THE AVIONICS LOWDOWN
A focus on new and retrofit avionics for the cockpit.
Nowhere in any other operational area of the aviation industry has technology so drastically changed the way an aircraft looks than in the cockpit. Avionics have completely revolutionized the way an aircraft is flown and navigated- as well as how communications are made and handled - both between the aircraft and ground stations as well as other aircraft.
Today- it seems- avionics are developing faster than ever before and anybody looking to buy or upgrade an older aircraft should have an understanding of what is available in new aircraft and also for retrofit.
Even the universally-accepted standard of flight instrument layout - the six-pack (Airspeed- Attitude- Altitude- Vertical Speed- Direction and Turn/Bank) - has become obsolete in the ever-evolving world of Electronic Flight Instrument Systems (EFIS) displays. At the very beginning of aviation (pre-1910) pilots relied on how the slipstream air pressure changes felt on their faces- and how lively the controls felt in order to determine their airspeed.
Soon airspeed indicators were developed in various guises- before air pressure sensitive altimeters- time pieces and a spirit-filled compass emerged. By the mid-1930s the basic avionics equipment on a modern transport aircraft had become somewhat standardized to include the 'six pack'- a communications radio- and an Automatic Direction Finding unit (ADF).
In the 1950s the Visual-Aural Range (VAR) system was put into use as an aid to navigation before Very High-Frequency Omni-directional Range beacons (VOR) quickly made VAR obsolete. Then came localizer and glideslope guidance as well as en route navigation- all of which changed the reliability of flight made under Instrument Meteorology Conditions (IMC).
Until the early 1990s most turbojet aircraft were navigated using a combination of Long Range Navigation (LORAN)- Very Low Frequency Omega (VLF-Omega)- ADF- VOR- RADAR- remote compass and stand-alone onboard Inertial Navigation systems. In 1994- however- the world of avionics was turned on its head by the Global Positioning System (GPS) being made openly available.
Avionics manufacturers were quick to develop receivers that integrated into the then current Flight Management Systems (FMS) and by doing so- navigational accuracies never before seen by older systems were instantly achieved. GPS provided accuracy down to 100 meters initially- subsequently reducing to a positional accuracy to within nine meters (30 feet) of precision.
A new avionics age had dawned- and now aviation authorities across the globe saw opportunity to reduce their costly infrastructure - substituted instead by failsafe on-board systems that would allow certain autonomy of aircraft in-flight without having the ground beaming signals to keep them separated and heading in the correct direction/flight path. The concept of 'free flight' as it pertains to navigation and separation had become possible.
INTEGRATED AVIONICS SYSTEMS
There are three principle functions that an Integrated Avionics System must accomplish for an aircraft and its crew. These are: Aviate; navigate; communicate. Beyond these three functions- everything else is a bonus. Most modern business aircraft incorporate one complete Avionics System 'straight out of the box'- that includes all of the main families of primary- secondary and sub-systems to enable aviation- navigation and communication functions.
Gone (mostly) are the myriad of options that must be requested- specified and paid for prior to delivery. Most optional changes today are driven by the certification requirements of the governing authority under whose flag the aircraft shall be operated following delivery. This easy decision-making during the placement of an order for a new aircraft is not applicable to older aircraft that were born before many of these fully integrated systems were either available- or indeed before some of the mandatory systems were required. Before considering retrofit issues- let’s explore what the current de'riguer is in the latest-and-greatest in-production aircraft.
Bombardier’s Global 5000 and XRS aircraft utilize Rockwell Collins’ Pro Line Fusion avionics suite- incorporating four LCD screens- HUD- Bombardier’s third generation Enhanced Vision System and Onboard Maintenance System (OMS). Meanwhile- the avionics and ergonomic advantages of the Bombardier Challenger 850 cockpit are generously sized and superbly organized. The flight management suite is an all-glass cockpit- designed and equipped to maximize pilot productivity- safety- comfort and convenience.
The Collins Pro Line 4 suite incorporates groundbreaking technology to reduce pilot workload and increase situational awareness. The fully integrated display is arranged in classic “T” configuration for improved crew situational awareness- and each of the six displays is interchangeable to facilitate troubleshooting and improve dispatchability.
The Flight Management System (FMS) is integrated with the EFIS (allowing for head-forward display) - and not only does it provide full departure and approach procedures worldwide- but it also offers the full complement of nav-aids- intersections and airport data.
Meanwhile- the EICAS Primary Display shows engine operating information in both digital and analog form. The crew annunciation and alerting system displays color-coded messages and warnings- accompanied by some aural messages. This uses a “dark cockpit” concept- helping pilots focus exclusively on pertinent items.
