Motor Pod falls off in flight

KR200 · Aug 9, 2016

Yesterday I was flying my H over water along the shoreline of lake Huron when the video twitched about 90 degrees and corrected itself in forward facing mode. About 30 seconds later I got a warning that the H was in 5 motor mode, then all connection was lost. It was approximately 1000' away so I missed seeing the actual crash. The video ends before the drop to the water. It took 20-30 minutes to get to the H. It was in approximately 30 cm of water. The H and camera were physically intact except for one motor pod hanging by it's wires with a broken prop. The gear was still retracted, so I guess 5 motor mode doesn't lower the gear. I noticed the body light was still dimly flashing red. I quickly removed the battery to prevent further electrical damage.

Returning home I immediately put the battery on my charger/ballancer using QUADCAM's connector. The voltage was just over 9v !!! I charged it to storage charge successfully, so I guess it's ok despite the low voltage discharge. I drained as much water as I could and left the H to dry for a few days.

I found that the rivet holding the motor pod to the arm was missing but there was no damage to the arm or pod. It appears that the rivet came out in flight causing the video twitches. The pod then worked it's way off, breaking the prop resulting in the 5 motor mode warning and subsequent water ditching.

I will give the H and camera a few days to dry then pack them in rice for a few more days before I try to power up. I will contact Yuneec today.

Rayray · Aug 9, 2016

Yikes! The nightmare scenario...Kindly follow up to let us know your results. How many estimated hours of flight time have you had with that H?
Good luck.

Brandon Lowe · Aug 9, 2016

I think I will add inspect mounting rivets to my pre-flight check list now. I think with something like the H a good pre-flight is a good idea.

anthony h-ellary · Aug 9, 2016

Brandon Lowe said:
I think I will add inspect mounting rivets to my pre-flight check list now. I think with something like the H a good pre-flight is a good idea.

brandon

why not post up your pre flight check list so others can learn from it and maybe add to it also

i dont have my h yet as waiting for the pro version in the uk is like waiting for christmas

SevenTypesOfDumb · Aug 9, 2016

anthony h-ellary said:
brandon

why not post up your pre flight check list so others can learn from it and maybe add to it also

Yeah, GREAT idea!

Burntpixel · Aug 9, 2016

KR200 said:
Yesterday I was flying my H over water along the shoreline of lake Huron when the video twitched about 90 degrees and corrected itself in forward facing mode. About 30 seconds later I got a warning that the H was in 5 motor mode, then all connection was lost. It was approximately 1000' away so I missed seeing the actual crash. The video ends before the drop to the water. It took 20-30 minutes to get to the H. It was in approximately 30 cm of water. The H and camera were physically intact except for one motor pod hanging by it's wires with a broken prop. The gear was still retracted, so I guess 5 motor mode doesn't lower the gear. I noticed the body light was still dimly flashing red. I quickly removed the battery to prevent further electrical damage.

Returning home I immediately put the battery on my charger/ballancer using QUADCAM's connector. The voltage was just over 9v !!! I charged it to storage charge successfully, so I guess it's ok despite the low voltage discharge. I drained as much water as I could and left the H to dry for a few days.

I found that the rivet holding the motor pod to the arm was missing but there was no damage to the arm or pod. It appears that the rivet came out in flight causing the video twitches. The pod then worked it's way off, breaking the prop resulting in the 5 motor mode warning and subsequent water ditching.

I will give the H and camera a few days to dry then pack them in rice for a few more days before I try to power up. I will contact Yuneec today.

I have seen this very same issue on other craft that have aluminum pop rivets used on round carbon fiber motor boom arms. Sorry to hear you had the crash. If anything can come good out of your situation,it would be to warn others to pay very close attention to those point on the H that use aluminum pop rivets.

Brandon Lowe · Aug 9, 2016

I have not started it yet as my H is grounded right now waiting for my camera to come back but as soon as I have it done I will post. Then others can add or improve it for all of us.

Reasty · Aug 9, 2016

anthony h-ellary said:
brandon

why not post up your pre flight check list so others can learn from it and maybe add to it also

i dont have my h yet as waiting for the pro version in the uk is like waiting for christmas

You could also say "waiting for the pro version in the uk is like waiting for the backpack"

Batfire · Aug 13, 2016

Wow, that really is a bad time. Sorry to here that but interesting to learn the results of crash. If they are loose etc....then maybe since its easy enough replace them with small aircraft bolts and castle nuts with lock wire. As a comm. pilot I have seen this many times in aviation industry. With the vibrations our copters get it might be a good idea. You can find cosmetically desired bolts and castle nuts and just paint to match color. Just an idea.

