NCC.OP.110 Aerodrome operating minima — general

COMMERCIALLY AVAILABLE INFORMATION An acceptable method of specifying aerodrome operating minima is through the use of commercially available information.

GENERAL

(a)The aerodrome operating minima should not be lower than the values given in NCC.OP.111 or AMC3 NCC.OP.110(c).

(b)Whenever practical approaches should be flown as stabilised approaches (SAps). Different procedures may be used for a particular approach to a particular runway.

(c)Whenever practical, non-precision approaches should be flown using the continuous descent final approach (CDFA) technique. Different procedures may be used for a particular approach to a particular runway.

(d)For approaches not flown using the CDFA technique: when calculating the minima in accordance with NCC.OP.111, the applicable minimum runway visual range (RVR) should be increased by 200 m for Category A and B aeroplanes and by 400 m for Category C and D aeroplanes, provided the resulting RVR/converted meteorological visibility (CMV) value does not exceed 5 000 m. SAp or CDFA should be used as soon as facilities are improved to allow these techniques.

TAKE-OFF OPERATIONS

(a)General

(1)Take-off minima should be expressed as VIS or RVR limits, taking into account all relevant factors for each aerodrome planned to be used and aircraft characteristics and equipment. Where there is a specific need to see and avoid obstacles on departure and/or for a forced landing, additional conditions, e.g. ceiling, should be specified.

(2)The pilot-in-command should not commence take-off unless the weather conditions at the aerodrome of departure are equal to or better than applicable minima for landing at that aerodrome, unless a weather-permissible take-off alternate aerodrome is available.

(3)When the reported VIS is below that required for take-off and the RVR is not reported, a take-off should only be commenced if the pilot-in-command can determine that the visibility along the take-off runway/area is equal to or better than the required minimum.

(4)When no reported VIS or RVR is available, a take-off should only be commenced if the pilot-in-command can determine that the visibility along the take-off runway/area is equal to or better than the required minimum.

(b)Visual reference

(1)The take-off minima should be selected to ensure sufficient guidance to control the aircraft in the event of both a rejected take-off in adverse circumstances and a continued take-off after failure of the critical engine.

(2)For night operations, the prescribed runway lights should be in operation to mark the runway and any obstacles.

(c)Required RVR or VIS

(1)Aeroplanes

(i)For multi-engined aeroplanes, with such performance that in the event of a critical engine failure at any point during take-off the aeroplane can either stop or continue the take-off to a height of 1 500 ft above the aerodrome while clearing obstacles by the required margins, the take-off minima specified by the operator should be expressed as RVR or VIS values not lower than those specified in Table 1.

(ii)Multi-engined aeroplanes without the performance to comply with the conditions in (c)(1)(i) in the event of a critical engine failure may need to re-land immediately and to see and avoid obstacles in the take-off area. Such aeroplanes may be operated to the following take-off minima provided that they are able to comply with the applicable obstacle clearance criteria, assuming engine failure at the specified height:

(A)The take-off minima specified by the operator should be based on the height from which the one-engine-inoperative (OEI) net take-off flight path can be constructed.

(B)The RVR minima used should not be lower than either of the values specified in Table 1 or Table 2.

(iii)For single-engined complex aeroplane operations, the take-off minima specified by the operator should be expressed as RVR/CMV values not lower than those specified in Table 1 below. Unless the operator is using a risk period, whenever the surface in front of the runway does not allow for a safe forced landing, the RVR values should not be lower than 800 m. In this case, the proportion of the flight to be considered starts at the lift-off position and ends when the aeroplane is able to turn back and land on the runway in the opposite direction or glide to the next landing site in case of power loss.

(iv)When the RVR or the VIS is not available, the commander should not commence take-off unless he or she can determine that the actual conditions satisfy the applicable take-off minima. Table 1 Take-off — aeroplanes (without LVTO approval) RVR or VIS

* The reported RVR or VIS value representative of the initial part of the take-off run can be replaced by pilot assessment. ** The pilot is able to continuously identify the take-off surface and maintain directional control.

Table 2 Take-off — aeroplanes (without LVTO approval) Assumed engine failure height above the runway versus RVR or VIS

* The reported RVR or VIS value representative of the initial part of the take-off run can be replaced by pilot assessment.

(2)Helicopters

(i)For helicopters having a mass where it is possible to reject the take-off and land on the FATO in case of the critical engine failure being recognised at or before the take-off decision point (TDP), the operator should specify an RVR or VIS as takeoff minima in accordance with Table 3.

(ii)For all other cases, the pilot-in-command should operate to take-off minima of 800 m RVR or VIS and remain clear of cloud during the take-off manoeuvre until reaching the performance capabilities of (c)(2)(i).

