AOPA has released 12 employees as part of an effort that will cut costs and make the organization "focus on grassroots events and reaching out to our members in real and tangible ways," said AOPA spokeswoman Katie Prybil. "We are focusing on creating member value in everything that we do. The changes announced today will also ensure that AOPA has a sustainable business model that brings expenses in line with revenue." In an extensive interview with AVweb's Paul Bertorelli, new AOPA CEO Mark Baker said major changes were coming in the way the organization conducts its business and it appears Thursday's realignment was the opening move in that effort. "This was the first step to ensuring that AOPA will be really listening to our members and using their feedback to align our resources to accomplish member’s needs," Pribyl said. Government Affairs and AOPA's fledgling Center To Advance the Pilot Community were the areas most affected by the reshuffle.
AOPA's Katie Pribyl issued this statement (PDF) to AVweb late Thursday.
Pribyl would not discuss the names or positions of those let go but AVweb has learned that Adam Smith, who was hired to head up the pilot community division, was released along with two other staff in his department. AVwebspoke with Smith about the new department last year. Pribyl said there are still staff dedicated to promote flying clubs, support flight training and to lure inactive pilots back. "AOPA feels we can be most effective in the area of growing the pilot population with a budget and infrastructure that maximizes development of very focused and tangible resources that assist clubs and flight training providers," she said. As for government affairs, Pribyl said the changes were made to "more closely align and integrate AOPA’s legislative activities with its work in the regulatory arena. " Two staff members were released in that department and the remainder of the layoffs were spread through the organization in "ones and twos," said Pribyl.
Bloomberg is reporting that Beechcraft is for sale again and that Cessna might be one of the interested parties. Bloomberg quotes unnamed sources and Beechcraft spokeswoman Nicole Alexander said the company does "not comment on market rumors or speculation about the company." The Bloomberg story says Credit Suisse Group AG is actively shopping the storied Wichita planemaker around on behalf of its owners and the price could be in the $1.5 billion range. Beechcraft restructured less than a year ago from the bankrupt Hawker Beechcraft and with its fresh financial perspective might be an attractive acquisition for an established company, turbine aircraft analyst Richard Aboulafia told Bloomberg.
“You get military trainers, you get the world’s most popular turboprop aircraft,” Aboulafia is quoted by Bloomberg as saying. He was referring to the T-6 trainer that is in widespread use by air forces all over the world and the King Air, which is the company's best-selling aircraft. As part of the restructuring, Beechcraft shed its former Hawker jet line and has been looking for a buyer.
Continental Motors' Cylinders
Our cylinders begin with raw forging and casting components with the highest standards in material properties. Each is then machined, honed, and assembled into a complete cylinder package that we firmly stand behind. Our employees take pride in building a quality product every step of the way.
Vulnerable. That’s essentially how Eric Geisleman and a group of aviation safety researchers described flight crews when it comes to operating transport category flight control systems. Are general aviation pilots just as vulnerable? That's debatable.
One article (Flight Deck Automation: Invaluable Collaborator or Insidious Enabler?) that was published in the July 2013 Ergonomics in Design focused on two high-profile 2009 crashes—Colgan Air in Buffalo and Air France off the coast of Brazil—concluded that current autopilot design and automation is flawed and "creates unnecessary emergencies by surprising pilots during critical, high-workload episodes."
The two-series article, co-written by Christopher M. Johnson and David R. Buck, responds to claims that airline pilots may be losing their ability to manually control aircraft because overreliance on automation is eroding basic manual flying skills.
Geisleman and his co-authors have combined expertise as airline pilots, flight instructors, crew resource management instructors and human factors researchers. According to their research, modern cockpit automation does not, among other things, effectively communicate to the pilots two of the most common modes of autopilot operation: heading command and navigational tracking.
In another article (Flightdeck Automation: A Call for Context-Aware Logic to Improve Safety) to appear in the October 2013 issue of Ergonomics and Design, the researchers suggest that flight displays can be redesigned using a more context-aware navigation interface. Moreover, the researchers state that placing blame solely on pilots for automation-related airline disasters fails to delve deep enough into the human-machine interface and note that better training is only a partial solution.
