335 a320 landing performance

8/22/2019 335 a320 Landing Performance

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A320 LANDING PERFORMANCE

GENERAL

FACTORED LANDING DISTANCE

The definition of the In-Flight Landing Distance is not deemed to include margins. Itassumes a stabilized approach in outside conditions consistent with the computationassumptions.In order to cover the variability in flying techniques and unexpected conditions atlanding, the flight crew should apply an appropriate margin to the in-flight landingdistances (either determined with or without failure).The Airbus recommendation is to add a margin of 15% to the in-flight landing distance.Under exceptional circumstances, the flight crew may disregard this margin.

MEL CONSIDERATIONS

Some MEL items affect the landing distance. For these items, the MEL provides acoefficient that the flight crew must apply on top of the In-Flight Landing Distance.Even in the case of an in-flight failure, the flight crew must apply the MEL coefficients ontop of the In-Flight Landing Distance.Taking the above into consideration, the flight crew should determine the landingdistance (either with or without failure) following the below general formula:

Landing distance= In-Fl ight L anding Distance x Safety Margin x MEL Coeff ic ient.

RUNWAY CONDITION ASSESSMENT MATRIX (RCAM)

The aim of the RCAM is to provide the flight crew with a combination of all availableinformation (runway condition, contaminant type, and reported braking action) in order to assess the realistic aircraft landing performance.The RCAM provides 6 braking performance levels:

‐ Good

‐ Good to Medium

‐ Medium

‐ Medium to Poor

‐ Poor

The RCAM also provides the maximum crosswind value for each braking performancelevel.

USE OF THE RCAM

In order to assess the landing performance, the flight crew determines a brakingperformance level using the RCAM.



The flight crew makes a primary assessment based on Runway Condition information(i.e. contaminant type, depth, temperature). This results in a primary brakingperformance level.Then, the flight crew downgrades this primary braking performance level, if:

A Reported Braking Action (RBA) is available and this RBA corresponds to a

lower braking performance level, Complementary information is available and is related to a possible degradation

of the Runway Condition or braking action.In any case, the flight crew must not use an RBA or any other complementaryinformation in order to upgrade a primary braking performance level that was based onRunway Condition information.

CROSSWIND CONSIDERATIONS

The maximum crosswind value that the flight crew should retain is the onecorresponding to the worse braking performance. This means that if the flight crew

downgrades the braking performance assessment after considering additionalinformation, they should also downgrade the maximum crosswind value.

NORMAL OPERATIONS PRINCIPLE

In order to assess the landing performance without failure, the flight crew should followthe three main steps described below:

1. Identify the Braking Action with the RCAM,2. Determine the VAPP by referring to the VAPP computation table without failure.3. Calculate the Landing Distance with the In-Flight Landing Distance tables

without failure.

VAPP DETERMINATION WITHOUT FAILURE

After the flight crew has determined the Braking Action with the RCAM, they shoulddetermine the Approach Speed (VAPP).

The Approach Speed (VAPP) is function of the aircraft landing weight, slats/flapsconfiguration, headwind, use of auto thrust, icing conditions and downburst.In most cases, the FMGC provides a correct VAPP value on the MCDU PERF APPRpage, when tower wind and FLAP3 or FLAP FULL landing configuration have beeninserted.

The flight crew can insert a lower VAPP in the MCDU APPR page, down to VLS, if landing is performed without A/THR, without headwind, without downburst and withouticing.The flight crew can insert a higher VAPP in case of suspected downburst, but thisincrement is limited to 15 kt above VLS. In case of strong or gusty crosswind greater than 20 kt, VAPP should be at least VLS +5 kt; the 5 kt increment above VLS may beincreased up to 15 kt at the flight crew's discretion.



VAPP is computed at predicted landing weight while the aircraft is in CRZ or DESphase, provided that the F-PLN is correctly sequenced.When the approach phase is activated, VAPP is computed using current gross weight.Managed speed should be used for final approach as it provides Ground Speed mini(GS mini) guidance even when the VAPP has been manually inserted.

Generally, the VAPP value is the sum of the VLS and the Approach Correction (APPRCOR):VAPP = VLS + APPR COR

USE OF THE TABLE FOR COMPUTING VAPP WITHOUT FAILURE

The QRH provides table for determining the VAPP without failure (In-Flight Performancechapter).The flight crew should first determine the VLS as a function of the estimated aircraftweight at landing and of the landing configuration.Then they should add the Approach Correction, which is the maximum of:

5 kt if the A/THR is ON, or

5 kt in case of ice accretion in CONF FULL10 kt in case of ice accretion in CONF 3, or

1/3 of the headwind component value reported by the ATC. (This correctionshould be limited to 15 kt).

