SPA.LVO.100 Low-visibility operations and operations with operational credits

DOCUMENTS CONTAINING INFORMATION RELATED TO LVOs and OPERATIONS WITH OPERATIONAL CREDITS The following documents provide further information related to low-visibility operations (LVOs):

(a)ICAO Annex 2 — Rules of the Air;

(b)ICAO Annex 6 — Operation of Aircraft;

(c)ICAO Annex 10 — Aeronautical Telecommunications (Volume I — Radio Navigation Aids);

(d)ICAO Annex 14 — Aerodromes (Volume I — Aerodrome Design and Operations);

(e)ICAO Doc 8168 — PANS - OPS — Procedures For Air Navigation Services — Aircraft Operations;

(f)ICAO Doc 9365 — Manual of All-Weather Operations;

(g)ICAO Doc 9476 — Manual of surface movement guidance and control systems (SMGCS);

(h)ICAO Doc 9157 — Aerodrome Design Manual;

(i)ICAO Doc 9328 — Manual of RVR Observing and Reporting Practices;

(j)ICAO EUR Doc 013 — European Guidance Material on All Weather Operations at Aerodromes;

(k)ECAC Doc 17, Issue 3; and

(l)CS-AWO All-weather operations.

ILS AND GLS CLASSIFICATION

(a)The ILS and GLS/GBAS classification systems are specified in ICAO Annex 10 and GM2 SPA.LVO.110.

LOW-VISIBILITY CONDITIONS

(b)Low visibility conditions means meteorological conditions with a runway visual range (RVR) less than 550 m.

LOW-VISIBILITY TAKE-OFF (LVTO) OPERATIONS — AEROPLANES IN AN RVR OF LESS THAN 400 M

(a)Required RVR

(1)For multi-engined aeroplanes which, in the event of a critical engine failure at any point during take-off, 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 criteria in Table 1 should apply: Table 1 LVTO operations with aeroplanes — RVR versus facilities

(2)For multi-engined aeroplanes not complying with the conditions in (a)(1), there may be a need to land immediately and to see and avoid obstacles. Such aeroplanes may be operated to the take-off minima shown in Table 2 and the marking and lighting criteria shown in Table 1, provided that they are able to comply with the applicable obstacle clearance criteria, assuming engine failure at the height specified: Table 2 LVTO operations with aeroplanes — assumed engine failure height versus RVR

(b)The reported RVR value representative of the initial part of the take-off run can be replaced by pilot assessment.

(c)The minimum RVR value specified in Table 1 or 2 should be achieved for all reporting points representative of the parts of the runway from the point at which the aircraft commences the take-off until the calculated accelerate-stop distance from that point. LVTO OPERATIONS — AEROPLANES IN AN RVR OF LESS THAN 125 M

(d)For LVTO operations with an RVR of less than 125 m, the following additional elements should apply:

(1)The runway has centre line lights spaced at intervals of 15 m or less;

(2)If an ILS signal is used for lateral guidance, the ILS localiser signal meets the requirements for category III operations, unless otherwise stated in the AFM;

(3)If an ILS signal is to be used, low-visibility procedures (LVPs) include protection of the runway and, where an ILS localiser signal is used, it should include protection of the ILS-sensitive area unless otherwise stated in the AFM; and

(4)If a GLS signal is used for lateral guidance, the GLS performance type meets the requirements for category III operations (GAST D and to GBAS point to which guidance is required), unless otherwise stated in the AFM.

(e)For LVTO operations with an RVR of less than 125 m, the reported RVR should be not less than the minimum specified in the AFM or, if no such minimum is specified, not less than 75 m.

(f)The minimum required RVR should be achieved for all reporting points representative of the parts of the runway from the point at which the aircraft commences the take-off until the greater of the calculated take-off distance or accelerate-stop distance from that point.

(g)The reported RVR value representative of the initial part of the take-off run can be replaced by pilot assessment.

LVTO OPERATIONS — HELICOPTERS The following should apply to LVTOs for helicopters with an RVR of less than 400 m:

(a)For take-off from onshore aerodromes or operating sites with IFR departure procedures, the criteria in Table 3 should apply: Table 3 LVTO operations with helicopters — RVR versus facilities onshore

* On PinS departures to IDF, VIS should not be less than 800 m and ceiling should not be less than 250 ft.

(b)For take-off from offshore helidecks where the take-off flight path is free of obstacles, the minimum RVR for take-off should not be less than: 500 m for single-pilot operations; or 250 m for two-pilot operations.

CLASSIFICATION OF LVTO OPERATIONS Take-off operations are classified as ‘normal take-off operations’ with an RVR at or above 550 m and ‘LVTO operations’ with an RVR below 550 m. Only LVTO operations in an RVR of less than 400 m require a specific approval.

VISUAL SEGMENT FOR TAKE-OFF The value of 125 m RVR for take-off with 15 m centre line light spacing has been selected because flight deck geometry means that this will provide at least a 90-m visual segment for the large majority of aircraft types. In a 90-m visual segment the pilot is expected to be able to see six centre line light intervals (seven centre line lights) at 15 m spacing once lined up on the runway centre line.