Using real-world examples, the researchers describe the scenario of an airliner in cruise flight, with the autopilot coupled in navigation mode and flying a preprogrammed route. ATC then instructs the crew to fly the current heading to avoid a traffic conflict, requiring the crew to switch the autopilot into heading command mode and continue flying straight ahead. Once cleared back on course (which is still straight ahead) the scenario has the pilot forgetting to reengage navigation tracking mode and missing the next waypoint in the FMS-programmed flight plan—sending the airliner off course and deviating from ATC instructions.
This scenario points out that although the autopilot tracking mode has changed (and is properly annunciated) the navigation display, which still shows the FMSs active flight plan, looks no different in autopilot heading mode than it does in navigation tracking mode and is a critical piece of data that complacent flight crews can miss.
The researchers suggest that a more context-aware navigation interface would differentiate between a route flown in heading and navigation mode, while alerting the pilot of a deviation. One example is an updated display that shows a virtual corridor of the aircrafts course (and where the aircraft won’t be flying in the current autopilot state) when deviating from a programmed route.
The report goes on to describe other scenarios of airliners overflying destinations by hundreds of miles because crews failed to notice which mode the autopilot was in, compounded by dialing an incorrect ATC comm frequency that put the crew out of radio contact. The authors note that a more context-aware system could have utilized geographic location to alert the crew of the erroneous radio frequency and the missed descent point.
What lessens might general aviation pilots learn from these blunders? For starters, it's to maintain a healthy level of awareness as to what mode the autopilot is flying while avoiding automation-induced complacency. On the other hand, autopilot manufacturers we spoke with know this isn't as easy as it sounds, despite designing the new breed of autopilots with large amounts of failsafe features and pilot-friendly operating logic.
Autopilot Automation for the Rest of Us
While the research didn't focus on the automation that's found in smaller cockpits, the manufacturers we spoke with had some valuable insight to help pilots avoid ugly situations and pointed out that it's up to the pilot to closely monitor the system and act quickly and correctly when the system fails.
According to Garmin's Bill Stone, the most important thing a pilot can do is read the aircraft flight manual supplement to become thoroughly familiar with all aspects of autopilot operation and its interface with other systems in the aircraft. He also knows that pilots aren't doing enough reading.
"An awful lot of time and effort goes into producing the content of a flight manual supplement and pilots really need to read and understand what's in that supplement, particulalrly when it comes to autopilots. You know as well as I do that this isn't happening," Stone told AVweb.
Garmin's GFC700 is a full-featured, digital autopilot that's a major part of the company's G-series integrated flight deck. You'll find it in a wide variety of small and large airframes, including models from Cirrus, Cessna and Beechcraft, to name a few. Stone made it clear that the system is designed with sizable amounts of self-diagnostic and crew-advisory technology.
"The GFC700 has tremendous amounts of redundant safety monitoring in it, including two seperate paths for comparing ADAHRS inputs, two seperate paths for monitoring servo direction, speed and torque—all of which are measured and compared by two seperate processor boards. The likelyhood of a system runaway is extremely small," said Stone.
Should a pitch, trim, roll or yaw channel fail, the GFC700 will alert the pilot through interactive warning messages. From there, it's up to the pilot to acknowledge these warnings and react appropriately. It's important to understand that a failure may or may not automatically disconnect the autopilot. Garmin's Stone offered good advice for these situations.
"The pilot should be prepared for the autopilot-to-hand-flying handoff. This includes gripping the controls—tighly—because the aircraft could be in an out of trim condition, requiring sizable amounts of control force to counteract. If the autopilot hasn't disconnected, it's up to the pilot to do so. These kinds of procedures are clearly stated in the flight manual supplement and pilots need to be have these procedures memorized because they are as important as memorizing procedures for dealing with a critical engine failure," warned Stone.
This is good advice for any autopilot, especially for older analog pilots that don't have the sophisticated channel monitoring that the GFC700 has. This means that the pilot should know the proper procedure for disconnecting the autopilot. While this sounds trivial, it's an important part of quickly gaining control of the aircraft. Speaking of gaining control, certified autopilots are required to have drive servos that can be overridden. This means that a capable pilot should have enough strength to slip the servo clutch.
When disconnecting most autopilots, the preferred method is to use the yoke or panel-mounted disconnect button. This disconnect circuitry immediately removes the input drive-voltage from the servos. Disconnecting the autopilot by chopping power at the main autopilot master switch could leave residual voltage on the servo clutch—preventing it from disengaging and keeping the controls locked. Of course, if all else fails, pull the autopilot circuit breaker. Again, consult the flight manual supplement for specific instructions on the system you are flying with.
