Story ID: 093
Legacy Universal FMSs Face Obsolescence
By: Matt Thurber
Caption: Business jets equipped with legacy Universal Avionics FMSs will need upgrades due to parts obsolescence issues. 
Word Count: 698
Last year, Universal Avionics notified aircraft owners and operators that certain parts of legacy flight management systems (FMS) are becoming obsolete and that repairs may soon be unavailable for these units. The Universal service letters published in November of 2019 apply to UNS-1K/1K+, -1Csp/1Csp+/1C/1C+, and -1D/1D+ FMS models. Universal was first to market with an FMS in 1983 and its products are installed in more than 50 different aircraft types in all aviation segments.

According to Universal Avionics, the problem isn’t that these FMSs will suddenly stop working, but parts such as the LCD display, CPU board, GPS board, and GPS sensor are no longer available. Universal is continuing to offer repairs to these FMSs as long as these parts are available or it can do repairs unrelated to these parts, but the parts are expected to run out around December. 

While the legacy FMSs are still perfectly usable, there are reasons to consider upgrading besides the fact that a component failure could render them inoperable. 

An important feature is that the newer FMSs available from Universal Avionics are needed for ADS-B Out compliance. An ADS-B Out transponder is also needed, but the modern FMS’s SBAS-capable GPS sensor is required. 

Some operators of older business jets have run into problems accessing instrument approach procedures at some airports because the legacy FMS’s database isn’t large enough to contain all the available approaches. Data provider Jeppesen chooses which approach is primary. 

In one recent case, a flight crew was told to go elsewhere while trying to land at Teterboro Airport because their FMS didn’t have the approach that was in use and the controllers were too busy to offer an alternative. The legacy database for Teterboro has only four approaches, versus nine in the SBAS FMS. At Dallas’s Love Field, the full database includes 14 approaches, but there are only four available with the legacy database. 

With a new FMS, a huge benefit is LPV approaches, which are proliferating and offer lower minima and new precision approaches at many airports. There are more than 4,000 LPV approaches in the U.S., 538 in Canada, and 701 in Europe. An LPV monitor is also required to enable this capability for a single FMS installation but not dual FMSs. The SBAS FMS also adds basic RNP 0.3 approaches and Arinc 424 legs capability.

The modern FMS also serves as the foundation for other new capabilities that can be added later, such as digital clearances, which require a UniLink Communications Management Unit and a data-capable cockpit voice recorder. Adding a suitable satcom can then enable FANS 1/A.

It’s also important to note that older Universal Data Transfer Units are also reaching the end of life and need to be replaced with solid-state DTUs. Like the original DTU, the solid-state units are available in fixed or portable versions. The problem with the older units is they use disk drives for uploading data, and the Zip disks and drives are no longer available. The solid-state DTU uses SD cards or USB for uploads. 

Universal Avionics dealer Flightstar has been promoting the SBAS FMS upgrade for the past year and a half, according to avionics sales manager Greg Vail. Flightstar is the only avionics installer with an STC for a single Universal FMS upgrade with LPV monitor for the Learjet 45, Vail said. “It’s a better option than a standalone GPS.” 

Now is a good time to take advantage of upgrade pricing from Universal, he said. “Because of the pandemic and Universal trying to do the right thing, they have some crazy aggressive pricing. I’m doing two to three quotes a week for FMSs.”

Another dealer, C&L Aviation Group, has partnered with Universal Avionics to present a pair of free webinars on upgrades to the legacy FMS. The webinars, “Support Issues and Solutions for Your Universal Legacy FMS: Answers for Current System Obsolescence and Navigation Database Restrictions,” will be held at 10:30 a.m. ET on July 8 and at 3:30 p.m. ET on July 14.