INSTRUMENT APPROACH OPERATIONS IN LOW-VISIBILITY CONDITIONS — CAT II OPERATIONS For CAT II operations, the following should apply:

(a)The DH should be determined by the use of a radio altimeter or other device capable of providing equivalent performance and be not lower than the highest of:

(1)the minimum DH specified in the AFM, if stated;

(2)the applicable obstacle clearance height (OCH) for the category of aircraft;

(3)the DH to which the flight crew is qualified to operate; or

(4)100 ft.

(b)The lowest RVR minima to be used are specified in Table 4: Table 4 CAT II operation minima: RVR (m) versus DH (ft)

* An RVR of 300 m may be used for a Category D aeroplane conducting an autoland or using HUDLS to touchdown.

INSTRUMENT APPROACH OPERATIONS IN LOW-VISIBILITY CONDITIONS — CAT III OPERATIONS For CAT III operations, the following should apply:

(a)For operations in which a DH is used, the DH should be determined by the use of a radio altimeter or other device capable of providing equivalent performance and be not lower than:

(1)the minimum DH specified in the AFM, if stated;

(2)the DH to which the flight crew is qualified to operate.

(b)Operations with no DH should only be conducted if:

(1)operation with no DH is specified in the AFM;

(2)there is no published information indicating that the approach aid or aerodrome facilities cannot support operations with no DH; and

(3)the flight crew is qualified to operate with no DH.

(c)The lowest RVR to be used should be determined in accordance with Table 5. Table 5 CAT III operations minima: RVR (m) versus DH (ft)

* Note: For a fail-passive or HUD roll-out control system, a lower RVR value (no lower than 75 m) can be used if stated in the AFM provided that the equipment demonstrated such capability as part of the certification process. This is provided that the operator has implemented the appropriate operating procedures and training.

INSTRUMENT APPROACH OPERATIONS IN LOW-VISIBILITY CONDITIONS — EFFECT ON LANDING MINIMA OF TEMPORARILY FAILED OR DOWNGRADED EQUIPMENT FOR APPROACH OPERATIONS

(a)Only those facilities mentioned in Table 6 should be acceptable to be used to determine the effect of temporarily failed of downgraded equipment on the required RVR for CAT II/III approach operations.

(b)The following conditions should be applied to Table 6:

(1)multiple failures of runway/FATO lights other than those indicated in Table 6 are not acceptable;

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

(3)for approach operations with a DH below 200 ft, a combination of deficiencies in runway/FATO lights and RVR assessment equipment are not permitted; and

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

Table 6 Failed or downgraded equipment — effect on landing minima CAT II/III operations

Table 7 Failed or downgraded equipment — effect on landing minima Operational credits

INSTRUMENT APPROACH OPERATIONS IN LOW-VISIBILITY CONDITIONS — CLASSIFICATION OF STANDARD APPROACH OPERATIONS The different types of approach and landing operations are classified according to the lowest DH (or MDH) and RVR applicable to the approach type. The classification of approach types does not depend on the technology used for the approach. The lowest minima specified do not take account of ‘operational credits’ that may allow for lower operating minima. The classification does not subdivide CAT III operations into CAT IIIA, IIIB, and IIIC. The actual minima applicable to any operation depends on the aircraft equipment and the specific LVO approval held by the air operator. The AFM for aircraft certified for CAT III operations will state the lowest usable DH, or no DH. Some AFMs may refer to the previous ICAO classifications as follows: CAT IIIA: a DH lower than 30 m (100 ft) or no DH and an RVR not less than 175 m; CAT IIIB: a DH lower than 15 m (50 ft) or no DH and an RVR less than 175 m but not less than 50 m; and CAT IIIC: no DH and no RVR limitations. CAT IIIC has not been used in Europe and the minimum RVR in the EU regulations is 75 m. Where an operational credit allows operation to lower-than-standard minima, this is not considered a separate approach classification.

INSTRUMENT APPROACH OPERATIONS IN LOW-VISIBILITY CONDITIONS — EQUIPMENT CERTIFICATION FOR LOW-VISIBILITY APPROACH OPERATIONS OTHER THAN EFVS This GM describes the certification requirements of CS-AWO. Operators should always refer to CSAWO for the actual requirements. Aircraft suitable for low-visibility approach operations are certified according to the minimum usable DH which is stated in the AFM. Certification specifications (CS-AWO) allow for systems to be certified for SA CAT I, CAT II or CAT III operations. Systems certified for CAT III operations may specify: a lowest usable DH of: less than 100 ft but not less than 50 ft; less than 50 ft; or no DH. Legacy systems may be described as capable of ‘CAT 3A’ or ‘CAT IIIA' operations. This implies a minimum DH of less than 100 ft but not less than 50 ft. Systems described as capable of ‘CAT 3B’ or ‘CAT IIIB’ may be certified for a DH of less than 50 ft or no DH. Operations to a DH of less than 100 ft but not less than 50 ft will typically require a fail-passive automatic landing system or a HUDLS or equivalent system. Operations to a DH of less than 50 ft will require a fail-operational landing system, a fail-passive go-around system, automatic thrust control and either automatic ground roll control or ground roll guidance using a HUDLS. For no DH operations, a fail-passive or fail-operational ground roll control system is required. The RVR required for SA CAT I, CAT II and SA CAT II approach operations is determined by the DH and the aircraft approach speed category. The RVR required for CAT III approach operations is determined by the DH and the capability of the ground-roll control system. Operations with fail-passive roll control systems require a greater RVR than operations with fail-operational ground control systems because the pilots would need to have sufficient visibility to maintain lateral control in the event of a system failure.