The researchers note that, by regulation, autopilot disconnect functions do not adhere to the CRM (crew resource management) protocol for a postive exchange of aircraft control between humans.
One of the aspects of autopilot automation that Geiselman and his co-authors say needs to be changed is the process of acknowleding that the autopilot has been disengaged. They believe that pilots need more advanced warning before the autopilot disconnects and use the Air France Flight 447 Airbus accident as an example.
Approximately two hours after takeoff, the airspeed data was disrupted due to a sensor malfunction, which caused the autopilot and the autothrust systems to disconnect. No warning was provided to the aircrew prior to the disconnection. After the autopilot disconnected, the airplane performed an uncommanded right roll, before the crews' situational awareness progressively began to unravel and the aircraft became uncontrollable.
Ultimately, the accident was attributed to the crew misdiagnosing the aircraft state and inappropriate reaction to the loss of airspeed information. The actions of the pilot flying who executed excessive roll and nose-up inputs were attributed to being surprised by the sudden autopilot disconnection. Also, according to researchers, multiple aural/visual alerts and warnings created a confusing environment.
"The sudden disengagement of the autopilot is analogous to a pilot suddenly throwing up his or her hands and blurting to the co-pilot, 'Your plane!'', said Geiselman. His point is that before control of an aircraft shifts from the autopilot to the pilot, the system should require the receiving pilot to acknowledge that he or she has assumed control of the aircraft.
The researchers also cite the Colgan Air Flight 3407 crash, where a contributing factor was the lack of forewarning when the autopilot automatically disconnected during the landing approach. Again, their point is that a positive exchange of control—with clear and concise communication about why aircraft control is being transferred—is what's required between two pilots that are flying and it should be required before the autopilot disconnects, too.
Built-in Envelope Protection
That's the design philosphy behind Avidyne's DFC90 retrofit autopilot (it's designed to fit into an existing S-TEC 55X installation and interface with Aspen's Evolution PFD and the Avidyne R9 integrated flight deck system).
According to Avidyne's Jake Jacobson, the company designed the DFC90 flight computer to be a natural extension of the pilot. This includes an architecture that's molded not around the behavior of professional flight crews but instead, around the pilot who may not always be in complete control of the aircraft. Avidyne's intent was to build in as much envelope protection as possible, while designing a feature set that creates no confusion as to what the autopilot is doing or what mode it's in.
"The pilot who's barely hanging onto a rope a mile behind the airplane and the better pilot who is on his or her game. We build in as much envelope protection as we can for both kinds of pilots. The DFC90 is a tightly-coupled and tightly-integrated system, with modes that are logically more helpful for a wide variety of pilots," according to Jacobson.
The DFC90 and higher-end DFC100 have internal monitors and internal comparitors that act as aircraft-level diagnostic self-test units. This includes monitoring of trim tabs, control rigging, drive servos and the electrical inputs to the critical components that a pilot may not have any idea are out of specification.
On a recent flight, Avidyne's Jacobson demonstrated the impressive capabilities of the DFC90, including intercepting a final approach course within a quarter-mile of the final approach fix— at a 150 degree angle, at high speed and with a tail wind. The idea behind the demonstration is that the system can handle situations that a pilot who's behind the aircraft might find themself in. There's also a straight-and-level mode, for unusual attitude recovery and stall protection.
As for the graphical interface issues the researchers say needs to be changed, Avidyne has already done so, attempting to create an autopilot mode annunciation logic that's intuitive, specifically designing the system so that different autopilot modes present differently on the PFD. This includes Vector Mode—a dashed magenta line on the PFD that's overlaid over the flight plan—responding to changes made with the autopilot heading bug. At the same time, you can manually create your own vector or course intercept that visually differentiates between what's loaded in the flight plan and what the autopilot is actually flying. The current mode of tracking is always displayed at the top of the PFD.
If there's a lesson to be learned from the examples of automation-gone-wild in airliner cockpits, it's that vigilance is needed when flying behind the automation in smaller cockpits, too. This includes understanding and learning newly-installed retrofit interfaces, reading the flight manual supplement and following along with the autopilot when it's flying. Most important is being preloaded to quickly react to failures.
Even basic autopilot systems like the Cobham/S-TEC System 30 require a self-test before every flight to ensure the servos move the controls in the proper direction, the disconnect circuitry works correctly and that the pilot can override the system.
