss vs Asset Offline
Section titled “C2 Loss vs Asset Offline”There is a distinction between an Asset being offline and C2 Loss. C2 Loss can only occur on Zips, and only while they are assigned a mission.
If an individual asset is offline in Fleet Wrangler, and we have ruled out a site or asset networking issue, see Asset Offline Troubleshooting Landing Page.
Troubleshooting Steps
Section titled “Troubleshooting Steps”graph TD
was-c2-loss-observed-on-multiple-assets{"<small><b>Step 1</b></small><br/>Question: Was C2 loss observed on multiple asse..."}
was-c2-loss-observed-on-multiple-assets-2{"<small><b>Step 2</b></small><br/>Question: Was C2 loss observed on multiple asse..."}
are-the-assets-specifically-reporting-c2{"<small><b>Step 3</b></small><br/>Question: Are the assets specifically reporting..."}
escalate-to-asw-delivery-support-on-cal{{"<small><b>Step 4</b></small><br/>Escalation: Escalate to ASW Delivery Support On Call"}}
escalate-to-application-software-on-cal{{"<small><b>Step 5</b></small><br/>Escalation: Escalate to Application Software on call"}}
follow-asset-offline-due-to-comms-or-pro["<small><b>Step 6</b></small><br/>Action: Follow Asset Offline Due To Comms OR..."]
was-the-aircraft-docked-and-not-in-pre-f{"<small><b>Step 7</b></small><br/>Question: Was the aircraft docked and NOT in pr..."}
was-the-aircraft-docked-and-in-pre-fligh{"<small><b>Step 8</b></small><br/>Question: Was the aircraft docked and in pre-fl..."}
if-the-dock-does-not-have-an-internet-co{"<small><b>Step 9</b></small><br/>Question: If the Dock does not have an internet..."}
follow-no-internet-via-ethernet["<small><b>Step 10</b></small><br/>Action: Follow NO_INTERNET_VIA_ETHERNET/to..."]
if-the-aircraft-is-online-retry-the-miss["<small><b>Step 11</b></small><br/>Action: If the Aircraft is online, retry the ..."]
have-there-been-repeated-back-to-back-fa{"<small><b>Step 12</b></small><br/>Question: Have there been repeated back to back..."}
return-the-aircraft-to-service-and-reatt["<small><b>Step 13</b></small><br/>Action: Return the aircraft to service."]
are-validator-results-available{"<small><b>Step 14</b></small><br/>Question: Check validator results for root caus..."}
return-the-aircraft-to-service-if-were-n["<small><b>Step 15</b></small><br/>Action: Return the aircraft to service if we’..."]
access-the-processed-flight-log-in-baraz["<small><b>Step 16</b></small><br/>Action: Access the processed flight log in Ba..."]
what-is-the-c2-extended-loss-field-valid{"<small><b>Step 17</b></small><br/>Question: What is the **c2_extended_loss** fiel..."}
this-means-that-the-aircraft-could-not-r["<small><b>Step 18</b></small><br/>Action: This means that the Aircraft could no..."]
if-the-validator-failure-mode-is-not-no-["<small><b>Step 19</b></small><br/>Action: If the validator failure mode is not ..."]
was-c2-loss-observed-on-multiple-assets -->|Yes| are-the-assets-specifically-reporting-c2
was-c2-loss-observed-on-multiple-assets -->|No| was-the-aircraft-docked-and-not-in-pre-f
was-c2-loss-observed-on-multiple-assets-2 -->|Yes| are-the-assets-specifically-reporting-c2
was-c2-loss-observed-on-multiple-assets-2 -->|No| was-the-aircraft-docked-and-in-pre-fligh
are-the-assets-specifically-reporting-c2 -->|Yes| escalate-to-asw-delivery-support-on-cal
are-the-assets-specifically-reporting-c2 -->|No| follow-asset-offline-due-to-comms-or-pro
was-the-aircraft-docked-and-not-in-pre-f -->|Yes| if-the-dock-does-not-have-an-internet-co
was-the-aircraft-docked-and-not-in-pre-f -->|No| have-there-been-repeated-back-to-back-fa
was-the-aircraft-docked-and-in-pre-fligh -->|Yes| if-the-dock-does-not-have-an-internet-co
was-the-aircraft-docked-and-in-pre-fligh -->|No| have-there-been-repeated-back-to-back-fa
if-the-dock-does-not-have-an-internet-co -->|Yes| follow-no-internet-via-ethernet
if-the-dock-does-not-have-an-internet-co -->|No| if-the-aircraft-is-online-retry-the-miss
have-there-been-repeated-back-to-back-fa -->|Yes| are-validator-results-available
have-there-been-repeated-back-to-back-fa -->|No| return-the-aircraft-to-service-and-reatt
are-validator-results-available -->|Yes| access-the-processed-flight-log-in-baraz
are-validator-results-available -->|No| return-the-aircraft-to-service-if-were-n
return-the-aircraft-to-service-if-were-n --> access-the-processed-flight-log-in-baraz
access-the-processed-flight-log-in-baraz --> what-is-the-c2-extended-loss-field-valid
what-is-the-c2-extended-loss-field-valid -->|NO_INTERNET| this-means-that-the-aircraft-could-not-r
