Mysterious Malfunction, Crash & PARM LOG Interpretation for P4P V1 (SOLVED)

[AllenArmy]

Detailed Description of DJI Phantom 4 Pro V1 Malfunction/Crash

Equipment: DJI Phantom 4 Pro Version 1 with GL300E Remote Controller

I am writing to seek expertise and guidance regarding a recent incident involving my DJI Phantom 4 Pro V1 drone. I would like to provide you with a comprehensive account of what transpired, my initial attempts at addressing the issues, and my current situation in the hopes of determining the necessary steps for repair and restoration. Additionally, I would like to understand how to interpret the PARM Log data.

Incident Description: On August 19, 2023, I powered on my DJI Phantom 4 Pro V1 drone, and everything appeared to be functioning as usual. After takeoff, I hovered at an altitude of approximately 7-8 feet to ensure that the drone was flying smoothly and without errors. However, I noticed that the GPS system was experiencing difficulties locking onto the drone's position despite being in "P" mode. This resulted in the drone behaving as if it were in ATTI mode for an unusually extended period, approximately 15-20 seconds. Subsequently, the drone successfully locked onto GPS signals, establishing a home point.

At this point, I initiated an ascent by increasing power using the left stick. It was during this ascent that several error messages appeared on the screen, including "Backward Obstacle Sensing is not functioning," "Exit backward, Forward Sensing system," and "Forward Obstacle Sensing is not functioning." It was at this juncture that I observed what appeared to be a collision or contact between one of the propellers, leading to its breakage. Importantly, I wish to clarify that the drone was operating in an open environment, devoid of proximity to trees, structures, power lines, or any other potential obstacles.

The drone subsequently plummeted to the ground, resulting in observable damage to the left rear arm of the top shell. This damaged arm coincided with the location of the propeller that had broken off (while in flight) as evidenced by photographs taken after the incident. Additionally, an LED cover and a white panel providing access to the landing gear antenna were dislodged in the crash.

Upon further inspection, I noted that while there was no visible external damage to the gimbal, both the gimbal and camera systems were malfunctioning. The camera displayed a fuzzy image on the remote receiver's screen, and the gimbal exhibited erratic movements, failing to initialize and stabilize during the initial power-on sequence of the drone.

Actions Taken: In my efforts to address the situation, I undertook the following actions:

1. I attempted to download flight records in DAT format to discern the cause of the malfunction and crash.
2. I made efforts to decrypt the DAT file, which purportedly contains flight records. Regrettably, I encountered challenges in successfully using the DatCon application for this purpose.
3. FYI - My laptop is a MacBook Pro and the DAT file is appearing in VLC when I try to access which leads to no data being revealed
4. I managed to download flight data via a file called PARM LOG which I am unfamiliar with.

Current Status and Next Steps: Presently, I find myself at a juncture where the drone has been partially dismantled. I have separated the top shell from the middle shell and removed the gimbal and camera assembly. However, I am uncertain about the optimal course of action moving forward. I believe a comprehensive systems check is imperative to determine which components require repair or replacement. However, I lack the requisite expertise to conduct these checks effectively. I am also eager to identify a method for decrypting the flight records to shed light on the sequence of events leading to the malfunction and crash. More than anything, I am curious to find answers.

Therefore, I kindly request your professional insights on the following matters:

1. Guidance on successfully decrypting the (PARM LOG) flight records contained in the DAT file.
2. Recommendations on how to proceed with a comprehensive systems check to identify damaged or malfunctioning components.
3. Assistance in determining the specific parts that require repair or replacement based on the aforementioned incident and subsequent checks.
4. Any additional steps or precautions I should consider in the repair process.
5. An estimate of the feasibility and cost of restoring the drone to operational status, given the described circumstances.

Your expertise in addressing this matter would be greatly appreciated, and I am willing to provide any further information or details as required. I understand the complexity of drone repairs and prioritize safety throughout this process therefore I am more than willing to part ways with this drone.

Thank you for your time and consideration. I eagerly await your guidance and recommendations.

Kind Regards,

Sean Allen
Spokane, Wa..

DAT File Google Drive Link:

FLY359.DAT

drive.google.com

PARM Log Google Drive Link:

PARM.LOG

drive.google.com

Google Drive P4P Crash Photos/Data:

P4P Crash Details/Info. - Google Drive

drive.google.com

Photos: broken propeller while in flight, damaged arm/top shell, screenshot of warnings/errors right before malfunction.

 

[msinger]

It was at this juncture that I observed what appeared to be a collision or contact between one of the propellers, leading to its breakage

If the area was completely void of obstacles, then it seems like a collision would have been impossible. Or are you suggesting maybe that you saw the drone crash into something?

the propeller that had broken off (while in flight) as evidenced by photographs taken after the incident.

Assuming there really was no collision, this seems to be the most likely cause. Perhaps the prop hub area was damaged and became too weak to remain attached after takeoff.

Can you post your TXT flight log here? If needed, you can find instructions for locating that TXT file here.

 

[AllenArmy]

If the area was completely void of obstacles, then it seems like a collision would have been impossible. Or are you suggesting maybe that you saw the drone crash into something?


Assuming there really was no collision, this seems to be the most likely cause. Perhaps the prop hub area was damaged and became too weak to remain attached after takeoff.

Can you post your TXT flight log here? If needed, you can find instructions for locating that TXT file here.

The drone did not collide with anything however when the incident occurred, it “sounded like” a collision of the propeller making contact with the drone itself or the sound made when a drone is flown up into a tree branch. The drone was out in the open though. My daughters and I watched in disbelief as the drone tumbled to the ground.