INSTRUMENT APPROACH OPERATIONS IN LOW-VISIBILITY CONDITIONS — ESTABLISHMENT OF MINIMUM RVR FOR APPROACH OPERATIONS WITH A DH BELOW 200 ft

(a)General

(1)When establishing minimum RVR for CAT II and CAT III operations, operators should pay attention to the following information that originates in ECAC Doc 17 3rd Edition, Subpart A. It is retained as background information and, to some extent, for historical purposes although there may be some conflict with current practices.

(2)Since the inception of precision approach and landing operations various methods have been devised for the calculation of aerodrome operating minima in terms of DH and RVR. It is a comparatively straightforward matter to establish the DH for an operation but establishing the minimum RVR to be associated with that DH so as to provide a high probability that the required visual reference will be available at that DH has been more of a problem.

(3)The methods adopted by various States to resolve the DH/RVR relationship in respect of CAT II and CAT III operations have varied considerably. In one instance there has been a simple approach that entailed the application of empirical data based on actual operating experience in a particular environment. This has given satisfactory results for application within the environment for which it was developed. In another instance a more sophisticated method was employed which utilised a fairly complex computer programme to take account of a wide range of variables. However, in the latter case, it has been found that with the improvement in the performance of visual aids, and the increased use of automatic equipment in the many different types of new aircraft, most of the variables cancel each other out and a simple tabulation can be constructed that is applicable to a wide range of aircraft. The basic principles that are observed in establishing the values in such a table are that the scale of visual reference required by a pilot at and below DH depends on the task that he/she has to carry out, and that the degree to which his/her vision is obscured depends on the obscuring medium, the general rule in fog being that it becomes more dense with increase in height. Research using flight simulation training devices (FSTDs) coupled with flight trials has shown the following:

(i)most pilots require visual contact to be established about 3 seconds above DH though it has been observed that this reduces to about 1 second when a fail-operational automatic landing system is being used;

(ii)to establish lateral position and cross-track velocity most pilots need to see not less than a three light segment of the centre line of the approach lights, or runway centre line, or runway edge lights;

(iii)for roll guidance most pilots need to see a lateral element of the ground pattern, i.e. an approach light cross bar, the landing threshold, or a barrette of the touchdown zone light; and

(iv)to make an accurate adjustment to the flight path in the vertical plane, such as a flare, using purely visual cues, most pilots need to see a point on the ground which has a low or zero rate of apparent movement relative to the aircraft.

(v)With regard to fog structure, data gathered in the United Kingdom over a 20 year period have shown that in deep stable fog there is a 90 % probability that the slant visual range from eye heights higher than 15 ft above the ground will be less than the horizontal visibility at ground level, i.e. RVR. There are at present no data available to show what the relationship is between the slant visual range and RVR in other low visibility conditions such as blowing snow, dust or heavy rain, but there is some evidence in pilot reports that the lack of contrast between visual aids and the background in such conditions can produce a relationship similar to that observed in fog.

(b)CAT II operations The selection of the dimensions of the required visual segments that are used for CAT II operations is based on the following visual provisions:

(1)a visual segment of not less than 90 m will need to be in view at and below DH for pilot to be able to monitor an automatic system;

(2)a visual segment of not less than 120 m will need to be in view for a pilot to be able to maintain the roll attitude manually at and below DH; and

(3)for a manual landing using only external visual cues, a visual segment of 225 m will be required at the height at which flare initiation starts in order to provide the pilot with sight of a point of low relative movement on the ground. Before using a CAT II ILS for landing, the quality of the localiser between 50 ft and touchdown should be verified.

(c)CAT III fail-passive operations

(1)CAT III operations utilising fail-passive automatic landing equipment were introduced in the late 1960s and it is desirable that the principles governing the establishment of the minimum RVR for such operations be dealt with in some detail.

(2)During an automatic landing the pilot needs to monitor the performance of the aircraft system, not in order to detect a failure that is better done by the monitoring devices built into the system, but so as to know precisely the flight situation. In the final stages the pilot should establish visual contact and, by the time the pilot reaches DH, the pilot should have checked the aircraft position relative to the approach or runway centre line lights. For this the pilot will need sight of horizontal elements (for roll reference) and part of the touchdown area. The pilot should check for lateral position and cross-track velocity and, if not within the pre-stated lateral limits, the pilot should carry out a missed approach procedure. The pilot should also check longitudinal progress and sight of the landing threshold is useful for this purpose, as is sight of the touchdown zone TDZ lights. Where a fail-operational automatic landing and roll-out system is used, it is not considered necessary for the pilot to check the lateral position and cross-track velocity, and thus it is not necessary for the visual reference requirements to include horizontal elements of the lighting system.

