DJI Mavic Pro Unmanned Air Vehicle – The Ultimate Prepper X-Factor

Editor’s Note: This post is another entry in the Prepper Writing Contest from Vermont Prepper. If you have information for Preppers that you would like to share and possibly win a $300 Amazon Gift Card to purchase your own prepping supplies, enter today.

The concept of preppers utilizing unmanned air vehicles (UAVs) for forward surveillance and other situations is not new.  Until recently, the technology has been unattainable except for those with deep pockets. In recent years a decent consumer UAV with desirable features would cost thousands of dollars to achieve what DJI has done for a fraction of the cost in designing the DJI Mavic Pro.  Out of the box, the Mavic Pro is extremely easy to fly, has collision avoidance technology, and a 4.3 mile range (the longest range offered by a DJI – even more than their most expensive UAV).   If you combine this aircraft with a $22.00 app by Litchi Software, it adds an ability to pre-program a flight plan with waypoints, while varying your altitude, speed, and camera orientation to focus on points of interest (POIs) along its route.  Additionally, if in the event that you lose signal, the Mavic can be programmed to hover in place or automatically “go home”, or to wherever the controller may be – if you happen to be on the move.  The bottom line is that this craft is not a toy and with proper training, it has some serious tactical applications.  I have detailed a series of flight testing below to show that the Mavic can successfully drop a small payload via parachute for very little cost.

Before I continue, I want to quickly get two things out-of-the-way.  First, I have no connection at all to DJI and receive zero in return from them for writing this article. Secondly, you may be asking yourself, why do I keep referring to these machines as UAVs?  The simple answer is that I believe the use of the word “drone” does not do a UAV justice.  A drone can be a form of AI (a robot), or some other ground based machine or gadget.  Back in the mid to late 80s, prior to the adoption of the term Unmanned Air Vehicle, the pioneers initially used the term “Remotely Piloted Vehicles”, or RPVs.  I will use both RPV and UAV interchangeably as I believe these terms better define the Mavic.  That said, I realize most people refer to them as drones as do I in other content that I produce.

Much like most advanced technology, the consumer use of UAVs was born from the pioneers in the US Government that began using them for surveillance and lethal applications in the late 1980s/early 1990s.  The technology was cutting edge at the time, but rudimentary by today’s standards.  Think of the difference between the first cell phones versus the smartphones of today.

Additionally, the concept of using UAVs to many in the Government was scary.  In the beginning, they were inherently unstable and a lost signal would result in a crash.  They could only be tested on military ranges or large swathes of private land, primarily with the sanction of generous landowners in the Southwest.  As an added obstacle, some in the Government lacked foresight into the program capabilities and wanted to cut off funding as they believed these vehicles could never be stable or reliable enough to use in tactical situations.  Thankfully, the ragtag team of pioneers persevered and were able to eventually produce one of the first stable

UAVs of its kind known as the gas-powered EXDRONE (I never liked the name).  Launched from a rocket, or as I refer to it as a big bottle rocket, the EXDRONE had a rudimentary autopilot, with a fraction of the accuracy built into the Mavic Pro, that has a built-in GPS.  It also had a real-time video feed, mostly unheard of at the time.  Basically, a heading could be programmed into its system, but the EXDRONE required some old school flight planning including wind calculations.  With some bright communication experts on hand to fine tune the antennas, the RPV range was extended from about 20 miles to 50 miles, and teams along the route could be deployed along high points to keep line of sight for the real-time video feed and take control as necessary utilizing a regular Futaba controller, which was the prevalent RC aircraft controller at the time (and still now to a certain extent).  Each team would have its own portable base unit and use a 4×4 Sony video screen to navigate along the flight path.  As a note, prior to the autopilot, the teams would need to fly it manually from the start and practice handing it off by giving notification to the forward team that they were turning off their Futaba in “3, 2, 1”….  At the same time the forward team would turn their controller on when the countdown ended.  This “handoff” was the time when the RPV was at most risk.  Lost communication would result in a crash.  Again, the technology was rudimentary, but it was shown that forward surveillance could be achieved via UAV.

