The likelihood is that there’s an upgrade available for your business jet, but for those with older panels, what are the advantages of upgrading to embedded radio tuning? Dave Higdon discusses…
Today's glass cockpit replicates the information from the old-school instrument panels in graphical displays (often a single Primary Flight Display (PFD)). The digital renderings of navigation indicators and navigation graphics display their information on both PFDs and Multifunction Display (MFD).
Early incarnations of today's modern flight decks, however, often stopped short of integrating architecture into the graphical displays to monitor and control the sundry radios and other systems indigenous to almost every cockpit. So separate boxes housing VHF communication and navigation radios were commonplace until the advent of the wholly-integrated flight deck systems dominating new-aircraft deliveries today.
Integrated flight decks largely eliminate the separate panel-mounted communications and navigation boxes, each with its own status displays and controls. In their place the integrated flight deck provides embedded controls available through those dominant display screens.
The result is less ‘head-down’ time, increased ‘eyes-out-the-windows’ diligence and (thanks to the greater integration of these systems) smarter, easier and more-convenient control over those radios – all with the bonus of fewer ways to make an input mistake.
Simply put, embedded tuning is another control indigenous to the integrated avionics stack, and the numerous benefits have turned more than a few aviators into true fans of the integration that embeds controls on the same screen the pilots spend most of their time monitoring.
Variety in Integration
Embedded tuning is available in two forms. In one form the radio (be it a VHF Comm or Nav radio, or GPS navigator) may be a remotely mounted box wired into the glass displays to give the flight crew direct control of the box through the controls displayed on a glass-cockpit panel.
In the other (more dominant) form the radios don't exist as stand-alone boxes, but as functions built into the integrated flight deck system, typically as part of one or more Line Replaceable Units (LRUs). Both forms are controlled by a pop-up box on the PFD display, or through a separate input device, and each has its fans with their own reason for preferring that form.
On the one hand, with stand-alone radios remotely-controlled, a malfunction generally won't impact the main glass cockpit system, and the radio is easily replaced with little impact on the rest of the avionics. As devices built into the integrated flight-deck package, though the LRUs are easily replaceable, a malfunction of a VHF comm or nav radio may (albeit rarely) impact the functionality of other parts of the avionics.
Maximizing Eyes-Out and Head-Up Time
As mentioned already, the primary benefit of integrated radio tuning grows out of the technology’s ability to reduce head-down time while maximizing head-up time to look outside while continuing to monitor the aircraft's situational awareness tools.
Touch a soft key on the PFD bezel or, if a touch-controlled device the display screen, and up pops a keypad-like image on which the pilot enters a frequency – or an airport designation, navigation waypoint or transponder squawk. Another button or two loads the information directly into the appropriate piece of avionics (be it a comm frequency, a navigation beacon, an airport code or transponder squawk).
When, like today, a PFD can simultaneously display terrain, traffic, airspeed, altitude, attitude, heading, course and vertical speed, you might worry that the displaying screen is getting a little crowded. These PFDs also may display traffic as part of a collision-avoidance system and, in a few cases, let the pilot overlay weather graphics on the display.
But with remote, embedded-tuning capabilities, the free space in the panel increasingly gets filled with larger displays, making discerning the information easier at every step. And with ever more systems available for retrofit, the era of the analog panel appears headed toward extinction.
The control software embedded into the integrated flight decks often totally eliminate separate control heads – with their knobs and switches – in favor of so-called ‘soft controls’ which appear and disappear on a PFD or MFD display with the touch of a button.
The integrated flight decks employing embedded radio tuning generally include a display box on the PFD or MFD displaying the frequencies in use, even when the control box isn't displayed. With today's increasing proliferation of touch-sensitive displays the pilot of one of these modern marvels has fewer reasons to have their head down in the cockpit to find and tune in a comm or nav frequency.
Today's most advanced cockpits, with their head-up displays or guidance systems, often display comm and nav frequencies on the HUD, further reducing head-down time.
With today's advanced integrated flight decks, the embedded radio-tuning function is often designed to work directly with other radios, increasing their operational benefits. With the most-advanced systems a frequency entered on an embedded-tuning screen can often be entered directly into a flight plan with the correct combination of button pushes.
Along the same lines information in navigation databases can often be entered directly into a Flight Management System (FMS) to speed along flight planning and pre-departure preparations.
Or a radio frequency in a GPS database can be internally transferred directly into a VHF Comm or Nav radio, saving the pilot extra steps and safety and efficiency.
Touch a button to enter frequency choices for the VHF navigation receiver and communications transceiver and a separate key brings up a window in which to enter navigation information for the WAAS GPS increasingly found in today's aircraft. Alternatively, call up a published instrument approach or airport diagram and all the relevant radio frequencies come up on the display, from which a button or two loads that frequency into the appropriate avionics.
Indeed, that transfer by button push eliminates the prospect of incorrectly entered numbers, waypoints or other items subject to direct tuning.
Not all aircraft sport integrated flight decks and not all integrated flight decks support remote tuning of older radios. To that end companies such as Rockwell Collins (among others) offers stand-alone remote radio tuning for their legacy systems and newer flight decks.
As an example, Rockwell Collins' RTU-42XX Radio Tuning Unit product family provides integrated control of all Rockwell Collins ProLine II and 400 Series CNS sensors and the HF-9000. The RTU-42XX incorporates a complete set of radio management functions into a single unit and gives you a convenient means of selecting frequencies, codes, channels, operating modes and volume.
The RTU-42XX may also be integrated with the Flight Management System, allowing frequency to always be displayed on the RTU regardless of the tuning source. The key to these performing as desired is their integration with the appropriate avionics and placement so that the pilot spends minimal time to enter the desired information.
With systems available for virtually any aircraft, it's an option increasingly embraced by pilots today – because the option almost always saves weight, reduces power load and increases performance.
But the most welcome aspect of remote-radio tuning is its ability to reduce, maybe even eliminate, the likelihood of entering an incorrect code or frequency. And anything that helps reduce the possibility of an entry error can't help but advance the cause of safer flying – one of the catalysts to the glass cockpit revolution.