Landing Distances - EASA CAT.POL.A.230
400 meter margin may sound like a lot, but is it? Those ALD performance figures are not real, they were never demonstrated properly. The aircraft manufacturer is allowed to combine the best segments from different flights: Best flare, best touch down, best braking - and add each up a combined ALD. The PERFECT (unachievable) landing, made by a test pilot, with no regard for pax comfort and probably with little fear of making a hard landing and damage to the aircraft. Probably they had perfect tires and brakes installed as well.
The International Federation of Airline Pilots has the best description of the difference between Certified and Advisory here:http://www.ifalpa.org/downloads/Leve...20aircraft.pdf
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Thank you for correcting me about the brakes. I wasn't sure hence, the "probably". The rest I wrote is however, to the best of my knowledge correct, also for the advisory (inflight) normal configuration landing distances.
305 meter (1000 feet) air distance (from 50 feet), is the only allowance I can find. Please tell what allowance is further added?
The inclusion of reverse is a disadvantage for you. That means that the reversers are already included in the calculation, and they do not provide you with additional margin.
The 15% additive is only for braking action good to poor. Not for dry and wet. Wet data is not included in my QRH, but our performance tool calculates it as dry x 1.15 (factor, not additive), not a whole lot! If we are calculating to the last meter, with good or worse braking action, I am already sipping coffee at my alternate 15% additive or not.
The advisory landing distance is "real world" with allowance for line pilot operations and the inclusion of reverse thrust and in some cases a further 15% is added.
The inclusion of reverse is a disadvantage for you. That means that the reversers are already included in the calculation, and they do not provide you with additional margin.
The 15% additive is only for braking action good to poor. Not for dry and wet. Wet data is not included in my QRH, but our performance tool calculates it as dry x 1.15 (factor, not additive), not a whole lot! If we are calculating to the last meter, with good or worse braking action, I am already sipping coffee at my alternate 15% additive or not.
My regulator has already required the 15% addition to inflight landing distance as recommended by the FAA in SAFO 06012 (hence "and in some cases a further 15% is added") as part of our OPS SPEC. So in my case we have a 15% buffer!
Landing Performance Assessments at Time of Arrival (Turbojets)
1. Purpose. This SAFO urgently recommends that operators of turbojet airplanes develop procedures for flightcrews to assess landing performance based on conditions actually existing at time of arrival, as distinct from conditions presumed at time of dispatch. Those conditions include weather, runway conditions, the airplane’s weight, and braking systems to be used. Once the actual landing distance is determined an additional safety margin of at least 15% should be added to that distance. Except under emergency conditions flightcrews should not attempt to land on runways that do not meet the assessment criteria and safety margins as specified in this SAFO.
1. Purpose. This SAFO urgently recommends that operators of turbojet airplanes develop procedures for flightcrews to assess landing performance based on conditions actually existing at time of arrival, as distinct from conditions presumed at time of dispatch. Those conditions include weather, runway conditions, the airplane’s weight, and braking systems to be used. Once the actual landing distance is determined an additional safety margin of at least 15% should be added to that distance. Except under emergency conditions flightcrews should not attempt to land on runways that do not meet the assessment criteria and safety margins as specified in this SAFO.
3. Applicability:
a. This SAFO applies to all turbojet operators under Title 14 of the Code of Federal Regulations (14 CFR) parts 121, 135, 125, and 91 subpart K. The intent of providing this information is to assist operators in developing methods of ensuring that sufficient landing distance exists to safely make a full stop landing with an acceptable safety margin on the runway to be used, in the conditions existing at the time of arrival, and with the deceleration means and airplane configuration that will be used. The FAA considers a 15% margin between the expected actual airplane landing distance and the landing distance available at the time of arrival as the minimum acceptable safety margin for normal operations.
a. This SAFO applies to all turbojet operators under Title 14 of the Code of Federal Regulations (14 CFR) parts 121, 135, 125, and 91 subpart K. The intent of providing this information is to assist operators in developing methods of ensuring that sufficient landing distance exists to safely make a full stop landing with an acceptable safety margin on the runway to be used, in the conditions existing at the time of arrival, and with the deceleration means and airplane configuration that will be used. The FAA considers a 15% margin between the expected actual airplane landing distance and the landing distance available at the time of arrival as the minimum acceptable safety margin for normal operations.
