CAT.OP.MPA.303 In-flight check of the landing distance at time of arrival – aeroplanes

ASSESSMENT OF THE LDTA BASED ON DISPATCH CRITERIA

(a)The required landing distance for dry runways, determined in accordance with CAT.POL.A.230(a), contains adequate margin to fulfil the intent of the assessment of the landing distance at time of arrival (LDTA) on a dry runway, as it includes allowance for the additional parameters considered in that calculation.

(b)The required landing distance for wet runways also contains adequate margin to fulfil the intent of the assessment of the LDTA on such runways with specific friction-improving characteristics, as it includes allowance for the additional parameters considered in that calculation.

(c)When at the time of arrival the runway is dry or is a wet runway with specific friction-improving characteristics and the overall conditions, including weather at the aerodrome and runway condition, have been confirmed as not changed significantly compared to those assumed at the time of dispatch, the assessment of the LDTA may be carried out by confirming that the assumptions made at the time of dispatch are still valid.

(d)Before taking any performance credit for the assessment of the LDTA for runways with friction-improving characteristics, the operator should verify that the runways intended to be operated on are maintained to the extent necessary to ensure the expected improved friction characteristics.

GENERAL The assessment of the LDTA begins with the acquisition of the latest available weather information and the RCR. The information provided in the RCR is divided in two sections:

(a)The ‘aircraft performance’ section which contains information that is directly relevant in a performance computation.

(b)The ‘situational awareness’ section which contains information that the flight crew should be aware of for a safe operation, but which does not have a direct impact on the performance assessment. The ‘aircraft performance’ section of the RCR includes a runway condition code (RWYCC), the contaminant type, depth and coverage for each third of the runway. The determination of the RWYCC is based on the use of the runway condition assessment matrix (RCAM); however, the presentation of the information in the RCAM is appropriate for use by aerodrome personnel trained and competent in assessing the runway condition in a way that is relevant to aircraft performance. It is the task of the aerodrome personnel to report the appropriate RWYCC in order to allow the flight crew to assess the landing performance characteristics of the runway in use. When no RWYCC is available in winter conditions, the RCAM provides the flight crew with a combination of the relevant information (runway surface conditions: state and/or contaminant or pilot report of braking action (AIREP)) in order to determine the RWYCC. Table 1 below is an excerpt of the RCAM and permits to carry out the primary assessment based on the reported contaminant type and depth, as well as on the OAT.

Table 1: Association between the runway surface condition and the RWYCC based on the reported contaminant type and depth and on the OAT

Note 1: Under certain conditions, frost may cause the surface to become very slippery. Note 2: Operations in conditions where less-than-poor braking action prevails are prohibited. Note 3: The runway surface temperature should preferably be used where available. A primary assessment may have to be downgraded by the aerodrome operator based on an AIREP of lower braking action than the one typically associated with the type and depth of contaminant on the runway or any other observation. Upgrading a RWYCC 5, 4, 3 or 2 determined by the aerodrome operator from the observed contaminant type is not allowed. A RWYCC 1 or 0 maybe be upgraded by the aerodrome operator to a maximum of RWYCC 3. The reason for the upgrade will be specified in the ‘situational awareness’ section of the RCR. When the aerodrome operator is approved for operations on specially prepared winter runways, in accordance with Annex V (Part-ADR.OPS) to Regulation (EU) No 139/2014, the RWYCC of a runway that is contaminated with compacted snow or ice, may be reported as RWYCC 4 depending upon a specific treatment of the runway. In such cases, the reason for the upgrade will be specified in the ‘situational awareness’ section of the RCR. When the aerodrome operator is approved for specially prepared winter runways, in accordance with Annex IV (Part-ADR.OPS) to Regulation (EU) No 139/2014, a runway that is contaminated with compacted snow or ice and has been treated according to specific procedures, will normally be reported as a maximum of RWYCC 4 SPECIALLY PREPARED WINTER RUNWAY. If the aerodrome operator is in doubt about the quality of the surface, it will be reported with a lower RWYCC, but the runway descriptor will still be SPECIALLY PREPARED WINTER RUNWAY. The term DOWNGRADED will be used in the ‘situational awareness’ section of the RCR. A SPECIALLY PREPARED WINTER RUNWAY has no loose contaminant; hence no contaminant drag on acceleration, and stopping performance corresponding to the reported RWYCC. Performance information for the assessment of the LDTA correlates the aircraft performance with the RWYCC contained in the RCR, hence the calculation will be based on the RWYCC of the intended runway of landing.