Bottom line: You want to avoid the automation-induced complacency, surprises and confusion that occassionally gets the best of professionally-trained airline crews.
Time for the Ultimate Flight Bag?
"The praise continues for the Flight Bag PLC Pro ... . Easily converted with either a shoulder strap or a super comfortable backpack-style strap, the bag is easy to carry for a few steps or across terminals." -- Robert Goyer, editor of Flying magazine. Modern, lightweight, and checkpoint-friendly, the Flight Bag PLC Pro is the ultimate flight bag. As a shoulder bag or backpack, it provides iPad/computer protection and is designed to easily store and find all of your gear. For more information, click here.
Invest in quality. Invest in MyGoFlight.
Phone (303) 364-7400 or visit MyGoFlight.com.
The Wright Brothers were successful because they combined two vital elements of airplane design: control and stability. Wilbur and Orville achieved control through a pioneering design that evolved into what's used in almost all fixed-wing aircraft today -- a system that makes use of the stability designed into the airplane. Controllability cannot exist without some measure of stability. Stability, in turn, is affected by several factors. One variable even changes over the course of a single flight -- the location of the center of gravity (CG).
When was the last time you computed aircraft weight and balance? What practical effect does knowing the CG location have on your flight planning? What happens to your airplane's stability as you burn off fuel in flight?
Computing the Load
By computing the CG location, you can predict how the airplane will handle. In some airplanes, handling can vary greatly with variations in CG location. If the CG is outside design limits, the airplane may not be controllable at all. How does CG location affect control, even within the certified envelope?
The further forward the CG, the greater its tendency to straighten the airplane out if disturbed by turbulence or control movement. Moving the CG forward increases stability. This is normally a good thing (especially for instrument flight), but even within the CG envelope, a forward CG has some adverse effects on performance, including:
The need of additional elevator force -- and therefore more speed -- to raise the nose for takeoff. This means it'll take a longer runway to get up to control-force speed.
For a given airspeed, a greater control deflection to hold a pitch attitude. Greater control deflection increases aerodynamic drag, reducing performance.
In most flight regimes, increased downward force on the tail to resist the nose's tendency to drop. This results in increased drag and, indirectly, flight at a higher angle of attack for a given speed, both of which reduce performance even further.
Reduced cruise speed for a given power setting and airplane weight, for the same reasons.
Increased power (and fuel burn) necessary to achieve a given cruise speed.
The need for additional up-elevator to flare for landing.
Note that all these effects happen even when the CG is within certified limits. If the airplane is loaded outside the limits on the forward edge of the allowable loading envelope, the airplane may be so stable that even full control deflection isn't enough to overcome the nose-down tendency. The airplane, in effect, becomes too stable to fly. A forward-CG loading that is controllable in flight, with ample airflow over the elevator, may become uncontrollably nose-heavy as the airplane is slowed and control effectiveness is lost. The nose-heavy airplane may be more likely to "mush" into the ground short of the runway, or land hard on the nosewheel when control effectiveness is lost in the flare.
What's typically nose-heavy? Some airplane designs are naturally nose-heavy. Turbocharged aircraft are particularly nose-heavy (from the weight of the extra turbo equipment ahead of the firewall), especially if there are no occupants or baggage in the airplane's aft cabin. Some fairly short airframes also end up nose-heavy without rear-seat passengers or baggage.
As CG goes aft, there is less distance between the CG and the center of lift, and the airplane becomes less stable. In the extreme, modern fighter jets are designed to be completely unstable for maximum maneuverability, depending on computer-driven controls to "create" stability for aircraft control. Although reduced stability increases maneuverability, a rearward CG also induces these effects:
A tendency to nose up prematurely on takeoff, and to pitch up excessively in response to the "normal" pilot inputs for takeoff. This makes the airplane more likely to stall, and increases drag to reduce initial climb performance.
If disturbed by turbulence, the airplane will not return to stable flight, but may "hunt in pitch" and require more active control input by the pilot. The aft-CG airplane is a much higher-workload aircraft to fly precisely -- an unstable balancing act.
When slowed for landing, it may require nose-down elevator to avoid a pitch-up tendency. If "normal" control inputs are applied, the airplane will be more likely to increase angle of attack and land short, or stall.
The tail-heavy airplane will, however, trim out at a lower angle of attack in cruise, and so for a given power setting, it'll fly a little faster than the same airplane loaded at a further-forward CG.
