A funny thing happened in the race to develop retrofit avionics systems for light airplanes: competition. Just a few years ago the price of a retrofit LCD primary flight display for your light single or twin was … well, there was no such thing. What a difference a few years makes. Today there are no fewer than six different systems available and the prices of those systems has dropped substantially, making it possible to get flat-panel systems with built-in solid-state attitude and more installed in your airplane at revolutionary prices.
With the introduction of its KFD 840, Bendix/King (a division of Honeywell) has jumped into the fray, bringing to the game not only its legendary name but much of the expertise that has gone into its sister company Honeywell's Primus Epic flat-panel systems, which are standard equipment in some of the most technologically advanced and expensive business jets in the world.
I recently flew up to Olathe, Kansas, home to Bendix/King's flight test development facility, to fly the KFD 840. I was the first journalist to get the chance to do so.
The display was installed in the company's Cessna 182 test bed, which I thought was a great platform for the test, as it represents the kind of mid-level single into which these new lower-priced retrofit PFDs are already finding their way. The plan is for Bendix/King to earn a multiple airplane certification for the PFD, one that will initially cover the vast majority of piston singles and twins up through 6,000 pounds.
The 840 should be certified and available as you read this. We flew the unit in early June, and at that point, the company planned to have it ready by AirVenture in late July. Honeywell had originally targeted the end of 2008 for first deliveries.
Last year at AirVenture, Bendix/King also launched an MFD, the KSN 770, which has also slipped. It features dual navcoms, GPS/WAAS receivers and more. When it becomes available, the 770 will interface nicely with the 840.
But Bendix/King realized that with more than 100,000 Garmin GNS 400/500 series navigators in airplanes, there might be more of a market opportunity for a new PFD than for a new MFD, no matter how nice. So it very smartly designed the 840 to work nicely with a Garmin GNS 430 or GNS 530 and to install easily into a panel already occupied by one or more of those multifunction navigators.
A Different Vision
The KFD 840 is Bendix/King's vision of what a flat-panel retrofit primary flight display should be, and that vision stands in some contrast to its competitors.
The philosophy behind the 840 is clear: to create a smart-sized, low-cost, elegant, easy to use, reliable and expandable system that many pilots will be able to afford to put in their panels.
In terms of size, King looked to the "just right" solution, opting for an 8.4-inch diagonal LCD that would fit into most airplanes without requiring too much panel surgery while still giving pilots the wide horizon that is one of the most praised safety benefits of flat-panel PFDs. The display is a good deal smaller than the 10.4-inch diagonal displays that are common with most Garmin G1000 and Avidyne Entegra installations (neither of which is widely available as a retrofit product), but it's a lot bigger than the Aspen PFD display, which is only about as wide as a standard 3.5-inch steam gauge. And the choice to go with a single, standalone PFD, as opposed to the composite design of the Garmin G600, lets the 840 boast a lot more real estate for the PFD function while letting the already installed multifunction display, presumably a 430 or a 530, do the job it's already doing so well.
The display fits into the space vacated by the primary flight instruments. The main body of the display makes use of the universal horizontal split, with the attitude indicator above with vertical "tapes" for airspeed on the left and altitude and VSI on the right. Each of the tapes features various bugs for setting target speeds or altitudes. There is, in addition, a minimums window on the lower left side of the airspeed tape. The bugs are purely advisory, reminding you, for example, what altitude to stop your climb at. There's no direct link to the autopilot, which you continue to control through its dedicated controller.
Aesthetically, the 840 is clean and businesslike. There are relatively few buttons and knobs. A pair of dual concentric knobs, one at either end, and five semisoft keys lined up along the bottom of the bezel are it.
Even though it has so few keys, the 840 is still remarkably easy to operate. To access a function, you push the knob until the desired one appears. Then you select that function and you're done. It works great.
To get to the baro setting, for instance, you push the right-hand knob a couple of times until you get to baro. Then you turn the knob itself to enter the setting, and you're done. The knob "times out" after a few seconds to its primary function, in this case heading, so you don't accidentally reset the altimeter when you're trying to enter a new heading.
The lower half of the display, in standard fashion, is the HSI section, and the pilot can select either a 360-degree compass rose or a 120-degree arc mode. I prefer the rose, as it helps me verify the correct direction when given a big turn by ATC.
On either side of the HSI are information strips, one with GPS track and heading, plus wind, true airspeed, air temperature and groundspeed, as well as next waypoint info.
The HSI does not have a "stick map," with waypoints and obstacles depicted, as some other displays do. And neither does the KFD 840 yet boast synthetic vision, a utility that Honeywell has pioneered in the bizjet world. Both features could appear on the KFD 840 at some point down the line, perhaps soon, though the company has not said just when that might be or how much the software upgrades would cost, if at all.
Another potential addition is a KI-256 converter, a device that converts the digital signal from the ADAHRS of the KFD 840 into an analog signal, making it usable by analog Bendix/King attitude-based autopilots. The converter would allow owners to retire their vacuum-powered KI-256 "iron gyro" attitude indicator and replace it in the panel with, for instance, a less maintenance intensive, electrically powered backup. You do still need a backup of some kind, though there's no need for it to be a vacuum-powered one.