GM8 SPA.LVO.110 Aerodrome-related requirements, including instrument flight procedures

SUITABLE AERODROMES — OPERATIONAL ASSESSMENT — PROCESS TO DETERMINE THE NUMBER OF APPROACHES AND LANDINGS — AEROPLANES

(a)     When performing an operational assessment to determine the suitability of an aerodrome for the intended operations, the operator should have a process to determine the number of approaches and landings, in accordance with point (l) of AMC1 SPA.LVO.110. The following guidance provides examples of criteria that can be used to evaluate level complexity of the runway versus a landing system for the purpose of the determination of the number of approaches and landings. Depending on the landing system used, some criteria might not be relevant, or others might need to be considered.

(1)     Pre-threshold terrain profile

The typical length of pre-runway threshold is calculated from the published threshold (displaced threshold if present) to 300 m on the extended centre line unless otherwise specified by the AFM or additional data from the TC/STC holder, the State of the aerodrome or AIP data, or the competent authority issuing the operator’s LVO approval. The complexity of the pre-threshold terrain profiles is described as follows:

(i)      Simple

(A)     approximately + 1 m variation from runway threshold elevation in the typical length; or

(B)     previous experience in more constraining pre-threshold terrain in the same aircraft type or variant.

(ii)     Moderate

(A)     presence of ARAS; or

(B)     approximately + 1 m variation from runway threshold elevation within the last 60 m prior to runway threshold; and

(C)     prior to 60 m and up to typical length:

—                   moderate rising slope (less than 7 % rising); or

—                   moderate ‘sea wall’ (less than 3 m).

(iii)     Complex

(A)     approximately + 2 m variation from runway threshold elevation within the last 60 m prior to runway threshold; and

(B)     prior to 60 m and up to typical length:

—                   significant rising slope (up to 15 % rising); or

—                   significant ‘see wall’ (up to 6 m); or

—                   significant change of slope (rising then descending or descending then rising close to the limit values).

(iv)     Very complex

Outside any of the limits defined above for complex pre-threshold terrain profiles.

Note: The term ‘sea wall’ refers to sudden changes of terrain elevation that typically occur when runway thresholds are located near the sea. Sea level may change due to tides. Other cases of sudden terrain elevation may occur in other cases, a slope of 100 % may be considered as comparable to ‘sea wall’ (e.g. Boston USA).

Figure 0: Typical example of ‘very complex’ with greater than 6 m ‘sea wall’ at 300 m (Asturias, LEAS 29 dated 2007) that after suitability assessment and due to the presence of ARAS, may be changed to ‘moderate’.

Example: A pre-threshold terrain with the following features would be considered as ‘moderate’.

(1)     Less than 1 m variation of pre-threshold terrain elevation from runway threshold elevation, in the area from runway threshold up to 100 m prior to runway threshold

(2)     Less than 3 m variation of pre-threshold terrain elevation from runway threshold elevation, in the area from 100 m prior to runway threshold up to 300 m prior to runway threshold

(2)     Landing system assessment area (LSAA) slope

Note: 600 metres after the threshold is the standard length; however depending on the landing system, other lengths might be relevant.

Although not recommended by ICAO Annex 14 Volume 1, slope variation in the LSAA can exist (refer to point 3.1.15 to point 3.1.18) and represent a factor of risk to be considered. For the purpose of determining the relevant parameters characterising slope and slope variation, the following definitions may be used (Figure 1):

—                  Mean LSAA slope: Slope computed from runway threshold elevation up to runway elevation at 600 metres after the threshold.

—                  Deviation from mean LSAA slope: greatest elevation difference between any runway elevation inside LSAA and mean LSAA slope.

Figure 1: Mean LSAA slope & Deviation from mean LSAA slope

Note: Published runway profiles usually contain the position and elevation of each significant runway longitudinal slope change. Elevation at other location can be interpolated assuming straight slope between each published elevation. The highest/ lowest elevation of the LSAA might not be the one where the deviation from mean LSAA slope is the greatest.

(i)      Simple

(A)     Approximately + 0.4 % mean LSAA slope and less than 1 m (3 ft) variation around mean LSAA slope; or

(B)     previous experience in more constraining touch down condition in the same aircraft type or variant.

(ii)     Moderate

Approximately + 0.8 % mean LSAA slope and less than 2 m (6 ft) variation around mean LSAA slope.

(iii)     Complex

Approximately + 1.0 % mean LSAA slope and less than 4 m (12 ft) variation around mean LSAA slope.

(iv)     Very complex

Outside any of the limits defined above.

