Do you have an older aircraft and want to know if it can support an upgraded flight management system and landing approach? There’s been a lot of recent information on upgrading to an FMS/LPV system, so you may be wondering if the upgrade is necessary and, if so, what criteria you would need to meet for the installation.

We often get asked about FMS/LPV installations. In this article, we explain what an FMS/LPV system is, why someone might choose to upgrade, and what options are available based on an aircraft’s current FMS capabilities.

What is an FMS/LPV?

A flight management system (FMS) is a specialized computer system on board the aircraft that reduces the flight crew’s workload by automating various in-flight tasks. The FMS contains a navigation database, providing flight crews with data for navigation, performance, and aircraft operations.

LPV stands for Localizer Performance with Vertical guidance. It is becoming the most common landing approach at U.S. airports. This precise landing approach requires a Wide Area Augmentation System (WAAS) enabled system. The aircraft must be equipped with either a dual WAAS/SBAS (Satellite-Based Augmentation System) LPV capable FMS or a single FMS with a standalone LPV monitor.

Why Upgrade to an FMS/LPV System?

Improved navigation systems, such as WAAS/SBAS are becoming more prevalent. Most airports are adopting WAAS with LPV, LNAV (Lateral Navigation), VNAV (Vertical Navigation), or LP (Localizer Performance) capable landing approaches. Older landing approaches, like ILS (Instrument Landing System), are being phased out at airports as LPV capabilities become more widespread. 

Criteria for FMS/LPV Upgrade

Whether your aircraft can have FMS/LPV capabilities installed will depend on what FMS is currently in the aircraft. The installation agency will need to ask the following questions to know what upgrade option to choose: 

• What type of FMS is currently installed on the aircraft? Is it a single or dual FMS system?
• Is the FMS displayed laterally and vertically on the primary flight instruments?
• Is the aircraft currently coupled with autopilot both laterally and vertically from the FMS?
• What type of flight director and autopilot does the aircraft have?
• Is the aircraft equipped with an electronic flight instrument system (EFIS)? If so, what type?

How you answer these questions will help the installation agency determine what products to install on the aircraft. Review the following sections for possible upgrade options.

FMS/LPV Upgrade Options

The following examples – Universal Avionics and Honeywell – demonstrate the requirements for product installation based on the aircraft’s current FMS capabilities.

Universal Avionics

With Universal Avionics Systems, the UNS-1(x)W FMS requires either a dual system or an approved single FMS with an LP/LPV monitor installed to meet LPV requirements.

Universal Avionics Systems also implemented an FAA-approved document called “Engineering Assisted Field Approval Process” (EAFAP). This document allows authorized Universal Avionics dealers to work with their FAA/FSDO (Flight Standards District Office), allowing field approvals with the following guidelines:

• Aircraft must have existing Universal Avionics installed.
• Aircraft must already have VNAV displayed.
• Aircraft must already have VNAV coupled to the autopilot (if you desire a coupled LPV).
• The type of aircraft must have been previously approved. (See the table below for a partial list of approved aircraft from the EAFAP Table 2.)       

After meeting the above requirements, the engineering department will provide the design for the dual FMS installation, single installation with an LP/LPV monitor, or both. Then, a shop will perform the installation. The engineering department will work with the FAA Designated Engineering Representative (DER) agency to approve this installation for vertical coupling with an FAA form 8110-3 and with an FAA flight test DER to approve LPV operation or integration. The FAA/DER then approves an airframe flight manual supplement (AFMS).

Watch: “Support Issues & Solutions for Universal Legacy FMS [webinar]”

Honeywell

The Honeywell WAAS/LPV capability is accomplished via an FAA/DER flight test engineer, supplemental type certificate (STC), or both. Honeywell and other manufacturers do not have an EAFAP like Universal Avionics for accomplishing installations. Therefore, you will have to use alternate methods to gain approval.