RUNWAY CONDITION CONSIDERATIONS When available for the portion of the runway that will be used for landing, the following elements are relevant for consideration:

(a)RWYCC;

(b)expected runway conditions (contaminant type and depth);

(c)other information contained in the RCR related to the following elements:

(1)width of the runway to which the RWYCC applies if less than the published runway width;

(2)reduced runway length;

(3)drifting snow on the runway;

(4)loose sand on the runway;

(5)chemical treatment on the runway;

(6)snowbanks on the runway;

(7)snowbanks on taxiways;

(8)snowbanks adjacent to the runway;

(9)taxiway conditions;

(10)apron conditions;

(11)State approved and published use of measured friction coefficient;

(12)plain language remarks;

(d)AIREP of braking action.

AIRCRAFT PERFORMANCE CONSIDERATIONS The following elements may impact landing distance calculations:

(a)runway slope;

(b)aerodrome elevation;

(c)wind;

(d)temperature;

(e)aeroplane mass and configuration;

(f)approach speed at threshold;

(g)eventual adjustments to the landing distance, such as autoland; and

(h)planned use of available and operative aeroplane ground deceleration devices.

AUTOBRAKE USAGE While autobrakes are a part of the aeroplane’s landing configuration, the landing distance assessment at the time of arrival is not intended to force a higher-than-necessary autobrake selection. For operations where the RWYCC is 6 or 5, if the manual braking distance provides at least 15 % safety margin, then the braking technique may include a combination of autobrakes and manual braking even if the selected autobrake landing data does not provide a 15 % safety margin.

GENERAL Background information and further guidance on the in-flight check of the LDTA may be found in ICAO Doc 10064 ‘Aeroplane Performance Manual’.

RCR, RWYCC AND RCAM A detailed description of the RCR format and content, the RWYCC and the RCAM may be found in Annex V (Part-ADR.OPS) to Regulation (EU) No 139/2014. Further guidance may be found in the following documents:

(a)ICAO Doc 9981 ‘PANS Aerodromes’;

(b)ICAO Doc 4444 ‘PANS ATM’;

(c)ICAO Doc 10064 ‘Aeroplane Performance Manual’; and

(d)ICAO Circular 355 ‘Assessment, Measurement and Reporting of Runway Surface Conditions’.

PERFORMANCE INFORMATION FOR THE ASSESSMENT OF THE LDTA — APPROVED DATA Approved data for the assessment of the LDTA contained in the AFM should be developed in accordance with AMC 25.1592, or equivalent. PERFORMANCE INFORMATION FOR THE ASSESSMENT OF THE LDTA — SUPPLEMENTARY DATA When approved data for the assessment of the LDTA contained in the AFM is insufficient, the content of the AFM should be supplemented with one of the following sets of data, provided by the aircraft manufacturer or the type certificate holder (TCH) or an organisation approved under Part 21 and having the relevant privileges within the scope of its organisation approval:

(a)Data for the assessment of the LDTA produced for aeroplanes not having CS 25.1592 or equivalent in their certification basis. Such data may be presented in terms of runway surface conditions, pilot-reported braking actions, or both, and should include at least:

(1)an operational airborne distance;

(2)the range of braking actions as related to the RWYCC;

(3)the effect of speed increments over threshold;

(4)the effect of temperature; and

(5)the effect of runway slope. When data is provided only in terms of pilot-reported braking actions, instructions should be provided on how to use such data to carry out an assessment of the LDTA in terms of a runway surface condition description.

(b)Data developed in accordance with FAA AC 25-32.

(c)Data for wet runways corrected to meet the criteria of LDTA, as listed under point (a), in accordance with a methodology provided by the aircraft manufacturer or the type certificate holder (TCH) or an organisation approved under Part 21 and having the relevant privileges in the scope of its organisation approval.

(d)Data for contaminated runways developed in compliance with CS 25.1591 or equivalent, which were in use before the implementation of the LDTA, and are corrected to meet the criteria of the LDTA, as listed under point (a), in accordance with a methodology provided by the aircraft manufacturer or the TCH or an organisation approved under Part 21 and having the relevant privileges within the scope of its organisation approval. PERFORMANCE INFORMATION FOR THE ASSESSMENT OF THE LDTA — DATA DETERMINED BY EASA When there is no data available for the assessment of the LDTA, performance information for the assessment of the LDTA may be determined by applying the following method:

(a)Correction factors may be applied to the certified landing distances on dry runway published in the AFM for turbojet-powered aeroplanes and turbopropeller-powered aeroplanes.

