If you follow General Aviation technology news, it’d be obvious to you that GA airplanes are gradually being designed and made into “mini airliners”. Glass cockpit, synthetic vision, sophisticated autopilot, and anti-ice: you name it. Now there is a group of graduating engineering students at the University of Wisconsin-Madison who decided to take it even further. This group of 5 mechanical engineers has taken up an opportunity from their senior design course to find a cheap solution to an expensive altimetry device that gives pilots more precise information when they come in for landing, a very critical and accident-prone phase of flight. The leader of the group, Sean Sporie, a pilot himself, discovered a common issue that pilots encounter: the difficulty in the timing of a “landing flare” due to inadequate information by existing instrumentation. (Note: A landing flare is a maneuver that reduces the descent rate and adjusts a plane into a proper attitude for a smooth touchdown. A good flare requires almost surgical precision; flaring too soon or too late could be very hazardous). As is known to every pilot, landing and flaring a small plane is solely based on pilots’ sight picture and feel of the airplane as it’s approaching the runway. Perhaps none of the gauges other than the airspeed indicator is accurate enough for pilots to make informed decisions based on them once they get close to the ground. Airliners are equipped with radio altimeters that help guide pilots down to a safe landing, and such systems also guide the auto-land system for both approach and landing. However, a radio altimeter would be too bulky for a light plane and too expensive for its operator. So for Sean and his team, the goal is to make their product portable and affordable.
How exactly does it work? One might ask. Perhaps you have already learned it in high school physics: distance equals the product of speed and time, for a wave in this case. The land assist device (LAD) utilizes a precise laser optic sensor connected to an intelligent microcontroller to deliver rapid and accurate true altitude measurements to the pilot when coming in for landing. The system itself is comprised of two individual units; the first is an external housing which contains the optical sensor and is securely mounted to the underside of the wing. The second is a compact internal display that provides both direct altitude measurement values and a visual graph for quick and easy feedback to the pilot during landing. The small size of the internal display allows it to be mounted just about anywhere inside the cockpit without interfering with other gauges or equipment inside the aircraft. Each unit communicates with the other wirelessly for easy installation and operation; all you have to do is mount each in place and flip the power switch, then you are ready to go. Currently the as tested prototype has a range of about 200 feet and accurate within 2.5 inches. However there are plans to test a future model with the capability to measure over 1000 feet off the ground so it can be used throughout the entire traffic pattern and landing process. In future models the internal display will be changed to allow user customization so that he or she may choose a method of feedback which works best for them. There will be options such as audible readouts or bar graphs that could save the pilot valuable visual attention during landing. Ultimately, as Sean put it, this innovation is designed to save people.
One might argue that “innovation” is an overstatement as similar technologies have already existed in different forms for decades. However, innovation is not always the birth of unexplored ideas or designs. It often is the refinement of existing ones stranded by impractical and unmarketable crudeness. This is particularly true in the world of aviation. To name a few, the widely known Cirrus whole-plane parachute system isn’t entirely a genius idea originated from Duluth, but an old one fully developed into the tip of its potential. Mounting a parachute on a plane has been a common practice in ultralight aircrafts for decades, however, it was the Cirrus brothers that dug out this chunk of undiscovered gold by, first time in history, mandating one of these chutes in their luxury single engine personal plane. In recent years, a lot of newly developed business jets boast their “enhanced vision system” and/or “synthetic vision system”, a device that utilizes infrared imaging and synthesized topography to present its users a clearer picture/view of what’s in front of them, thus to help approaching airplanes and it pilots “see better” in poor meteorological conditions. Again, it was another revamped idea first conceived in as well as tested by NASA and the US Air Force in the 1970s. Perhaps the most relevant case would be that of the Angle of Attack indicator, commonly seen in fighter jets and commercial jets. The AoA indicator is one that shows how close an airframe (i.e. your wing) is to an aerodynamic stall, or to put it in more simple terms, AoA warns the pilot before the wings quit generating lift and it gives suggestions as to the preventions and remedies for such an event. Just as expected, these indicators are now being applied onto small GA aircrafts and were adopted by the high-profile amphibious light sport aircraft ICON A5. Again, it’s not a new concept, but if you go to an ICON press conference, it would sure sound like one.
This is not to say, however, that the LAD is guaranteed to be a successful gap-filler. It certainly needs to address many technical and legal difficulties before the aviation family can accept this adopted child. One of the biggest issues the team has been facing is the product’s potential liabilities. “What if a user mounts it incorrectly and the external unit falls into some pedestrian?”
But overall they are very confident in the future and potential of this device. A market for LAD might actually also exist in bush flying, helicopter medevac (medical evacuation) missions, crop-dusting, etc. The team’s confidence is also built upon the possibility of incorporating this device with other data collectors such as an AoA and airspeed indicator to deliver more sophisticated information. Maybe one day we’d be able to auto-land a single engine piston aircraft with a system originated from this design.
Editor’s Note: As of the writing of this article, Diamond Aircraft has announced that it will offer, by 2016, the first General Aviation fly-by-wire autoland system for its single engine DA-50 and twin-engine DA-52. It’s not unreasonable to conclude that a vertical distance measuring system with similar workings to the LAD would be applied to make it possible, another proof of concept by industry leaders that precise altimetry technology is not just a privilege of multi-million dollar jets that few could fly.