PBN in Business Aircraft: Certification Needs

For aircraft, most navigation implementations involving hardware are based on a Supplemental Type Certificate (STC) and may be issued in the form of a Service Bulletin by the aircraft manufacturer.

Minor changes, including software, may then be implemented during maintenance via data updates incorporated in the aircraft hangar. Note that PBN is sensitive to data currency. It is crucial to ensure all databases are up to date with the latest versions, issued by the system manufacturer.

Operations (including flight crew) ICAO

Reference PBN Manual Doc 9613 and ICAO Circular 336 that in place of RNAV Approaches states to use RNP Approach (and derivatives) charts only, prior to December 1, 2022. Other useful ICAO guidance for operators is ICAO PBN iKit and Doc 9997, PBN Operational Approval Manual.

Eurocontrol

Reference European GNSS Contingency/Reversion Handbook for PBN Operations – edition 6. Utilize the Eurocontrol Navigation Domain website hosting PBN training modules. The European Commission has regulation 2016/539 for pilot training, testing and checks for PBN.

FAA

Reference Aeronautical Information Manual (AIM) via ATPubs and PBN Nav Strategy (July 2022). Various Airworthiness Circulars, TSOs and RTCA DO standards are available under the general definition of PBN.

These have EASA and other aviation authority equivalencies. Also reference FAA InFO 16020 for PBN naming of Instrument Approach Procedures (IAP). PBN & Flight Management Future

Further enhancements in DME/DME deployment, for alternate position, navigation and timing (APNT) will result in a long-term, reliable and highly accurate secondary form of navigation for airspace operations.

Under PBN Implementing Regulation (IR) 2018-1048, by June 6, 2030, all approach operations down to Category I in Europe must be conducted as RNP. ILS only becomes a contingency approach procedure at that time.

In the US and elsewhere, as A-RNP navigation is being implemented there will be a future progression to the inclusion of three new features. These are considered as ICAO-optional for any aviation authority to implement. They are:

• RNAV Holding. This may be ATC-defined holding patterns or published and flown as RNP with performance monitoring.
• Fixed Radius Transitions (FRT). Turn transitions between enroute segments, flown with a specific radius.
• Time of Arrival Control (TOAC). Adjusting aircraft speed to arrive at airspace points at a specific time or within limits. This is still being defined.

Dynamic-RNP is a future where timing and predictive maneuvering will route aircraft to artificial airspace fixes. These are based on the aircraft’s ability and certification to navigate independently, without the use of navaids or intervention of ATC.

Moreover, Interval Management (IM) employed by the aircraft themselves will provide close in spacing and more parallel operations at airports.

In Summary

PBN uses an extensive set of avionics technologies, guiding aircraft along varied corridors of containment and spacing. The key to PBN is the ability of each aircraft to consistently perform, independent of external technologies, given that satellites are considered part of the overall aircraft system.

The ability of APNT, using trusted DME and IRS position sensors, offers a backup for satellites, but again relies on adequate aircraft equipage.

Eventually, when ADS-B and navigation mature to ensure position, spacing, speed, roll angle and altitude changes are automatically adjusted, in real time, PBN will function sufficiently for ATC to provide a monitoring role.

With the introduction of Advanced Air Mobility (AAM), both the maneuverability and precision navigation requirements of airborne platforms increase. When PBN (as navigation) is included with advancements in communication and surveillance, the airspace will be an even safer place than it is today.

But to be truly successful, it requires each operator to maintain currency in equipage, training and operational certification.