The EICAS Secondary Display provides “real time” information on six aircraft systems through concise color-coded synoptics diagrams- and is designed to further improve crew awareness.
The Garmin G5000 avionics system that is to be incorporated in the Citation Ten features three widescreen-format LCDs. Full-color touch-screen LCD control panels provide the primary user interface with the G5000 system. Two PFDs are located on the pilot's and copilot's instrument panels- and one MFD is located on the center panel. In addition to flight display information- the PFDs can display an inset window with moving map imagery.
The MFD displays detailed moving map- terrain- traffic- and weather information as well as a dedicated engine and systems information window. Display of electronic charts and taxi diagrams with aircraft position is included. The MFD can operate in full-screen or split-screen mode with one or two independent multifunction display windows. Multiple reversionary display formats provide for redundancy.
Garmin Synthetic Vision Technology (SVT) is included- with terrain and obstacle information displayed on the PFDs in a dynamic 3D format. Airports- runways- heading- traffic- color-coded terrain alerts and a flight path indicator are also displayed on the SVT presentation.
The G5000 system includes a full-featured Automatic Flight Control System (AFCS)- dual Inertial Navigation Systems (INS) for attitude and heading reference as well as inertial navigation information- dual Integrated Avionics Units (including GPS- WAAS receivers- VHF comms- VHF nav- and glideslope receivers) in addition to supporting input/output processing- aural alert generation and flight director functions.
Dual Flight Management Systems (FMS) provide extensive navigation and flight planning capabilities as well as en-route- takeoff- and landing performance calculations- while Garmin’s GWX 70 weather radar system with a 12-inch antenna is included. Further features include TCAS II- TAWS- ADS-B Out Capability- Datalink Management System and Controller Pilot Datalink Communications.
Dassault’s EASy System is based upon the Honeywell EPIC Avionics platform. Dassault’s engineers have rewritten the software and integrated some of their own hardware to create the intuitive EASy flight-deck that is incorporated into current production Dassault aircraft.
The system displays information on four flat-panel LCD screens arranged in a T-shape- and allows pilots to make ‘heads-up’ data entry using a Cursor Control Device (CCD) and menu-driven selections. The Cursor Control Device (developed by Dassault for EASy) gives an unprecedented ease of use for the pilots in all situations.
By limiting the time spent punching numbers into a FMS and with the common workspace allowing the crew to better work as a team- the chance for input errors is reduced. EASy is the result of extensive input from pilots- aviation authorities and safety experts and is designed to simplify flight management tasks- improve crew coordination and provide unsurpassed situational awareness at all times. This new avionics standard is available today on Falcon aircraft and engineered to meet tomorrow's pilots' safety needs.
Embraer's Phenom 300 will very soon feature the Prodigy flight deck- designed for Embraer by Garmin. This will offer new levels of integration- display flexibility and monitoring of aircraft systems. The Prodigy is based on Garmin's G1000 avionics system and will eventually be offered to both the Phenom 100 and Phenom 300 operator.
This pilot-friendly cockpit features three large displays (two PFDs and one MFD). The system integrates all primary flight- navigation- communication- terrain- traffic- weather- engine instrumentation- and crew-alerting system data while presenting the composite information in brilliant- sunlight-readable color on high-definition displays.
Among the features offered by Prodigy flight are dual integrated solid-state AHRS; integrated Engine Indication and Crew Alerting System (EICAS); integrated Mode S transponder with Traffic Information Service; GPS/WAAS; VHF navigation with ILS; integrated TAWS; and XM Satellite Radio.
The current production large-cabin- long-range Gulfstream aircraft are delivered with the PlaneView cockpit. A unique interpretation of Honeywell's Primus Epic architecture and display system- the G550's PlaneView cockpit (for example) features an integrated avionics suite with four liquid crystal displays.
The new system provides essential flight information to the pilots on displays that are considerably larger than other avionics systems. Not only do they reduce the pilots' workload- they also improve the level of situational awareness on the flight deck. The PlaneView cockpit presented pilots with the first fully synchronous triple FMS. By using the Gulfstream Signature CCD- pilots can interact with the FMS and the navigation map that displays the flight plan along with surrounding terrain- airways- airports- navigational aids and radar data.
Another new technological feature involves the latest in Head-Up Display (HUD) technology which displays flight information and guidance cues on the optical combiner in the pilot's forward-field of view- eliminating the need for pilots to divert their attention from outside the cockpit to the instrument panel in-flight.
Using advanced infrared imaging technology- the Gulfstream Enhanced Vision System (EVS) II captures images of the surrounding environment and presents the pilot with a clear picture of runway markings- taxiways and surrounding terrain at night and in deteriorating weather- not only improving flight safety- but promoting greater situational awareness.
