Advanced navigation systems

Traditional piloting methods give way to new technologies featured in state-of-the-art business aircraft flight decks.

By Shannon Forrest
ATP/CFII. Challenger 604, G-IV
Contributing Writer

It is a safe to say that most general aviation (GA) airplanes have a global positioning system (GPS) installed, and that it is used as the primary means of navigation. Even owners of aerobatic aircraft, classic tail-draggers, and war birds that refrain from installing a GPS permanently on the panel likely use a portable version to get from point to point.

The Advanced Cockpit Environment (ACE) in the Pilatus PC-24 is powered by Honeywell’s Primus Epic 2.0 integrated avionics. Benefits for pilots include advanced navigation tools, enhanced situational awareness, and more efficient workload management.

It is ironic that an open-cockpit biplane designed to navigate by looking out the window can now be flown accurately to its destination using an iPad connected to a satellite.

Every pilot learns the technique of pilotage – the practice of using landmarks and geographical features to navigate. It is specifically mentioned in the Airman Certification Standards (ACS).

The goal is that a pilot should be able to get where he is going, or at least make it back to the airport, by looking at a sectional chart and comparing it with what he sees on the ground.

The next skill that follows pilotage is the mathematical principle of dead reckoning – the time–rate–distance equation that determines a pilot’s final position if he/she leaves from a known position and travels in a fixed direction for a constant time. Both skills go hand in hand and are tested on a private pilot check ride.

Neither pilotage nor dead reckoning require the use of electronic navigational aids. Before the widespread use and proliferation of GPS throughout the 1990s, a pilot who became hopelessly lost in a GA aircraft outside of radar coverage could call a nearby Flight Service Station (FSS) for a direction finding (DF) steer.

FSS would tell the pilot to key his microphone for a couple of seconds, and this act could accurately triangulate the position of the aircraft using only radio transmissions. This allowed the FSS to provide a heading back to the course.

Savvy CFIs – myself included – taught this practice by giving the student some instrument work under the hood or goggles and then telling them to resume the cross‑country from an unknown and unfamiliar position. Getting “unlost” using a map and mathematics in an era where everyone has a GPS in their pocket is a lost or dwindling skill.

The VOR training challenge

According to the ACS, a pilot is also expected to exhibit electronic navigation skills using a VHF omni-directional range (VOR). This can be problematic during flight training, because VORs have been or are in the process of being decommissioned. It might mean flying for more than an hour just to find one that is working. As an example, in the DFW (Dallas–Fort Worth TX) metroplex, the only fully functioning VOR as of recently is located on the Class B airport.

To get a student to fully understand VOR navigation, it is necessary to fly to and from the station and intercept and track radials. Also important is to get close to the station to demonstrate the “cone of confusion” and zone of ambiguity.

This can technically be done on a simulator, but there is nothing like flying over the station and looking down at the “bowling pin” to demonstrate these concepts. The ATC controllers at DFW would laugh you out of the sky if you made the request to overfly the field for VOR training.

There is a similar problem with instrument training. VOR approaches still exist, but finding them to train on can be challenging. An IFR check ride requires one precision and 2 non‑precision approaches. The non‑precision approaches can include a VOR, but GPS, localizer‑only, ASR, and NDB approaches also qualify. So, as it stands, a pilot could become instrument‑rated without ever flying a VOR approach.

From the standpoint of human factors, the navigation paradigm is a bit of a conundrum. There is massive reliance on high‑technology satellite navigation. However, at the same time, the regulations dictate the need for training and proficiency in traditional ground‑based navigation systems, pilotage, and dead reckoning. The problem is that only a small portion of the pilot population is knowledgeable or stays proficient in those older systems or techniques.

The GPS revolution

The Bombardier Global 8000’s Vision Flight Deck, powered by Collins Aerospace Pro Line Fusion, merges synthetic and enhanced imagery onto dual head-up displays, delivering unmatched situational awareness and precision navigation.

The transition started when GPS installations became ubiquitous. The most prevalent instrument flight rules (IFR) GPS unit in the GA fleet is the Garmin 430.

It came to market in 1998 and was followed by the WAAS version in 2006. The 430 was superseded by the Garmin 530. Both are still functioning and legal more than 20 years later, provided the owner updates the database and keeps it current.

Any CFII who has conducted an instrument proficiency check in an aircraft with a Garmin 430/530 can attest that the most worn‑out button on the face of the unit is the one labeled “Direct.” When filing a flight with “/G” became the norm, pilots filed direct to the destination instead of using traditional V or J airways.

Often the IFR clearance was “as filed,” so flying direct became an expectation. The Garmin 430 lacked the ability to enter airways, but it did have the capability to load standard instrument departure (SIDs) and standard terminal arrival routes (STARs).

Understanding RNAV and FMS

Although GPS is often given credit for the advent of area navigation (RNAV), the concept had been around since the 1970s. According to the Aeronautical Information Manual (AIM), RNAV is defined as a method of navigation that permits aircraft operation on any desired flightpath within the coverage of ground- or space‑based navigational aids, or within the limits of self‑contained aids, or a combination of these.

