Propeller apparently broke off mid flight...epilogue...

[Harleydude]

Hey doods;

So in lieu of finding anyone in this forum who shared my "prop fly off" experience, I thought I'd query the folks at DJI. I wrote the following email:

----------------------- Email TO DJI ---------------------------

Dear sirs;

You recently replaced my drone under warranty. And for that I am grateful. However, I have 2 requests:

1) I would like to know who ruled on my case so I can thank them.

2) I would like to speak with an engineer to know if they have seen this kind of failure before.

I do a lot of mapping, and my concern is that I might have another random prop failure. I just want to know if my case was an isolated incident, or if this is a fairly common occurrence. If the former, I shan't worry. If the latter, I'd like to know what signs I can look for to prevent this from happening again.

Thank you for your time.

Regards,

Donnie Frank



------------------------- Reply FROM DJI ---------------------------

Hi Donie,

I hope you have a pleasant day today!

Thank you for contacting DJI Technical support!

Thank you so much for sending us an email and that's good to hear you have just received your new drone. No worries we will provide you with the best support possible.

I will answer your question coordinately. Regarding your question number one, currently only our repair team who handle your case and in replacing you're done and we don't have their names.

Regarding your question number two, We do apologize we don't have a number of our engineers, and as of this moment, we could not tell also on why your drone randomly got a props failure. To answer your question directly, as far as we know this is a product malfunction.

You don't have to worry about it, since your drone got replaced the issue will never be happened again. If you encounter another issue with your new drone, feel free to contact us back.

Your cooperation and understanding is so much appreciated. Looking forward to hearing from you soon.

You will receive an email survey two days after this email if not responded.
If you happen to be away and won’t be able to answer this email timely, please disregard the survey and reply to us directly.

Best regards,

John Gabrielle

------------------------- END Reply from DJI ---------------------------

So...from what I gather, apparently my prop fly-off was an isolated incident that will "never be happened again." I can only assume that if DJI had seen this kind of failure before, they would inform me.

I flew a very small 13.5-acre mapping gig yesterday in fairly high winds, and the new drone did well. I'm sure gusts were over 30 mph. I usually let the bird drift in ATTI mode to get a definitive wind speed and direction, but didn't have time yesterday. Plus, the wind was picking up so I wanted to get her down out of the sky ASAP.

I'm going to fly another 13.4-acre job in Santa Fe today, along with a commercial real estate shoot (two for one, love those). I've been using the Mavic for real estate, but this client is a little more media-savvy, so I'm going to use the P4P for the higher bitrate.

My business partner also owns a P4P (his is an Obsidion). Unlike mine, his was brand new. Unfortunately, we saw camera failure during a large, 1800 acre mapping gig last week. Because the camera seemed to be working intermittently, we have random missing photos, so we're going to have to go back and refly some small plots. Eventually, the camera just failed altogether.

Hopefully, these are both freak occurrences. I'll probably start up another thread to query the collective regarding camera failure. We believe firmly in redundancy, but our P4P's have suffered some reliability issues. So we're thinking of adding one more P4P to the coral. In the P4P's defense, we use the bejesus out of them. But I digress....

Anyway...good day to you all.

D

 

[Timinator]

I've found that intermittent failure of an electronic component is usually just a prelude to full failure in the very near future. Sounds like just another electronic failure that happened to catch your partner's aircraft. Sucks, but it happens. You say it was brand new but do you know how many hours total time were on it?

 

[BigAl07]

@Harleydude is Donnie Frank? You mean THE Donnie Frank?

He's a freaking legend!! Good to see you brother!!

 

[Harleydude]

I've found that intermittent failure of an electronic component is usually just a prelude to full failure in the very near future. Sounds like just another electronic failure that happened to catch your partner's aircraft. Sucks, but it happens. You say it was brand new but do you know how many hours total time were on it?

The drone had roughly 2-3 hours of total flight time. My partner purchased it new about a month ago, flew it a few times to make sure all was good, and then we took it to a mapping gig. We usually use my P4P, but mine was in the midst of a warranty transaction with DJI. His is the spare.

The total job we're doing right now is over 1800 acres, but we had flown maybe 300 acres that day of a planned 600 acre day.

There were early signs of failure that I simply had never seen before. For instance, the time stamp (metadata) changed by a couple hours right in the middle of a flight. As you can imagine, the time stamp helps organize the photo files. I'm pretty good about keeping good records, which is how I knew the time stamp was off. I just blew it off as some kind of glitch or maybe I had done something wrong (user error).

The other canary in the cave was missing photos. I had made a spreadsheet denoting photo estimates. So when the photos came up about 10% shy, again, I blew it off as "margin of error." After all, this is the first time we had done a job this big.

