PBN Training

An important regulatory development in Europe this year has been the deadline of the 25th August 2018 for air operators to establish compliance with performance based navigation (PBN) crew training requirements which has affected both EASA aircrew and air operations regulations. Mario Pierobon provides an update.

Performance-based navigation training requirements have been designed in order to regulate the usage of performance-based navigation procedures. Vytautas Stankevicius, head of Training at BAA Training explained, “It means that now it is not mandatory for air operators to use PBN procedures during the initial climb and approach. However, if they do want to operate according to these specifications, they must do that under the particular regulations, i.e. having certain equipment implemented into the aircraft as well as flight crews with PBN qualification.”

While area navigation (RNAV) and its associated procedures have been around for a few decades, PBN is a completely new navigation concept.

“RNAV, which also forms a part of PBN, is sensor driven, i.e. the airspace is designed around and restricted by the equipment it requires. The requirements for PBN are defined solely by operational needs and hence are not limited to the presence of certain equipment/sensors,” said Thorsten Rösch, chief instructor Boeing Fleets at Lufthansa Aviation Training. “This makes the PBN concept quite complex requiring a thorough understanding of its various parts and applications. The crew is ultimately responsible for deciding if their airplane is sufficiently equipped to operate through certain airspaces. The need for PBN training further arises from the requirement to operate with on-board navigation performance monitoring and alerting equipment, which has to be fully understood.”

Conforming to New Requirements

Air operators have had to make sure all crews were properly trained and their PBN competency demonstrated and documented to their respective competent authorities.

“As of 25th August 2018, the pilots who are not PBN qualified may only operate outside PBN route segments and approaches. In some cases national regulations with regards to PBN grandfathering rights for current instrument rating (IR) holders and training/checking requirements were released at a rather late stage, requiring additional line proficiency checks (LPC) or operator proficiency checks (OPC) events to be scheduled to generate sufficient training and checking events,” commented Rösch. “Training organisations on the other hand had to design the theoretical and practical training courses and seek approval with their competent authorities. Since national interpretations of the PBN crew training regulations were not harmonised, this task was especially challenging for training organisations with a trans-border customer base.”

Before this year’s deadline the majority of operators had already been operating PBN in accordance with their approvals and operations specifications.

“The new regulatory approach brought in by EASA from 2016 shifted the emphasis towards pilot training and checking on proportionate PBN-related operating procedures, such that PBN privileges are now endorsed into the pilot’s instrument rating,” said Nick Leontidis, CAE Group President, Civil Aviation Training Solutions. “This resulted in mandatory PBN-related training in theoretical knowledge and practical skills and inclusion of PBN operations to testing and checking for both a licence and aircraft rating. As a training provider, CAE has developed all of the courses required to meet these new training requirements, as well as ensuring our cadre of instructors and examiners are appropriately trained and qualified to provide the necessary training and checking.”

Due to the sufficient lead time provided by EASA and the fact that PBN is an ICAO driven initiative, the transition was generally handled well.

“With the release of the PBN crew training regulations, both operators and training organisations had a broad idea of the requirements to be stipulated by competent authorities and were able to set up their training courses accordingly,” continued Rösch. “Some authorities required more time than expected for implementation causing some uncertainty with regard to crew qualification and certification. FSTD certification is still a work-in-progress, similar to the required harmonisation regarding PBN licensing requirements among EASA member states.”

At FlightSafety International PBN training includes a 3.5 hour online e-Learning module.  Screenshot: FlightSafety International.

Structure and Contents

PBN qualification training consists of both theoretical and practical training. Paul Ozmer, regional director of Training Operations at FlightSafety International described PBN training at his company. “At FlightSafety International, all PBN training is provided in two steps. The first step is a 3.5 hour online e-Learning module, covering all the detailed requirements and information a pilot would need to operate using global navigation satellite systems (GNSS) signals, leading to a certificate or course completion. The second step is practical flight training for applying the PBN principles during departures, arrivals, approaches and en-route procedures. Our e-Learning training course covers the topics required by the various authorities, ICAO, EASA, the FAA and any available guidance material. All PBN practical training should be trained in the simulator if available. This is much more effective and allows for flexibility in adapting the scenarios and demonstrating equipment failures that cannot be shown safely in the aircraft. Training in the actual aircraft is not as effective and there are many safety concerns for all in-aircraft training. Most pilots know the Navigation requirement of the equipment that is installed and certified in their specific aircraft. Pilots learn more about PBN requirements, operations and limitations during training.”

