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Drone Maintenance Plan V1

Introduction

Fly your drone for any number of flight hours[1], and you will face the issue of aircraft maintenance. As a remote pilot you will have a strategy for this, even if your choice is to let it ride or do nothing. That is still a strategy. Admittedly it’s not a good one that exposes you to unnecessary risk. The FAA[2] has a strong opinion on unmanned aircraft vehicle(uav) maintenance that we will review. This in of its self is not quite enough. You as a remote pilot must internalize your approach to this workload and develop an understanding of the FAA’s rational. You also want to keep your drone in the air, right?

My Experience

My own maintenance experience initially started of with an adhoc approach to repairs, my budget is small. To enable this approach I made it mandatory to inspect the drone before and after every flight as well as arrival at home. My thinking here was to always have the drone in a flight ready state. So arriving back home from an assignment the following tasks where conducted:

Recharge all drone main batteries (3x)
Replace SD card with a new one
Check state of propellers (replace as needed)
Purchase more propellers if needed (minimum 4 for complete replacement)
Clean motors and arms
Check gimbal and camera
Repack drone backpack for next assignment

If anything was found in the inspection at home and maintenance was required then parts where ordered and worked would be done when parts arrived. Eventually I created a workspace for drone maintenance. I call it my hangar or maintenance bay, but really it’s an old high school science table, a bright blue 24” by 36” cutting mat and movable overhead lighting. The most important aspect to this is that is a dedicated workspace clear of un-related junk. I did not create maintenance logs but relied on me being the sole remote pilot with a single drone.

While flying a dji[3] drone this approach seem to work well. Amazon and dji have a very healthy supply chain and the most I would wait for parts was 1 to 3 days. However, my dji flying days did not last long due to coastlines and bad math. I could not take off in my own backyard. I live in a costal town and to cut a long story short the dji geo-fenced no-fly zone for the body of water next to my town includes half of my town and my home. I could fly the drone up to about 10 ft then it would land it’s self. I switched to an Autel[4] drone, to get around the geofencing no fly issue. It is with this Autel drone I have spent nearly all of my time flying.

Grounded!

Finally, after two years of flying I had an incident that grounds me for over 3 weeks and results in this article and a review of my approach to maintenance and a few missed sunsets. Why? The incident it’s self was small. A stress facture finally snapped in the backpack as I was about to leave for an assignment. The front left landing foot had a stress facture that snapped along the foot’s securing holes leaving the foot misaligned and floating but still attached to the arm. No problem I thought since it was a maintenance task I had conducted more than once on a dji mavic drone. Total time for the work was less than 5 minutes once parts where in hand.

pjh: add photos here

I thought, I would jump on Amazon. Get the part and do the work in a day or two. Well no part, no maintenance. It slowly dawned on me, I was grounded![5]. That’s it, I am not flying until I carry out maintenance on my drone. The retail supply chain for Autel is not as robust as dji’s was my initial finding, I could not find the part new. Thinking of other sources for the part I checked out 3d printing and found a printable[6] and began honing my online searches. Eventually EBay panned out, and I was able to purchase a number of the parts. I was also able to get the 3d printable made, but the quality of the printer very much effected the output. The resolution was not good enough. Interestly, printing the part cost 0.6 cents!

Ok, that was a slew of logistical details I did not really care for. Now I know drone companies offer enterprise services and if it’s within your reach, do it! But I am an independent remote pilot with a limited budget. This is a position I actually like, it generally means that purchasing choices need to backed by rational decisions and a commitment to a plan, however loose. I am not too big to fail 😉

Observations

I disliked spending my flight time on logistics! That and not actually flying where the biggest setbacks. And I certainly did not like being grounded along with the uncertainty of being able to purchase the required part(s).

3D print looks promising for prototyping drone parts. I need to understand 3D print materials and their tensile strength.

Drone pre-flight and post-flight inspections are a critical component of your flight plan and drone maintenance. However, it is entirely possible that an inspection may not reveal all damage. For example hairline cracks in the drone body shell can be easily missed in bad light.

As an owner of a consumer/retail drone the supply chain is outside your control. To so some degree the bigger, the better here. For example dji is one of the biggest drone companies out there and there is a health secondary market for parts.

I need to fully understand what this means for my relationship with the drone manufacturer and how I should stay update on a drone’s development lifecycle.

FAA Regulation

THe FAA’s position is made clear in chapter 7 of the Advisory Circular 107-2 document (AC_107-2.pdf). Yup, there’s a whole chapter called sUAS Maintenance and Inspection. It’s a great sign that the title includes the word inspection as I believe it is foundational action to a good maintenance plan. Makes me happy that me and the FAA align.

7.2 Maintenance. sUAS maintenance includes scheduled and unscheduled overhaul, repair,
inspection, modification, replacement, and system software upgrades of the sUAS and its
components necessary for flight. Whenever possible, the operator should maintain the
sUAS and its components in accordance with manufacturer’s instructions. The aircraft
manufacturer may provide the maintenance program, or, if one is not provided, the
applicant may choose to develop one. See paragraph 7.3.5 for suggested benefits of
recordkeeping.

There’s more, so it’s worth reading the document (AC_107-2.pdf) even if it’s a refresher.

Conclusion

I need to update and formalize my maintenance plan and have a higher frequency of checkins with the governing body - the FAA[2]

There are elements of my maintenance plan that are working.

Drone Inspections (1 pre-flight and 2 post-flight)
Cleaning the drone after every assignment on arrival at home
Prepare drone for next assignment at the end of every assignment
The concept of flight readiness[7] is the keystone of my informal maintenance plan

Overall I pleased with the first iteration of my maintenance strategy. I would not call it a plan yet. Another iteration is required but the path forward is clear - more alignment with the FAA’s position. Internalization of your maintenance strategy is a good, but a plan, documentation and logs are even better!

Keep Flying…

Drone

Federal Aviation Administration

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