(3)In the event of a failure of the automatic flight guidance system below DH, there are two possible courses of action; the first is a procedure that allows the pilot to complete the landing manually if there is adequate visual reference for him/her to do so, or to initiate a missed approach procedure if there is not; the second is to make a missed approach procedure mandatory if there is a system disconnect regardless of the pilot’s assessment of the visual reference available:

(i)If the first option is selected then the overriding rule in the determination of a minimum RVR is for sufficient visual cues to be available at and below DH for the pilot to be able to carry out a manual landing. Data presented in ECAC Doc 17 showed that a minimum value of 300 m would give a high probability that the cues needed by the pilot to assess the aircraft in pitch and roll will be available and this should be the minimum RVR for this procedure.

(ii)The second option, to require a missed approach procedure to be carried out should the automatic flight-guidance system fail below DH, will permit a lower minimum RVR because the visual reference provision will be less if there is no need to provide for the possibility of a manual landing. However, this option is only acceptable if it can be shown that the probability of a system failure below DH is acceptably low. It should be recognised that the inclination of a pilot who experiences such a failure would be to continue the landing manually but the results of flight trials in actual conditions and of simulator experiments show that pilots do not always recognise that the visual cues are inadequate in such situations and present recorded data reveal that pilots’ landing performance reduces progressively as the RVR is reduced below 300 m. It should further be recognised that there is some risk in carrying out a manual missed approach procedure from below 50 ft in very low visibility and it should therefore be accepted that if an RVR lower than 300 m is to be approved, the flight deck procedure should not normally allow the pilot to continue the landing manually in such conditions and the aircraft system should be sufficiently reliable for the missed approach procedure rate to be low.

(4)These criteria may be relaxed in the case of an aircraft with a fail-passive automatic landing system that is supplemented by a head-up display that does not qualify as a fail-operational system but that gives guidance that will enable the pilot to complete a landing in the event of a failure of the automatic landing system. In this case it is not necessary to make a missed approach procedure mandatory in the event of a failure of the automatic landing system when the RVR is less than 300 m.

(d)CAT III fail-operational operations - with a DH

(1)For CAT III operations utilising a fail-operational landing system with a DH, a pilot should be able to see at least one centre line light.

(2)For CAT III operations utilising a fail-operational hybrid landing system with a DH, a pilot should have a visual reference containing a segment of at least three consecutive lights of the runway centre line lights.

(e)CAT III fail operational operations - with no DH

(1)For CAT III operations with no DH the pilot is not required to see the runway prior to touchdown. The permitted RVR is dependent on the level of aircraft equipment.

(2)A CAT III runway may be assumed to support operations with no DH unless specifically restricted as published in the AIP or NOTAM.

INSTRUMENT APPROACH OPERATIONS IN LOW-VISIBILITY CONDITIONS — EFFECT ON LANDING MINIMA OF TEMPORARILY FAILED OR DOWNGRADED EQUIPMENT FOR APPROACH OPERATIONS The instructions for the effect on landing minima of temporarily failed or downgraded equipment are intended for use both before flight and during flight. It is, however, not expected that the pilot-in-command/commander 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/commander’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 6, and the approach may have to be abandoned.

OPERATIONS WITH OPERATIONAL CREDITS — SPECIAL AUTHORISATION CATEGORY I (SA CAT I) For special authorisation category I (SA CAT I) operations, the following should apply:

(a)The DH of an SA CAT I operation should not be lower than the highest of:

(1)the minimum DH specified in the AFM, if stated;

(2)the applicable OCH for the category of aeroplane;

(3)the DH to which the flight crew is qualified to operate; or

(4)150 ft.

(b)Where the DH for an SA CAT I operation is less than 200 ft, it should be determined by the use of a radio altimeter or other device capable of providing equivalent performance.

(c)The following visual aids should be available:

(1)approach lights as specified in Table 8;

(2)precision approach (PA) runway markings;

(3)category I runway lights.

(d)The lowest RVR should not be lower than the higher of:

(1)the minimum RVR specified in the AFM, if stated; or

(2)the RVR specified in Table 8. Table 8 SA CAT I operation minima RVR (m) versus approach lighting system

Note: For class of approach lighting facility, see GM2 CAT.OP.MPA.110.

OPERATIONS WITH OPERATIONAL CREDITS — SPECIAL AUTHORISATION CATEGORY II (SA CAT II) For special authorisation category II (SA CAT II) operations, the following should apply:

(a)The DH should be determined by the use of a radio altimeter or other device capable of providing equivalent performance, if so determined by the aircraft certification process, and be not lower than the highest of:

(1)the minimum DH specified in the AFM, if stated;

(2)the applicable OCH for the category of aeroplane;

(3)the DH to which the flight crew is qualified to operate; or

(4)100 ft.