(iii)For point-in-space (PinS) departures to an initial departure fix (IDF), the takeoff minima should be selected to ensure sufficient guidance to see and avoid obstacles and return to the heliport if the flight cannot continue visually to the IDF.

Table 3 Take-off — helicopters (without LVTO approval) RVR or VIS

* The take-off flight path to be free of obstacles. ** On PinS departures to IDF, VIS should not be less than 800 m and the ceiling should not be less than 250 ft.

DETERMINATION OF DH/MDH FOR INSTRUMENT APPROACH OPERATIONS — AEROPLANES

(a)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;

(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.

(b)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;

(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

(c)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

* 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

Table 6 Type of runway/FATO versus lowest DH/MDH — helicopters

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

DETERMINATION OF RVR OR VIS FOR INSTRUMENT APPROACH OPERATIONS — AEROPLANES

(a)The RVR or VIS for straight-in instrument approach operations should not be less than the greatest of the following:

(1)the minimum RVR or VIS for the type of runway used according to Table 7; or

(2)the minimum RVR determined according to the MDH or DH and class of lighting facility according to Table 8; or

(3)the minimum RVR according to the visual and non-visual aids and on-board equipment used according to Table 9. If the value determined in (1) is a VIS, then the result is a minimum VIS. In all other cases, the result is a minimum RVR.

(b)For Category A and B aeroplanes, if the RVR or VIS determined in accordance with point (a) is greater than 1 500 m, then 1 500 m should be used.

(c)If the approach is flown with a level flight segment at or above the MDA/H, then 200 m should be added to the RVR calculated in accordance with (a) and (b) for Category A and B aeroplanes and 400 m for Category C and D aeroplanes.

(d)The visual aids should comprise standard runway day markings, runway edge lights, threshold lights, runway end lights and approach lights as defined in Table 10. Table 7 Type of runway versus minimum RVR or VIS — aeroplanes

Table 8 RVR versus DH/MDH

Table 9 Visual and non-visual aids and/or on-board equipment versus minimum RVR — aeroplanes

Table 10 Approach lighting systems — aeroplanes

(e)For night operations or for any operation where credit for visual aids is required, the lights should be on and serviceable except as provided for in Table 15.

(f)Where any visual or non-visual aid specified for the approach and assumed to be available in the determination of operating minima is unavailable, revised operating minima will need to be determined.

DETERMINATION OF RVR OR VIS FOR TYPE A INSTRUMENT APPROACH AND TYPE B CAT I INSTRUMENT APPROACH OPERATIONS — HELICOPTERS

(a)For IFR operations, the RVR or VIS should not be less than the greatest of:

(1)the minimum RVR or VIS for the type of runway/FATO used according to Table 11;

(2)the minimum RVR determined according to the MDH or DH and class of lighting facility according to Table 12; or

(3)for PinS operations with instructions to ‘proceed visually’, the distance between the MAPt of the PinS and the FATO or its approach light system. If the value determined in (1) is a VIS, then the result is a minimum VIS. In all other cases, the result is a minimum RVR.

(b)For PinS operations with instructions to ‘proceed VFR’, the VIS should be compatible with visual flight rules.

(c)For type A instrument approaches where the MAPt is within ½ NM of the landing threshold, the approach minima specified for FALS may be used regardless of the length of approach lights available. However, FATO/runway edge lights, threshold lights, end lights and FATO/runway markings are still required.

(d)An RVR of less than 800 m should not be used except when using a suitable autopilot coupled to an ILS, MLS, GLS or LPV, in which case normal minima apply.

(e)For night operations, ground lights should be available to illuminate the FATO/runway and any obstacles.

(f)The visual aids should comprise standard runway day markings, runway edge lights, threshold lights and runway end lights and approach lights as specified in Table 13.

(g)For night operations or for any operation where credit for runway and approach lights as defined in Table 13 is required, the lights should be on and serviceable except as provided for in Table 15. Table 11 Type of runway/FATO versus minimum RVR or VIS — helicopters

Table 12 Onshore helicopter instrument approach minima

* Minima on 2D approach operations should be no lower than 800 m.

Table 13 Approach lighting systems — helicopters

VISUAL APPROACH OPERATIONS For a visual approach operation the RVR should not be less than 800 m.

CONVERSION OF VISIBILITY TO CMV — AEROPLANES The following conditions should apply to the use of CMV instead of RVR:

(a)If the reported RVR is not available, a CMV may be substituted for the RVR, except:

(1)to satisfy take-off minima; or

(2)for the purpose of continuation of an approach in LVO.