Upon loading the photos in Pix4D at the office the next day, it was clear to see that entire flight lines (rows) were missing. We have to go back to finish that job anyway, but now we have to fly a couple "mini missions" to fill in the gaps of missing photos.

The other issue was that the drone would fly entire missions (battery) and take ZERO photos. Unfortunately, the software we use keeps count of how many photo clicks it SENDS, but does NOT confirm that photos are actually being taken. I didn't know this at the time. So the software's photo count left me with a false sense of security that photos were actually being taken. Lesson learned. I attributed this photo glitch to a possible MicroSD card issue (we use only SanDisk 90Mbps cards). So I installed a spare known-to-be-working MicroSD card, and the beast started taking photos again. But around the 3rd mission, it quit taking photos again. Okay...so I extrapolated that is was NOT the card.

Finally, after like 10 flights that day, the camera just failed completely. It wouldn't even send a video signal. This is a blessing in disguise, as lord knows how long we would've tried to get that **** thing to work had it not failed completely.

The thing about mapping is it isn't just flying the drone. We have to lay out GCP's (Ground Control Points). These are active 2' x 2' panels that have to be laid out and collected by hand. We have 10 of them, so for large jobs like this one, my partner and I leap frog the flights and panels. Once I fly over and photograph the panels, he collects them and moves them to the next parcel of land. So it's not just a matter of just flying the drone. It's a real song-and-dance of placing panels, flying the mission, moving panels, etc. Depending on the location of the missing photos, we may be able to "get away with" flying small "filler" missions, or may have to fly the entire parcel over again, which includes replacing the panels. It's time consuming.

Needless to say, it was all a major PITA. Fortunately, my new, warranted P4P showed up the day after he shipped his off to DJI, so we're still in business.

Over the past couple days we did a couple very small mapping missions; 13.5 and 13.4 acres. Despite strong winds on the first job, my new P4P flew beautifully. So we're going to head back out there next week and HOPEFULLY finish this job so we can get paid. It's been kind of a saga.

The thing is, the P4P camera issue could be something as simple as a loose ribbon cable. But the thing is brand new, so I didn't want to start opening it up and chance voiding the warranty.

And for the record, both my partner and I are very experienced drone pilots. So all the landings are soft. There were no crashes or hard landings on either drone.

D

 

[Timinator]

Harleydude, sounds like that was a real chore. As you say, good thing it failed relatively quickly instead of lingering for weeks and pulling your hair out. Bit of a day from hell.

 

[Harleydude]

Harleydude, sounds like that was a real chore. As you say, good thing it failed relatively quickly instead of lingering for weeks and pulling your hair out. Bit of a day from hell.

The silver lining I try to take away from these experiences is that I now know to compare the app's photo count to actual photos taken. At the end of every job, my partner and I always say, "So....what did we learn today?" It's pretty amazing that after dozens of jobs - everything from mapping to shooting for the film industry - we almost ALWAYS learn SOMETHING.

We also realize that these "failures" are lessons in disguise. We're at the bleeding edge of mapping technology. So it's logical that we're going to be at the forefront of issues and problems. Take the knowledge, but it in a bag, and use it to make sure these kinds of things never happen again.

 

[JoBe]

You mean THE Donnie Frank? He's a freaking legend!! Good to see you brother!!

agreed. he already has created a legendary rep here in the short time hes been on the forum. new mexico drone pilots ( including the very helpful @sar104 ) can now put a name / face to his posts here when giving recommendations for pro drone services.

other then this site how is he famous?

 

[BigAl07]

agreed. he already has created a legendary rep here in the short time hes been on the forum. new mexico drone pilots (including the very helpful sar104) can now put a name / face to the posts here when giving recomendations for pro drone services.

other then this site how is he famous?

Donnie and I go a pretty good ways back in the sUAS world and he's known very well outside of PhantomPilots.

 

[JoBe]

thats good to hear since hes become a bit infamous in such a brief time here with those prop fly off posts.

 

[David Kraft]

Hey doods;

So in lieu of finding anyone in this forum who shared my "prop fly off" experience, I thought I'd query the folks at DJI. I wrote the following email:

----------------------- Email TO DJI ---------------------------

Dear sirs;

You recently replaced my drone under warranty. And for that I am grateful. However, I have 2 requests:

1) I would like to know who ruled on my case so I can thank them.

2) I would like to speak with an engineer to know if they have seen this kind of failure before.

I do a lot of mapping, and my concern is that I might have another random prop failure. I just want to know if my case was an isolated incident, or if this is a fairly common occurrence. If the former, I shan't worry. If the latter, I'd like to know what signs I can look for to prevent this from happening again.

Thank you for your time.