These pioneers had no idea that what they were doing would eventually provide a huge impact in keeping the world safe from terrorism.  Given the limited technology, support, and budget, it was hard for them to see the eventual development of RPVs such as the Predator and its use of hellfire missiles to take out terrorist targets.  In my view, we are still in the infancy of the UAV revolution.  The technology is advancing faster than ever and there are still many yet untapped uses for these vehicles.

Some preppers may still be hesitant on the utility of RPVs such as the Mavic Pro.  With a cost of $1000, it is not inexpensive, but given the possible uses in a SHTF scenario, it may be the best money you ever spent.  Let’s first take a brief look at some of the specific features of the Mavic and why I think it gives you the best bang for the buck.  I will follow with some tactical uses with a specific design I am testing to deploy a small payload.  I am sure some of the smarter readers can think of other uses and I would be happy to see them in the comments.

Features of Mavic Pro – base cost $1000

27 Minute Flight Time/4.3 Mile Range – The Mavic comes with one battery that gives a 27 minute flight time after a full charge.  This time is a little better than the average UAV.  The 4.3 mile range is one of the furthest ranges out there in the consumer market.  A reasonably priced special antenna boosting apparatus ($13.99/Amazon) can be used to boost the range of the transmitter, though given a 27 minute flight time limitation, flying out too far may drain out the battery on the return trip.   In contrast, the DJI Matrice 100 has a 40 minute flight time, but it is over triple the price of the Mavic.  Additionally, the range of the Matrice 100 is less than 3 miles.  If budget permits, it would be optimum to obtain a few extra batteries, which cost $89 each.  One benefit of using the Litchi software is that it will give an estimated flight plan time (assuming no wind) to prevent the battery from fully draining.

Lightweight, Foldable Arms and Props – The Mavic arms and props fold up nice and neatly to easily fit in a small backpack for deployment.  Alternatively, there are many hardshell cases available on Amazon if better protection for the RPV and its accessories are required.

Software – The Mavic can be controlled using free DJI GO software or via Litchi.  With DJI GO, there is currently no autopilot capability except auto takeoff and land.  I enjoy the use of this software when just flying around the vicinity to have fun.  It is not, however, recommend it for mission style sorties.  For missions, the Litchi software is highly recommended.  As mentioned above, a flight plan can be programmed into the aircraft so that you can concentrate on the real-time video feed to gather intelligence.  As mentioned previously, altitude changes, POI camera focus, loitering, and speed changes are all standard Litchi features.  In my view, Litchi is superior to the DJI app in with the exception of not having the ability to “Go Live”, namely on Facebook or YouTube (DJI allows live broadcasts).  You can also store missions for future repeat use.  Lastly, the software provides real-time verbal telemetry feedback (altitude, distance, battery power, etc.), which comes in handy if you might be focusing your attention on a POI.  The Litchi learning curve is helped with tons of YouTube instructional videos.

Collision Avoidance – The Mavic, unlike many similarly priced competitor UAVs, has a collision avoidance system built-in.  Even if you tried to manually fly it into an obstacle, the Mavic avoidance system would first beep as a warning and then stop.

Insurance – It is highly recommended to purchase DJI insurance ($99.00) which even covers damage from crashing into water.  It can be used twice.

Limitations

No Thermal Camera Capability – At the time of this writing, I do not know of any plans by DJI to offer a version of their Zenmuse thermal camera on the Mavic Pro.  In my opinion, a thermal camera offering would put this RPV at the top of the heap for first responders and the military, giving them the ability to conduct night search and rescue operations.  While the thermal cameras are not inexpensive (6-12k) for an average consumer, it would be a lot cheaper than using helicopters with FLIRs, and the Mavic noise signature would be virtually undetectable from above.

