Mavic Air Maiden: Into the Mouth of a Blue Whale

Mavic Air Maiden: Into the Mouth of a Blue Whale
The maiden flight of the Mavic Air - right after take off and straight into the mouth of this blue whale skeleton. I think this has to be one of the weirdest Mavic maiden flights ever. 

The new DJI Mavic Air has a lot to offer based on the specs, and I ordered one from the first shipment. By chance, at the same time I was invited to try something both challenging and exciting: to shoot movies of a Blue Whale skeleton in the atrium of the Beaty Biodiversity Museum (http://beatymuseum.ubc.ca/). So the maiden flight of my Mavic Air was unusual and difficult, but also serves as a good chance to review some characteristics of indoor flight in an extreme situation.  

Here is a video showing the outcome - some amazing clips of the skeleton from an individual of the largest animal that has ever lived on earth (that’s right, blue whales are bigger than any dinosaur or any other animal). 

I also used a DJI Spark for comparison and labeled images from it where they appear. This is a horizontal pano taken with the Spark. 

The physical location is challenging in several ways that really tested the Mavic: the whale skeleton is hanging by a lot of cables that extend to the ceiling in different directions and at different angles, it is surrounded by hanging lights, and all of this is suspended high above a uniformly grey concrete floor. The building has metal cladding that prevented both the GPS and compass from functioning, and we flew both during the day, and at night with what you might call ambiance lighting of the whale. All in all, this provided a substantial test of both the vision positioning system and the camera. But the rewards were also spectacular: the whale is an amazing subject to film, both day and night, as the video above shows and as I will describe below.

Settings used:

To make this useful as a review of the Mavic Air, all the photos in this post are screen shots ripped from 4K video using VLC, and have not been altered in terms of colour correction, etc (the footage in the video has been corrected). All camera settings were in Auto, and no filters were used. The daylight footage used a shutter speed of 1/40 and an ISO of 100, the night footage used a shutter speed of 1/30 and an ISO of 1943. Because these flights were literally the day it arrived, it flew with the firmware that came in the box: no updates (so no panorama mode since the initial shipping firmware did not include them). I only altered a few parameters to slow down the gimbal (an essential change) and allow it to rotate up (also an essential setting to change). Lastly, between the day and night flying, I adjusted the expo and gains, adding expo to all controls and reducing the gain for yaw, since it was a bit jerky for taking smooth video. I also flew a DJI spark, but all pictures here are from the Mavic Air unless otherwise noted. Flight times were pretty consistently just under 20 minutes, as these flights included lots of repositioning and hovering. If you are interested in more about the Mavic Air, please see a link to an ‘unboxing video’ at the bottom of this article.

This is a difficult place to fly, with lots of cables to the whale and to the lighting, the whale itself, no GPS or compass, and limited vision positioning. 

Daylight flying

Back to the whale. Since there was no functional GPS or compass in the building, the whole flight was stabilized only by the vision positioning system, or not stabilized at all. This worked relatively well: with the vision positioning system The Mavic Air drifted a bit as you would expect, but always slowly. It was pretty stable in a hover, but nowhere near as locked in as GPS - no surprises there. What did surprise me was the very low max altitude. Apparently (and you can comment on this if I am wrong), when you fly without GPS and use the vision positioning system, the Mavic (and Spark) have a max height over the ground of 15 feet. This is NOT measured from where you took off using the barometer, but rather measured directly under the airframe in real time by the vision system. I took off from a mezzanine level even with the whale, but when I crossed over the railing, both the Spark and Mavic Air quickly dropped to 15 feet above the floor below, and would not allow flight above this point unless all the bottom sensors were turned off (more on that later). In this case, I could not return to my take off point, and had to land below, or (weirdly) fly up the pedestrian ramp since the sensors will let you gain altitude as long as the ground below the airframe is no more than 15 feet away. This is an important consideration if you want to carry out any indoor flight in a large space with the Mavic Air.

Despite the challenging conditions, the Mavic Air flew smoothly right into the whale’s mouth within seconds on its first flight. 

