Present European Regulations for low visibility operations (LVO) such as CAT II/III or EVS require an operator to conduct an ‘operational demonstration’ before the Competent Authority issues an approval. This operational demonstration may require 100 or more approaches using CAT II/III equipment and procedures in weather conditions better than CAT I. Operators also have to conduct an approach to every runway at every airport before applying CAT III minima for that approach.
Fit for purpose?
The current requirements reflect the early days of CAT II/III operations when the large airlines collaborated with aircraft manufacturers and airport authorities to develop low visibility operations. They are no longer appropriate for the current operating environment where the different elements of the system (aircraft, avionics, ground equipment) have already been demonstrated to be highly reliable.
If Airbus A320s have been conducting CAT III approaches to Charles de Gaulle airport for the last 30 years, then is it necessary for a new operator to fly another 100 approaches to demonstrate that this is a safe operation? If some operators are forced to apply higher landing minima (e.g. CAT I) then, there will be more abandoned approaches and diversions. It could be argued that the operational disruption and additional workload imposed by these ‘go-arounds’ and diversions increases risk and reduces the safety of the aviation system.
The current requirements make it difficult or impossible for some operators to get CAT II/III approval, especially those with a small number of aircraft or a route network that doesn’t include many CAT III airports. They may also be part of the reason why so few operators have approval for the use of enhanced vision systems for approach.
New criteria for approval
EASA has published a notice of proposed amendment (NPA) for all weather operations [NPA 2018-06]. One of the proposals is that the requirements for approval of low visibility approach operations will be updated. Operators will still need to show that aircraft are appropriately equipped and certificated, that operating procedures are in place and that the flight crew have received the necessary training. In place of the ‘operational demonstration’, an operator will conduct a safety assessment to demonstrate that their operation will provide an acceptable level of safety.
Operator’s Safety Assessment
An operator applying for approval for low visibility operations will provide a safety case based on data and safety performance indicators. The safety case will show that the proposed low visibility operation will achieve at least the same level of safety as other operations and will comply with the operator’s safety policy.
Data will be collected from crew reports and flight data monitoring. The operator will determine how many approaches need to be flown at which airports to make up a representative sample of their operations and will also be able to use data shared by other operators or the aircraft manufacturer. An operator may use data from approaches flown in a flight simulator (FSTD) provided that the data is useful and relevant. Guidance is provided about the hazards and potential outcomes that should be considered in the safety assessment.
Performance Based Regulation
The proposed rules for all weather operations are a good example of EASA’s move towards ‘performance-based regulation’. Different operators may use different methods and may present their safety cases differently, but all operators will need to demonstrate an acceptable level of safety to the Authority. Operators will not be precluded from low visibility operations because their operation is different to the large airline model for which the regulations were previously developed.
Who wrote this?
Andrew McKechnie is an expert in Air Operations and Director of McKechnie Aviation LTD. Since 2015 Andrew has been working as a consultant to EASA RMT.0379 developing new regulations for All Weather Operations. Andrew is available to provide training and consultancy to Aviation Authorities and Aircraft Operators.