GM2 SPA.LVO.110 Aerodrome-related requirements, including instrument flight procedures

SUITABLE AERODROMES — ASSESSMENT — AVAILABILITY OF SUITABLE NAVIGATION FACILITIES

As detailed in point (a) of AMC1 SPA.LVO.110, the assessment of the suitability of an aerodrome, including instrument flight procedures, for the intended operations comprises the availability of suitable navigation facilities and associated instrument flight approach procedures.

When assessing the availability of suitable navigation facilities, the following information is relevant.

(a)     Classification for ILS: the ILS classification, e.g. ‘III/E/4’, II/T/3, ‘I/C/2’, etc., is defined in ICAO Annex 10 Volume 1 by using three characters:

(1)     I, II or III: this character indicates conformance to the facility performance category which is usually associated with the approach operational category.

(2)     A, B, C, T, D or E: this character defines the ILS points to which the localiser/glide path has been verified to be conformal to the course structure of a localiser CATII/III or glide path CAT II/III (where glide path is always limited to T).

(3)     1, 2, 3 or 4: this number indicates the level of integrity and continuity of service. The integrity relates to the trust which can be placed in localiser or glide path not radiating false guidance signals. The continuity of service relates to the rarity of signal interruptions. The minimum levels of integrity and continuity of service are represented by a single descriptor ‘level’ which would typically be associated as follows:

(i)      Level 1: the localiser’s or glide path’s integrity or continuity of service have not been demonstrated or they have been demonstrated but at least one of them does not meet the level 2 requirements.

(ii)     Level 2 is the performance objective for ILS equipment used to support LVOs when ILS guidance for position information in the landing phase is supplemented by visual cues/references.

(iii)     Level 3 is the performance objective for ILS equipment used to support operations which place a high degree of reliance on ILS guidance for positioning through touchdown.

(iv)     Level 4 is the performance objective for ILS equipment used to support operations which place a high degree of reliance on ILS guidance throughout touchdown and roll-out.

Further information may be found in ICAO Annex 10 Volume 1.

(b)     GBAS facility classification (GFC)

The facility classification, e.g. i.e. ‘C/G1/35/H’, refers to the station serving all approaches to a given airport and is defined in ICAO Annex 10 Volume 1 using four elements:

(1)     Facility approach service type (FAST): (A-D) indicate the service types supported by the navigation facility, i.e. ‘C’ means FAST C, which denotes a facility meeting all the performance and functional requirements necessary to support GBAS approach service type (GAST) C. GAST C has been designed to meet requirements for CAT I as well as, with additional constraints, CAT II. GAST D has been designed to meet requirements for CAT III. A downgrade from GAST D to C is possible and announced in the avionics.

(2)     Ranging source types: these indicate what ranging sources are augmented by the ground subsystem. i.e. ‘G1’ means GPS (‘G2’: SBAS, ‘G3’: GLONASS, ‘G4’: reserved for Galileo, etc.).

(3)     Facility coverage: this defines the outer horizontal coverage of the GBAS positioning service expressed in nautical miles. ‘0’ is for facilities that do not provide positioning service. The facility coverage for position service does not indicate the coverage for the GBAS approach service. The information on the coverage for the approach service is contained in the ‘Service volume radius from the GBAS reference point’ to the nearest kilometre or nautical mile as described in point (d) below.

(4)     Polarisation: this indicates the polarisation of the VHF Data Broadcast (VDB) signal. E indicates elliptical polarisation (option), and H indicates horizontal polarisation (standard). Aircraft operators that use vertically polarised receiving antennas will have to take this information into account when managing flight operations, including flight planning and contingency procedures.

Further information may be found in ICAO Annex 10 Volume 1.

(c)      Approach facility designation (AFD) for GBAS

The approach facility designation, e.g. ‘EDDF/G25A/20748/S/C’ or ‘ABCD/XABC/21278/150/CD’, describing parameters for an individual approach procedure, is defined in ICAO Annex 10 using five elements:

(1)     GBAS identification: 4-character facility identifier, e.g. ABCD.

(2)     Approach identifier: 4-character approach identifier, e.g. XABC.

(3)     Channel number: 5-digit channel number (20 001–39 999) associated with the approach.

(4)     Approach service volume: this indicates the inner limit of the service volume either by a numerical value in feet corresponding to the minimum decision height (DH), e.g. ‘150’, or by the GBAS points (i.e. A, B, C, T, D, E, or S). The GBAS points are equivalent to the ILS points, where ‘S’ is only specific to GBAS and denotes the stop end of the runway.

(5)     Supported service types: these designate the supported GBAS service types (A-D).

Further information may be found in ICAO Annex 10 Volume 1.

(d)     Service volume radius from the GBAS reference point

Maximum use distance (D_max): the maximum distance (slant range) from the GBAS reference point to the nearest kilometre or nautical mile within which pseudo-range corrections are applied by the aircraft system.

Note: This parameter does not indicate the distance within which VHF data broadcast field strength requirements for the approach service are met.

Further information may be found in ICAO Annex 10 Volume 1.

TYPE OF xLS NAVIGATION MEANS

(e)     In the context of AMC1 SPA.LVO.110 point (g)(3), ‘type of xLS navigation means’ means the facilities external to the aircraft and the associated limitations (if any) which have been used as the basis for certification.