Payload Limited (not really built for payload deployment) – The Mavic is really not built to carry a payload.  DJI has other UAVs for this purpose, but they are triple or quadruple the cost.  

Battery Life is Average – With a 27 minute battery life between charges, any mission would be limited to a short-range, especially if you decide to embark on the payload experiment detailed below.

Tactical Applications for a Drone

Tactical Use Caveats – all uses assume a SHTF environment.  My scenarios also assume you have a DJI Mavic Pro, not some toy that hovers 100 feet in the air.  Additionally, keep in mind the FAA has an altitude limit of 400 feet above ground level (AGL), no fly zones, and it is illegal to fly at night:

Threat assessment for specific location(s) – The Mavic can provide valuable intel if you might be concerned of a specific location in your vicinity.  With a preprogrammed flight plan, the UAV can circle the area from a safe distance and orient itself towards the POI.  It can be programmed to remain there as long as the battery limit permits (approximately 27 minute flight time per charge).

Avoid/Monitor Civil Unrest – In a SHTF scenario, it is quite possible there would be civil disturbance as people run out of food, water, and medical supplies.  Prior to making supply runs, the Mavic can scout ahead to determine if there are pockets of unrest blocking your route.

Avoid Capture by Hostiles – Much like the civil unrest scenario, the Mavic might provide some help in trying to avoid captors.  In this scenario, you might have a further standoff or climb to a higher altitude to minimize UAV detection.  The Mavic is pretty quiet and cannot be heard and is hard to see at 400 feet AGL.  In a SHTF environment, if the altitude limits go out the window, it would allow for an even further standoff.

Zombie Horde Herding/Redirection – I actually have to give my 16 year son credit for this one.  Given zombie affinity for sound, if flown low enough, the Mavic RPV could redirect a zombie horde away from you.  In all seriousness, I am sure there are some readers that can think of real life diversionary tactics that might be applied utilizing the Mavic (I mean no offense to Zombies).  I can see some kind of small battery operated sound generator, maybe on a timer, being attached and used as a diversion prior to an offensive (or defensive) operation.

Scout for Water/Food Supplies/Vehicles – Food, water, and other supplies will become harder to find in a disaster scenario.  While large bodies of water might be easier to identify, the Mavic may be able to assist in finding some lesser known streams or tributaries.  Additionally, while drones cannot be used for hunting, all bets are off in a survival situation.  The Mavic can help to possibly locate wildlife and even herd them towards your location.

Disaster Surveillance (Inaccessible Area) – A survival situation can occur not only from nefarious individuals/governments, but also from natural disasters such as earthquakes, tornados, and hurricanes.  In August of 1992 I was at ground zero in S.W. Miami Florida in my house with my mother and brother when Category 5 Hurricane Andrew hit.  For anyone that was there, they would remember that it hit landfall at 4:30 AM and the worst of it lasted for about two hours.  It was a relatively small hurricane, but it left $23 billion in damage in its aftermath (As a memento, I framed the front page of the August 25th Miami Herald publication, titled “Destruction at Dawn”, where the picture taken was about a mile from my house).

It was almost like a nuclear bomb hit, and it was this event that spurred me into a prepper mindset in my 20s.  Communities were reduced to rubble.  There were many dishonest people both within and from out-of-state who swooped in and took advantage of the less fortunate.  It was sickening to see blocks of ice being sold for $50.00, and $300.00 generators being sold for thousands.  The roads were not navigable due to flooding and debris.  I think back quite often as to how a Mavic Pro could have helped us avoid a lot of dead ends, obstacles, and gridlock in trying to get out of the city, which would not restore full power for 6 months.