FD, your argument is flawed – “You can land safely if ALD (actual landing distance) is less than LDA - in flight calculation requirement.”
The statement assumes that have a specific definition of ‘safe’ – the process of risk management (acceptable to the authority, etc, etc, and after the event), and also that you can calculate ALD with sufficient accuracy.
Using the Boeing format for ALD, it is generally recognised that the baseline data is not consistently achievable in normal operations, thus a factor is required to provide a starting point for corrections.
The alternative OLD, provides a much more realistically achievable baseline, FOLD provides a factor, normally 15%, so that this value is a better starting point for corrections and additions.
JM, c100, it would be incorrect to consider reverse as a benefit. Certificated data does not normally include credit for reverse, only if it mests the requirements for reliability. Comparing reversers with other systems, then they are not that reliable, and don’t forget that the engine can also fail.
The 15% in the SAFO might only increase ‘actual’ data to a value that can be expected to be achieved in normal operations, i.e. similar to the distances in OLD. FOLD adds a further 15% minimum with an expectation that the crew will add more according to the landing conditons.
The statement assumes that have a specific definition of ‘safe’ – the process of risk management (acceptable to the authority, etc, etc, and after the event), and also that you can calculate ALD with sufficient accuracy.
Using the Boeing format for ALD, it is generally recognised that the baseline data is not consistently achievable in normal operations, thus a factor is required to provide a starting point for corrections.
The alternative OLD, provides a much more realistically achievable baseline, FOLD provides a factor, normally 15%, so that this value is a better starting point for corrections and additions.
JM, c100, it would be incorrect to consider reverse as a benefit. Certificated data does not normally include credit for reverse, only if it mests the requirements for reliability. Comparing reversers with other systems, then they are not that reliable, and don’t forget that the engine can also fail.
The 15% in the SAFO might only increase ‘actual’ data to a value that can be expected to be achieved in normal operations, i.e. similar to the distances in OLD. FOLD adds a further 15% minimum with an expectation that the crew will add more according to the landing conditons.
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Well congratulations for the 15% margin in USA. But this was a discussion about IR-OPS. That is the regulations of the European Union.
There is no requirement in EU or ICAO regulations to add 15% to ALD. Hence the requirement to make a near perfect (test pilot skills) landing to achieve the performance data we are provided.
There is no requirement in EU or ICAO regulations to add 15% to ALD. Hence the requirement to make a near perfect (test pilot skills) landing to achieve the performance data we are provided.
Thread Starter
Thank you CK, we do seem to be diverging slightly from the initial question.
EASA IR-OPS, normal Operations (Abnormal/Emergency situations not considered in the scope of this discussion)
EASA IR-OPS, normal Operations (Abnormal/Emergency situations not considered in the scope of this discussion)
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Pre Dispatch the factor is applied with forecast landing weight but no credit given for reversers and planned using max manual brakes... Realistically this configuration is never actually used, hence the factor to achieve operational factors.
Actual inflight distances take into account actual landing weight, actual weather and runways conditions, actual configuration used such as auto brakes instead of max manual braking and use of reverse thrust vs no reverse or idle.
If unable pre-dispatch to use destination due forecast weather conditions, two alternates are required. If during the flight conditions at destination improved a new 'dispatch' calculation can be made which may well allow landing at destination, but rather than making two calculations only inflight calculations are now required.
The 305m air distance comes from the FAA 1000' markers used. ICAO national generally have markers set at 400m, and this correction of an additional 95m should always be taken into account. Actual location of the markers can be found in the AIP for the airport/nation thus when performance is limited the actual value should be used to ensure actual distance available for calculation purposes.
Actual inflight distances take into account actual landing weight, actual weather and runways conditions, actual configuration used such as auto brakes instead of max manual braking and use of reverse thrust vs no reverse or idle.