(b)The following visual aids should be available:

(1)approach lights as specified in Table 9;

(2)precision approach runway markings;

(3)category I runway lights.

(c)The lowest RVR minima to be used are specified in Table 9: Table 9 SA CAT II operation minima: RVR (m) versus DH (ft)

OPERATIONS WITH OPERATIONAL CREDITS — EFVS OPERATIONS TO A RUNWAY When conducting EFVS operations to a runway:

(a)the DA/H used should be the same as for operations without EFVS;

(b)the lowest RVR minima to be used should be determined:

(1)in accordance with criteria specified in the AFM for the expected weather conditions; or

(2)if no such criteria are specified, by reducing the RVR determined for operation without the use of EFVS/CVS in accordance with Table 10;

(c)where the lowest RVR to be used, determined in accordance with (b), is less than 550 m, then this should be increased to 550 m unless LVPs are established at the aerodrome of intended landing;

(d)where the EFVS is part of a CVS, it is only the EFVS element that should provide the operational credits. The other part of the CVS, the synthetic vision system (SVS), should not provide operational credits. Table 10 Operations using EFVS/CVS — RVR/CMV reduction

OPERATIONS WITH OPERATIONAL CREDITS — HELICOPTER SPECIAL AUTHORISATION CATEGORY I (HELI SA CAT I) OPERATIONS For HELI SA CAT I operations, the following should apply:

(a)HELI SA CAT I operations should only be conducted to a runway with an approach lighting system. The following visual aids should be available:

(1)standard runway day markings, approach lights, runway edge lights, threshold lights, and runway end lights;

(2)for operations with an RVR below 450 m, runway centre line markings.

(b)An ILS/MLS that supports a HELI SA CAT I operation should be an unrestricted facility.

(c)The helicopter should be:

(1)equipped with a 3-axis autopilot capable of flying the approach to the minima;

(2)able to maintain Vy in IMC on a coupled Type B approach;

(3)equipped with a radio altimeter or other device capable of providing equivalent performance; and

(4)equipped with two independent navigation aids capable of Type B CAT I approaches and certified for CAT I.

(d)The DH of a HELI SA CAT I operation should not be lower than the highest of:

(1)the minimum DH specified in the AFM, if stated;

(2)the minimum height to which the PA aid can be used without the specified visual reference;

(3)the applicable OCH for Category A aeroplanes or the OCH for Category H if available;

(4)the DH to which the flight crew is qualified to operate;

(5)130 ft on a CAT II landing system;

(6)150 ft on a CAT I ILS certified to Class I/C/1 or MLS certified to 100 ft/E/1; or

(7)200 ft on other landing systems;

(8)200 ft unless the autopilot is a 4-axis autopilot with automatic level-off capability.

(e)The lowest RVR minima to be used are specified in Table 11. Table 11 HELI SA CAT I operation minima

(f)Operations

(1)The minimum crew should be two pilots or one pilot and a technical crew member. The technical crew member should be seated in the front seat and be allocated no other task than assisting the pilot, from the initial approach fix (IAF) onwards.

(2)On a CAT II landing system, the flight crew should use the radio altimeter or other equivalent device for the determination of the DH.

(3)On a CAT I ILS, the flight crew should use the altimeter for the determination of the DH. The crew should cross-check the altitude with the radio altimeter or equivalent device, considering the local geography.

(4)The AFCS and radio altimeter should be serviceable prior to commencing the approach.

(5)The approach should be flown in coupled 4-axis mode down to minima or below.

(6)The flight crew should promptly initiate a go-around if any of the following conditions are met below a 1 000-ft height:

(i)discrepancy in altitude/radio altitude information;

(ii)discrepancy in navigation information;

(iii)partial or total failure of an AFCS system or navigation system;

(iv)deviation of ¼ scale or more on the landing system navigation display.

(7)The planning minima at the alternate where a HELI SA CAT I approach is envisaged should be as defined in Table 12. Table 12 Planning minima at the alternate with HELI SA CAT I operations

* The higher of the usable DA/H or MDA/H. ** The higher of the usable RVR or VIS. *** Compliance with CAT.OP.MPA.192(d) should be ensured.

(8)Under commercial air transport, if no other alternate is selected and the weather forecast at destination is not based on Part-MET of Regulation (EU) 2017/373, the planning minima at the alternate where a HELI SA CAT I approach is envisaged should be as defined in Table 13. Table 13 Planning minima at the alternate with HELI SA CAT I operations with alternative weather source at destination

* The higher of the usable DA/H or MDA/H. ** The higher of the usable RVR or VIS. *** Compliance with CAT.OP.MPA.192(d) should be ensured.

(g)Crew training and competency

(1)Under CAT, NCC and SPO, the aerodrome used for HELI SA CAT I operations should be considered as a Category C aerodrome under ORO.FC.105.

