From the role of fail-operational autoland systems to the importance of maintenance records and MEL compliance, each element supports operational readiness and regulatory approval. This FAQ addresses the most pressing questions faced by maintenance and airworthiness professionals working within an EASA-compliant environment.
All Weather Operations (AWO) enable aircraft and crew to conduct take-offs, landings, and taxiing in conditions of reduced visibility. This includes operations under CAT II and CAT III Instrument Landing System (ILS) minima. AWO are essential for maintaining flight regularity and minimizing disruptions caused by poor weather, while ensuring safety through adherence to strict regulatory and technical standards.
2. What roles do CAMO and AMO staff play in AWO compliance?
CAMO staff ensure continuing airworthiness and confirm that all AWO-critical systems are inspected and maintained within approved intervals. AMO personnel carry out the actual technical maintenance, testing, and repair of systems such as autopilots, ILS receivers, and radio altimeters. Both roles are essential to maintain AWO operational readiness and regulatory compliance.
LVO Approval is a formal authorization from a competent authority allowing an operator to conduct CAT II/III operations. It confirms that the operator has demonstrated compliance across aircraft equipment, flight crew training, operational procedures, maintenance processes, and ground infrastructure. Without this approval, such operations cannot be conducted legally.
Essential systems include:
Autopilot (dual or triple redundant)
ILS receivers
Autoland system
Radio altimeter
Auto-throttle
Flight Director
Weather radar
Each must meet performance criteria and redundancy requirements to enable safe low-visibility landings.
Fail-Passive: If a fault occurs, the system disengages but leaves the aircraft in a stable condition—requiring pilot intervention.
Fail-Operational: Even after a failure, the system can complete the landing without pilot action.
Fail-Operational systems are required for CAT IIIb and essential for maintaining safety during zero-visibility landings.
AWO is regulated under:
ICAO Annex 6
EASA AIR OPS Regulation (EU 965/2012)
AMC/GM guidance material
National aviation authority guidance
These frameworks define the technical, operational, training, and procedural requirements for safe low-visibility operations.
Training includes ground theory, simulator sessions focused on approach and landing procedures (including failure scenarios), line training, and recurrent training every six months. Recency requirements must also be met, ensuring pilots are familiar with low-visibility procedures and aircraft automation.
The Minimum Equipment List (MEL) specifies the systems that must be fully operational for CAT II/III approaches. Even a single fault—like an inoperative autopilot channel or radio altimeter—could restrict the aircraft to a lower category or prevent low-visibility operations altogether.
Accurate and complete maintenance documentation is crucial. It provides evidence of compliance, tracks the serviceability of critical systems, and supports audits by both internal QA and external regulatory bodies. Records must reflect test results, system resets, configuration changes, and any corrective actions.
Interested in gaining a deeper understanding of these essential topics?
Sofema Online offers the perfect solution:
Introduction to All Weather Operations (CAT II & CAT III) For CAMO & AMO Staff
This fully online, self-paced course provides the practical knowledge and skills necessary to enhance compliance oversight and strengthen operational effectiveness across your organization.
