Honeywell‘s KFD 840

A cool new six-pack in a box

Eight pounds. Doesn't sound like much. But aviators understand the significance of weight---particularly decreasing it. We consider weight in equipment decisions: Something new better do more if it weighs more. If it weighs less and does more, well, now that's a score. Add affordability and you have a hat trick.

Honeywell designed the eight-pound KFD 840 integrated flight display to replace the standard six-pack of primary flight instruments and a couple of NAV indicators. And it scores on all three points: It weighs less than what it replaces, adds functionality and meets the value equation. But complexity isn't one of its features.

The KFD 840's large, bright 8.4-inch-diagonal color display brings alive its functions; it works smoothly and seamlessly in flight, provides new and useful features---and needs little effort to learn to use. Honeywell scored all these points and what may be the KFD 840's biggest breakthrough: a price under $17,000.

Everything You Need (& Some You Might Need)
A technology known as "MEMS" underpins the KFD 840. It has been more than a decade since Honeywell embraced the benefits of MEMS---or microelectromechanical systems---for motion and attitude sensing.

For the heart of the KFD 840, Honeywell integrates MEMS technology into a low-cost, high-reliability and compact ADAHRS (air-data attitude and heading reference system) that drives the system. The ADAHRS senses the airplane's altitude, airspeed and vertical speed, plus, as the name implies, its motion around all three axes---roll, pitch and yaw---and its magnetic heading. A separate external sensor provides heading information to the KFD 840 and serves as the compass module to provide heading stabilization for the heading readout.

An important design element of the KFD 840 ADAHRS is that the AHRS (attitude and heading reference system) continues to provide attitude and heading information independent of an air-data or pitot-static input fault. Thus, the KFD 840 continues to function when other systems stop because they need air-data input for the ADAHRS to work properly. In the event of an air-data failure, the KFD 840 puts a red "X" where the air-data readouts play on the unit's screen. And it's quite a screen.

Display Dominance: How Does 32 Inches Sound?
The KFD 840's high-resolution color display measures a sizeable 8.4 inches diagonally---larger than other options and slightly smaller than some more expensive choices. This screen size allowed Honeywell's engineers to give the pilot an attitude indicator (AI) display that's seven full inches wide and 3.5 inches tall, with air data displayed on opposite sides: airspeed and airspeed bugs on the left; vertical speed, altitude and altitude bugs on the right.


The full screen measures 6.75 inches by 5.125 inches; the directional gyro (DG)/compass/horizontal situation indicator (HSI)/course deviation indicator (CDI) is shown in the lower third of the display. The pilot chooses between a full 360-degree compass/DG arc or a 120-degree view. Overall, the box measures 8.5 inches wide, seven inches tall and 7.3 inches deep---a form factor that lets the KFD 840 fit into the same panel real estate as the six primary flight instruments it replaces.

Functionality Abounds
Thanks to a host of built-in interfaces (digital and analog), the KFD 840 comes ready to work with a host of common panel-mounted equipment, including most NAV radios and GPS NAVs, plus most autopilots. That means you can install the KFD 840 to replace multiple NAV indicators while adding a full-function, compass-slaved HSI in panels with separate indicators and a plain DG. The AI readout provides flight director bars for autopilots that support them.

The KFD 840 also sports a couple of the slickest new tricks seen in a while. First, it serves up the turn gyro at the top of the AI with standard-rate markers that move farther apart as the plane flies faster. Because standard-rate bank angle increases with speed, this bit of computer magic shows the actual bank angle needed.

Second, the pointer for that turn gyro actually has a split personality. The upper half of this carat always shows bank angle relative to the AI and turn gyro, while the lower half slides side to side in place of the traditional slip/skid ball. It takes little time in flight to "step on the carat" the same way you learned to "step on the ball."

More Functionality---Made Simple
Among the benefits of the glass revolution is the increased functionality of available situational-awareness tools. The KFD 840 delivers plenty with user-controlled airspeed and compass bugs; an altitude bug and a low-altitude bug; a trend indicator showing altitude and airspeed six seconds ahead; and integral aircraft-specific checklists. Additionally, in the works is a very neat graphical, airplane-specific weight-and-balance chart. Together, these tools are among the many easy-to-learn advanced features that Honeywell engineers created for the KFD 840. Two knobs and five buttons control inputs and functions, baro setting and the various bugs. An intuitive menu system makes the KFD 840 among the easiest displays to use in my experience.

You can use the old AI, airspeed and altimeter in vacated space as backup instruments. Furthermore, you can enhance the redundancy aspects of the system and pick up a backup battery from Mid-Continent Instruments, which is capable of powering the KFD 840 and a radio or two, independently of the aircraft's electrical system, for about 45 minutes.

At a suggested retail price of $16,995, you'll likely spend less by selling off the indicators you can remove. Any plane with a standard six-pack has the room and weight capacity to move that old panel firmly into the glass-panel era of the 21st century.

Next Up: Part Two Of Apex Edge
While the KFD 840 serves up many of the heavyweight functions of business turbine systems with a large display and a value price, it solves only half the glass-cockpit desires of pilots not yet on board. So Honeywell will soon offer the second Apex Edge component to complement the KFD 840: the upcoming KSN 770.

Honeywell's eagerly awaited entry into the all-in-one NAV/COM/GPS/ILS/moving-map realm long dominated by its Olathe, Kans., neighbor, Garmin, is due next year, offering features heretofore unavailable in this class of equipment: a fully capable NAV system with graphical flight-planning capability, graphical datalink weather (with future options for an embedded terrain warning and awareness system), and interfaces for other external hazard sensors, including onboard weather radar.

Together, the complete glass-cockpit transition comes at a hardware price of about $30,000---and allows pilots to lose weight while gaining heavyweight functionality. Visit www.bendixking.com.

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