PROP_IMBALANCE_TEST: OUT_OF_RANGE
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Applicable alarms (3)
PROP_IMBALANCE_TESTMOTOR_CONTROL_UNINITIALIZEDZIP_EXECUTIVE_V4_TEST_OUT_OF_RANGE
Likely outcomes — click to expand
Based on 0 missions where this alarm fired in the last
90 days
(for PROP_IMBALANCE_TEST) as of 2026-10-13
Aggregated from fleet operations and refreshed daily. Individual outcomes may vary by site and configuration.
Background
Section titled “Background”This test is intended to check if the propeller motors are balanced. If this test fails, it could indicate an issue with the motor assembly or propeller. However, if a motor is not powered or not communicating, this will also cause this test to fail.
Troubleshooting Steps
Section titled “Troubleshooting Steps”graph TD
is-motor-control-uninitialized-active{"<small><b>Step 1</b></small><br/>Question: Is MOTOR_CONTROL_UNINITIALIZED active?"}
this-failure-is-not-because-of-an-issue("<small><b>Step 2</b></small><br/>Reference: This failure is not because of an iss...")
identify-the-motor-that-caused-the-fail["<small><b>Step 3</b></small><br/>Action: Identify the motor that caused the fa..."]
is-this-the-first-time-on-this-aircraft{"<small><b>Step 4</b></small><br/>Question: Is this the first time on this Aircra..."}
the-aircraft-may-return-to-service("<small><b>Step 5</b></small><br/>Reference: The Aircraft may return to service.")
inspect-the-motor["<small><b>Step 6</b></small><br/>Action: Inspect the motor. 1. Spin the motor ..."]
is-there-damage-to-the-motor{"<small><b>Step 7</b></small><br/>Question: Is there damage to the motor?"}
replace-the-motor-see-umm-chapter-60-fo["<small><b>Step 8</b></small><br/>Action: Replace the motor. See UMM Chapter 60..."]
replace-the-propellers-see-umm-chapter["<small><b>Step 9</b></small><br/>Action: Replace the propellers. See UMM Chapt..."]
run-a-diagnostics-check-with-motors-is{"<small><b>Step 10</b></small><br/>Question: Run a Diagnostics check with motors -..."}
the-aircraft-may-return-to-service-2("<small><b>Step 11</b></small><br/>Reference: The Aircraft may return to service.")
escalate-to-p2-aircraft-hardware-on-cal{{"<small><b>Step 12</b></small><br/>Escalation: Escalate to P2 Aircraft Hardware On C..."}}
is-motor-control-uninitialized-active -->|Yes| this-failure-is-not-because-of-an-issue
is-motor-control-uninitialized-active -->|No| identify-the-motor-that-caused-the-fail
identify-the-motor-that-caused-the-fail --> is-this-the-first-time-on-this-aircraft
is-this-the-first-time-on-this-aircraft -->|First occurrence| the-aircraft-may-return-to-service
is-this-the-first-time-on-this-aircraft -->|More than one occurrence| inspect-the-motor
inspect-the-motor --> is-there-damage-to-the-motor
is-there-damage-to-the-motor -->|Yes| replace-the-motor-see-umm-chapter-60-fo
is-there-damage-to-the-motor -->|No| replace-the-propellers-see-umm-chapter
replace-the-motor-see-umm-chapter-60-fo --> run-a-diagnostics-check-with-motors-is
replace-the-propellers-see-umm-chapter --> run-a-diagnostics-check-with-motors-is
run-a-diagnostics-check-with-motors-is -->|Yes| the-aircraft-may-return-to-service-2
run-a-diagnostics-check-with-motors-is -->|No| escalate-to-p2-aircraft-hardware-on-cal
style is-motor-control-uninitialized-active fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style this-failure-is-not-because-of-an-issue fill:#f3e8ff,stroke:#a855f7,color:#581c87
style identify-the-motor-that-caused-the-fail fill:#dcfce7,stroke:#22c55e,color:#14532d
style is-this-the-first-time-on-this-aircraft fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style the-aircraft-may-return-to-service fill:#f3e8ff,stroke:#a855f7,color:#581c87
style inspect-the-motor fill:#dcfce7,stroke:#22c55e,color:#14532d
style is-there-damage-to-the-motor fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style replace-the-motor-see-umm-chapter-60-fo fill:#dcfce7,stroke:#22c55e,color:#14532d
style replace-the-propellers-see-umm-chapter fill:#dcfce7,stroke:#22c55e,color:#14532d
style run-a-diagnostics-check-with-motors-is fill:#dbeafe,stroke:#3b82f6,color:#1e3a5f
style the-aircraft-may-return-to-service-2 fill:#f3e8ff,stroke:#a855f7,color:#581c87
style escalate-to-p2-aircraft-hardware-on-cal fill:#fef3c7,stroke:#f59e0b,color:#78350f Hover or focus a block to preview it. Select the block to keep the preview open.
1 question
Is
MOTOR_CONTROL_UNINITIALIZED active? 2 reference
This failure is not because of an issue with the props. See ZIP_MOTOR_CONTROL_UNINITIALIZED.
3 action
Identify the motor that caused the failure and then continue to the next step.
How to determine which motor caused the Prop Imbalance IBIT to fail
Check the following messages to identify the source of the failure.
-
-
-
-
The result will be
If any of the motor results read
How to determine which motor caused the Prop Imbalance IBIT to fail
Check the following messages to identify the source of the failure.
-
prop_imbalance_result.hover_port_aft-
prop_imbalance_result.hover_port_fwd-
prop_imbalance_result.hover_stbd_aft-
prop_imbalance_result.hover_stbd_fwdThe result will be
OUT_OF_RANGE for the motor at fault.If any of the motor results read
FEEDBACK_LOSS double check Step 1. 4 question
Is this the first time on this Aircraft with this motor?
5 reference
The Aircraft may return to service.
6 action
Inspect the motor.
1. Spin the motor shaft by hand and ensure that it rotates freely.
2. Check for obvious damage to the motor shaft.
1. Spin the motor shaft by hand and ensure that it rotates freely.
2. Check for obvious damage to the motor shaft.
7 question
Is there damage to the motor?
8 action
Replace the motor. See UMM Chapter 60 for steps.
9 action
Replace the propellers. See UMM Chapter 60 for steps.
10 question
Run a Diagnostics check with motors - is the issue resolved?
11 reference
The Aircraft may return to service.
12 escalation
Escalate to P2 Aircraft Hardware On Call.
Resolution note
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