Business & GA, Commercial

New Generation of UNS-1

By David Jensen | April 1, 2000
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It is autumn 1982, and a one-year-old avionics manufacturer introduces its first product at the National Business Aircraft Association (NBAA) show, the UNS-1 flight management system (FMS). Universal Avionics Systems Corp. of Tucson, Ariz., unveils at the show the first multisensor FMS, which integrates sensors from DME, VOR, Omega VLF, inertial nav and Loran-C.

Seventeen years and some 8,000 fielded units later, a larger and more diverse (see sidebar) Universal Avionics introduces at the 1999 NBAA show the latest versions of the UNS-1. These new variants are to be approved by the U.S. Federal Aviation Administration and available this month.

UNS-1 History Lesson

Universal has introduced several generations of the UNS-1 over the years. The -1A variant replaced the monochrome 3-inch (diagonal) screen on the UNS-1 with a 5-inch screen in which a liquid crystal shutter provided limited color in the display.

Then came the UNS-1B, virtually a new system, with an increased processor speed, more memory, and much more information in the database. The -1B was followed by the single-box -1C and dual box (control display unit with remote processor) -1D, which incorporated the Global Positioning System (GPS) receiver and full color liquid crystal display (LCD). Finally came the more compact UNS-1K with the 4-inch (10.2-cm) display.

All models of Universal’s FMS include such functions as flight planning, navigation, vertical guidance (VNav), fuel management, radio frequency management, and an extensive library of messages and alerts. The databases include airports, navaids, en route and terminal waypoints, standard instrument departures (SIDs), standard terminal arrival routes (STARs), airway routes, holding patterns, approaches and runways.

Despite the similarities, each succeeding model of the UNS-1 included advancements in programs and features. And the recently introduced variants are no exception. Universal Avionics refers to its new offerings as "super FMSes." Individually, they are designated the UNS-1E, -1F and -1L.

Preparing for CNS/ATM

Universal’s prime reason for the latest upgrade is to incorporate systems growth in preparation for the communication, navigation, surveillance/air traffic management (CNS/ATM) future flight environment. The new features will be available for retrofit in -1C, -1D and -1K models by the second quarter of this year, according to Don Berlin, Universal’s marketing division vice president and general manager.

Universal added to its UNS-1 more advanced active matrix flat panel displays, designed to provide higher contrast and resolution and offer a wider viewing angle. The company developed 4-inch and 5-inch (12.7-cm) AMLCDs, with the latter capable of accommodating graphics and video and supporting weather and terrain awareness warning system (TAWS) displays.

An integral 12-channel GPS/GLONASS receiver also was added to the new UNS-1s. The receiver contains receiver autonomous integrity monitoring (RAIM), automatic fault (of the satellite signal) detection and exclusion (FDE), and manual satellite deselection to make GPS alone the primary navaid. A Windows-based program allows the pilot to predict FDE availability when flying over oceans or remote areas. The GPS/GLONASS receiver will be certified to TSO C129a, Class A1/B1/C1, for all phases of flight, including approach.

Universal also increased the processing power and memory in its new UNS-1s. The units’ new 32-bit processor provides 25 times the computer horsepower of the current system; program and database memory have been increased four-fold.

Individually, the three new units vary in configuration to suit customer needs:

  • The UNS-1E is an all-in-one system, which includes a 5-inch screen and a single housing for the control/display unit (CDU) and the navigation computer. Its normal housing depth is 9 inches (22.9 cm), but a special version, the -1Esp, offers a housing with 7.6-inch (19.3-cm) depth.

  • The UNS-1F has the CDU and processor as separate units. The CDU is less than 3.25 inches (8.3 cm) deep, and the navigation computer, remotely mounted in the avionics bay, is housed in a 2-MCU (modular concept unit) line replaceable unit (LRU). The -1F offers the option of either a 4-inch or 5-inch display.

  • The UNS-1L is comparable to the -1F, with its remotely mounted processor, but comes with the smaller, 4-inch LCD display.

For more information, see

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