AMC4 NCC.OP.110 Aerodrome operating minima – general

CAA ORS9 Decision No. 47

Text in magenta in force from 30 October 2025

CRITERIA FOR ESTABLISHING RVR/CMV

(a) In order to qualify for the lowest allowable values of RVR/CMV specified in Table 4.A, the instrument approach should meet at least the following facility requirements and associated conditions:

    (1) Instrument approaches with designated vertical profile up to and including 4.5° for Category A and B aeroplanes, or 3.77° for Category C and D aeroplanes, where the facilities are:

      (i) instrument landing system (ILS)/microwave landing system (MLS)/GBAS landing system (GLS)/precision approach radar (PAR); or

      (ii) approach procedure with vertical guidance (APV); and

      where the final approach track is offset by not more than 15° for Category A and B aeroplanes or by not more than 5° for Category C and D aeroplanes.

    (2) Instrument approach operations flown using the CDFA technique with a nominal vertical profile, up to and including 4.5° for Category A and B aeroplanes, or 3.77° for Category C and D aeroplanes, where the facilities are non-directional beacon (NDB), NDB/distance measuring equipment (DME), VHF omnidirectional radio range (VOR), VOR/DME, localiser (LOC), LOC/DME, VHF direction finder (VDF), surveillance radar approach (SRA) or global navigation satellite system (GNSS)/lateral navigation (LNAV), with a final approach segment of at least 3 NM, which also fulfil the following criteria:

      (i) the final approach track is offset by not more than 15° for Category A and B aeroplanes or by not more than 5° for Category C and D aeroplanes;

      (ii) the final approach fix (FAF) or another appropriate fix where descent is initiated is available, or distance to threshold (THR) is available by flight management system (FMS)/area navigation (NDB/DME) or DME; and

      (iii) the missed approach point (MAPt) is determined by timing, the distance from FAF to THR is ≤ 8 NM.

    (3) Instrument approaches where the facilities are NDB, NDB/DME, VOR, VOR/DME, LOC, LOC/DME, VDF, SRA or GNSS/LNAV, not fulfilling the criteria in (a)(2), or with an minimum descent height (MDH) ≥ 1 200 ft.

(b) The missed approach operation, after an approach operation has been flown using the CDFA technique, should be executed when reaching the decision height/altitude (DH/A) or the MAPt, whichever occurs first. The lateral part of the missed approach procedure should be flown via the MAPt unless otherwise stated on the approach chart.

The text below will replace the text above on 30 October 2025:

DETERMINATION OF DH/MDH FOR INSTRUMENT APPROACH OPERATIONS — AEROPLANES

  1. The decision height (DH) to be used for a 3D approach operation or a 2D approach operation flown using the continuous descent final approach (CDFA) technique should not be lower than the highest of:

    1. the obstacle clearance height (OCH) for the category of aircraft used;

    2. the published approach procedure DH or minimum descent height (MDH) where applicable;

    3. the system minima specified in Table 4;

    4. the minimum DH permitted for the runway specified in Table 5; or

    5. the minimum DH specified in the AFM or equivalent document, if stated.

  2. The MDH for a 2D approach operation flown not using the CDFA technique should not be lower than the highest of:

    1. the OCH for the category of aircraft used;

    2. the published approach procedure MDH where applicable;

    3. the system minima specified in Table 4;

    4. the lowest MDH permitted for the runway specified in Table 5; or

    5. the lowest MDH specified in the AFM, if stated.

DETERMINATION OF DH/MDH FOR INSTRUMENT APPROACH OPERATIONS — HELICOPTERS

  1. The DH or MDH should not be lower than the highest of:

    1. the OCH for the category of aircraft used;

    2. the published approach procedure DH or MDH where applicable;

    3. the system minima specified in Table 4;

    4. the lowest DH or MDH permitted for the runway/FATO specified in Table 6 if applicable; or

    5. the lowest DH or MDH specified in the AFM, if stated.

Table 4

System minima — all aircraft

Facility Lowest DH/MDH (ft)
ILS/MLS/GLS 200
GNSS/SBAS (LPV) 200*
Precision approach radar (PAR) 200
GNSS/SBAS (LP) 250
GNSS (LNAV) 250
GNSS/Baro VNAV (LNAV/VNAV) 250
Helicopter PinS approach 250**
LOC with or without DME 250
SRA (terminating at ½ NM) 250
SRA (terminating at 1 NM 300
SRA (terminating at 2 NM or more) 350
VOR 300
VOR/DME 250
NDB 350
NDB/DME 300
VDF 350

* For localiser performance with vertical guidance (LPV), a DH of 200 ft may be used only if the published final approach segment (FAS) datablock sets a vertical alert limit not exceeding 35 m. Otherwise, the DH should not be lower than 250 ft.

** For PinS approaches with instructions to ‘proceed VFR’ to an undefined or virtual destination, the DH or MDH should be with reference to the ground below the MAPt.

Table 5

Runway type minima — aeroplanes

Runway type Lowest DH/MDH (ft)
Precision approach (PA) runway, category I 200
NPA runway 250
Non-instrument runway Circling minima as shown in Table 1 in NCC.OP.112

Table 6

Type of runway/FATO versus lowest DH/MDH — helicopters

Type of runway/FATO Lowest DH/MDH (ft)
PA runway, category I 200
NPA runway 200
Non-instrument runway 200
Instrument FATO 200
FATO 250

Table 6 does not apply to helicopter PinS approaches with instructions to ‘proceed VFR’.