If CG is aft of the airplane's certified loading envelope, the airplane may be so unstable it cannot be safely flown. The effect would be more pronounced at slower speeds, such as landing, when reduced air flow makes the elevator less effective.
What's typically tail-heavy? Airplanes with large aft baggage areas and long-body airplanes with seats near the back of the cabin are most commonly loaded near (or beyond) their aft CG limit.
Fuel Burn and CG
We all learned to compute CG location as part of our initial pilot training. But how many of us were taught to compute weight and balance not only for the takeoff condition, but for the anticipated landing condition as well? Many airplanes may be loaded within limits for takeoff, only to go out of the CG envelope after some amount of fuel is burned out of the tanks. I surprised renters of a Cessna 172 I flew early in my instructor career by showing them the airplane was safely within limits at nearly fuel with two people in the back seats, but that after burning about half of the fuel in flight the CG was drifting dangerously aft of the aft limit.
Computed CG location for a Cessna 172S with two standard occupants up front, a pair of 150-pound passengers in the rear seats, and baggage for a weekend trip, at (1) full fuel, (2) half tanks and (3) a zero-fuel condition. Note the CG gets closer to the aft limit as fuel is burned, going out of limits well within the fueled range of the aircraft.
Since most airplanes carry their fuel in the forward part of the wing it's most common for CG to translate aft with fuel burn. Individual airplane design and optional auxiliary fuel tanks can complicate this rule.
Here's an exercise: Using weight-and-balance data for an airplane you regularly fly, with a given passenger and baggage load, compute CG location at full fuel, half fuel and zero fuel. See where the CG goes with fuel burn, and whether it'll go beyond the aft limit as loaded while there's still fuel in the tanks. If so, you've now established a shorter aircraft range (including reserves) before you need to land for fuel to maintain controllability.
Knowing Your Limits
If you're inside but near the forward CG limit, the airplane will take more runway to take off and a firm hand to get into a climb attitude. But the airplane will be more stable in turbulence, giving your passengers (and you) a smoother ride. Take advantage of a forward CG and plan fuel stops and your load to be near the forward limit when you fly in rough air or near mountains. If the air is smooth, you might plan for a rearward-but-within-limits CG, for a faster cruise speed. Either way, account for the CG effect of fuel burn and ensure you'll still be safely within the envelope at the completion of your trip, including flight to an alternate airport if needed.
Some pilots like "stable" airplanes, especially for instrument flight. Others like "maneuverable" aircraft. The "stable" types consider more maneuverable airplanes to be "squirrelly," while the "maneuverable" crowd says stable airplanes "fly like a truck." Whatever your preference, the way the airplane handles is in large part a function of its CG.
Thomas P. Turner's Leading Edge columns are collected here.
Would You Like to Participate in Crafting the Future of Aviation?
If so, please take a short (ten-minute) survey to help us understand the elements of trust, safety, and cost that may be essential in the decision to be a passenger on an unmanned, autonomous airliner. Click this link to take the survey.
As China struggles to expand its aviation infrastructure at a breakneck pace, it's seeking help from every corner of the globe, and the European Union is stepping up expertise in airport design. AVweb's Tim Cole interviews Norbert Gronak of Aviare Consult GmbH about China's airport design needs.
Anyone who flies out west understands the need for turbocharging and pressurization isn’t a bad idea, either. An older Cessna P210 fits this requirement perfectly and this month, we’re featuring Steve Biggs’ P210N, which is based in Bozeman, Montana.
I'm proud to submit my newly refurbished P210N for your consideration as Refurb of the Month. I've owned this wonderful airplane for 16 years and prior to retirement, used it routinely for fast, efficient transportation in my work. Now I'm looking forward to visiting family and friends around the country with my wife.
Considering the utility and comfortable cross-country travel of my P210 and given today's vast selection of retrofit avionics and instruments, a complete refurbishment seemed a prudent choice versus trading for a late model or new pressurized aircraft. The result of the project is a very capable and beautiful airplane at a fraction of the cost of new.
An important side benefit of refurbishment is staying with an aircraft whose flight handling characteristics, performance and maintenance history you already know. Here are just a few pictures of the project:
The old panel was loaded with Cessna 400 gear and a KLN90B GPS. Functional but hardly modern. I completed panel with a very long list of upgrades, options, improvements and cosmetics. Yes, that's an ADF. Some things you just can't give up!