(2)A crew member should undergo training to determine the eligibility of a HELI SA CAT I approach as determined under points (a) to (c), and to determine the applicable minima under points (d) and (e).

(3)A crew member should have the relevant knowledge to implement the operating procedures described in point (f).

(4)A crew member that is involved in HELI SA CAT I operations should undergo initial and recurrent training to proficiency using a suitable FSTD, including one approach and landing and one go-around using the lowest minima defined in points (d) and (e).

(5)The recurrent training should have a validity of 6 calendar months. The validity period should be counted from the end of the month when the check was taken. When the training is undertaken within the last 3 months of the validity period, the new validity period should be counted from the previous expiry date.

(6)In addition to (5), a technical crew member that is involved in HELI SA CAT I operations should be trained to perform navigation and monitoring functions under IFR, as described under AMC3 SPA.NVIS.130(f). The training and checking should include all of the following on the given helicopter type:

(i)initial and recurrent general training;

(ii)initial and recurrent monitoring training;

(iii)initial and recurrent navigation training;

(iv)initial and recurrent aircraft/FSTD training focusing on crew cooperation with the pilot;

(v)line flying under supervision (LIFUS);

(vi)initial and recurrent operator proficiency checks, which should meet all of the following criteria:

(A)the technical crew member should complete an operator proficiency check to demonstrate competence in carrying out normal, abnormal and emergency procedures, covering the relevant aspects associated with the flight operational tasks described in the operations manual and not covered in the line check;

(B)the initial training course should include an operator proficiency check;

(C)the operator proficiency check should be valid for a given helicopter type. In order to consider an operator proficiency check to be valid for several helicopter types, the operator should demonstrate that the types are sufficiently similar from the technical crew member’s perspective;

(D)the validity period of the operator proficiency check should be 12 calendar months. The validity period should be counted from the end of the month when the check was performed. When the operator proficiency check is undertaken within the last 3 months of the validity period, the new validity period shall be counted from the original expiry date;

(E)the operator proficiency check should be conducted by a suitably qualified instructor nominated by the operator to conduct flight crew operator proficiency checks;

(vii)initial and recurrent line checks, which should meet all of the following criteria:

(A)the line check should be performed on the helicopter;

(B)the technical crew member should demonstrate competence in carrying out normal operations described in the operator’s operations manual;

(C)the line check should take place after the completion of the LIFUS;

(D)the validity period of the line check should be 12 calendar months. The validity period should be counted from the end of the month when the check was performed. When the line check is undertaken within the last 3 months of the validity period, the new validity period should be counted from the original expiry date;

(E)the line check should be conducted by a suitably qualified commander nominated by the operator;

(F)any task-specific items may be checked by a suitably qualified technical crew member nominated by the operator and trained in CRM concepts and the assessment of non-technical skills.

THE CONCEPT OF OPERATIONS WITH OPERATIONAL CREDITS For each specific class of standard take-off or approach operations, a standard combination of airborne equipment, aerodrome infrastructure and equipment, and procedures (system components) needs to be available to ensure the required performance of the total system. In real-life operations, one or more system components may exceed the required standard performance. The aim of the concept of operations with operational credits is to exploit such enhanced performance to provide operational flexibility beyond the limits of standard operations. In certain circumstances it may be possible to achieve the required system performance without some standard items being available by using other enhanced equipment or procedures. In order to apply an operational credit, it is necessary that the equipment or procedures employed mitigate effectively the shortcomings in other system components. Another application of operational credits is to use the enhanced performance of certain system components to allow operations to lower than the standard minima. For approach operations, an operational credit can be applied to the instrument or the visual segment or both. Where an operational credit allows operation to lower than standard minima, this is not considered a separate approach classification.

OPERATIONS WITH OPERATIONAL CREDITS — SPECIAL AUTHORISATION CATEGORY I (SA CAT I) OPERATIONS SA CAT I is an operational credit that exploits a navigation solution with superior performance to that required for standard CAT I by extending the instrument segment of CAT I approach operations. This navigation solution may be an ILS installation with the necessary performance coupled to a suitably certified autoland system or a HUD or equivalent display system or SVGS. The extended instrument segment means that the DH can be reduced from the standard minimum of 200 down to 150 ft. The lower DH allows a corresponding reduction in the RVR required for the approach. SA CAT I is not a separate approach classification; it is an operational credit applied to a CAT I operation.

OPERATIONS WITH OPERATIONAL CREDITS — SPECIAL AUTHORISATION CATEGORY II (SA CAT II) OPERATIONS SA CAT II is an operational credit that applies to the visual segment of an approach conducted where aerodrome, runway and approach lighting systems do not meet the usual requirements for a CAT II precision lighting system. SA CAT II exploits the performance of a suitably certified HUDLS or autoland system. The DH will be the same as for standard CAT II, and the required RVR will depend on the class of light facility installed. SA CAT II is not a separate approach classification; it is an operational credit applied to a CAT II operation usually in a CAT I runway.