Cheers

Batfire

Photo · Aug 13, 2016

KR200 said:
Yesterday I was flying my H over water along the shoreline of lake Huron when the video twitched about 90 degrees and corrected itself in forward facing mode. About 30 seconds later I got a warning that the H was in 5 motor mode, then all connection was lost. It was approximately 1000' away so I missed seeing the actual crash. The video ends before the drop to the water. It took 20-30 minutes to get to the H. It was in approximately 30 cm of water. The H and camera were physically intact except for one motor pod hanging by it's wires with a broken prop. The gear was still retracted, so I guess 5 motor mode doesn't lower the gear. I noticed the body light was still dimly flashing red. I quickly removed the battery to prevent further electrical damage.

Returning home I immediately put the battery on my charger/ballancer using QUADCAM's connector. The voltage was just over 9v !!! I charged it to storage charge successfully, so I guess it's ok despite the low voltage discharge. I drained as much water as I could and left the H to dry for a few days.

I found that the rivet holding the motor pod to the arm was missing but there was no damage to the arm or pod. It appears that the rivet came out in flight causing the video twitches. The pod then worked it's way off, breaking the prop resulting in the 5 motor mode warning and subsequent water ditching.

I will give the H and camera a few days to dry then pack them in rice for a few more days before I try to power up. I will contact Yuneec today.

Can you pls explain in more detail what the "rivet" is? Where to look at motor probs?

Keimon Lawrence · Aug 13, 2016

Can you post a picture of the part in question please as I'm not sure what it part it is.

KR200 · Aug 13, 2016

Google Pop Rivet, you'll get lots of info and pictures. It's on the bottom of the motor mount where it pushes onto the motor arm. There's a hole in the carbon fiber tube that the rivet passes thru and locks the motor mount in place. If it comes out, there's only friction and the wiring holding the motor on. The thrust and vibration will gradually work the mount off the tube if the rivet falls out.

I dried out the H for 5 days and recharged the battery, but it's dead

Next step is Yuneec Support. The landing gear is still up, so I may have to remove it for shipping.

Sparkorc · Aug 13, 2016

Sorry to hear about your TH losing a rivet and causing a crash hope Yuneec help you out, it certainly made me check all the rivets on each arm and the landing gear I'm glad to know all of my rivets are good at the moment, with no sign of coming lose hopefully yours was due to a isolated incident of that rivet not forming correctly during manufacture, I could see that a rivet that becomes lose could wear the fixing hole slightly and drop out, apart from applying a bit of electrical tape or liquid electric tape to hopefully stop the rivet vibrating and dropping out, there's not much else you can do apart from checking the rivets for security on each flight.

Photo · Aug 14, 2016

KR200 said:
Google Pop Rivet, you'll get lots of info and pictures. It's on the bottom of the motor mount where it pushes onto the motor arm. There's a hole in the carbon fiber tube that the rivet passes thru and locks the motor mount in place. If it comes out, there's only friction and the wiring holding the motor on. The thrust and vibration will gradually work the mount off the tube if the rivet falls out.

I dried out the H for 5 days and recharged the battery, but it's dead Next step is Yuneec Support. The landing gear is still up, so I may have to remove it for shipping. View attachment 2476

KR200! Thanx, now I understand!! Great tips!!

BobW55 · Aug 14, 2016

Added to my Preflight check!

KR200 · Aug 14, 2016

Batfire said:
Wow, that really is a bad time. Sorry to here that but interesting to learn the results of crash. If they are loose etc....then maybe since its easy enough replace them with small aircraft bolts and castle nuts with lock wire. As a comm. pilot I have seen this many times in aviation industry. With the vibrations our copters get it might be a good idea. You can find cosmetically desired bolts and castle nuts and just paint to match color. Just an idea.

Cheers

Batfire

I don't think it's possible to fit bolts as there is no access to the inside of the tube when the pod is on, hence the blind rivets.

KR200 · Aug 15, 2016

Talked to Yuneec Support today. They answered immediately!!! I didn't even have time to switch to speaker for the anticipated voicemail **** and Muzak. They requested log files and sales info.
In searching the log files on the transmitter, I discovered a media folder that contained the continuous video received right up to the crash. The camera sd recording was broken into 5 min. segments. Unfortunately the crash segment was corrupted.

martins · Aug 16, 2016

Hi
hope you get it solved by yuneec

i make some tesa_mod

on my own all arm to hold rivet in place. ( optimal would be heat-shrink tube but no both side to big)

KR200 · Aug 16, 2016

I believe you can get heat shrink large enough. I would probably just wrap with packing tape. It's light and strong with good grip.

FlyBry · Oct 31, 2016

martins said:
Hi
hope you get it solved by yuneec

i make some tesa_mod on my own all arm to hold rivet in place. ( optimal would be heat-shrink tube but no both side to big)

I like what you did and I am going to put shrink tubing on mine however, there is another potential fail point at the other end that needs to be addressed as well.