I'm often asked how I manage to get the flying photos from the perspective of the wing. Here I decided to write a short article about my experiences with externally mounting cameras, and provide recommendations and suggestsions for anyone else interested in doing the same.
Is temporarily affixing a camera to the outside of your aircraft legal? Well, technically, yes. Unless the mounted camera constitutes a change in the design (eg. you have to drill a hole, requires tools to isntall, any change to the structure), then you probably don't need a supplemental type certificate (STC).
According to FAR 21.111:
Any person who alters a product by introducing a major change in type design, not great enough to require a new application for a type certificate under § 21.19, shall apply to the Administrator for a supplemental type certificate...
That said, this is a gray area, and mounting a camera to any part of an airframe necessarily alters its aerodynamic characteristics. Just because it's legal, doesn't mean it's safe. Additionally, should the camera detach in-flight, you may be subject FAR 91.13:
Aircraft operations for the purpose of air navigation. No person may operate an aircraft in a careless or reckless manner so as to endanger the life or property of another.
This isn't meant to scare pilots away from externally mounted cameras, but rather ensure that they understand the possible legal ramifications, as well as the importance of sharing their aviation experiences in a way that is both safe and in compliance with the law.
You'll notice in my photos that there's a distinct lack in variety of perspectives. There are several reasons for this:
In terms of perspective, the wing placement is one of the best options because it provides a large surface area for placement, and any disruption in airflow will be small in comparison to the size of the wing (at least compared to other surfaces like the vertical and horizontal stabilizers).
Near the edge of the wing, and away from the ailerons might be a good bet. Disrupting the airflow around the ailerons could have negative impacts on their effectiveness.
Mounting on the strut is another option, but not for the suction-cup approach. A company called WingItMounts manufactures mounts specifically designed to fit around the struts of a wing (for high wing aircraft), and provides a very stable and sturdy platform for multiple cameras
Another safe option would be the belly of the aircraft, as it is aerodynamically less important than other surfaces, and very low risk of have anytihng impacting the aircraft if it were to fall off (unless you fly inverted often).
Finally, a permanent mount can be machined and installed if you're the owner of the aircraft. This is the best option, but it also requires the most work, documentation, and of course, ownership of the aircraft
The introduction of small form-factor action cameras and industrial strength suction cups has made mounting cameras to aircraft a simple matter. I fly with the GoPro Hero 4 and GoPro Suction Cup Mount.
These mounts, if used properly, are extraordinarily strong. The suction cup mount has some helpful features that make it a good choice for this application:
Suction cups work on some simple physics. When we push down, we remove all the air that was once present within the sealed region and create a vacuum when we mechanically expand that region. There now exists an imbalance of pressure on each side of the suction cup membrane. Inside we have very low pressure, and outside we have 1 atmosphere, or 14.7 PSI.
Thus, the atmosphere is pushing the suction cup onto the surface with 14.7 pounds per square-inch. The GoPro suction cup mount has a base radius of 1.7 in., so that makes about 9 square inches of suction cup. If you do the math, that's 9 in^2 X 14.7 pounds per square-inch = 132 pounds of force holding the mount onto the plane.
That's a lot of force! But it depends on the assumption that we removed all of the air initially inside the suction cup, and that we have a good seal.
My experience with the suction cup mounts has been positive, and it's a simple task to remove all the air with the simple push-button. The suction cups are then mechanically locked by flipping down a lever. This also makes removal easy by simply unlocking the lever and breaking the seal.
Getting a good seal depends on having a smooth, clean and solid surface. Before I attach the mount to a wing, I clean and dry the surface with a wet cloth, and make sure there are no dents that may compromise the seal. It's also a good idea to have the camera mounted on a panel that is unlikely to buckle.
It's also important to consider environmental factors. These suction cups are manufactured from a material whose properties greatly depend on temperature. If it's too cold, it may be difficult to form a reliable seal as the polymer membrane lacks the flexibility. On the other hand, if it's too hot, the membrane may be too flexible, and could create a leak in the gasket.
If you're using a GoPro, then I think one of the best solutions is to use a suction cup mount, and GoPro's own offering is quite impressive.
The reason I recommend this mount over other mounts is that it has proven itself over and over again on the wings of the planes I've flown. Other suction cup mounts might be up to the job, but I haven't needed found any reason to switch (yet).
GoPro also has great customer support and tends to make good products, so you have some confidence that the build quality will be high, and that it won't fail at the worst possible time
The design specs and reviews for the Fat Gecko suction cup mount suggest that it's up to the task of holding a camera on the wing.
The Fat Gecko has a similarily sized industrial suction cup, which means it has a likely has a similar holding force to the GoPro mount -- all other things being equal. The manufacturer recommends a load capacity of no more than 4lbs, which easily supports all major action camera brands.
The one major complaint from owners seems to be that you need a relatively flat surface, but this is true with the GoPro mount as well. Luckily, aircraft have plenty of flat surfaces.
This mount comes with a unniversal 1/4" tripod thread, which means it can be used with almost any standard camera. To use it with a GoPro though, you would need a separate adapter.
Though I fly with a GoPro Hero 4 Black, if I were picking a camera to buy today, I'd definitely go with their newer, cheaper, and smaller "session" offerings.