The theoretical training course discusses in detail which airspaces the various navigation specifications are defined, what navigation performance and equipment they stipulate and if they offer additional functionalities (RF Leg, Baro VNAV, etc.).

“Furthermore, each navigation specification is presented with regard to the sensors it requires, its en-route separation minima and the required contingency procedures. The practical training then applies the gained knowledge as crews are operating within the various navigation specifications. The main focus lies on arrival and departures and RNP approaches, as the lesson presents various equipment degradation scenarios requiring the trainees to actively analyse the situation in a timely manner and make their decision accordingly. FSTDs offer the possibility to present applied PBN scenarios (i.e. JFK Canarsie Approach) at the click of a button,” said Rösch. “We found that most pilots were generally not accustomed to PBN contingency procedure handling, including ATC phraseology, as well as the need to put more focus on FMC database and route management. One case in particular is the requirement to add cold temperature corrections during 2D approaches. Though this being not new, it has been largely ignored by operators and crews alike and now forms an essential part of the practical PBN training.”

Specific Approvals

Under the PBN umbrella some navigation specifications require a specific approval, i.e. RNP AR (authorisation required) APCH and RNP 0.3.

“Aircraft navigation systems and the overall complexity of the procedures require more attention by the operator and the crews. Since safety is the number one consideration, special training requirements have been established for these procedures,” said Ozmer.

Leontidis commented that the navigation specifications requiring a specific approval, requires detailed training for the pilot due in part to the location and/or complexity of the approach procedures. RNP 0.3 is primarily targeted towards rotorcraft operations; however fixed wing operations are not excluded.

Currently, RNP 0.3 is primarily targeting rotorcraft operations but might be extended to fixed wing operation as it is covered under advanced RNP (A-RNP), though few aircraft are currently equipped for A-RNP.

“The requirements to gain approval to conduct RNP AR approaches are set by EASA and the applicable acceptable means of compliance (AMC). The RNP AR APCH training programme has to include a structured ground and FSTD training course as outlined in the AMC,” said Rösch. “It should be noted that the competent authorities have the ultimate authority in defining RNP (AR) training requirements for approaches located within their territory, while requirements set by non-EASA member states might differ from those stipulated by EASA, i.e. FAA. In general RNP (AR) approaches are designed for airports that are restricted due to terrain or are located within noise sensitive areas. This often results in curvy final and missed approach paths, so called RF-Legs, while the required position accuracy (RNP) can be as low as 0.1 NM. Since lateral and vertical terrain clearance is significantly reduced when compared to conventional non-precision approaches, accurately following contingency procedures as a result of reduced navigation accuracy is crucial.”

Operational and Safety Benefits

There are valuable operational and safety benefits enabled by PBN, which include higher accuracy in vertical and lateral navigation, the simplification of cockpit procedures with the most modern avionics systems, automated system and accuracy monitoring, much more detailed information and failure indication possibilities to the pilot. PBN also allows for approaches to be established and certified into airports, where in the past only VFR operation was possible, stated Ozmer.

Performance-based area navigation requirements are applicable to aircraft conducting operations in an ATS route, in instrument approach procedures, or a designated airspace.

“Performance requirements are expressed in the navigation specifications in terms of the accuracy, integrity, continuity, availability and functionality. Navigation according to a specific route for approach to land and after departure allows flight crews to perform accurate manoeuvres with the aircraft, thus helping to avoid human errors not only for crews, but also for air traffic controllers. Additional benefits include avoiding collisions in the air, safely avoiding obstacles on the ground, saving on fuel, saving the time of the air traffic procedures, thus saving airport expenses,” said Stankevicius.

“We see a more efficient use of airspace and fewer requirements for ground-based equipment, together with the opportunity to create instrument approach procedures in challenging locations where the use of conventional navigation aids has not been possible,” said Leontidis. “We also support EASA in its aim to harmonise PBN implementation in the European Air Traffic Management (ATM) network, and the introduction of Approach Procedures with Vertical Guidance (APV) by 2024, which will allow for a harmonisation of the approach types, a better separation from obstacles and an improved pilot situational awareness.”

The PBN concept offers shorter and therefore more fuel-efficient routes and reduces en-route separation minima allowing denser airspace utilisation.

“There is less need for expensive navigation systems on the ground while approaches and departures can now be flown at much higher accuracy, especially at airports which are restricted by terrain or noise sensitive areas, while at the same time allowing lower landing minima. By advancing on-board navigation technology, the crew workload is significantly reduced and the PBN concept allows this new technology to be easily implemented, without the need to redesign airspace structure or the concept itself,” concluded Rösch.

Published in CAT issue 5/2018