Maybe its purely the prevalence of gadgetry in everyone’s pockets these days, or possibly the crippling expense of certified systems. Whatever the reason, it seems that most modern light aircraft pilots are carrying GPS enabled phones or tablets, whether as a backup to installed equipment or simply as a kneeboard ‘cheat’ to navigate by.
Bad Elf don’t make fully featured navigation apps in their own right, but rather a collection of GPS recievers designed to provide your chosen system with a reliable signal. Since we tend to use Airbox Aerospace’s excellent RunwayHD on an iPad mini, we chose to review the Bad Elf Lightning Adapter version which only fits Apple devices with that connector.
These units are a godsend for anybody who doesn’t want to pay the premium for a cellular-equipped iPad purely for the GPS functionality. Moreover, the internal GPS is notoriously prone to cease operating when the screen is off, when you change apps, and sometimes seemingly for no reason whatsoever. These types of GPS antennas protect you from finding yourself having to go ‘heads-in’ to trouble-shoot your iPad at a critical stage of flight.
We have had the unit for nearly a year now, and we’ve tested it thoroughly. It might seem a bit over the top for such a simple piece of kit, but we stress tested our unit not only in the friendly skies of the UK, but also in mid-summer in the Middle East in a non-air conditioned helicopter, at cockpit temperatures of up to +45oC. Here’s what we thought.
Function & Reliability
Since the unit plugs straight into your device, no batteries are required; it uses power from whatever you’ve plugged it into. A small green LED flashes while it’s acquiring a signal and then goes solid once it’s got a fix. You need to install the Bad Elf app in order to use the receiver, and this can be used to give you more information on the quality of signal and some basic mapping and telemetry.
A mini USB port on the side is used to update the device firmware, and can also be used to provide pass-through charging of your iPad. While this is very useful, it would be nice to have a pass-through that uses the same charging port as the device itself.
The unit is able to receive both GPS and GLONASS location, as well as 66-channel WAAS (Wide Area Augmentation System) which essentially means that you’ll get the most accurate position possible, down to about 9 feet circular error probable.
When compared to the internal GPS, we found the Bad Elf adapter to have much greater accuracy. It was also far less prone to random drops in service than the internal GPS. It dropped signal on one occasion (possibly due to temperature) but all that was required to encourage it back to life was to disconnect and reseat the adapter.
The GPS antenna is extremely small, and comes attached to a lanyard by means of a plastic quick-release buckle. This means that it can be easily transferred between your nav bag and kneeboard or mount, but still secured to prevent it from becoming a loose article hazard if you knock it out of your device. It does protrude a fair way out of the bottom of the phone or tablet, but it didn’t interfere with any of the mounts we trialled, and even wearing it on a kneeboard it wasn’t ever caught or knocked out of the device accidentally. While it isn’t compatible with all device cases (our Lifeproof case being an example) a lightning connector extension lead can be used to get around this issue.
Ease of Use
It’s hard to imagine anything easier to use, frankly. Install the app, plug in the antenna and when the light is a solid green its providing your GPS signal.
The Bad Elf is a small unit made of plastic, which we were initially a little concerned about. We decided that the best way to stress-test the diminutive device was to send it on two operational tours of the Middle East with a group of military helicopter pilots. After a year of being dropped, banged off parts of aircraft and generally abused, it is still without any cracks or damage. It also functioned flawlessly at insane cockpit temperatures and in dusty conditions that no right-minded GA pilot would expose themselves to.
Units are on sale from www.gps.co.uk at £118.00 inc VAT. This might seem a little steep, but consider that a cellular iPad (required for internal GPS) is £100 more expensive than the wifi only option and it begins to look more appealing, especially when you take into account the vastly improved reliability and accuracy.