Small Payload Drop – In certain scenarios, small amounts of food, medical supplies, or communications can be dropped from a Mavic.  By my best estimates, the Mavic has between a 1-2 lb. payload capability.  I am currently flight testing it for payload stability and experimenting with a payload drop mechanism that does not require the addition of any electronics.  If you use the idea below, I just ask that proper credit for the theory be given (a link to this article would be greatly appreciated).  I have not seen too many YouTube videos with Mavic payload experiments, so I will share my idea as I believe we all benefit if someone has success.  Here is a YouTube link to the maiden voyage where the Mavic drops a 1.5 lb. ham radio.  It is recommended you have a detailed plan and be sure to consult some flight testing reference material.  If you decide to experiment on your own, perform tests in small increments at low altitudes.  Keep good notes, develop a flight test checklist, and be aware of your area.  Most of all, expect that things will not goes as planned and both major and minor adjustments will be required:

Eight Design Payload Deployment Criteria

• Low cost, material readily available
• Max 2 LB payload (actual payload weight will be determined during flight testing)
• Use of parachute to drop from high altitudes, protecting the payload
• No servos or other added electronics
• Aircraft stability
• Avoid prop wash
• Simple to Fabricate
• Reusable

Theory – Before you crack up laughing at some of the materials, keep in mind that I have a method to my madness and an Aerospace Engineering degree with some UAV flight testing experience.  Before the current technological revolution in UAVs, in the late 80’s and early 90’s, the pioneers activated certain features during flight by extreme altitude drop (free fall).  The solution offered below utilizes this same premise, mixing old theory with the new technology demonstrated with the DJI Mavic Pro.  All of the items were purchased on EBay for less than $20.00.  Keep in mind I have seen payload release systems that range from $100-$1000, all of which are servo actuated.  These are great, but I do not know of any application that uses a payload mechanism without having to add some kind of electronic actuation.

Design – A Tupperware container will be attached to the four UAV arms via fishing line and zip ties.  Eye hooks will be fastened to the four corners of the container, hung from the arms via four pieces of fishing line, each cut to 2 feet.  The end result would be that the container with payload will fly approximately 2 feet below the UAV to avoid prop wash.  Four lines were used for flight stability purposes.  The payload will be attached to a parachute via zip ties and placed in the container.

A trap door will be fabricated at the bottom of the container with a release mechanism that uses gravity to release the payload.  You can buy a 36” flare parachute on eBay or fabricate a parachute from bedsheets (36” is the size needed to safely drop up to a 2 LB payload – there are templates online).  The payload will be dropped by using its own weight first by vertically rising at the fastest rate possible, then descending quickly to break the bond of the release mechanism.  The trap door “release will be fabricated from a black office clip, zip ties, and an electrical connector.  The trap door was made by cutting out three sides of the bottom part of the container, leaving one short side intact.

The reason for leaving one side intact is that it will act as a “hinge” to allow the payload to fall through.  I also put duct tape around the edges of the cuts so the parachute would not get snagged.  The free side of the trap door will be attached to the side of the container utilizing the zip ties, the electrical connector, and office clip.

The idea is that the weight of the payload, combined with a sudden upward or downward movement, will cause the electrical connector to release from the office clip, allowing the payload to deploy through the trapdoor at the bottom of the container.  The payload I used is a Baofeng BF-F8HP ham radio.   I attached it with the antenna via zip ties to the chute.

Challenges/Risks

• The payload may be too heavy for the container and deploy before desired
• Wind may cause the payload to prematurely deploy
• The fishing line could break and get tangled into the props, causing catastrophic failure
• Sudden RPV turns or altitude change can prematurely deploy the parachute
• The setup may cause unstable flight
• Flight time most likely shortened
• Undue strain on electrical system

The key to success is to find the optimum payload weight so that the UAV can fly stable without premature deployment.

If it is too heavy, the payload will be deployed before it is desired since the mechanism works via gravity.  If too light, it would not deploy at all.  Once the optimum weight is found, quarters can be added or removed to balance it out depending on the payload.

As you can see, though the Mavic cannot carry huge payloads like some of its older brothers and sisters in the DJI line up, I believe you get the most bang for the buck if you want to utilize it in a SHTF scenario or even as a First Responder.  With a little bit of ingenuity, I am sure others can come up with a fancier/prettier payload release for the system.