Avionics News June 2012 - 57

FLYING THE DFC90 AND PFD1000: COULD BE A PILOT’S BEST, UNSLEEPING, FRIEND The powerful capabilities of this package showed vividly in a pair of 45-minute demonstrations arranged by the partners, one in Aspen’s SR22 test bed, the other in Avidyne’s 1977 Cessna 182. There’s a lot to learn. But, the partners’ systems both operate so straightforwardly that using the combination also is easy to learn. Avidyne programmed the DFC90 to always engage at least a hold in lateral and vertical mode if the pilot doesn’t engage a specific lateral mode – a climb or descent in vertical mode, for example, and a heading input in the lateral mode. Without specific pilot input, the DFC90 defaults to roll hold mode and holds the wings level. Without a specific vertical mode selected, the DFC90 defaults to pitch hold mode and holds the plane level. Operation and interface are similar to the S-TEC 55X. A single button press typically engages a desired mode, while a dual button press typically captures a new target setting. For example, to engage altitude hold, press ALT once; to engage heading hold, press HDG once; to hold indicated airspeed, press IAS once. Similarly, to engage a vertical mode that will result in capturing a new altitude, set the altitude bug on the EFD1000, then press both IAS and ALT or VS and ALT on the DFC90. To capture a course, set the heading bug and press both HDG and NAV, or GPSS and NAV for flying off a navigator. To engage IAS hold, the pilot sets the speed target in climb or descent. If using the VS hold function, the pilot sets the rate desired for the altitude change. The GPSS gives the DFC90 the ability to fly GPS-driven flight plans, anticipating turns and carving corners to maintain a centerline-to-centerline track. Beyond en route functions, the DFC90 flies quite well in approach mode with the vertical control enabled by the autopilot. It can fly approaches as published and stored in a WAAS GPS database and capture both the localizer and glideslope of an ILS. The DFC90/EFD1000 works in ways not seen on other autopilots. For example, turning the DG heading bug past 180 degrees – all the way to 360 degrees – and the DFC90 turns the aircraft in the direction the pilot rotated the heading bug. Most autopilots want to take the shortest course to the new heading – for example, turning left 100 degrees when the pilot turned the heading bug right 260 degrees. But, when responding to ATC directions, the DFC90’s outcome is far preferable. Otherwise, the pilot must reset the heading bug in stages… first 170 degrees right, then the remaining 90 to the right.

The DFC90/EFD1000 also flies quite smoothly, even intercepting a course from a 90-degree angle – and at cruiselevel speeds. No hunting, only a stop a few degrees short of the desired course, followed by a small correction to the final course. And, the EFD1000 itself is so logical and easy to use. It’s easy to learn and become comfortable with its various functions – altitude and heading bugs, airspeed bugs and pre-sets for the DFC90. The display is easy to read, the functions easy to work and the capabilities large. While outstanding in performance, the best of the combination shows itself only when the pilot is at his or her worst. LIFESAVER CAPABILITIES Thanks to the attitude-based functionality of the AspenAvidyne combination, pilots flying aircraft with this retrofit package get to learn a few new features/phrases, including envelope alerting and flight envelope protection. EA protects against flight-envelope excesses – too fast or too slow – with aural and visual warnings to the pilot with a non-muting input through the audio panel. EP virtually eliminates autopilot-induced stalls – underspeed condition – or red-line-pushing over-speed excursions, announcing that it’s acting as it applies the needed recovery. Upset recovery is the most impressive of all the DFC90’s protective capabilities. Time can be critical when an upset occurs during a descent, at pattern altitude or at the approach entry. The DFC90/EFD1000 combination makes recovery onestep easy after recognition: push the button marked “straight & level.” Straight & level sounds almost too benign – until you engage in some mild aerobatic maneuvering in the two companies’ test beds: Aspen’s early year SR22 and Avidyne’s 1977 182. Both demonstrations began with wings rolled at several degrees past vertical, the nose down 10 or more degrees, then up about the same. Pushing the blue button started the DFC90 to command a smooth, gentle roll to level followed by a smooth, less-thana-G pull-up to level. Where it stops is where it stays, until the pilot intercedes. Teaching a non-pilot the basics about the autopilot system could be a significant benefit, should the pilot become incapacitated or disoriented. It is features like these that will nudge many owners across the line and help make avionics shops a bit busier as demand for this package gains steam. q
avionics news

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june

2012

Avionics News June 2012

Table of Contents for the Digital Edition of Avionics News June 2012