GM31 Annex I Definitions

DEFINITIONS OF TERMS RELATED TO ALL-WEATHER OPERATIONS

The following terms and concepts are used in the provisions related to all-weather operations in the AMC and GM to Regulation (EU) No 965/2012:

‘Advanced aircraft’ means an aircraft with equipment in addition to that required for a basic aircraft for a given take-off, approach or landing operation.

‘AFM or additional data from the TC/STC holder’ — an AFM or additional data from the TC/STC holder may provide:

—         limitations, in accordance with which the aircraft must be operated, as described under point 4.1 of Annex V to Regulation (EU) 2018/1139. This means that the aircraft may NOT exceed those given values; or

—         demonstrated capabilities, which are the assumptions, envelope or conditions that were used to demonstrate adequate performance to comply with the appropriate certification specifications.

However, some AFMs (especially for those aircraft or landing systems that were certified before the introduction of CS-AWO Issue 2) may not include all of the assumptions, envelope or conditions that were used to demonstrate adequate performance. Information regarding the assumptions, envelope, or conditions that were used to demonstrate adequate performance of a landing system can be provided by equivalent documentation issued by TC/STC holder.

Other types of information issued by the TC/STC holder may include (not an exhaustive list):

—         equivalence between different aircraft models (types);

—         equivalence between aircraft types and variants;

—         landing systems equivalence;

—         a list of runways with their demonstrated performance;

—         a letter of no-technical objection/evaluation letter.

Note: ‘TC/STC holder’ should be understood as the holder of the certificate for the landing system.

‘Basic aircraft’ means an aircraft which has the minimum equipment required to perform the intended take-off, approach or landing operation.

‘Continuous descent final approach (CDFA)’: when the circling altitude/height is reached, it is acceptable to maintain altitude (level-off) and transition to the visual segment. The operator may provide a point in the visual segment in which the descent may be resumed to follow a continuous descent to a point approximately 15 m (50 ft) above the landing runway threshold or the point where the flare manoeuvre begins for the type of aircraft flown.

‘Enhanced flight vision system (EFVS)-Approach (EFVS-A)’ means a system that has been demonstrated to meet the criteria to be used for approach operations from a decision altitude/height (DA/H) or a minimum descent altitude/height (MDA/H) to 100 ft (30 m) threshold elevation while all system components are functioning as intended, but may have failure modes that could result in the loss of EFVS capability. It should be assumed for an EFVS-A that:

(a)     the pilot will conduct a go-around at or above 100 ft threshold elevation, in the event of an EFVS failure; and

(b)     descent below 100 ft above the threshold elevation through to touchdown and roll-out should be conducted using natural vision so that any failure of the EFVS does not prevent the pilot from completing the approach and landing.

‘Enhanced flight vision system (EFVS)-Landing (EFVS-L)’ means a system that has been demonstrated to meet the criteria to be used for approach and landing operations that rely on sufficient visibility conditions to enable unaided roll-out and to mitigate for loss of EFVS function. 

‘Head-up display (HUD) or equivalent display system’ means a display system which presents flight information to the pilot’s forward external field of view (FOV), and which does not significantly restrict the external view.

‘Landing system’ means an airborne equipment, which:

(a)        provides automatic control of the aircraft during the approach and landing (i.e. automatic landing system); or

(b)        has been demonstrated to meet the criteria to be used for approach and landing operations (e.g. HUD landing system, EFVS-L or any other approved system).

‘Landing system assessment area (LSAA)’ means the part of the runway that extends from the threshold to a distance of 600 m from the threshold.

Note — Although the landing systems certification criteria use a value greater than 600 m after the threshold to evaluate limit conditions, for the purpose of flight operations assessment a distance of 600 m is the relevant part as landing beyond this point is not expected to occur in day-to-day operations. The LSAA may not necessarily be coincident with the touchdown zone. The touchdown zone is specified in CS-ADR DSN.

‘Low-visibility procedures (LVPs)’ means procedures applied by an aerodrome for the purpose of ensuring safety during low-visibility operations (LVOs).

Regular runway means a runway whose characteristics fit within the acceptable limits demonstrated by the original equipment manufacturer (OEM) during certification. The classification of a runway as a ‘regular runway’ is different from one set of equipment to another.

‘Required visual reference’ refers to that section of the visual aids or of the approach area which should have been in view for sufficient time for the pilot to have made an assessment of the aircraft position and rate of change of position, in relation to the desired flight path. In the case of a circling approach, the required visual reference is the runway environment.

‘Satellite-based augmentation system (SBAS)’ means a wide coverage augmentation system in which the user receives augmentation information from a satellite-based transmitter. The most common form of SBAS in Europe is the European Geostationary Navigation Overlay Service (EGNOS).

‘Synthetic vision system (SVS)’ means a system that displays data derived synthetic images of the external scene from the perspective of the flight deck.

‘Landing area’ means that part of a movement area intended for the landing or take-off of aircraft.

‘Touchdown zone (TDZ)’ means the portion of a runway, beyond the threshold, where landing aeroplanes are intended to first contact the runway.

‘Type B instrument approach operations categories’: where decision height (DH) and runway visual range (RVR) fall into different categories of operation, the instrument approach operation would be conducted in accordance with requirements of the most demanding category. This does not apply if the RVR and/or DH has been approved as operational credits.