Feb 11, 2023 - Cornflakes

Owned by Hamza Ali
Last updated: 2023-02-15
2 min read
1 Incident overview | 2  Executive summary | 3  Incident timeline | 4  Postmortem report | 5  Recommendations for future

Incident overview

Postmortem owner

@Hamza Ali @Alison Thompson @Nathan Green

Airframe

Frosted Flakes

Related incidents

-

Incident date

Feb 11, 2023

Approx. Damage Costs

$100

Report Date

Feb 14 2023

 Executive summary

Frosted Flakes was powered up, and the thrust produced snapped the motor mount and hit the airframe and destroyed the propeller, and also damaged the motor

 Incident timeline

Describe (approximate) timelines, cross-correlate with telemetry/video recordings/etc if any.

Day of Flight:

  • The back motor mounts (specifically motor 2 and motor 4) were extremely wobbly due to the mounting brack was bent up from plate flexing.

  • The motor was determined to not be level with the frame, however it does not seem to be the cause of the breaking of the motor, since it was addressed before the flight test.

T-0:

The aircraft powered up and got into the air, the aircraft pitches up

T-1:

The aircraft then starts to correct itself by pitching down, as it does this, it banks to the right and the motor 3 mount destroys itself

T-2:

The motor violently hits the airframe and the flight test is aborted

After flight inspection:

Motor 2 was observed to be very lose and severely damaged the airfoil. Had motor 3’s mount not destroyed itself, motor 2 would have most definitely caused a crash.

 

 Postmortem report

Instructions

Report

Instructions

Report

 Leadup


List the sequence of events that led to the incident.

  • Clearance was not properly confirmed before the flight

  • A lot of force was used to install motor 3, the structural integrity of the motor was compromised

  • Motors were wobbly at the bay

 Fault


Describe what didn't work as expected. If available, include relevant data visualizations.

  • Motor mount gussets were backwards

  • Front motor mount was destroyed and snapped

 Detection


Report when the team detected the incident and how they knew it was happening. Describe how the team could've improved time to detection.

  • Potential cause: heat gunning the motor mount might have reduced the structural integrity

 Response


Report who responded to the incident and describe what they did at what times. Include any delays or obstacles to responding.

  • Carbon Fiber motor mounts for motors 1 and 3

    • Different orientation for 3d printing mounting

  • Motor mounts for motors 2 and 4 with counter-sunk holes with different orientation for the mounting holes to disburse the force into the frame

 Recovery


Report how the user impact was mitigated and when the incident was deemed resolved. Describe how the team could've improved time to mitigation.

Nil

Related records


Check if any past incidents could've had the same root cause. Note what mitigation was attempted in those incidents and ask why this incident occurred again.

-

 Lessons learned


Describe what you learned, what went well, and how you can improve.

  • Verify clearance before aircraft leaves the bay

  • Motor mount surfaces need to be addressed

  • Follow timelines, delegate tasks more effectively

  •  

 

 Recommendations for future

Actionable Recommendation

Reasoning

Actionable Recommendation

Reasoning