Garmin Rolls Out New G3X With 'Free' Autopilot
by J. Mac McClellan
March 25, 2013 - A free autopilot from the biggest name in avionics? Unbelievable, but true. At Sun 'n Fun in April Garmin will unveil a complete G3X flat glass avionics system for experimentals, including a new two-axis autopilot, for the same price as the previous G3X system alone.
This magic comes from a new group of engineers that Garmin calls Team X, which includes a number of homebuilders. Team X was pulled out of the certified world and put to work designing the most capable avionics Garmin could make for E-AB at the most reasonable cost. Team X certainly leveraged the knowledge Garmin has amassed in the certified world, but worked from the ground up without the encumbrance of rigid certification standards.
The autopilot uses all-new compact GSA 28 servos that weigh just 1.4 pounds each. The servos contain the software smarts needed to fly the airplane instead of relying on a centralized computer. They also have slip clutches so a pilot can overpower the system instead of using shear pins to protect against failure. The servo drivetrain places no drag on the control system when the autopilot is disengaged as do some other experimental autopilot servos that use stepper motors.
Each GSA 28 servo supports autotrim, so no extra sensors are required. Because the servos are interchangeable for pitch or roll, the roll servo can support autotrim for the ailerons. The servos are made from die-cast and machined metal parts, not plastic.
The new autopilot can be operated using the keys on the G3X panel, but a more capable option is to install a dedicated autopilot control panel. With the GMC 305 control panel the autopilot still functions if the G3X display should fail, and adds extra capability, the most important being a "level" button. A press of the level button rights the airplane from an unusual attitude and holds present altitude while the pilot reorients himself.
The autopilot is full capability including flying coupled approaches, holding airspeed, vertical speed, and so on if you install the GMC 305 dedicated control panel for an added $750. You can also add a third servo to provide yaw damping.
Much of the cost savings come from new ADAHRS designed from scratch for the experimental application. The new GSU 25 ADAHRS has a third pressure inlet that can measure angle of attack. The AOA sensing comes from a new pitot tube that contains ports for both pitot and AOA and fits in a standard wing mounting. So, for $199 you can add AOA sensing to the G3X system, including a visual approach to stall warning on the PFD, and aural warning tones. As the AOA increases, a horizontal line appears on the attitude indicator and moves up or down to show approach to a stall.
Though package pricing for the new G3X system with the autopilot is most attractive, you can also install the autopilot or new ADAHRS and AOA with an existing G3X system. Garmin uses a CAN computer bus to link the components of the system, so you can add a second ADAHRS or add a yaw damper or the AOA capability without rewiring the system or installing all components at the same time.
Package pricing for the new G3X system is even more attractive if you opt for dual flat glass displays. The previous price for a dual display was $8,570, but the new system, complete with autopilot, is $8,000. Step up to three displays and the old price was $11,145 but is now $10,000 including the autopilot.
We have all come to expect more capability for less money in consumer electronics, and now Garmin has done the same thing for experimental avionics. Deliveries of the new equipment will begin at Sun ín Fun. For more information, visit the Garmin website.