Note: This means that when using the A/THR with ice accretion but without headwind, APPR COR equals to 5 kt.

Correction of the Landing Distance

The flight crew should take into account the effect of the aircraft ground speed atlanding (due to VAPP) in the landing distance computation by applying the SPDcorrection:

‐ If APPR COR is not due to headwind (APPR COR > 1/3 headwind component),the flight crew should apply SPD correction (SPD = APPR COR),

‐ If APPR COR is due to headwind (APPR COR = 1/3 headwind component), theflight crew should not apply SPD correction.

If the flight crew decides to increase the VAPP (in order to cover strong or gustycrosswind conditions for example), the flight crew should apply SPD correction for thelanding distance computation.

LANDING DISTANCE WITHOUT FAILURE

In order to determine the landing distance, the flight crew should refer to the landingdistance table of the QRH for the braking action that they determined with the RCAM(Dry, Good, Good to Medium, etc…). The QRH provides two tables for each braking action: one for landing in CONF FULLand one for landing in CONF 3.



REFERENCE LANDING DISTANCE

The flight crew should determine the reference landing distance (REF DIST)depending on the braking mode:

manual braking.

autobrake LOW. autobrake MED.

The QRH provides reference landing distances for:

Given aircraft weight. Landing at sea level. In ISA conditions. Without wind. On runway with no slope.

Without reverse thrust. In manual landing, and VAPP equal to the VLS of the corresponding configuration.

CORRECTIONS TO BE APPLIED TO THE REFERENCE LANDING DISTANCE

When the flight crew has determined the reference landing distance, they apply thecorrections for each parameter having an effect on the landing distance:

WEIGHT: weight correction to cover the difference between the actual landingweight and the fixed weight relative to the reference landing distance,

SPD: speed correction calculated during the VAPP determination, ALT: altitude correction to cover the landing airport elevation, WIND: tailwind correction (the headwind is not taken into account), TEMP: temperature correction for temperatures above ISA conditions, SLOPE: downward slope correction of the runway (the upward slope effect is not

taken into account), REV: reverse thrust correction to take into account the benefit of each available

thrust reverser.

ADDITIONAL CORRECTIONS

The QRH provides specific corrections to cover: The case of a landing in overweight ,and The case of a landing with the autoland.



EXAMPLE OF LANDING PERFORMANCE ASSESSMENT WITHOUTFAILURE:

• Aircraft :A320 • Runway Condition : 2 mm of slush • Reported Braking Action : Good to Medium• Runway Slope : 1% UP • Wind / OAT : 12 kt headwind / -5 °C• Airport Pressure Altitude : Sea Level • Estimated Landing Weight : 58 t • Landing Configuration : CONF FULL• Autothrust : ON • Autobrake : MED • Thrust Reversers : use of all thrust reversers

STEP 1: IDENTIFY THE BRAKING ACTION



STEP 2: DETERMINE THE VAPP



STEP 3: CALCULATE THE LANDING DISTANCE



ABNORMAL OPERATIONS

PRINCIPLE

In order to assess the landing performance with failure, the flight crew should follow the

three main steps described below:1. Identify the Braking Action with the RCAM,2. Determine the VAPP by referring to the VAPP computation table with failure.3. Calculate the Landing Distance with the In-Flight Landing Distance tables with

failure.Due to the low probability of having several in-flight failures leading to an increase of thelanding distance, the Airbus Operational Documentation for the landing performanceassessment does not address the combination of in-flight failures of different systems.

VAPP DETERMINATION WITH FAILURE

Some failures affect the approach speed: Some failures (typically slat or flap failure) increase the VLS. In this case, the

VLS displayed on the PFD (if available) takes into account the actualconfiguration,

In some others failures, it is required to fly at speed higher than VLS to improvethe handling characteristics of the aircraft. This speed increment is to be addedto the VLS displayed on the PFD when the landing configuration is reached.

In order to prepare the approach and landing, the flight crew needs to calculate theVAPP in advance.The appropriate VLS is not necessarily available at that time on the PFD, because thelanding configuration is not yet established.