One interesting observation about this limitation is that it takes a few seconds for the sensors to determine that the airframe is higher than 15 feet. Consequently, I was able to take off on the mezzanine and gain enough altitude to be higher than the whale, then, as long as I moved fairly briskly, fly over the railing, the drop, and over the whale skeleton before the sensors had a chance to react. Once over the skeleton, you could fly normally with the benefits of the downward vision system.

Pictures taken over the actual skeleton looking down (these ones from the Spark). 

Even with that limitation, the flight characteristics were still outstanding, given this is a challenging situation. The Mavic Air was quite nimble, and easy to control. It negotiated the many cables and lights easily if you pay close attention via a combination of FPV and LOS. It was good at maintaining altitude, allowing you to focus on the shot and keeping clear of the many hazards. The camera field of view is similar to the Mavic, so even what looks like a close call is still actually relatively far away. The reverse sensors proved useful, and are well executed. The one exception here is that it was hard to land safely in some tight spaces, since it would object to backing up too closely to the operator.

Great depth of field and a nice crisp picture, even frames from video. 

In daylight indoor conditions, the film quality was great, both for still and video, and even with the slight drift great quality shots can be achieved thanks to the 3-axis gimbal. With the Spark, the same drift is badly manifested in the film, because there is no yaw correction on the camera. So this is a major advantage of the Mavic Air. In these conditions, the ability to slow the gimbal control, and tilt it up were also major advantages for the Mavic Air.

The lighting around the whale at night is spectacular, but also presented some special problems for flying. 

Night flying

The night flying revealed some noteworthy issues. Basically, the vision positioning system completely failed in these conditions. The lighting is certainly adequate to fly LOS and FPV, and the video was fine, although the frame rate was noticeably slower and the ISO higher, this means crisp stills were rare and some noise was visible, but really good given the conditions. However, the vision positioning system could not cope, and proved somewhat dangerous. On two occasions while hovering, the system led the Mavic Air to begin a rapid drift with no input that could not be stopped with stick movements. In this situation, this made flying with the vision positioning system completely impossible, and all downward sensors had to be turned off. Not really a big surprise, but I had hoped it was bright enough to see the floor - apparently not. Without any stabilization, the Mavic Air is predictably a bit drifty, but it did a surprisingly great job of maintaining altitude, and if you tone down the sticks with expo it’s possible to get pretty smooth shots, although flying the entire length of the whale in a straight line was beyond my abilities since eventually it drifted off the centre line. You can see signs of this drifting in the videos, but again keep in mind these are challenging conditions.

Flying  into the chest cavity was certainly the biggest challenge, especially a night. Here even a bit of drift is unacceptable, and manual flying with a close eye on your position from below proved necessary.  

Bottom line: the Mavic Air does the job. 

I have a Spark and a Mavic Pro, I have traveled with both, and used both in relatively difficult conditions (mountains, at sea off boats, in extreme cold, etc.). They both have their strong points, and I always wished he Spark was just a little bit better, especially in having a 3-axis gimbal, and some firmware upgrades like gimbal controls and expo. The Mavic Pro, on the other hand, has been hard to find fault with while it's flying - it is really good at what it was made to do, and its form factor was amazing when it came out, but it's a heavy load in a backpack with five batteries for a long climb, for example. My hope was the Mavic Air might be the middle ground, and so far I have to say it does look that way. Near-20 minute flights, great stability with GPS (I have flown about 10 batteries outside now with updated firmware, including some tough flights necessitating hand-catching on boats in windy, not-very-calm seas, so I can say outside it’s a champ). The main thing I really miss is a second wheel for exposure compensation, but the weight of the airframe and especially the batteries is an amazing difference for taking the Mavic Air outside and going places with it.

For indoor flight, as described here with this very strange maiden outing, I was also very impressed. I can’t think of a much more difficult set of conditions to put this though than zero GPS, no compass, and sketchy conditions for visual stabilization, plus a location with a lot of obstructions, wires and cables, a subject you really don’t want to hit, and it still performed admirably, and the quality of the video is great.

If you want to see more about the Mavic Air, here is a video describing what’s in the box in the Fly More Combo. 

Thanks to The Beaty Biodiversity Museum for their co-operation in all things, as well as specifically Derek Tan, Varsha Mathur, and Nick Irwin for access and help with the shoot, and also the AdrenalineEXP team and Innov8ive Designs for support.