2023-03-04 - RCA for Houston Failsafe-Disarm Crash

Owned by Aidan Bowers (Deactivated), created
Last updated: 2023-03-04 by Daniel Puratich
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 Getting Flight Details and finishing this RCA

@Daniel Puratich Documenting the initial situation

Airframe

Houston

Related incidents

None

Incident date

Feb 13, 2023

Approx. Damage Costs

To be determined as everything was covered in snow.

One antenna was broken on the SMA connector

One Prop destroyed in crash

Report Date

Feb 13, 2023

 Executive summary

  • PPM failsafe was configured to RTL

    • Tested on ground and worked properly

    • Short test in air worked properly when controller was powerred off to cause a link losted situation

    • When controller off it went to RTL correctly

    • When controller was rebooted the switch warning flagged the arming switch

    • The pre boot switch check flagged the arm switch on and would not transmit till it was disabled

    • arm was set to disarm

    • then radio connected to aircraft

    • then aircraft disarmed and fell out of the sky from less than 30 meters

    • the arm switch was enabled as the aircraft was falling

    • throttled up and then disarmed when it was in the snow

    • props did to spin as it was falling but it was not enough power to save it

    • The rest of this @Hamza Ali and logs

      • Determine if it rearmed

      • Determine more information about the crash

Crash Photo lol

 Incident timeline

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

 Postmortem report

Instructions

Report

Instructions

Report

 Leadup

List the sequence of events that led to the incident.

 

 Fault

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

 

 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.

 

 Response

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

 

 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.

 

Five whys root cause identification

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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.

 

 Recommendations for future

Actionable Recommendation

Reasoning

Actionable Recommendation

Reasoning

We need a suitable test plan before the flight test

if we had talked through this fail safe test plan we would have considered that this was a possibility. The switch arming thing wasn’t considered. It’s easy to get caught up at the flight test.

This all comes to poor planning

We didn’t even know we wanted to test the failsafe before we were at the grounds.

Possibly a better way to handle failsafe though we need to research this

We need to research this, possibly a better way to handle failure