OPERATIONS WITH OPERATIONAL CREDITS — EFVS OPERATIONS

(a)EFVS operations, if approved, exploit the improved visibility provided by the EFVS to allow an operational credit applied to the visual segment of an instrument approach. An EFVS cannot be used to extend the instrument segment of an approach and thus the DH for operation with an EFVS is always the same as for the same approach conducted without an operational credit.

(b)EFVS operations require specific approval from the competent authority in accordance with Part-SPA. However, other EFVS operations may be conducted by operators and without a specific approval if specifically covered in accordance with Part-CAT, Part-NCC or Part-SPO (e.g. ‘EFVS 200’).

(c)Equipment for EFVS operations

(1)In order to conduct EFVS operations, a certified EFVS is used. An EFVS is an enhanced vision system (EVS) that also incorporates a flight guidance system and displays the image on a HUD or an equivalent display. The flight guidance system will incorporate aircraft flight information and flight symbology.

(2)For operations for which a minimum flight crew of more than one pilot is required, the aircraft will also be equipped with a suitable display of EFVS sensory imagery for the pilot monitoring the progress of the approach.

(3)Legacy systems may be certified as ‘EVS with an operational credit’. Such a system may be considered an EFVS used for approach (EFVS-A).

(4)Aircraft holding a type certificate issued by a third country may be certified for operations equivalent to EFVS operations. Specific approval for an operational credit for EFVS operations will be available only if the operator can demonstrate that the equipment meets all the requirements for certification in accordance with CS-AWO.

(5)For approaches for which natural visual reference is not required prior to touchdown, the EFVS (EFVS used for landing (EFVS-L)) will additionally display:

(i)flare prompt or flare guidance information; and

(ii)height AGL.

(d)Suitable approach procedures

(1)For types of approach operation, refer to AMC1 SPA.LVO.110 ‘Additional verification of the suitability of runways for EFVS operations’. EFVS operations may be used for 3D approach operations. These may include operations based on non-precision approach (NPA) procedures, approach procedures with vertical guidance and PA procedures including approach operations requiring specific approvals, provided that the operator holds the necessary approvals. An NPA procedure flown using vertical guidance from computer-generated navigation data from ground-based, space-based, self-contained navigation aids, or a combination of these may be considered a 3D instrument approach operation, so EFVSs may be used for NPA procedures provided that vertical guidance is available to the pilot.

(2)Offset approaches The extent to which EFVSs can be used for offset approaches will depend on the FOV of the specific system. Where an EFVS has been demonstrated to be usable with a final approach track offset more than 3 degrees from the runway centre line, this will be stated in the AFM. Instrument approach procedures (IAPs) may have the final approach course significantly offset from the centre line of the runway and still be considered ‘straight-in approaches’. Many approach procedures with an offset final approach course are constructed so that the final approach course crosses the runway centre line extended well out from the runway. Depending on the construction of a particular procedure, the wind conditions and the available FOV of a specific EFVS installation, the required visual references may not come into view before the aircraft reaches the DH.

(3)Circling approaches EFVSs incorporate a HUD or an equivalent system so that the EFVS image is visible in the pilot’s forward external FOV. Circling operations require the pilot to maintain visual references which may not be directly ahead of the aircraft and may not be aligned with the current flight path. EFVSs cannot therefore be used in place of natural visual reference for circling approaches.

(e)For aerodrome operating minima for EFVS operations, refer to AMC3 SPA.LVO.100(c). The performance of EFVSs depends on the technology used and weather conditions encountered. The minimum RVR for an approach is based on the specific capabilities of the installed equipment in the expected weather conditions, so the RVR for a particular operation is determined according to criteria stipulated in the AFM. Table 10 has been provided to allow calculation of an appropriate RVR for aircraft where the AFM does not contain criteria to determine the minimum usable RVR. This table has been developed after an operational evaluation of two different EVSs both using infrared sensors, along with data and support provided by the Federal Aviation Administration (FAA). Approaches were flown in a variety of conditions including fog, rain and snow showers, as well as at night to aerodromes located in mountainous terrain. Table 10 contains conservative figures to cater for the expected performance of infrared sensors in the variety of conditions that might be encountered.

(f)The conditions for commencement and continuation of the approach are in accordance with CAT.OP.MPA.305, NCC.OP.230, NCO.OP.210 and SPO.OP.215 as applicable. Pilots conducting EFVS operations may commence an approach and continue that approach below 1 000 ft above the aerodrome or into the final approach segment (FAS) if:

(1)the reported RVR or converted meteorological visibility (CMV) is equal to or greater than the lowest RVR minima determined; and

(2)all the conditions for conducting EFVS operations are met. If any equipment required for EFVS operations is unserviceable or unavailable, then the conditions for conducting EFVS operations would not be satisfied, and the approach cannot be commenced. Operators may develop procedures for flight crew to follow in the event of unserviceability arising after the aircraft descends below 1 000 ft above the aerodrome or into the FAS. Such procedures should ensure that the approach is not continued unless the RVR is sufficient for the type of approach that can be conducted with equipment that remains available. In the event of failure of the equipment required for EFVS operations, a go-around would be executed unless the RVR reported prior to commencement of the approach was sufficient for the approach to be flown without the use of EFVS in lieu of natural vision.