(b)If the minimum RVR for an approach is more than the maximum value assessed by the aerodrome operator, then CMV should be used.

(c)In order to determine CMV from visibility:

(1)for flight planning purposes, a factor of 1.0 should be used;

(2)for purposes other than flight planning, the conversion factors specified in Table 14 should be used.

Table 14 Conversion of reported VIS to CMV

EFFECT ON LANDING MINIMA OF TEMPORARILY FAILED OR DOWNGRADED GROUND EQUIPMENT

(a)General These instructions are intended for both pre-flight and in-flight use. It is, however, not expected that the pilot-in-command would consult such instructions after passing 1 000 ft above the aerodrome. If failures of ground aids are announced at such a late stage, the approach could be continued at the pilot-in-command’s discretion. If failures are announced before such a late stage in the approach, their effect on the approach should be considered as described in Table 15 and, if considered necessary, the approach should be abandoned.

(b)Conditions applicable to Table 15:

(1)multiple failures of runway/FATO lights other than those indicated in Table 15 should not be acceptable;

(2)failures of approach and runway/FATO lights are acceptable at the same time, and the most demanding consequence should be applied; and

(3)failures other than ILS, GLS, or MLS affect RVR only and not DH.

Table 15 Failed or downgraded equipment — effect on landing minima

AIRCRAFT CATEGORIES

(a)Aircraft categories should be based on the indicated airspeed at threshold (VAT), which is equal to the stalling speed (VSO) multiplied by 1.3 or where published 1-g (gravity) stall speed (VS1g) multiplied by 1.23 in the landing configuration at the maximum certified landing mass. If both VSO and VS1g are available, the higher resulting VAT should be used.

(b)The aircraft categories specified in the following table should be used.

Table 16 Aircraft categories corresponding to VAT values

CONTINUOUS DESCENT FINAL APPROACH (CDFA) — AEROPLANES

(a)Introduction

(1)Controlled flight into terrain (CFIT) is a major hazard in aviation. Most CFIT accidents occur in the final approach segment of non-precision approaches; the use of stabilised-approach criteria on a continuous descent with a constant, predetermined vertical path is seen as a major improvement in safety during the conduct of such approaches. Operators should ensure that the following techniques are adopted as widely as possible, for all approaches.

(2)The elimination of level flight segments at MDA close to the ground during approaches, and the avoidance of major changes in attitude and power/thrust close to the runway that can destabilise approaches, are seen as ways to reduce operational risks significantly.

(3)The term CDFA has been selected to cover a flight technique for any type of NPA operation.

(4)The advantages of CDFA are as follows:

(i)the technique enhances safe approach operations by the utilisation of standard operating practices;

(ii)the technique is similar to that used when flying an ILS approach, including when executing the missed approach and the associated missed approach procedure manoeuvre;

(iii)the aeroplane attitude may enable better acquisition of visual cues;

(iv)the technique may reduce pilot workload;

(v)the approach profile is fuel-efficient;

(vi)the approach profile affords reduced noise levels;

(vii)the technique affords procedural integration with APV operations; and

(viii)when used and the approach is flown in a stabilised manner, CDFA is the safest approach technique for all NPA operations.

(b)CDFA

(1)Continuous descent final approach is defined in Annex I to the Regulation on Air Operations.

(2)An approach is only suitable for application of a CDFA technique when it is flown along a nominal vertical profile; a nominal vertical profile is not forming part of the approach procedure design, but can be flown as a continuous descent. The nominal vertical profile information may be published or displayed on the approach chart to the pilot by depicting the nominal slope or range/distance vs. height. Approaches with a nominal vertical profile are considered to be:

(i)NDB, NDB/DME (non-directional beacon/distance measuring equipment);

(ii)VOR (VHF omnidirectional radio range), VOR/DME;

(iii)LOC (localiser), LOC/DME;

(iv)VDF (VHF direction finder), SRA (surveillance radar approach); or

(v)GNSS/LNAV (global navigation satellite system/lateral navigation);

(3)Stabilised approach (SAp) is defined in Annex I to the Regulation on Air Operations.

(i)The control of the descent path is not the only consideration when using the CDFA technique. Control of the aeroplane’s configuration and energy is also vital to the safe conduct of an approach.

(ii)The control of the flight path, described above as one of the requirements for conducting an SAp, should not be confused with the path requirements for using the CDFA technique. The predetermined path requirements for conducting an SAp are established by the operator and published in the operations manual part B.

(iii)The predetermined approach slope requirements for applying the CDFA technique are established by the following:

(A)the published ‘nominal’ slope information when the approach has a nominal vertical profile; and

(B)the designated final approach segment minimum of 3 NM, and maximum, when using timing techniques, of 8 NM.