what-is-the-c2-extended-loss-field-valid -->|The validator result is som...| if-the-validator-failure-mode-is-not-no-
style was-c2-loss-observed-on-multiple-assets fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style was-c2-loss-observed-on-multiple-assets-2 fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style are-the-assets-specifically-reporting-c2 fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style escalate-to-asw-delivery-support-on-cal fill:#fef3c7,stroke:#f59e0b,color:#78350f
style escalate-to-application-software-on-cal fill:#fef3c7,stroke:#f59e0b,color:#78350f
style follow-asset-offline-due-to-comms-or-pro fill:#dcfce7,stroke:#22c55e,color:#14532d
style was-the-aircraft-docked-and-not-in-pre-f fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style was-the-aircraft-docked-and-in-pre-fligh fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style if-the-dock-does-not-have-an-internet-co fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style follow-no-internet-via-ethernet fill:#dcfce7,stroke:#22c55e,color:#14532d
style if-the-aircraft-is-online-retry-the-miss fill:#dcfce7,stroke:#22c55e,color:#14532d
style have-there-been-repeated-back-to-back-fa fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style return-the-aircraft-to-service-and-reatt fill:#dcfce7,stroke:#22c55e,color:#14532d
style are-validator-results-available fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style return-the-aircraft-to-service-if-were-n fill:#dcfce7,stroke:#22c55e,color:#14532d
style access-the-processed-flight-log-in-baraz fill:#dcfce7,stroke:#22c55e,color:#14532d
style what-is-the-c2-extended-loss-field-valid fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style this-means-that-the-aircraft-could-not-r fill:#dcfce7,stroke:#22c55e,color:#14532d
style if-the-validator-failure-mode-is-not-no- fill:#dcfce7,stroke:#22c55e,color:#14532d Hover or focus a block to preview it. Select the block to keep the preview open.
1 question
Was C2 loss observed on multiple assets simultaneously (within seconds of each other)?
2 question 2026.03
Was C2 loss observed on multiple assets simultaneously?
3 question
Are the assets specifically reporting C2 loss / setting C2 loss alarms?
4 escalation
Escalate to ASW Delivery Support On Call
5 escalation 2026.03
Escalate to Application Software on call
6 action
Follow Asset Offline Due To Comms OR Provisioning Agent Error if assets are just offline or to determine if there are site network issues
7 question
Was the aircraft docked and NOT in pre-flight at the time C2 loss was observed?
8 question 2026.03
Was the aircraft docked and in pre-flight at the time C2 loss was observed?
9 question
If the Dock does not have an internet connection via ethernet, C2 loss will occur. Is the
NO_INTERNET_VIA_ETHERNET alarm set on the Dock? 10 action
Follow NO_INTERNET_VIA_ETHERNET.
11 action
If the Aircraft is online, retry the mission. If the Aircraft is not online, follow Asset Offline Due To Comms OR Provisioning Agent Error for other possible causes.
12 question
Have there been repeated back to back failures (> 3) of the same mission?
13 action
Return the aircraft to service.
14 question
Check validator results for root cause analysis. Are validator results available?
15 action
Return the aircraft to service if we’re not flying another mission to the same DAR. Once validator results are available, continue to the next step and check the validator results
16 action
Access the processed flight log in Baraza (see How to Find Validator Results in Baraza. The c2 loss validator is named
c2-loss-reason-validator/c2-alarm-was-set so locate that validator’s results) and review the c2_zip_a validator results to determine the specific failure mode: 17 question
What is the c2_extended_loss field validator result?
18 action
This means that the Aircraft could not reach the internet at all, and the cell modem itself was disconnected. If C2 loss repeatedly occurs in the same location and the validator failure reasons is set to this specific failure mode in each case, escalate to the maps team to create a ZFR.
19 action
If the validator failure mode is not NO_INTERNET, return the Aircraft to service and reattempt the mission.
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:
Session is too large to fit in a URL. Use Download session JSON to share the timeline out-of-band.
Did this guide help you get unblocked?
Open suggestions
There are no open suggestions.