Gulfstream IV and V series aircraft remain two of the most capable lines of business jets designed in the past three decades because of their range, speed and cabin comfort. The GIV can fly 4,200 nm and the GV can fly 6,500 nm. Both aircraft routinely cruise at Mach 0.80 or faster and they can seat up to 12 to 14 passengers.

The GIV and GV are equipped with Honeywell SPZ-8000 series avionics systems that were cutting edge when introduced in the late 20th century. But back then, augmented GPS was in its infancy, the airspace was considerably less congested, paperless cockpits were mere science projects and uplinked weather graphics were pipe dreams. And CRT displays were cutting edge.

Fast forward to the 21st century. At the beginning of the new millennium, it became clear to Gulfstream Aerospace, among other OEMs, that older aircraft equipped with this generation of Honeywell avionics would need comprehensive cockpit display, FMS and radio upgrades to operate efficiently in the future.

PlaneDeck is Gulfstream's trade name for its Honeywell Primus Elite flat-panel display retrofit for SPZ-8000, -8400 and -8500 avionics suites. A six-pack of 8-by-8-in. DU-885 AMLCDs, which fit into the same mounting racks, replaces the original half dozen DU-880 CRTs. Additional wiring and connectors, though, are needed to connect the displays to new left and right cursor control devices mounted in the cockpit side ledges, to a new USB thumb drive/SanDisk data loader and to an XM satellite radio weather receiver.

Each flat-panel display has its own internal graphics processors and database that enables it to host specific functions when plugged into a specific rack in the panel. At present, display units 2 and 5, which function as left and right navigation displays (NDs), can host Jeppesen electronic charts, enhanced map graphics with XM radio weather overlays and video provided by on-aircraft visible light or infrared EVS cameras.

Swapping out the CRTs for LCDs has other benefits. The LCDs consume so much less power that they have double the expected life and don't require external cooling fans or air filters that must be changed. The LCD boxes also aren't prone to CRT phosphor screen burn-in, so they don't have to be rotated around the panel every 100 hr. to assure even wear characteristics. So, if you do trade an LCD PFD for an LCD ND, the navigation display won't have ghost images of an attitude indicator, air data tapes and a compass rose.

Each DU-885 LCD weighs about 7 lb. less than a DU-880 CRT, plus there's a weight savings from removing the external cooling fans and ducts. Gulfstream officials say overall weight reduction is close to 50 lb.

PlaneDeck isn't inexpensive, being priced at $725,000. But it's Gulfstream's own conversion program, downtime is only 10 days, it's fully supported by the OEM in the aftermarket and it's available through ASC-476A for GIV/IV-SP/G300/G400 aircraft and through ASC-183A for GV airplanes.

FMS 6.1 is sold separately from PlaneDeck and it's the second and equally valuable part of Gulfstream's avionics upgrade program for GIV and GV series aircraft. It's a hardware and software upgrade for the stand-alone NZ-2000 nav computer boxes and CD-820 MCDUs. (Early GIV aircraft were equipped with NZ-800 FMS boxes. They need to be swapped out for NZ-2000 computers to be eligible for FMS 6.1.) It's available as ASC-477 for GIV series aircraft and ASC-186A for the GV family. FMS 6.1 is priced at $153,000 for dual FMS and $171,000 for triple FMS. Installation time is 15 days, mainly due to the need to swap out GPS receivers and antennae for WAAS GPS equipment.

Generically, Honeywell's FMS 6.1 upgrade offers three key provisions — satellite-based augmentation system (SBAS) GPS/localizer performance with vertical guidance (LPV) approach, Future Air Navigation System (FANS) provisions and required navigation performance (RNP) functionality.

Gulfstream's current version includes a WAAS/LPV approach capability. That provides ILS look-alike guidance to more than 3,340 runways in the U.S., including more than 2,240 that don't have ILS. Notably, Canada now has more than 80 SBAS LPV procedures and Europe has more than 75 EGNOS-based LPVs.

The FANS functions are more limited, more works in progress. Aboard GIV and GV aircraft, FMS 6.1 installs provisions to accommodate controller to pilot data link communications (CPDLC), automatic dependent surveillance — contract (ADS-C) for transoceanic operations and air traffic services facilities notification, essentially the initial communications handshake between aircraft and ATC that's required before either CPDLC or ADS-C can be activated.

For FANS, the MCDU CD-820 control display units also must be upgraded with new faces having an “ATC” button to provide access to CPDLC functions.

FMS 6.1 includes an RNP with 0.3-nm accuracy function. But it cannot yet be used to fly RNP Authorization Required approaches. That will require certification of the FMS, aircraft flight guidance system and autopilot as an integrated system capable of flying with RNP 0.3 precision. One prime reason is that GIV and GV aircraft are not yet certified to fly radius to fix legs, curved segments that are used to construct many RNP AR approach procedures.

The NZ-2000 upgrade also adds circling approaches to the navigation database, a vector to final feature, temperature compensation for cold weather baro VNAV and full vertical navigation, plus automatic hold to altitude, heading to altitude and heading to intercept functions, along with supporting multiple approaches to the same runway, TACAN approaches for Defense Department operators and database cross-loading between FMS boxes.

Make a note. If you're using the FMS to fly down to circling minimums, you'll still have to hand fly the aircraft, or use the flight guidance system's heading and altitude hold modes, to maneuver inside the protected circling airspace and position the aircraft for the final landing approach.