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Head-Up Display: The See-Through ViewHead-Up Display: The See-Through View

A heads-up display with a low-down price. Pilots listen to two voices.

A heads-up display with a low-down price.

Pilots listen to two voices. One says to keep an eye out for traffic and surface features. The other demands a rapid, effective scan of the instrument panel. The dissonance of these two voices can escalate to the argumentative stage at certain critical phases of flight.

One is during for-real instrument approaches, when pilots have to divide their attention between flying the airplane and looking for the runway environment. One moment you're scoping out the gauges to make sure you're staying on track and altitude. The next, you're straining — and hoping — for a view of the airport. When you're close to the ground it can be very, very dangerous to spend too much time at either job.

IFR operations aren't the only time the panel also competes for attention with the world outside the cockpit. Flying VFR at uncontrolled airports can also dial up the stress. Here, you're also performing a juggling act: trying to spot traffic, and flying a precise pattern.

Head-up displays (HUDs, for short) help solve these kinds of problems. In effect, HUDs put the panel in the windshield and let you look outside at the same time. There's no head-tilting or gaze-shifting. The most essential flight information is all front and center.

Until now, HUDs have been installed only on military aircraft, airliners, and high-end corporate jets. Now, Flight Visions, Incorporated, of Sugar Grove, Illinois, has developed a low-cost HUD certified for use in the Beech King Air series of turboprops. The Flight Visions HUD, called the FV-2000, is also certified for use in the Bell 230 helicopter, and it's been doing military duty on U.S. Air Force KC-135s, the PZL Orlik and Pilatus PC-9 military trainers, and the Czech L-59 and L-139 fighter jets.

You're probably asking what "low cost" means. In the HUD world, that's a relative term. HUDs used in the military, with their weapons-aiming capability and other super high-tech features, can run into the millions. The least expensive airline-style HUD, built by Flight Dynamics of Portland, Oregon, goes for $250,000 to $300,000 (see "Turbine Pilot: Flight Dynamics' Head-Up Guidance System," May Pilot).

The basic FV-2000 sells for an extremely competitive $50,000. To that, add 100 hours' worth of labor charges to install one in a King Air.

Though the FV-2000 supplemental type certificate applies to the entire King Air line, the first STC was granted for the Model A100. That's because Flight Visions operates an A100 of its own, which served as the FV-2000's second testbed. The first was a Grumman Tiger.

The FV-2000's hardware consists of just three components: a computer, a pedestal-mounted control panel, and the optical combiner. The computer takes inputs from the ship's air data computer, gyro instruments, navigation receivers, and radar altimeter, if so equipped. The computer can accept either digital or analog inputs, which means that the FV-2000 can show information from conventional instrumentation as easily as it can from all-digital "glass cockpits" or flight management systems like the Honeywell SPZ-8000.

The computer converts these signals into imagery, then sends it along to the optical head, which is encased in a rectangular bulge above the pilot's head. The optical head then projects the imagery on the combiner glass.

This may sound complicated. But as HUDs go, the King Air version of the FV-2000 is simple. Unlike the military and airline models, the FV-2000 doesn't need inputs from those airplanes' very expensive inertial reference and guidance hardware to do its primary job. While this helps keep the price down, there is a down side. The King Air FV-2000 shows the horizon and aircraft flight path as interpreted by the panel instruments, not the real world.

However, a variant of the plain-Jane FV-2000 can accept inertial guidance information. Champion Paper is the launch customer for this model, which is installed in that company's Falcon 50. The price of this upgraded FV-2000 is $65,000 — still a relative bargain.

With inertial guidance, a HUD shows the real horizon in a so-called "conformal" (i.e., conforming with the earth's horizon) display and can perform other helpful tricks. One is to provide velocity vectoring, a feature that shows exactly where an aircraft is going. This allows a pilot to follow a precise climb or descent angle, or determine an aircraft's exact runway touchdown point.

We flew Flight Visions' King Air A100 to sample the system and found it very user-friendly and a real help in situational awareness. It may not have all the conformal options, but it's still a very useful tool.

To turn the unit on, rotate the control panel's brightness switch clockwise. After a 45-second warmup time, the imagery appears on the combiner.

The combiner is a flat plate of optical-quality glass that contains a very thin layer of reflective material. You won't see the imagery, however, unless the combiner is set at the proper viewing angle — about 45 degrees to the viewer's line of sight. To do this, you disengage a locking lever, then tilt the glass until the imagery appears. It's a small glass by conventional HUD standards, just 4 x 6 inches. Thumbscrews let you tighten the glass so it stays at the correct angle. (There's a release feature that moves the glass forward if you should accidentally strike it, or if the airplane decelerates at more than 3 Gs.)

