Insider Green

One of the new concepts within global aviation that you will hear about this week is Trajectory Based Operations (TBO). TBO is Performance Based Navigation (PBN) plus Time Based Management (TBM). It will have an impact on how the National Airspace System (NAS) is operated in the near future.

Let’s break down PBN and TBM.

PBN is an advanced, satellite-enabled form of air navigation that enables flights to fly precise paths. Repeatable paths are defined with PBN procedures. Some of the key technologies that support PBN include:

  • Flight Management System (FMS)
  • Area Navigation (RNAV)
  • Lateral/Vertical Navigation (LNAV/VNAV)
  • Required Navigation Performance (RNP)
  • Required Navigation Performance–Authorization Required (RNP-AR)
  • Advanced-Required Navigation Performance (A-RNP)

TBM schedules the flow of air traffic to a predefined meter point based on time. Key technologies that support TBM include

  • Traffic Flow Management System (TFMS)
  • Time Based Flow Management (TBFM)
  • Terminal Flight Data Manager (TFDM)
  • En Route Automation Modernization (ERAM)
  • Standard Terminal Automation Replacement System (STARS)
  • System Wide Information Management (SWIM)
  • Integrated Departure/Arrival Capability (IDAC)
  • Ground Interval Management – Spacing (GIM-S)
  • Terminal Sequencing and Spacing (TSAS)

All of these technologies work together to draw desired benefits. It is a very complicated and difficult task.

TBO is designed to allow aircraft to fly more precise flight paths, using time rather than miles-in-trail. As it evolves, TBO, in theory, will maximize throughput and improve airspace, airport, and in-flight efficiency.

The hope is this will lead to more predictable, repeatable routes that are highly reliable. With the large amount of data that will be gathered and the planned decision support tools for ATC, NAS users should benefit from a more predictable schedule that will reduce operation costs, fuel burn, and delays.

On June 28, 2017, EUROCONTROL issued the following information:

“EUROCONTROL supports and is a main contributor to Trajectory Based Operations (TBO), which is the exchange, maintenance and use of consistent aircraft trajectory and flight information for collaborative decision-making on the flight (‘collaborative’ here means the involvement of the aircraft operator and all parties that have an interest in a flight).”

They further stated: “TBO is at the heart of all the latest ATM strategies and concepts including the SESAR Master Plan and ICAO’s Global Air Navigation Plan (GANP). TBO is also the main focus of validation conducted in regional programmes such as SESAR, NextGen (U.S.), CARATS (Japan), and Sirius (Brasil).”

As you can see, TBO is more than just an idea, and NATCA has been involved in discussions regarding TBO since its concept was first discussed here in the United States. It has been discussed at meetings in which NATCA is a participant, including the NextGen Advisory Committee, of which NATCA President Paul Rinaldi is a member.

The plan is for TBO implementation to be incremental, coordinated, and cross-facility focused for NAS-wide benefits. FAA and NATCA are committed to providing the right tools for the right location at the right time. The goal is provide the sustained communications, training, and technical support needed to effectively transition to TBO in the field.

TBO is not a 100 percent solution. The plan is for controllers and managers to still have the flexibility to manage tactical situations like weather, go-arounds, and other things that controllers deal with on an minute-by-minute basis every day.

There remain many questions and NATCA has been vocal with some of its concerns, including its belief that the more standard use of TBFM is a key foundation to any iTBO success. NATCA remains resolved to be a collaborative partner with the FAA and other aviation stakeholders as we face the challenges of implementing some of these concepts.