I will work on extracting the TXT flight log.

 

[AllenArmy]

If the area was completely void of obstacles, then it seems like a collision would have been impossible. Or are you suggesting maybe that you saw the drone crash into something?


Assuming there really was no collision, this seems to be the most likely cause. Perhaps the prop hub area was damaged and became too weak to remain attached after takeoff.

Can you post your TXT flight log here? If needed, you can find instructions for locating that TXT file here.

Additionally, the broken propeller was still attached to the prop hub after crash.

 

[msinger]

Additionally, the broken propeller was still attached to the prop hub after crash

More details would be helpful. Are you saying half of the prop was attached and the other half landed elsewhere?

 

[AllenArmy]

More details would be helpful. Are you saying half of the prop was attached and the other half landed elsewhere?

 

[AllenArmy]

When the drone came crashing down, all the propellers were still attached to the drone. We have not been able to find/recover other half of the broken propeller. Though the drone was only 10-15 feet above the ground, we have not been able to find the missing piece.

 

[Starz]

The sound you heard was likely the exiting piece of the prop contacting with other parts of the aircraft. Could have been exiting through one of the other spinning props.

The picture of the damaged prop(could be just my old eyes,but looks like some discoloration in the hub area)looks to be an older piece of hardware that has seen better days. Is it possible that the visible cracks in the hub area were there prior to takeoff? Are the other props of similar characteristics?

 

[CR125Honda]

My V1 had an odd occasional GPS issue that was becoming more frequent before I sent it into DJI for repair. They confirmed the issue in an email before sending back a new replacement. Pretty sure I posted a thread on it if you want to check. Seems like the prop split while in flight. My advice.. Put it back together, send it to DJI for repair. Costs were very reasonable for me and for many others from what I’ve read. I’d ask if it’s possible to upgrade to a V2 for a cost. Only because the V2 is supposed to have an RID upgrade soon. Best of luck.

 

[AllenArmy]

The sound you heard was likely the exiting piece of the prop contacting with other parts of the aircraft. Could have been exiting through one of the other spinning props.

The picture of the damaged prop(could be just my old eyes,but looks like some discoloration in the hub area)looks to be an older piece of hardware that has seen better days. Is it possible that the visible cracks in the hub area were there prior to takeoff? Are the other props of similar characteristics?

Thanks for the reply. I agree with your assessment. Regarding the prop hubs, they all checked out and appeared to be in good condition. I have attached photos of the other three props used in this flight. All props looked this way prior to the flight.

 

[Capt KO]

Agree with above, reassemble and open a repair ticket with DJI. They supply shipping labels. May be pleasantly surprised.

 

[AllenArmy]

If the area was completely void of obstacles, then it seems like a collision would have been impossible. Or are you suggesting maybe that you saw the drone crash into something?


Assuming there really was no collision, this seems to be the most likely cause. Perhaps the prop hub area was damaged and became too weak to remain attached after takeoff.

Can you post your TXT flight log here? If needed, you can find instructions for locating that TXT file here.

 

[AllenArmy]

-.138 : 3907 [L-FMU/MOTOR]Start. reason:REQ_RC_NORMAL
-.138 : 3907 [L-PWM]set actuator mode:CTRL
-.135 : 3907 [L-FLYMODE][Ctrl<2>] REQ_RC_COMMAND ENGINE_START ctrl_engine_start
-.135 : 3907 [L-FDI]tilt when motor on = 0.006300, static flag = 1
-.134 : 3907 [L-FMU/FSM]state changed. cur: on ground
-.119 : 3908 [L-IMU]set imu switch level = 8
-.118 : 3908 [L-IOC]Set CL. 64.2 Degree
-.118 : 3908 [L-TAKEOFF]alti: 695.523804 tors: 64.200462
1.405 : 3984 [L-FLYMODE][Ctrl<2>] REQ_RC_COMMAND ASST_TAKEOFF ctrl_asst_takeoff
14.005 : 4614 [L-RC]mode switch changed!
14.025 : 4615 [L-RC]mode switch changed!
50.823 : 6455 [L-FMU/MOTOR] Stop. reason:landing.exit_takeoff

 

[CR125Honda]

 

[msinger]

@AllenArmy none of those files are the TXT flight log. Can you please follow the instructions I linked you to and retrieve the TXT flight log file?

 

[AllenArmy]

Loading Google Sheets

P4P Crash.recDefs.txt

drive.google.com

P4P Crash.log.txt

drive.google.com

P4P Crash.config.txt

drive.google.com

 

[AllenArmy]

My V1 had an odd occasional GPS issue that was becoming more frequent before I sent it into DJI for repair. They confirmed the issue in an email before sending back a new replacement. Pretty sure I posted a thread on it if you want to check. Seems like the prop split while in flight. My advice.. Put it back together, send it to DJI for repair. Costs were very reasonable for me and for many others from what I’ve read. I’d ask if it’s possible to upgrade to a V2 for a cost. Only because the V2 is supposed to have an RID upgrade soon. Best of luck.

Thank you. I will look into this option.

 

[AllenArmy]

@AllenArmy none of those files are the TXT flight log. Can you please follow the instructions I linked you to and retrieve the TXT flight log file?

I am working on it....: )) (struggling with my MacBook Pro)

 

[AllenArmy]

View attachment 125464

Yes, I noticed this as well. This "dent" was not present prior to flight so I would assume the broken piece of the other propeller made contact with the propeller in this photo.

 

[msinger]

Here's a link to the flight log:

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com