Unlike previous GoPro cameras, these are about half the size (38 x 38 x 36 mm), and three-quarters of the weight (74g). More importantly though, they're also about half the price, with a respectable $200 price point.
However, they aren't half the quality. Though owners of both cameras claim that a full-size GoPro shoots slightly higher quality video, the difference is small. The main difference is that the session has been stripped of its back facing touch screen, and front-facing lcd screen. It can instead be controlled and configured over WiFi through a mobile app, and set to record in a pre-configured setting with simple button presses.
It's almost as if the GoPro Session was designed to be wing-mounted. It's small, its free of fluff, and it won't make nearly as big of a dent on the ground or your wallet if it were to detach.
Though the GoPro Session is an ideal camera for this application, it's lack of touchscreen, and user interface, makes it less convenient overall. If you're looking for a camera that you can multi-purpose for a variety of activities, then hands-down the best choice is the GoPro Hero 5, which is GoPro's latest offering in it's long line of Hero cameras.
Unlike the Session, the Hero 5 has a full-featured touch screen, making it completely independent of any other devices. When mounted to an aircraft, you can use this screen to see what the camera sees, and properly position the camera (to be fair, you can do this with the Session as well, using the smartphone app).
Personally, I use a full-sized GoPro because it's the only action camera I own, and I use it for everything. I'll use it for timelapse sequences on the beach, for snowboarding, and of course for flying.
Finally, there are cameras like the AKASO EK700. These are chinese knock-offs, and there are many of them, and they go by many different names.
There's not too much to say here. They look and feel like a GoPro, and they tout many of the same features, including 4K video, and 120fps at 1080P. They include full-featured touch screens, and all the same accessories.
However, they're about a quarter of the price of a GoPro, and maybe half the recording quality. There are cheaper ones, too, that run $30 on sale. So, if you're looking for something that won't make you nervous about losing an investment, give the chinese knock-offs a chance.
I think it's important to provide some tips, based on my own experiences, for successful and safe operation of an externally mounted camera. These are my opinions, and aren't necessarily correct. However, they have helped me feel both safe and confident with my externally mounted cameras.
Unlike a DSLR, action cameras are designed to be easy to use, and to have very reliable automatic shooting modes. As a result, we relinquish a lot of control over how our cameras choose to expose shots.
Cameras generally have 3 ways to adapt to low-light: increase exposure duration, decrease focal ratio, and increase sensor sensitivity. Focal ratio is a property of the optics, and can't be changed on most action cameras. That leaves exposure duration and sensor sensitivity .
Generally there's a happy balance between these two controls that results in a good outcome. However, they each have a drawback. Increasing sensor sensitivity increases the noise of your image. Increasing exposure length means that the sensor is exposed for a longer period of time, and any movement will result in blurring. In the shakey, windy environment out on a wing, you want a short exposure length, not a long one.
There's no real way to control this on most action cameras, but if you shoot in video mode, then the camera is forced to shoot a defined framerate. So if you're shooting at 60fps, then the exposure length can necessarily be no shorter than 1/60th of a second, meaning it will boost sensor sensitivity isntead.
I never use a tether, and I'm not a fan of tethering anything to an aircraft I'm flying (unless I were a banner or tow pilot). The motivation for using a tether is two-fold. One, it saves your camera in the event it were to dettach, sparing you a financial loss. Two, it prevents injury to persons on the ground. I think the latter of these is noble, but not worth the potential risks, unless you're flying over popualted areas.
The issue with a tether is that, once a camera detaches from its proper mounting position, it is now a liability, and it's a liability dangling from your airplane. It could whip back and forth in the airstream, impact flight surfaces, or get tangled in something important. There are probably safe ways to tether, but it's a tough thing to experiment with, so I avoid it altogether.
As much as I can help it, I do not fly over populated areas while there is a camera attached to my wing. If the camera and mount were to detach, they could do serious damage to persons or property on the ground, and I'm not willing to put other people's lives at risk to share my aviation experiences.
A strategy I suggest, if you're departing an airport in a metro or otherwise popualted area, is to have an intermediate, rural destination, where you can get out, and configure your camera and mount. I'm lucky in this regard, as most of my flights are along the Oregon coast, which has many small airports, and lots and lots of water for my camera to safely dunk into.
The GoPro suction cup mount allows you to configure the camera in a variety of ways, but it's probably best to keep it as low to the airfoil surface as possible. Putting a big hunk of plastic onto a wing is undoubtedly going to change the airflow characteristics in that region. This changes stall characteristics, performance, and adds an assymetry to the aircraft. Keeping the mount in a low-profile configuration may help minimize this effect.
A low profile also reduces the lever arm distance, and decreases the amount of rotational force acting on the pannel supporting the suction cup. As a bonus, it also means you'll probably have more stable and less shakey footage.
Your goal should be to share the joys of aviation, but not at the risk of others or yourself. Cameras, whether in the cockpit or outside, can be a distraction. I like the "set it and forget it" kind of attitude. Once mounted and recording, you have no reason to be thinking about it. Your job, as a pilot, is to fly the airplane.
This is a good opportunity for resource management. If you have a passenger, have them be responsible for checking on any cameras, or making sure things are working properly. This will keep you focused on looking for other traffic, and keeping your plane coordinated.