2024-04-08 AEAC Freestyle

Brief summary of the flight test! Comp sim 2. This entire meeting focused around CS2 on April 6 2024.

Flight test team will be required to go through timelines. All members encouraged to ask questions and dig into the content at flight test!

End goal is to determine what went wrong this flight test, and what caused it.

We had 2 main incidents!

1. crash on Pegasus - dynamic rollover (ON GROUND)

2. crash on Houston - lack of control in flight, uncontrolled descent.

Flight test team incident reports and debrief

Pegasus Flight Test Timeline

2024-04-06 Pegasus CS2

Pre-Flight

• Did not go through week-before and day-before checklists - no time.

• Motor A was tested for direction on the ground

Flight-Line

First flight test card:

• Recalibrated Magnetometer

  • Did not change anything on the drone after calibration

• Cleared for takeoff, full throttle and experienced a rollover

  • Loiter the drone, slowly raised the drone - ~ 20% throttle

  • 2 props damaged

• Assess damage & determined flight should continue

  • Not enough time/ flight tests to continue

  • had conversation w/flight line team members

Decided to tape the landing gear bracket and send it up again.

Other Notes

Had a well equipped flight line.

• Ran 4-motor direction test post incident to determine 1 motor wrong direction

2024-04-06 Pegasus CS2 | Checklists

• Did go through the checklists during CS1, not aware of any changes

  • Phone, lidar, arm changed,

    • can’t mess up orientation of MT30

• In future - will bring replacement parts

  • need to make sure that person doing the repair has requisite knowledge / experience. Otherwise risk can outweigh potential benefits

• Forgot jackets (payload), one side of the cabin in the bay

• flying without battery shrouds

  • one of the battery clips on the shrouds came off?

• 2 of the ESCs (identified upon landing, after long flight) has missing capacitors.

  • How do we want to address these? Mechanical solutinos? electrical quality control

  • of the 2 caps remaining, one of them was hot glued.

    • how was this done originally? why?

      • ESCs were reused from last year. could have been reused.

  • Photos of the broken things.

    • Put them in the debrief! → take pics before fixing them

Concerns

• nobody doing week-before checklist on Wednesday, because work session is cancelled (nobody currently organizing this session).

• observed issue during flight test: one of the batteries is not plugged in.

  • normally, you plug in when the battery is slid in.

  • This flight test, battery wasn’t plugged in initially

    • three people doing battery plugging. one mistake, two missed the issue.

• Lack of communication about mechanical damage

  • Mech lead found out drone was damaged when they came into the bay and saw the drone broken

  • Could have caused significantly further damage?

    • decision from past flight test was not kept consistent?

• Mechanical damage un-noticed / un-documented

• Flightline coordination

  • Flight line roles were assigned vaguely, and not assigned explicitly

  • No clear owner for every task - assigned as they come up

    • procedures / SOP not communicated before hand “insert batteries” vs “plugging in the batteries” (mech may not know what happens when you plug in the battery)

Potential Action Items

• Clear procedures / SOP for each task. Clear owners for each task (w/core flightline team)

  • Value in more explicitly assigning responsibilities.

  • Relay / be clear on what is expected

  • Could be divided into sub-groups of tasks to be assigned out

    • regardless, need to make sure that people are used to fill their role

    • (person A/B/C/D will always be the same at competition)

  • no harm in having items checked multiple times

    • Need to have multiple people capable of doing the same thing

• Pilots should be responsible for final pre-flight check

  • They are ultimately the ones operating the vehicle!

  •  

If you are changing something on pegasus, or if you are instructed to change something on pegasus, it is extremely important to communicate this to the team and to ensure it is done to the best of your abilities!

getting agreement from FT to clear any changes with the respective system owners/ most knowledgeable about the system.

Please talk to your team!

Houston Flight

There was no flight test card written for Houston.

Goals of this flight:

• making sure that it works

• pilot training

Decision was made on Saturday morning to bring Houston.

• Motor crunchy was noticed before the flight

  • mechanical determined it was safe to fly?

  •  

Houston took off

• Took off in loiter

• throttle around 50%

• no pitch/roll/yaw input

• started circling really fast (fishbowling? toilet bowling?)

• Tried to land, but crashed

Concerns

• Houston flight was not communicated

  • We are often making changes to houston

• Houston landing gear change was not communicated?

• Props damaged (3/4 of them)

Include photos of props in debrief.

Theories for houston failure:

1. op flow mounted differently

   1. cancelled theory, it was mounted fine

2. flight controller shifted

3. compass variation issues??

4. high vibe that may have caused misalignment?

Action Items

• Need to follow week-before/day-before checklists.

  • can’t make day-of decisions to fly or not fly a drone

• AEAC sync is when we bring up what we’re flight testing so all teams are aware.

• Replacement parts:

  • we have a lot of props.

  • need new motors? one of them is crunchy(?)

  • Perhaps time to overhaul the ESCs too.