As I mentioned in my first post, aircraft health management systems have enjoyed much attention in the recent past. One particular trend within those systems that has become even more apparent lately is the need to extract the aircraft data seamlessly and…oh yes, in real-time.
Needless to say that in today’s world we’ve become very much accustomed to obtaining data (news, songs, videos, etc…) with the snap of our fingers. One need only think of the last time that we *didn’t* have access to the internet to realize just how much our individual expectations for obtaining data “now” have changed.
However, the aviation world has somewhat suffered from a lack of viable offerings from the standpoints of coverage and speed. Sure, 3G, 4G and Wi-Fi are all great, but you won’t have access to any of those at Flight Levels. On one of my recent outings, I was able to get a couple of bars on my cell phone while flying at 700ft AGL, but I would hardly qualify that as a ubiquitous service. So the question is: how do we harness the full power of today’s diagnostics and prognostics solutions by transferring the data to the ground in real time, even when flying at 30000ft? That’s where hybrid installations come into play: these solutions essentially rely on 3G, 4G and Wi-Fi while the aircraft is on ground, while letting air links do the heavy lifting when the aircraft is flying. Hopefully we’re all familiar with the former technologies; whereas the latter ones may merit some discussions.
Air link solutions come in two broad categories:
- Satellite solutions: a handful of industrious operators are offering satellite constellations for use in everything from downloading weather information to, yes, uploading aircraft data. To date, satellite offerings lag far behind home high speed connections (we’re still talking kbps at best, in case you’re wondering), so you won’t be streaming any YouTubeTM videos on those pipes, but for the transmission of key aircraft data they have proven to be remarkably efficient channels.
- Air-to-ground (ATG) solutions: For most people flying commercially over the continental United States, this is likely what they have witnessed if they decided to take advantage of internet access on their flights. These connections are much faster and, to simplify the concept a bit, they essentially boil down to cell phone-like towers pointing upwards: you connect to a wireless router located in the aircraft and that router then retransmits the information to ground-based towers. Speeds are much higher, but here’s the downside: they are air-to-ground solutions, with emphasis on “ground”. This is great if you’re flying from, say, Chicago to Indianapolis. Not so much if you’re flying from NYC to Heathrow, where the majority of your flight will be spent over an ocean with no transmitting/receiving tower beneath you.
Due to each solution’s shortcomings (coverage, speed), the industry appears to be trending towards installing hybrid solutions where both ground- and air-based solutions are installed on the same aircraft. But there is one more reason for that: financial. Satellite and ATG solutions may be available at 30000ft, but they are not cheap. Granted, prices have dropped significantly in the last decade, but I would argue that they are still not within reach of the broader GA population. Bizjets and commercial aviation may have the means to absorb the costs, but on an uneventful flight is it really necessary to download Kb or Mb of data while the aircraft is flying, or can it wait until the aircraft is at an FBO and within reach of a cheaper 3G signal? The question of course is rhetorical: the market has already answered it by adopting the aforementioned hybrid solution – Satellite or ATG links to transmit critical data while flying, Wi-Fi or 3G/4G to transmit the rest of the data while on ground.
Regardless, I think that some of the developments in real-time aircraft communications have been nothing short of remarkable. I am particularly excited about the relatively recent announcements of Ku- and Ka-band technologies that promise to revolutionize the way we think about real-time in aircraft applications.
I’m interested in hearing your thoughts on this subject. Have you had any experience with in-flight connectivity? What do you think of the adoption of hybrid solutions for aircraft health management?