As a general manner, the VAPP is the sum of the reference speed (VREF), defined asthe VLS in CONF FULL and of the effect of the fai lure on the reference speed (ΔVREF)and of the approach correction (APPR COR):

VAPP = VREF + ΔVREF + APPR COR

The Airbus recommendation is to limit the sum (ΔVREF + APPR COR) to 20 kt in order not to increase indefinitely the approach speed as it has a direct impact on the landingdistance.

As a result, for a failure, which increases the reference speed by more than 20 kt, thereis no approach correction. This also results in the display of N/A in the landing distance

tables in the column for the speed correction (SPD), since the reference landingdistance already takes into account the effect of the failure in the increased approachspeed.



USE OF THE TABLE FOR COMPUTING VAPP WITH FAILURE

The QRH provides table for determining the VAPP with failure (In-Flight Performancechapter)The flight crew should first determine the VREF as a function of the estimated aircraft

weight at landing.Then they should take into account the effect of the failure by referring to the applicablelanding distance tables which provide the ΔVREF and the FLAPS lever position for landing for each failure.Finally they should determine the approach correction (APPR COR) depending on thevalue of the ΔVREF and the FLAPS setting:

For a ΔVREF value lower than 10 kt, the flight crew should add the APPR CORvalue, which is the maximum of:

5 kt if the A/THR is ON, or

5 kt in case of ice accretion CONF FULL, or

10 kt in case of ice accretion CONF 3, or 1/3 of the headwind component value reported by the ATC. This correction

should be limited to 15 kt.Note: This means that when using the A/THR with ice accretion but without headwind,

APPR COR equals to 5 kt.

For a ΔVREF value between 10 kt and 20 kt, the flight crew should add an APPR COR value equal to 1/3 of the headwind component value reported by the ATC. This correction should be limited to 10 kt,

For a ΔVREF value greater than 20 kt, the flight crew should not add any

APPR COR.

Correction of the Landing Distance

The flight crew should take into account the effect of the aircraft ground speed atlanding (due to VAPP) in the landing distance computation by applying the SPDcorrection: If APPR COR is not due to headwind (APPR COR > 1/3 headwind component),

the flight crew should apply the SPD correction: SPD = APPR COR, If APPR COR is due to headwind (APPR COR = 1/3 headwind component), the

flight crew should not apply SPD correction.If the flight crew decides to increase the VAPP (in order to cover strong or gustycrosswind conditions for example), the flight crew should apply SPD correction for thelanding distance computation.



LANDING DISTANCE WITH FAILURE

In order to determine the landing distance, the flight crew should refer to the landingdistance table of the QRH for the aircraft system affected by the failure.For each aircraft system, the QRH provides tables for the associated braking action

(Dry, Good, Good to Medium, etc…).

REFERENCE LANDING DISTANCE

For each possible landing configuration, the tables provide the associated effect of thefailure on the reference speed (ΔVREF), which must be taken into account in the VAPP determination.

The QRH provides reference landing distances for:

Given aircraft weight. Landing at sea level.

In ISA conditions. Without wind. On runway with no slope. Without reverse thrust. In manual landing, and VAPP equal to the sum (VREF + ΔVREF).

CORRECTIONS TO BE APPLIED TO THE REFERENCE LANDING DISTANCE

When the flight crew has determined the reference landing distance, they apply thecorrections for each parameter having an effect on the landing distance:

WEIGHT: weight correction to cover the difference between the actual landingweight and the fixed weight relative to the reference landing distance,

SPD: speed correction calculated during the VAPP determination, ALT: altitude correction to cover the landing airport elevation, WIND: tailwind correction (the headwind is not taken into account), TEMP: temperature correction for temperatures above ISA conditions, SLOPE: downward slope correction of the runway (the upward slope effect is not

taken into account), REV: reverse thrust correction to take into account the benefit of each available

thrust reverser.



EXAMPLE OF LANDING PERFORMANCE ASSESSMENT WITH FAILURE

Aircraft : A320 Runway Condition : Compacted Snow Reported Braking Action : Good

Wind / OAT : 12 kt headwind / -15 °C Airport Pressure Altitude : 1 000 ft Estimated Landing Weight : 62 t

Autothrust : ON

In-Flight Failure : ENG 1 SHUTDOWN (no damage) Thrust Reversers : use of all available thrust reversers

STEP 1: IDENTIFY THE BRAKING ACTION



STEP 2: DETERMINE THE VAPP



STEP 3: CALCULATE THE LANDING DISTANCE

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335 a320 landing performance

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