Gulfstream became the first manufacturer to certify synthetic vision under FAA Part 25 rules. The Synthetic Vision Primary Flight Display (SV-PFD) projects a digitized view of the outside world on the pilot's primary display to give unprecedented levels of situational awareness regardless of the conditions outside. Additionally- the G550 PlaneView offers integrated Jeppesen Flight Deck charts and maps - the first business jet aircraft to do so.
The Hawker 4000 features the Honeywell Primus Epic avionics system- allowing pilots to effortlessly access large amounts of critical information in real-time and make smarter flight decisions. Based on the same advanced avionics as the Boeing 777- the fully-integrated Epic system is a true full-flight deck.
Five LCD screens provide clear read-outs under any lighting and incorporate (among other things) EICAS; Traffic Alert Collision Avoidance System (TCAS II); Dual On-Screen Cursor Control; and Turbulence-Detection Weather Radar.
The Hawker 900XP flight deck- meanwhile- is a fully integrated Rockwell Collins Pro Line 21 avionics suite with four LCD screens to keep critical data close at hand. Enhanced map overlays simplify routine tasks- while helping pilots to make more strategic decisions about developing weather (with powerful weather mapping). GPS Dual Flight Management Systems- Integrated Flight Information System- TCAS II and Electronic Charts are among the other features on the Hawker 900XP flight-deck.
RETROFITTING OLDER AIRCRAFT
In the case of taking an older aircraft that was never delivered with a fully-integrated avionics system (and some cases offers just a 'steam gage' analogue flight-deck)- there are multiple options available to owners who are convinced that they are better to keep their present aircraft rather than purchase new- and instead invest in a retrofit avionics suite.
When this choice is made- the biggest hurdle of matching the best retrofit system to your current aircraft is the make- model and capability of your existing autopilot- which now has become the core piece of equipment that retrofitted- integrated systems are built around.
If your current autopilot is not a digital unit (analog systems easily pick up any noise along its transmission wiring caused by poor insulation- local interference and also the random thermal vibrations of the atomic particles in the wire conductors)- all variations to the original analog signal will appear as noise. As the signal is transmitted over long distances- if not filtered- this noise will ultimately degrade the data signal sent from the system sensor.
Digital data transmission systems convert the base data inputs into a binary signal- i.e. a ‘square-wave’ signal that is a pulse representing either an “on” or “off”. This digital signal is not affected by noise- and therefore delivers pure- unaltered data to the receiving system component without the need of filtration- and the fear of lost or scrambled signal data.
Since its incorporation- ARINC has established standards that cover installation- wiring- data-buses- databases- data-parameters- software- analog and digital systems- cockpit displays- Ethernet networks- satellite systems- fiber-optics- and bandwidth issues. The internationally recognized standard for digital data transmission on-board aircraft- through an open digital-data-bus is ARINC standard 429- which employs unidirectional transmission of 32 bit words over two-wire twisted pairs. Messages are transmitted at a bit rate of either 12.5 or 100 kilobits per second to other system elements- which are monitoring the bus messages.
The most popular retrofit Avionics Suites installed today include the Collins Proline 21 System as well as the Universal Avionics product line. The Integrated system offered by Universal includes its EFI-890 EFIS units (the number of units that are installed are dependant on the dimensions of the cockpit panel to be retrofitted)- its Vision-1 Synthetic Vision System- Uni-Link Communications equipment- AHS-525 Attitude Heading Reference System and its digital Radio Control Units (RDUs).
All of these components are fully integrated to interact with the UNS-1Lw Flight Management System.
CARE AND FEEDING
A closing thought for this review of new and retrofit avionics gives a nod to the necessity of looking after the equipment you have installed in your flight panel.
• You should always cover over harnesses so as not to smash displays and knobs;
• Use a dry paintbrush to dust the panel regularly;
• Use sunscreens to protect the avionics panel from effects of exposure to long periods of heat and light;
• Power the airplane (and avionics) up every week using a GPU if you are not flying the aircraft to avoid periods of idleness- which can have an adverse effect.
If you follow these simple pointers- and look after your cockpit you will ensure that you get the best performance from them- you’ll spend less money in avionics maintenance over the span of your aircraft ownership- and once you come to sell your business aircraft- you will have as attractive a cockpit panel as possible.
Jeremy Cox draws on a wealth of experience as a pilot- an aircraft engineer/mechanic and an aviation writer. He currently serves as Vice President at JetBrokers- Inc - a professional aircraft sales company. More information from firstname.lastname@example.org