(g)EFVS image requirements at the DA/H are specified in AMC7 SPA.LVO.105(c). The requirements for features to be identifiable on the EFVS image in order to continue approach below DH are more stringent than the visual reference requirements for the same approach flown without EFVS. This is necessary because the EFVS might not display the colour of lights used to identify specific portions of the runway and might not consistently display the runway markings. Any visual approach path indicator using colour-coded lights may be unusable.

(h)Obstacle clearance in the visual segment The ‘visual segment’ is the portion of the approach between the DH and the runway threshold. In the case of EFVS operations, this part of the approach may be flown using the EFVS image as the primary reference and there may be obstacles that are not always identifiable on an EFVS image. Approach procedures designed in accordance with PANS-OPS criteria is required to ensure that the visual segment is protected for obstacles by the visual segment surface (VSS) that extends from 60 m before the threshold to the location of the OCH. Procedures not designed in accordance with PANS-OPS may have not been assessed for terrain or obstacle clearance below the OCH and may not provide a clear vertical path to the runway at the normally expected descent angle. SA CAT I and CAT II/III runways subject to EU aerodrome regulations are required to provide an OFZ, which offers protection from obstacles in the visual segment. Standard CAT I runways may also provide an OFZ and if not, the lack of an OFZ shall be indicated, according to ICAO Annex 4, normally on the approach chart.

(i)Visual reference requirements at minimum height to continue approach without natural visual reference For operations other than EFVS to touchdown, natural visual reference is required before landing. The objective of this requirement is to ensure that the pilot will have sufficient visual reference to land. The visual reference should be the same as the one required for the same approach flown without the use of EFVS. The specific height at which this is required will depend on the capability of the aircraft installation and will be specified in the AFM. For aircraft certified for EFVS operations but where no such height is specified in the AFM, natural visual reference is required by a height of 100 ft above the threshold elevation. Specific EFVSs may have additional requirements that must be fulfilled at this height to allow the approach to continue, such as a requirement to check that the elements of the EFVS display remain correctly aligned and scaled to the external view. Any such requirements will be detailed in the AFM.

(j)Use of EFVS to touchdown In order for the use of EFVS to touchdown to be approved, the EFVS will provide flare prompt or flare guidance (EFVS-L). This mitigates the fact that a 2D image and a narrow FOV displayed by the EFVS may cause erroneous perceptions of depth or height. The EFVS will also display height above the runway by the use of a radio altimeter or other device capable of providing equivalent performance. Unless the operator has verified that the terrain ahead of the threshold and landing system assessment area (LSAA) slope is suitable for the use of a radio altimeter, such a system should not be relied upon to provide accurate information about the height of the aircraft above the runway threshold until the aircraft is over the runway surface.

(k)Go-around A go-around will be promptly executed if the required visual references are not maintained on the EFVS image at any time after the aircraft has descended below the DA/H or if the required visual references are not distinctly visible and identifiable using natural vision after the aircraft is below the minimum height to continue approach without natural visual reference (if applicable). It is considered more likely that an operation with EFVS could result in initiation of a go-around below the DA/H than the equivalent approach flown without EFVS. According to AMC1 SPA.LVO.105(f), operators involved in EFVS operations should keep records of the number of successful and unsuccessful approaches using EFVS in order to detect and act on any undesirable trends. For category II and III PA procedures designed in accordance with PANS-OPS criteria, obstacle protection is provided for a go-around initiated below the DH (balked landing) by means of an obstacle free zone (OFZ). An OFZ may also be provided for category I PA procedures. Where an OFZ is not provided for a category I PA, this may be indicated on the approach chart. NPA procedures and approach procedures with vertical guidance provide obstacle clearance for the missed approach based on the assumption that the missed approach is executed at or above the DH. The DH should be located at or before the MAPt.

OPERATIONS WITH OPERATIONAL CREDITS — COMBINED VISION SYSTEMS A combined vision system (CVS) consisting of an EFVS and an SVS can be approved for EFVS operations if it meets all the certification requirements for an EFVS.

OPERATIONS WITH OPERATIONAL CREDITS — HELICOPTER SPECIAL AUTHORISATION CATEGORY I (HELI SA CAT I) OPERATIONS HELI SA CAT I is an operational credit that exploits a navigation solution with superior performance to that required for standard CAT I by extending the instrument segment of CAT I approach operations. This navigation solution may be an ILS installation with the necessary performance coupled to a suitably certified 3- or 4-axis autopilot capable of handling low speeds, together with the superior outside visibility of the helicopter on the visual segment, and the go-around performance of a helicopter. The better outside visibility and the lower speed allows a reduction in the RVR required for the approach, for a given DH. With a 4-axis autopilot and auto-level-off capability, the DH can also be reduced from the standard minimum of 200 ft down to 150 or 130 ft. HELI SA CAT I is not a separate approach classification; it is an operational credit applied to a CAT I operation.