Dynon’s new D1 “pocket panel” is an extremely clever, useful, and simple-to-use device that accelerates the march of Experimental avionics into the cockpits of Standard-category airplanes.
“When owners of FAA-certified airplanes expressed interest in buying our Experimental avionics products in the past, we used to have to tell them they couldn’t install them in their airplanes,” said Robert Hamilton, Dynon’s vice president of marketing. “Now, we have something they can buy.”
Dynon’s D1 is a portable, completely self-contained EFIS that fits in a standard 3 1/8-inch instrument hole. It displays GPS-derived heading, groundspeed, vertical speed, and altitude—and internal sensors and software provide pitch, bank, and turn-rate information. The D1 has a retail price of $1,425, and it aims to compete against standby attitude indicators and FAA-certified gyros that cost two or three times as much.
The Dynon D1 won’t lag or tumble during aggressive maneuvering. A variety of mounts and power options allow it to fit in just about any cockpit.
Instead of replacing a turn coordinator with an FAA-certified standby attitude indicator, for example, aircraft owners might elect to keep their turn coordinators and add a D1. The portable device can’t replace existing instruments, but it can supplement them. D1 owners can clip the devices into existing instrument holes, attach them to their panels with screws, or use suction-cup mounts or Velcro.
The D1 has an internal battery, but it also can use ship’s power via a hard wire or a cigarette-lighter adaptor.
The D1 isn’t meant as a primary source of attitude information, and a warning screen tells users each time the device is powered up that the D1 “isn’t certified by any regulatory body,” and that the pilot in command assumes “all risk and liability.”
A recent flight with the D1 showed that the unit’s performance closely matched the real horizon, and it won’t tumble or get confused by usual attitudes or aggressive maneuvering. The screen is bright and easy to read, even in direct sunlight, and its graphically depicted slip-skid ball gives timely, accurate information.
The unit is far from infallible, however.
It can’t function without GPS signals, and the screen will go dark if the unit loses GPS reception for more than one minute. Also, the D1 must be mounted precisely (and firmly) to provide accurate pitch and bank information. If the D1 is tilted slightly in pitch, for example, it will erroneously indicate the aircraft is climbing or descending. If it shifts in flight or becomes detached from its mount, it could create real problems.
Finally, the unit isn’t tied into the pitot/static system, so it can’t show indicated airspeed or barometric
altitude (only GPS-derived groundspeed and altitude). And the compass heading it displays is actually the airplane’s ground track, so pilots must keep these differences in mind, particularly while maneuvering in strong winds.
The D1 is ideal for Light Sport aircraft and vintage airplanes that lack electrical systems, or have extremely limited space behind their instrument panels. Aerobatic pilots flying airplanes without gyros to and from contests and airshows are likely customers, as well as glider pilots. And the D1 also is sure to be a hit among ferry pilots.
I used to know a World War II-era test pilot who, after a particularly harrowing nighttime electrical failure, brought an electric turn-and-slip indicator and a spare battery with him whenever he ferried an aircraft. If everything else in the panel went dark, he knew he could keep the airplane upright and on course with just a needle, ball, airspeed indicator, and compass. He passed away (of natural causes) a few years ago, but I’m sure he would have regarded the D1 as an absolute marvel—and it would have been a constant companion.
Email dave.hirschman@aopa.org