Regards,

Donnie Frank



------------------------- Reply FROM DJI ---------------------------

Hi Donie,

I hope you have a pleasant day today!

Thank you for contacting DJI Technical support!

Thank you so much for sending us an email and that's good to hear you have just received your new drone. No worries we will provide you with the best support possible.

I will answer your question coordinately. Regarding your question number one, currently only our repair team who handle your case and in replacing you're done and we don't have their names.

Regarding your question number two, We do apologize we don't have a number of our engineers, and as of this moment, we could not tell also on why your drone randomly got a props failure. To answer your question directly, as far as we know this is a product malfunction.

You don't have to worry about it, since your drone got replaced the issue will never be happened again. If you encounter another issue with your new drone, feel free to contact us back.

Your cooperation and understanding is so much appreciated. Looking forward to hearing from you soon.

You will receive an email survey two days after this email if not responded.
If you happen to be away and won’t be able to answer this email timely, please disregard the survey and reply to us directly.

Best regards,

John Gabrielle

------------------------- END Reply from DJI ---------------------------

So...from what I gather, apparently my prop fly-off was an isolated incident that will "never be happened again." I can only assume that if DJI had seen this kind of failure before, they would inform me.

I flew a very small 13.5-acre mapping gig yesterday in fairly high winds, and the new drone did well. I'm sure gusts were over 30 mph. I usually let the bird drift in ATTI mode to get a definitive wind speed and direction, but didn't have time yesterday. Plus, the wind was picking up so I wanted to get her down out of the sky ASAP.

I'm going to fly another 13.4-acre job in Santa Fe today, along with a commercial real estate shoot (two for one, love those). I've been using the Mavic for real estate, but this client is a little more media-savvy, so I'm going to use the P4P for the higher bitrate.

My business partner also owns a P4P (his is an Obsidion). Unlike mine, his was brand new. Unfortunately, we saw camera failure during a large, 1800 acre mapping gig last week. Because the camera seemed to be working intermittently, we have random missing photos, so we're going to have to go back and refly some small plots. Eventually, the camera just failed altogether.

Hopefully, these are both freak occurrences. I'll probably start up another thread to query the collective regarding camera failure. We believe firmly in redundancy, but our P4P's have suffered some reliability issues. So we're thinking of adding one more P4P to the coral. In the P4P's defense, we use the bejesus out of them. But I digress....

Anyway...good day to you all.

D

 

[Harleydude]

There are limits to image acquisition frequency, try changing to raw, it will raise to 5sec minimum between shots. This all assumes you have a proper fast sd card. Still over longer periods it will not meet the minimum.

Actually, DJI already replaced my partner's RC under warranty (the issue was with the RC, NOT the AC...odd). There was definitely a hardware issue, which is validated by the warranty replacement from DJI. That said...

You use RAW files for mapping? At this point, using compressed files, the results have been spectacular. This last job generated nearly 10,000 photos. Compressed, that's a lot of data. Uncompressed files use up 5x - 6x more disk space. I could only imagine how much storage space that would accumulate over time.

Regarding MicroSD cards, we use 90Mbps cards...nothing less.

Though we haven't tested my partner's P4P in the field yet, my P4P has been working spectacularly.

Question: Do the RAW files reduce your rendering times in Pix4D? Do you find 6x the storage space worth the trade off for quicker render times?

Our Standard practice is to keep more than it

80% overlap,

We've been using 75/75 with great success.

and have a 24” monitor or better to check acquired data .... BEFORE YOU LEAVE.

Data is ALWAYS scrutinized, confirmed and backed up on-site via my laptop after every mission (even if we have a dozen missions in one client area). If I suspect problems, data is backed up every battery change. Generally speaking, I'll back up the data after every mission, which has worked well.

To be clear, camera problems were discovered on site. The first symptoms manifested themselves as erroneous time stamps in the metadata. We check everything. Photo count. Photo quality. And if we have time, we'll do a quick import into Pix4D right there on-site to make sure there are no missing photos. We always catch the occasional missing photo, but these missing photos account for < 1% of the total photo count. We're very thorough. It simply costs WAY too much to reshoot 600 acres.

Our latest failure taught us that camera failure isn't always the camera. In our case, it was the RC. I've never seen an RC failure before. Next time, I'll consider the RC as a possible point of failure. Gotta love this business. Curve balls all day....

D

 

[umanbean]

@Harleydude is Donnie Frank? You mean THE Donnie Frank?

He's a freaking legend!! Good to see you brother!!

Please enlighten us?

 

[BigAl07]

Please enlighten us?

He's a very knowledgeable, out spoken, and experienced UAS operator. We've known each other a good while now and to say I highly respect him is an understatement.

 

[umanbean]

Thanks BigAl. Glad to know we have yet another Guru here