Pilot Products

S-Tec's GPSS

An autopilot has traditionally been one of the most expensive items in an airplane. Besides the obvious convenience, autopilots provide a major safety benefit — especially to those of us flying single-pilot. Through the use of moving maps, today's GPS receivers bring newfound capability to airplanes and eye-opening situational awareness to pilots. S-Tec has married GPS receivers and autopilots so that basic units can fly as well or better than those in airliners — at a reasonable price. S-Tec makes affordable autopilots that can be upgraded as your budget allows. Every S-Tec autopilot uses common servos for your airplane type. For example, if you want to swap a System 50 for a System 55, much of the installation is already complete, saving labor costs.

The building-block approach also works for S-Tec's GPSS (GPS steering) system. Any S-Tec autopilot can be modified with GPSS, provided the airplane has a GPS with the proper signal out-put. GPSS allows the autopilot to re-ceive composite roll steering commands directly from the GPS, leaving the course deviation indicator (CDI) on the nav display or horizontal situation indicator (HSI) out of the loop. This allows the autopilot to lead turns, intercept courses within 180 degrees, fly DME arcs, and fly the lateral portion of any procedure in the navigator's database.

Lancaster Avionics in Lititz, Pennsylvania, installed S-Tec's System Thirty autopilot as well as a used Garmin GNS 430 into the Beech Baron that I co-own. The System Thirty is a two-axis autopilot with brains that are contained within the turn coordinator. Without GPSS the autopilot is not able to intercept courses at anything more than 10 degrees. It also does not have automatic/electric pitch trim or the ability to fly an ILS glideslope. What it does do well is hold the wings level (or hold a heading if you have a heading indicator or HSI with a heading bug), track a nav course or localizer through the CDI, and hold altitude.

Because of a back order of GPSS converters, we had the System Thirty installed the traditional way so that it would track a VOR or GPS signal via the CDI. True to S-Tec's word, the Thirty would not intercept course changes of more than 10 degrees.

After the installation of GPSS, this was no longer the case. In the GPSS mode, the GPS digitally communicates roll commands directly to the Baron's autopilot, leaving the CDI out of the picture. The GPS, which knows the airplane's groundspeed, now steers the airplane from the centerline of one course to the next without overshooting or having to disconnect or manually steer the autopilot. Even if you have a high-end autopilot, GPSS puts an end to the waypoint overshoot and subsequent reinterception maneuvering that those systems have to perform.

GPSS allows the autopilot to fly any procedure in the GPS database with expert precision, including departure procedures, arrival routes, and approaches. On one flight, while approaching Washington, D.C., from the west, I was told to expect the Manne Four arrival to my destination, College Park Airport in Maryland. With a few punches of a button the airplane was flying the arrival while I fished out the chart to confirm the procedure. Without the Garmin and the GPSS-commanded autopilot, I would have entered the waypoints of the arrival into the flight plan while manually flying the first part of the procedure. It's doable but not my idea of fun when flying single-pilot in the soup.

With GPSS, DME arcs can be intercepted and flown with amazing precision, eliminating the mental math required to join such approaches or transitions. In the future, as more, including holding patterns, become part of the navigator's database, GPSS will be able to fly them with the same ease. The capabilities of the GPSS and System Thirty combination in the Baron rival the autopilot in the regional airliner I fly.

I also like GPSS' ability to immediately factor in the winds aloft. After spending many hours flying with a Bendix/King KFC 200 autopilot in a Beechcraft Bonanza A36, I would cringe as the autopilot would sail off-track to chase down the course dialed into the OBS, despite the fact that I was already holding the proper 20-degree crab into a stiff crosswind. GPSS knows the track error between the bearing to the station and the current ground track; therefore, it maintains the wind correction and disregards the OBS selector.

On my first flight with GPSS in 1999, the demonstrator airplane's HSI compass card locked up (see " Pilot Products: S-Tec GPSS," September 1999 Pilot). Since the autopilot was taking its cues directly from the GPS, the failed HSI didn't interrupt our flight plan and instrument approach. Without it we would have had to time turns using our watch and the whiskey compass. There's also the fact that S-Tec autopilots are rate-based, meaning that a vacuum-pump failure does not affect autopilot operations. If you lose your gyros in the soup, simply turn on the autopilot instead of your partial-panel skills.

The $999 GPSS system consists of a converter box that is the size of a deck of cards. It can be either panel- or remote-mounted. A button toggles the autopilot to take its cues from either the heading bug or GPSS. Installed weight is about one pound. The Garmin 430 and many other navigators output the roll steering commands that make GPSS work. Check with your installer to see if your GPS receiver outputs the ARINC 429 roll steering commands necessary for GPSS. S-Tec also makes a number of new autopilots that have GPSS built into them. For more information, contact S-Tec Corporation, One S-Tec Way, Municipal Airport, Mineral Wells, Texas 76067; telephone 940/325-9406; or visit the Web site ( www.s-tec.com). — Peter A. Bedell

Jeppesen's GFD Multi-Engine Manual

Jeppesen continues its Guided Flight Discovery programmed learning line of training materials with the release of the Multi-Engine Manual. The new offering illustrates important aerodynamic concepts and complex systems in approximately 375 full-color graphics. The Multi-Engine Manual builds on this practice with two new types of insets, one that highlights flying careers and another that discusses in-flight situations that bring together critical points made in the text.

