ALTA's purchased after Mar 18 Grounded - please read

Discussion in 'ALTA 8' started by Tabb Firchau, May 28, 2016.

  1. Chris Jackson

    Chris Jackson New Member

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    +1

    If can get the documentation, avoiding the shipping time to carry out the service bulletin would be much better.
     
  2. Davis DiLillo

    Davis DiLillo New Member

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    From my understanding this isn't just a bolt on fix. This is a structural failure in the aluminum that is supporting the motors.

    Perhaps freefly could ship you the motor mounts and you could change them yourself but I can also assume Freefly doesnt want this sort of practice.

    Perhaps you should consider getting a refund from Freefly? I'm sure Freefly will have no problems honoring that in your situation.
     
  3. Chris Jackson

    Chris Jackson New Member

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    The motor mounts are bolt on, I assume would simply be inspection to find the defective part and then replace them, and possibly realigning motors.
     
  4. Davis DiLillo

    Davis DiLillo New Member

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    Chris,
    There are electronics and a pcb board in the motor mounts.

    It is absolutely not bolt on.... The entire motor mount I assume will need to be replaced. Its the center aluminum that is giving way and the entire motor is pulling out. There is a pcb board at the bottom of the motor mount an d the motor leads will need to be disconnected to repair.

    As why I dont think Freefly wants just anybody making this repair as simple as it may be.
     
  5. Chris Jackson

    Chris Jackson New Member

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    Heya Davis, yeah Ive had an Alta in kitset form before, the ESCs do sit below the motors, but they are easy to remove. Certainly doesnt require a degree in rocket surgery to change the mounts.

    Chris
    UAV engineer/Aircraft Engineer/Rocket Surgeon :)
     
  6. Fabien Deregel

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    Hi, i confirm, changing a motor mount is simple and easy... But motor mount / support or motor base plate weakness giving a "flying away" motor can be a consequence of something, the root might be else.... I do not trust folding propelles in applications where there are instant accelerations / decelerations at all..
    BEst regards,
    Fabien
     
  7. Tabb Firchau

    Tabb Firchau Administrator
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    Hi everyone, thanks for your patience while we got to the bottom of this. We are just about to send out an update but I wanted to share it here first:




    Recently, two ALTA 8 aircrafts experienced in-field failures of the motor mounts. One machine landed safely, and the other machine experienced a rapid (but level) descent and had a hard landing with minimal damage to the ALTA or payload.

    Understanding the issue

    Freefly has spent this week diving into the issue to make sure we fully understand the root cause of the problem, as well as a viable solution.

    We have destructively tested dozens of ALTA motor mounts with accelerated lifecycle testing to better understand this failure mode. We have also destructively tested our solution to ensure it performs as expected. We have run simulations to better correlate the theoretical stresses on the motor mount to the ones seen in flight.

    Freefly immediately launched an investigation into the root cause of these failures and determined the failures were caused by the combination of two main issues.

    Root cause 1: Change in geometry

    Our supplier for machined aluminum components removed a radius on the inner surface of the motor mount. Removal of this radius led to a substantial increase in the stress concentration during flight loading which contributed to the failure. Our supplier changed this feature without approval or notification to Freefly. Freefly also failed to identify the removal of this radius in our incoming quality control inspection.

    Root cause 2: Sub-optimal thickness

    Some of the motor mounts shipped during the affected time frame exhibited wall thicknesses that were lower than intended. Freefly did not catch this issue in our incoming quality control process.

    Both of the failed motor mounts exhibited the lack of radius and were below nominal thickness. These two issues compounded to cause the accelerated failure of the motor mounts.

    Solution

    All of this testing and investigation has led us to the following solution:

    • Inspect all inbound ALTA 8 motor mounts for micro cracks, cracks, or any signs of stress

    • Replace any nonconforming mounts

    • Bond a reinforcement plate into the bottom of each motor mount to strengthen the motor mount

    • Institute a factory service interval for all ALTAs where customers can send their ALTA back to Freefly for inspection

    We estimate this process will take between 3-5 business days to complete from the time your unit arrives, and our team will be working around the clock to make it happen.

    Again, we want to apologize for the issue and thank all our customers for their patience. As fellow pilots, we take safety and our customers’ success very seriously, which is why we acted swiftly to ground the fleet until this issue was better understood.


    Thank you,


    Tabb
     
  8. Humberto Barchini

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    Hi Tabb, quick question... when will be shipped A8 again? (new ones)
     
  9. Tabb Firchau

    Tabb Firchau Administrator
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    Humberto, I need to confirm some details tomorrow but I expect ALTA 8 to begin shipping again in around 15 days or so.
     
    Humberto Barchini likes this.
  10. Ben Ruffell

    Ben Ruffell Active Member

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    Thanks for the update Tabb. Appreciate it.

    Also, thanks for this. It's a really great idea:
    • Institute a factory service interval for all ALTAs where customers can send their ALTA back to Freefly for inspection
     
  11. Fabien Deregel

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    Hi Tabb,

    thank you for the detailed explanations,

    best regards,
    fabien
     

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