Universal Avionics InSight features embedded synthetic vision with advanced mapping, weather, terrain, and traffic awareness to enhance safety and situational awareness.

Classic RNAV units generated waypoints using VORs.

A pilot selected a radial and distance measuring equipment (DME) distance from a VOR to create the point and could fly to or from that point as if the VOR was “moved” to that location.

The first units only allowed 2 waypoints, so pilots had to create the next one as they passed the last one.

GPS simplified the process and eliminated reliance on the ground‑based systems. More importantly, it achieved greater accuracy, which meant the signal could be used for instrument approaches.

GPS is the most common form of RNAV, but it does not have to be according to the definition. RNAV can be based on VORs, DME distances from VORs, and inertial reference systems – in addition to GPS signals. Combining all the signals into one comprehensive package and coupling it with a database makes it a flight management system (FMS).

The advantages of navigating via RNAV versus classic ground navigational aids are more efficient use of airspace, better routing, and less reliance on radar vectoring, ATC transmissions, and assignments. This equates to fuel savings and lower operating costs. To take advantage of these benefits, minimum navigational performance specifications are required for specific phases of flight.

For instance, RNAV DPs and STARs require RNAV 1, which means that the aircraft must stay within 1 nm of the published course for 95% of the time. Approach requirements are even more strict, with the required precision scaling down to 0.3 nm on the final approach segment.

The capability of the avionics package and the pilot determine approach minimums, and the ability to go lower is important to every flight department. A highly capable system allows localizer performance with vertical guidance (LPV) or LP minima, which translates to the equivalent of a basic instrument landing system (ILS).

Radial to fix (RF) – a curved approach path – is optional in a basic RNAV approach‑capable aircraft. The highest level one can achieve when it comes to RNAV procedures is the RNP AR (authorization required) approach. In addition to the equipment, the pilot(s) must also be approved to fly these approaches.

This means training and performance standards. RF capability and scalability are mandatory capabilities for an RNP AR, as is a requirement for on‑board performance monitoring and alerting, should the navigational parameters degrade to the point of requiring a missed approach.

RNP AR approaches commonly include curved approach paths that avoid terrain or noise‑sensitive areas. The RNAV (RNP) X RWY 33L at BOS (Intl, Boston MA) is used after midnight not for terrain or precision, but because the curved path over the harbor dissuades the residents of Massachusetts from filing noise complaints for after‑hours landings.

Advanced avionics platforms

Designed with single-pilot ops in mind, the Citation CJ3+ features Garmin G3000 avionics, pairing advanced synthetic vision with intuitive touchscreen navigation.

Those who have used the Garmin 430 WAAS consider it a capable unit for LPV approaches, but the biggest advantages come with the installation of Garmin advanced flight decks like the G5000.

The G5000 is factory‑installed on the Cessna Citation Longitude and can be retrofitted on the Excel and XLS product line.

Standard functionality includes RNP 0.3 capability, which permits LPV approaches, but the system is also certified for RNP AR operations.

If an operator decides it is worth obtaining the authorization to certify the pilots, it is a matter of training and FAA approval. Deciding to go this route is a case‑by‑case analysis and usually includes whether the AR approval provides substantial benefit to the flight department.

Any modern production aircraft is going to have RNP and RNP AR built into the aircraft by default. The Dassault Falcon 8X comes standard with the Honeywell EASy IV, which incorporates the possibility for RNP AR. EASy IV has a host of other situation‑enhancing features, like a vertical situation display that can depict thunderstorm development. The Collins Pro Line Fusion is also RNP AR capable and offers a synthetic vision display on its three 14‑in touchscreen displays.

When technology fails

Reliance on advanced satellite‑based navigation systems poses a potential risk. While RNP AR systems are designed to trigger a warning to abandon the approach due to degradation in signal, a basic GPS system failure might not be so obvious. Or the pilot might have become so reliant on GPS as a means of navigation that continuation or confirmation bias leads to tragedy.

On May 14, 2026, a Beech King Air 90 was destroyed because of a CFIT accident while attempting to land at night at RUI (Ruidoso NM). According to the NTSB preliminary report, GPS jamming activities were being conducted by the US Military in the area in question. The accident aircraft and three other aircraft in the area reported the loss of GPS capability at the time.

After reporting the loss of GPS capability, the pilot of the accident aircraft requested the RNAV (GPS) approach to runway 24, despite the loss of the GPS signal. The ATC controller cleared the pilot to a GPS fix, but the pilot then requested the ILS because of the GPS anomalies. While being vectored for the ILS, the King Air pilot stated they had the airport and could “go visual.” The pilot was cleared for the visual approach to runway 24 and impacted the terrain shortly thereafter.

Studies on monitoring behavior have shown it is hard to detect failure on things that function normally almost 100% of the time. And that is where we are with advanced navigation systems: nearly perfect almost all the time. Having the ability to display raw data signals – ”green needles” in pilot parlance – and how to interpret them can be crucial.

Unfortunately, that is not a practiced skill in modern times. Sometimes the most technologically advanced approach is not the best approach for whatever reason. The fact that the ILS still exists after all these years reinforces the old pilot mantra about dated technology: it works great and lasts a long time.