"It challenges readers to develop critical thinking skills about multiengine topics," says Liz Kailey, project editor of the manual.

This is evident in the section on engine-out aerodynamics. The authors used the scientific method to investigate single-engine aerodynamics and debunk some of the myths surrounding engine-out procedures. A wide variety of sources were tapped in the process, including one example presented by Pilot columnist Barry Schiff. The text also stays fun for the reader, with quotes and anecdotes peppered throughout. What other serious aviation text out there draws from both Anne Morrow Lindbergh and Monty Python? Retail price for the hardcover, 320-page book is $49.95. For more information, contact Jeppesen, 55 Inverness Drive East, Englewood, Colorado 80112; telephone 303/799-9090; fax 303/328-4153; or visit the Web site ( www.jeppesen.com). — JKB

Perrone Leather Cleaner Wipes

Need a quick way to clean up your aircraft's leather and vinyl surfaces? We tested Leather Cleaner Wipes by Perrone on the interior of a Lockheed Jetstar II. The cleaner, packaged in a pop-up container and applied with small, pretreated napkins, successfully removed built-up dirt on the heavily used portions of the seats. For example, the crew seats had a residue buildup on the seat backs where the pilots repeatedly grab hold to make a balanced entry to the cockpit. The cleaner took care of those spots well, was easy to use, and left the seats with a nice shine. Unfortunately, it did not cut through blue pen marks, although it did fade them somewhat. Also, the product left the seats with a not-so-pleasant odor as a result of the chemicals used — but the smell dissipated after several hours. The package of 50 12-by-14-inch wipes retails for $16.95. For more information, contact Perrone Leather LLC, 20 Industrial Parkway, Gloversville, New York 12078; telephone 800/222-6341 or 518/725-9144; fax 518/725-7044; or visit the Web site ( www.perroneleather.com). — JKB

Briefly Noted

Sporty's Pilot Shop adds to its new line of complete DVD courses with the Instrument Rating Course. The six-volume series allows pilots to study instrument approaches, air traffic control, en- route operations, and weather at their own pace, with questions in each segment to test knowledge. The kit comes with a syllabus, study guide, and DVD carrying case for $199. For more information, contact Sporty's Pilot Shop, Clermont County Airport, Batavia, Ohio 45103-9747; telephone 800/543-8633 or 513/735-9000; fax 513/735-9200; or visit the Web site ( www.sportys.com). — JKB

In response to the continuing notams affecting general aviation and as an added service to its customers, Control Vision announced the addition of temporary flight restrictions (TFRs) to the airspace database for its Anywhere Map line of GPS navigation software for personal digital assistants (PDAs). The free updates, posted as often as feasible for the company, depict newly implemented TFRs. "Of course, it's each pilot's responsibility to contact the FAA for current notams. But the main problem we're seeing is that flight service stations don't always have the information," says Jay Humbard, president of Control Vision. Though incomplete, the depictions offer pilots at least some TFR knowledge on a moving-map display.

The TFRs are shown as bright blue and red rings — enough to grab a pilot's attention no matter how much other information is posted on the display. The depictions are accurate when measured against those provided by Jeppesen on AOPA Online. For more information, contact Control Vision, 1902 East 27th Terrace, Post Office Box 596, Pittsburg, Kansas 66762-0596; telephone 800/292-1160 or 620/231-6647; fax 620/231-5816; or visit the Web site ( www.controlvision.com). — JKB

The new Goodrich Skywatch HP extends the capabilities of the company's Skywatch system, with greater display and surveillance range, better depiction of closure rates, and EFIS compatibility. The Skywatch HP tracks up to 35 aircraft within a 20-mile surveillance range. The display shows intruder aircraft up to 15 miles away, generating both visual and aural warnings. The unit is compatible with most EFIS installations and multifunction displays (MFDs). Pilots with the Goodrich Stormscope WX-1000 processor can toggle between traffic and lightning data on the Skywatch HP's dedicated display. The unit retails for $28,915 with the display and $24,630 without the display. For more information, contact Goodrich Corporation, 5353 52nd Street Southeast; Grand Rapids, Michigan 49512; telephone 800/253-9525 or 616/949-6600; fax 616/285-4224; or visit the Web site ( www.bfgavionics.com) — JKB

Unless otherwise stated, products listed herein have not been evaluated by AOPA Pilot editors. AOPA assumes no responsibility for products or services listed or for claims or actions by manufacturers or vendors. However, members unable to get satisfaction regarding products listed should advise AOPA. To submit products for evaluation, contact: New Products Editor, AOPA Pilot , 421 Aviation Way, Frederick, Maryland 21701; telephone 301/695-2350. Links to all Web sites referenced in this issue can be found on AOPA Online ( www.aopa.org/pilot/links.shtml).