(iv)An SAp will never have any level segment of flight at DA/H or MDA/H, as applicable. This enhances safety by mandating a prompt missed approach procedure manoeuvre at DA/H or MDA/H.

(v)An approach using the CDFA technique will always be flown as an SAp, since this is a requirement for applying CDFA. However, an SAp does not have to be flown using the CDFA technique, for example a visual approach.

TAKE-OFF MINIMA — HELICOPTERS To ensure sufficient control of the helicopter in IMC, the speed, before entering in IMC, should be above the minimum authorised speed in IMC, Vmini. This is a limitation in the AFM. Therefore, the lowest speed before entering in IMC is the highest of Vtoss (take-off safety speed) and Vmini. As example, Vtoss is 45 kt and Vmini 60 kt. In that case, the take–off minima have to include the distance to accelerate to 60 kt. The take-off distance should be increased accordingly.

APPROACH LIGHTING SYSTEMS — ICAO AND FAA SPECIFICATIONS The following table provides a comparison of the ICAO and FAA specifications. Table 17 Approach lighting systems — ICAO and FAA specifications

SBAS OPERATIONS

(a)SBAS LPV operations with a DH of 200 ft depend on an SBAS approved for operations down to a DH of 200 ft.

(b)The following systems are in operational use or in a planning phase:

(1)European geostationary navigation overlay service (EGNOS), operational in Europe;

(2)wide area augmentation system (WAAS), operational in the USA;

(3)multi-functional satellite augmentation system (MSAS), operational in Japan;

(4)system of differential correction and monitoring (SDCM), planned by Russia;

(5)GPS-aided geo-augmented navigation (GAGAN) system, planned by India; and

(6)satellite navigation augmentation system (SNAS), planned by China.

MEANS TO DETERMINE THE REQUIRED RVR BASED ON DH AND LIGHTING FACILITIES The values in Table 8 are derived from the formula below: RVR (m) = [(DH/MDH (ft) x 0.3048)/tanα] — length of approach lights (m), where α is the calculation angle, being a default value of 3.00° increasing in steps of 0.10° for each line in Table 8 up to 3.77° and then remaining constant. An upper RVR limit of 2 400 m has been applied to the table.

USE OF DH FOR NPAs FLOWN USING THE CDFA TECHNIQUE The safety of the use of MDH as DH in CDFA operations has been verified by at least two independent analyses concluding that a CDFA using MDH as DH without any add-on is safer than the traditional step-down and level flight NPA operation. A comparison was made between the safety level of using MDH as DH without an add-on with the well-established safety level resulting from the ILS collision risk model (CRM). The NPA used was the most demanding, i.e. most tightly designed NPA, which offers the least additional margins. It should be noted that the design limits of the ILS approach design, e.g. the maximum glide path (GP) angle of 3,5 degrees, must be observed for the CDFA in order to keep the validity of the comparison. There is a wealth of operational experience in Europe confirming the above-mentioned analytical assessments. It cannot be expected that each operator is able to conduct similar safety assessments, and this is not necessary. The safety assessments already performed take into account the most demanding circumstances at hand, like the most tightly designed NPA procedures and other ‘worstcase scenarios’. The assessments naturally focus on cases where the controlling obstacle is located in the missed approach area. However, it is necessary for operators to assess whether their cockpit procedures and training are adequate to ensure minimal height loss in case of a go-around manoeuvre. Suitable topics for the safety assessment required by each operator may include: understanding of the CDFA concept including use of the MDA/H as DA/H; cockpit procedures that ensure flight on speed, on path and with proper configuration and energy management; cockpit procedures that ensure gradual decision-making; and identification of cases where an increase of the DA/H may be necessary because of non-standard circumstances, etc.

INCREMENTS SPECIFIED BY THE COMPETENT AUTHORITY Additional increments to the published minima may be specified by the competent authority to take into account certain operations, such as downwind approaches, single-pilot operations or approaches flown not using the CDFA technique.

USE OF COMMERCIALLY AVAILABLE INFORMATION When an operator uses commercially available information to establish aerodrome operating minima, the operator remains responsible for ensuring that the material used is accurate and suitable for its operation, and that the aerodrome operating minima are calculated in accordance with the method specified in Part C of its operations manual. The operator should apply the procedures in ORO.GEN.205 ‘Contracted activities’.

VISUAL AND NON-VISUAL AIDS AND INFRASTRUCTURE ‘Visual and non-visual aids and infrastructure’ refers to all equipment and facilities required for the procedure to be used for the intended instrument approach operation. This includes but is not limited to lights, markings, ground- or space-based radio aids, etc.