Figure 2: Typical example of ‘simple’ LSAA Slope (ESSA 01L dated 2018)

Figure 3: Typical example of ‘moderate’ LSAA slope due to variation around mean LSAA slope greater than 1 m but lower than 2 m (EGNM 32 dated 2018)

Figure 4: Typical example of ‘complex’ mean LSAA slope greater than 0.8 % but lower than 1 % (EDD 23L dated 2009)

(b)     Operational assessment programme: the following guidance provides examples of typical flight programmes that can be used to demonstrate suitability of a landing system using the operational assessment method, considering the overall level of runway irregularities.

Note: For CAT II operations with no use of autoland nor guidance for the flare manoeuvre, the programmes could be alleviated.

The flight programmes are expected to depend on the level of runway irregularities. Table 1 provides examples of criteria that can be used to determine the level of runway irregularities.

Table 1

Level of runway irregularities to scale the flight programme

(1)     Simple runway

For simple runways, unless other factors can be identified as a source of concern, no in-flight approach and landing may be required.

(2)     Moderate runway

For moderate runways, a minimum of one successful approach/landing using the procedures, equipment and operationally relevant heights (DH/AH) for the intended operations is performed in the meteorological conditions described in AMC1 SPA.LVO.110 Table 15. More approaches could be required if any issue is identified during this approach/landing.

(3)     Complex runway

For complex runways, an initial minimum of three approaches/landings using the procedures, equipment and operationally relevant heights (DH/AH) for the intended operations is performed in the meteorological conditions described in AMC1 SPA.LVO.110 Table 15, with at least one of the landings close to the maximum landing weight for the intended operation and the other two with other different conditions; for example, with a mid-weight in one and low weight in another or with different wind conditions or aircraft configuration flap full/flap 3, or a combination of them. The flights for the assessment are conducted by pilots designated by the operator with defined minimum experience and qualifications, with procedures defined for the purpose. More approaches could be required if any issue is identified during these approaches/landings.

(4)     Very complex runway

For very complex runways, an initial minimum of four to six approaches/landings using the procedures, equipment and operationally relevant heights (DH/AH) for the intended operations is performed in the meteorological conditions described in AMC1 SPA.LVO.110 Table 15 in typical aircraft weight conditions in flights with no commercial passengers.

If no anomaly is observed after the first four to six approaches/landings, extend the condition progressively close to the maximum landing weight for the intended operation with at least 15 successful approaches or landings and report any anomalies with the meteorological conditions described in AMC1 SPA.LVO.110 Table 14 and with different conditions, for example with different range of weight conditions (high, mid, low) or with different wind conditions or aircraft configuration flap full/flap 3, or a combination of them. The flights for the assessment should be conducted by pilots designated by the operator with defined minimum experience and qualifications, with procedures defined for the purpose.

(c)      Operational assessment successful criteria

(1)     Data to be recorded

To assess adequate performance of the landing system, some form of quantitative data should be recorded and reviewed with the competent authority as verification of performance. Acceptable methods of data collection include but are not limited to:

(i)      Record of wind conditions and touch down point (can be observation).

(ii)     Record of pertinent landing system parameters (typically from a digital flight data recorder, quick-access recorder or equivalent) with sufficient sampling rate (typically higher than 1 sample per second) for the part of the flight paths of interest (typically from 300 ft height above touch down through de-rotation after touch down) including typically:

—                   barometric altitude;

—                   radio altitude;

—                   glide path error;

—                   vertical speed;

—                   elevator command;

—                   pitch attitude;

—                   throttle position/thrust commanded;

—                   airspeed;

—                   mode transition or engagement.

(iii)     Photo or video recording of pertinent instrument or instrument and outside view allowing post-flight replay and review of the above parameters.

(2)     Data review and analysis to assess acceptable performance

The final approach, flare and touch down profile should be reviewed with the competent authority to ensure suitability of at least each of the following:

(i)      suitability of the resulting flight path;

(ii)     acceptability of any flight path deviation from the nominal path (e.g. glide path deviation, deviation from nominal flare profile);

(iii)     proper mode switching;

(iv)     suitable touch down point;

(v)      suitable sink rate at touch down;

(vi)     proper flare initiation altitude;

(vii)    suitability flare quality (e.g. no evidence of early or late flare, no over-flare or under flare, no undue ‘pitch down’ tendency at flare initiation or during flare, no flare oscillation, no abrupt flare, no inappropriate pitch response during flare, no unacceptable floating tendency, or other unacceptable characteristic that a pilot could interpret as a failure or inappropriate response of the landing system);

(viii)   no unusual flight control displacement (e.g. elevator control input spikes or oscillation);

(ix)     appropriate throttle/thrust retard (e.g. no early or late retard, no failure to retard, no undue reversal of retard, no undue pitch/thrust coupling);

(x)      appropriate speed decay in flare (e.g. no unusually low speed risking high pitch attitude and tail strike, no excessive float, appropriate seed decay even if well above Vref at flare initiation due to planned wind or gust compensation);

(xi)     proper mode initiation or mode transition relating to altitude or radio altitude inputs (e.g. crosswind alignment).