Dominating the display is a large attitude indicator. On the left is a miniature airspeed indicator, to the right a mini-altimeter. Heading information is shown across the top. Navigation displays — from both pilot and copilot instruments, if need be — can be added to this basic mosaic. All of this fluorescent-green symbology is focused at infinity. You can look through the screen at distant objects, but the HUD information remains in focus.

The FV-2000 puts a lot of data in a small place, but after a few minutes, it's easy to settle into the new scan requirements. By the time I'd taxied the King Air to the active, I felt comfortable enough to use the HUD for the very first takeoff.

Airspeed, altitude, course, and heading bugs can be selected using the control panel Parameter Select knob. Flight Visions' David French selected a bug speed for rotation, and we took the active. Soon, I was storming down the runway, eyes glued to the HUD and the view ahead. (Okay, I did sneak a peek at the panel's airspeed indicator once or twice on the takeoff run.)

After rotating, the FV-2000's utility becomes immediately obvious. Our home base — the Frederick (Maryland) Municipal Airport — is a very busy uncontrolled field. Using the HUD, it was easy to keep the pitch angle and airspeed nailed and look beyond the combiner for any nearby traffic at the same time.

After a few practice ILS approaches at the Eastern West Virginia Regional/Shepherd Field in Martinsburg, I was spoiled. After an initial tendency to fixate on the display, it became second nature to quickly scan all the HUD images and the surrounding sky and terrain.

Everything — localizer, glideslope, marker beacons, DME, rate of descent, elapsed time, decision height, heading — was easy to read and interpret, and the system helped me fly the A100 very precisely.

One approach was a visual using raw data (i.e., not using an autopilot or flight director), one was a raw-data ILS, and the last one was an ILS flown with the flight director engaged. Any HUD-averse skeptics out there really owe it to themselves to try a few approaches with the FV-2000. You'll soon find your thinking transformed. The HUD makes a quick, though subtle, leap from being amusing and convenient to being a work-load-reducing necessity. On night or circling approaches, you could even call the FV-2000 — or any HUD — a potential life-saver.

Does an FV-2000 allow you to shoot approaches or make takeoffs at lower-than-published minimums? No. For that you need more precise localizer tracking and heading guidance capability for landing rollouts or takeoff runs — capability that is lacking in the current Flight Visions system. In any event, authorization to fly Category II or III approaches is not solely a matter of having the proper on-board hardware and software. The navaids serving a Category II or III runway have to meet higher tolerances than those at Category I runways, and the runway and runway markings must also meet different criteria. The pilots have to meet more stringent performance standards, and so, too, must the two requisite autopilots.

This is an important point that many pilots overlook. Just having a HUD — even the most sophisticated — isn't enough to legally land and take off in low, low IFR conditions.

Besides the features you'd usually expect in a HUD, the FV-2000 also has built-in testing and incident logging. The FV-2000 tests itself every 15 seconds of flight; there's a full system test every minute. If any anomalies crop up, they're logged so that they can later be called up from the HUD computer's maintenance terminal. They're also announced on the combiner with a CHECK INCIDENT LOG message.

Failure of critical flight and navigation instruments causes a MASTER WARNING message to appear on the combiner. Other annunciations get more specific. Should invalid pitch or bank signals be sensed, for example, an ATT FAIL message will pop up at the bottom of the display. At the same time, the pitch ladder and bank scale is deleted from the display. Similarly, problems with navigation receivers cause CDIs to disappear from the screen. In all, there are 23 situations that will either cause the display to issue a warning message or delete bad information. What is the most dramatic? A HUD computer failure. In that case, the screen goes completely blank.

Another important note: If an engine fails in instrument meteorological conditions, the FV-2000 can't be used. The HUD can't sense sideslip, so it can't issue commands to counter the yawing associated with asymmetric power. It's time to stow the HUD and go eyeballs-down.

Should the unit need maintenance, the Bendix/King network provides FV-2000 product support. This includes AOG (aircraft on ground) service for parts and exchange or rental units, and a 24-hour service hotline. There is a one-year warranty.

Flight Visions' next step is to certify the FV-2000 for use in the 500-series Cessna Citations. Add the 4,700-strong King Air fleet to the world's 1,500-odd Citations, mix in some Falcons, then pull in some additional foreign military sales and you have the makings of a fairly large market.

Chances are that we'll be seeing more FV-2000s on more ramps in the near future.

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