When an FMS/LPV Upgrade is Not Beneficial

The following situations demonstrate how upgrading to an FMS/LPV system may be less beneficial based on an aircraft’s existing systems.

First, if the EFIS, autopilot, or both are non-compliant, upgrade costs may exceed the value of the aircraft. This would make the upgrade an uneconomical choice.  

Second, the upgrade may be unbeneficial for aircraft flying routes that support ILS landing approaches, where LPV is unnecessary.

Aircraft Specifications for FMS/LPV Upgrade

FMS/LPV upgrades are typically intended for older aircraft types (i.e., those specified in Universal Avionics’ EAFAP). Newer aircraft have modern cockpits with LPV already enabled. These aircraft include the Gulfstream 450, 500, 550, 600, and 650, and the Embraer Legacy 500, 600, and 650.

A few lines from the EAFAP table have been reproduced here. Note that this list only includes the regional and corporate aircraft that C&L Aviation Group commonly services. Review Universal Avionics’ EAFAP Table 2 – 3D Coupled Approach Aircraft / Flight Guidance / Display Applicability for the entire list of aircraft models. 

Aircraft	Flight Guidance	Displays
ATR 42/72	SPZ-6000	SPZ-6000
Cessna 500 Citation I	FZ-500	AD-650 / RD-650
Cessna 550 Citation II	FZ-500	AD-650 / RD-650
Cessna 550 Citation Bravo	P-1000	P-1000
Cessna S550 Citation SII	FZ-500	AD-650 / RD-650
Cessna S550 Citation SII	FZ-500	IS&S ADVIZ
Cessna S550 Citation SII	FZ-500	EFI-550
Cessna 560 Citation V	FZ-500	EDZ-605/705/805
Cessna 560 Citation Ultra, Encore, Excel, XLS	P-1000	P-1000
Cessna 650 Citation III	FZ-500	Analog/EFIS/EFI-890R
Cessna 650 Citation VI	SPZ-650	EDZ-605
Challenger Cl-600-1A11/2A12	SPZ-600/FZ-500	AD-650/RD-650 (Analog)
Challenger CL-600-2B16 (CL-601-3A)	APS-85	EFI-890R
Challenger CL-600-2B16 (CL-604)	PL-4-4000/FCC-4006	PL-4-4000
Challenger C-600 (FAA FIAS)	PL-4-800	PL-4-800
Gulfstream Aerospace Astra 1125 SP/SPX, G100	APS-80/85/86	EFIS-85/86
Gulfstream Aerospace Astra 1125 SP/SPX, G100, Galaxy	PL-4-4000/FCC-4006 FCC-4005	PL4-4000
Gulfstream Aerospace LP 1125 Westwind Astra	FCS-80	Collins IDS-3000
Gulfstream Aerospace LP 1125 Westwind Astra	FCS-85	Collins IDS-3000
Gulfstream GII, GIII	SP-50/FC-500/SPZ-800	Analog
Gulfstream GII, GIII	SP-50/FC-500/SPZ-800	EDX-600/700/800
Gulfstream GII, GIII	SP-50/FC-500/SPZ-800	EFI-890R
Gulfstream G200, Galaxy	PL-4-4000/FCC-4006 FCC-4005	PL-4-4000
Hawker Beechcraft 800XP	APS-86	EFIS-86
Hawker Beechcraft 125-800A/B	APS-86	EFIS-86

If you want to learn more about FMS/LPV or are ready to upgrade your aircraft, contact your trusted avionics installation agent.

Acronym Key:

AFMS – Aircraft Flight Manual Supplement

DER – Designated Engineering Representative

EAFAP – Engineering Assisted Field Approval Process

EFIS – Electronic Flight Instrument System

FAA – Federal Aviation Administration

FMS – Flight Management System

FSDO – Flight Standards District Office

LP – Localizer Performance

LPV – Localizer Performance with Vertical Guidance 

VNAV – Vertical Navigation

Check out our complete list of Aviation Acronyms.

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