(b)For this purpose, the landing distance factors (LDFs) from Table 1 below may be used:

Table 1: LDFs

Note 1: Runway descriptors may be found in the RCAM for each RWYCC or braking action. Note 2: These LDFs apply only to modern turboprops with efficient disking drag. For older turboprops without adequate disking drag, use the LDFs for turbojet without reverse. Note 3: The LDFs can apply to any type of anti-skid system, i.e. fully-modulating, quasi-modulating or on-off system.

(1)To find the LDTA, multiply the AFM (dry, unfactored) landing distance by the applicable LDFs from Table 1 above for the runway conditions existing at the time of arrival. If the AFM landing distances are presented as factored landing distances, then that data needs to be adjusted to remove the applicable dispatch factors applied to that data before the LDFs from Table 1 above are applied. Note 1: Dispatch factors that are sometimes applied in AFMs to landing distances in order to provide factored distances to operators are not intended to be cumulated with the LDFs for the calculation of the LDTA.

(2)The LDFs given in Table 1 above include a 15 % safety margin and an air distance representative of normal operational practices. They account for variations of temperature up to international standard atmosphere (ISA) + 20 °C, runway slopes between –2 % and +2 %, and an average approach speed increment of 5 up to 20 kt. They may not be conservative for all configurations in case of unfavourable combinations of these parameters.

FLIGHT CREW TRAINING Flight crew members should be trained on the use of the RCR, on the use of performance data for the assessment of the LDTA and on reporting braking action using the AIREP format.

SYLLABUS A training syllabus should include, in addition to the requirements of Subpart FC of Annex III (ORO.FC), at least the following elements:

(a)General

(1)Contamination

(i)Definition

(ii)Contaminants which cause increased drag thus affecting acceleration, and contaminants which cause reduced braking action affecting deceleration

(iii)Slippery when wet condition

(2)Contaminated runway

(i)Runway surface condition descriptors

(ii)Operational observations with friction devices

(iii)Operator´s policy on the usage of: A. reduced take-off thrust B. reports by runway thirds

(iv)Stopway

(3)Runway condition codes

(i)RCAM A. Differences between those published for aerodromes and flight crew B. Format in use C. The use of runway friction measurements D. The use of temperature E. RWYCC F. Downgrade/upgrade criteria G. Difference between a calculation and an assessment

(ii)Braking action

(iii)Use of aircraft wind limit diagram with contamination

(4)Runway condition report

(i)Availability

(ii)Validity

(iii)Performance and situational awareness

(iv)Decoding

(v)Promulgation and reception

(5)Aeroplane control in take-off and landing

(i)Lateral control A. Windsock effect B. Effect of reversers C. Cornering forces D. Crosswind limitations (including operations when the cleared runway width is less than published

(ii)Longitudinal control A. V1 correction in correlation with minimum control speed on ground B. Aquaplaning C. Anti-skid D. Autobrake

(6)Take-off distance

(i)Acceleration and deceleration

(ii)Take-off performance limitations

(iii)Take-off distance models

(iv)Factors affecting TO distance

(v)Why to use the type and depth of contaminant instead of the RWYCC

(vi)Safety margins

(7)Landing distance

(i)Distance at time of arrival model

(ii)Factors affecting landing distance

(iii)Safety margins

(8)Exceptions

(i)States that do not comply with ICAO standards for RCR and assessment of the LDTA

(b)Flight planning

(1)Dispatch/in-flight conditions

(2)MEL/CDL items affecting take-off and landing performance

(3)Operator´s policy on variable wind and gusts

(4)Landing performance at destination and alternates

(i)Selection of alternates if an aerodrome is not available A. En-route alternates B. Destination alternates

(ii)Number of alternates

(iii)Runway condition

(c)Take-off

(1)Runway selection

(2)Take-off from a wet or contaminated runway

(d)In-flight

(1)Landing distance

(i)Distance at time of arrival calculations A. Considerations for flight crew B. Operator´s policy

(ii)Factors affecting landing distance

(iii)Runway selection for landing

(iv)Safety margins

(2)Use of aircraft systems

(i)Brakes/autobrakes

(ii)Difference between friction limited braking and different modes of autobrakes

(iii)Reversers

(e)Landing techniques

(1)Flight crew procedures and flying techniques when landing on length limited runway

(f)Safety considerations

(1)Types of errors possible

(2)Mindfulness principles to avoid biases that may lead to errors

(g)Documentation and records

(h)AIREPs

(1)Assessment of braking action

(2)Terminology

(3)Automated/aircraft-generated braking action reports, if applicable

(4)Air safety reports, if flight safety has been endangered due to insufficient braking action