The interior got all new fire-blocked leather and wool interior plus new memory foam cushions. And the icing on the cake: a new paint job.
The result; luxury cross country transportation and state of the art avionics and instrumentation for the pilot at a fraction of the cost of trading for a new comparable aircraft.
Life is good and grandchildren and aircraft ownership make it even better!
AVweb is the world's premier independent aviation news resource, online since 1995. Our reporting, features, and newsletters are brought to you by:
Publisher Tom Bliss
Editorial Director, Aviation Publications Paul Bertorelli
Editor-in-Chief Russ Niles
Webmaster Scott Simmons
Contributing Editors Mary Grady Glenn Pew
Avionics Editor Larry Anglisano
Contributors Kevin Lane-Cummings Paul Berge
Ad Coordinator Karen Lund
Click here to send a letter to the editor. (Please let us know if your letter is not intended for publication.)
Comments or questions about the news should be sent here.
Have a product or service to advertise on AVweb? Your advertising can reach over 225,000 loyal AVwebFlash, AVwebBiz, and AVweb web site readers every week. Over 80% of our readers are active pilots and aircraft owners. That's why our advertisers grow with us, year after year. For ad rates and scheduling, click here or contact Tom Bliss:
What with the government shutdown and politicians snarling at each other across a partisan divide that makes the Grand Canyon look like a sidewalk crack, there’s much to cheer about lately. So I was happy the other day to get a press release touting something simple that we can probably all agree on. I can’t really call it an organization so much as an organized effort with the sole declared purpose of putting Tom Poberezny back on the radar or at least affording him the respect he has earned. And for that, I’m cheering just for the hell of cheering.
Poberezny dropped off the edge of the earth in the middle of AirVenture 2011 and essentially hasn’t been heard from much since. At the time, I thought his treatment at the hands of either the EAA board or then president Rod Hightower—maybe both—was shabby at best. Whatever differences may have emerged that summer—and I’ve been told they were considerable—letting a guy of
Poberezny’s stature and achievement go loose in the middle of the very iconic airshow he helped create is simply not the way to do business. It was then and is still beneath an organization as important as EAA.
But that’s history and the next page of it is a groundswell movement that centers on a web site named simply HonorPoberezny.com.
The site details Poberezny’s achievements and contributions, both in aviation and to EAA. And let’s not forget his Dad, Paul, who died in August at the age of 91. He left a lasting aviation legacy that will long outlive him.
According to the press release sent to me by David Gustafson, Tom and family will appear at AirVenture again in 2014 and I’d say his return is overdue. You can click into the website and electronically sign a roster of support recognizing the younger Poberezny’s contribution. Isn’t that least all of us could do to offer a simple thanks? Here’s a guy who more than deserves at least that.
At AOPA Summit in Fort Worth, Texas, Dynon Avionics introduced a new product called the D2 Pocket Panel. It follows the company's popular D1 EFIS, but the new product, rather than being limited to a built-in display, communicates wirelessly with tablet apps.
At AOPA Summit, Garmin International is showing off something new: a sophisticated pilot watch that features GPS navigation, built-in altimetry with alerting, multiple timers, and even wireless camera control. The new gadget sells for $449 is expected to be available in November.
At every show, we see ever more functionality and high-level features in tablet apps. At AOPA Summit this year in Fort Worth, we’ve uncovered some useful new features in three apps we examined: ForeFlight, WingX Pro and Jeppesen’s FliteDeck app. In today’s video tour of these products, you can get a look how the new features work from Tyson Weihs of ForFlight, Hilton Goldstein of WingX Pro and Weston Greene from Jeppesen.
At AOPA Summit, you can try all of the major ANR headsets in a single booth and fill out a survey form to quantify exactly what you think of each one. If you buy any of the headsets from any manufacturer, Giant of Quiet will give you a $25 coupon toward the purchase. We'll play the game here and refrain from identifying which company is sponsoring the mystery headset challenge.
One way of attracting a crowd at shows like AOPA Summit is to have a clever gadget, and Anthony Chan definitely has one in his wirelessly controlled aircraft tug. Chan was putting the tug through its paces on the exhibit floor in Fort Worth this week and drawing plenty of interest. Unlike most tugs, which use rubber-tired wheels for traction, the AC Air Technology tug has a miniature tank tread system driven by a pair of powerful electric motors powered by a lithium-ion battery capable of multiple tows.