If unable pre-dispatch to use destination due forecast weather conditions, two alternates are required. If during the flight conditions at destination improved a new 'dispatch' calculation can be made which may well allow landing at destination, but rather than making two calculations only inflight calculations are now required.
The 305m air distance comes from the FAA 1000' markers used. ICAO national generally have markers set at 400m, and this correction of an additional 95m should always be taken into account. Actual location of the markers can be found in the AIP for the airport/nation thus when performance is limited the actual value should be used to ensure actual distance available for calculation purposes.
J M, your opening questions identify ambiguity in interpreting CAT.POL. The options appear as to either use the dispatch factor in-flight – no further discussion, or to use some other aspect for the pre landing assessment.
In the latter case IR-OPS has the catchall – the pre landing assessment of landing performance should be judged as 'safe'.
Thus much of the debate above is about what is safe. This should relate to the requirements and guidance in IR-OPS, various advisory information, and an awareness of best practices in industry including accident statistics (those aspects which the lawyers will look at).
EASA publishes regulations (rules) and may provide guidance. The National Authorities implement the regulations, provide additional guidance, and oversee operations; the operator bears the final responsibility for safety – Captain.
There is scant EASA guidance for the in-flight aspects, but the European Action Plan for the Prevention of Runway Excursions suggests that FOLD (providing a minimum of 15% addition) is an acceptable interpretation of the requirement for pre landing assessment.
The UK CAA provides some guidance under winter operations – “The operator is required to demonstrate that it can ensure safe operations, and by applying the same additional safety margin to the in-flight performance assessment as to the dispatch assessment demonstrates an equivalent level of safety. An FAA Safety Alert for Operators published in 2006 (SAFO 06012) recommends an additional safety margin of at least 15% on actual landing distance, except in an emergency”.
European Action Plan for the Prevention of Runway Excursions.
UK CAA Landing During Winter Operations.
In the latter case IR-OPS has the catchall – the pre landing assessment of landing performance should be judged as 'safe'.
Thus much of the debate above is about what is safe. This should relate to the requirements and guidance in IR-OPS, various advisory information, and an awareness of best practices in industry including accident statistics (those aspects which the lawyers will look at).
EASA publishes regulations (rules) and may provide guidance. The National Authorities implement the regulations, provide additional guidance, and oversee operations; the operator bears the final responsibility for safety – Captain.
There is scant EASA guidance for the in-flight aspects, but the European Action Plan for the Prevention of Runway Excursions suggests that FOLD (providing a minimum of 15% addition) is an acceptable interpretation of the requirement for pre landing assessment.
The UK CAA provides some guidance under winter operations – “The operator is required to demonstrate that it can ensure safe operations, and by applying the same additional safety margin to the in-flight performance assessment as to the dispatch assessment demonstrates an equivalent level of safety. An FAA Safety Alert for Operators published in 2006 (SAFO 06012) recommends an additional safety margin of at least 15% on actual landing distance, except in an emergency”.
European Action Plan for the Prevention of Runway Excursions.
UK CAA Landing During Winter Operations.
Thread Starter
At this point, after much deliberation, I'm converted to the factors being for planning purposes only.
We plan conservatively. We get a more direct routing, maybe a more favourable level, and save a bit of fuel. We're a little heavier, but we will be close to our planned weight and the conditions should be similar to those forecast. If it all changes horrendously for the worst, or we've had an abnormal situation, we revise with judgement. I take a while... But hopefully I get it in the end.
As I think safetypee spoke of in their previous thread (which was very informative - in case my previous post didn't seem to appreciate your input SP), we're judged over the course of months on a decision made in a dynamic situation.
Thanks to all who've contributed and helped clarify this for me. Without wanting to sound too sentimental: Merry Christmas!
We plan conservatively. We get a more direct routing, maybe a more favourable level, and save a bit of fuel. We're a little heavier, but we will be close to our planned weight and the conditions should be similar to those forecast. If it all changes horrendously for the worst, or we've had an abnormal situation, we revise with judgement. I take a while... But hopefully I get it in the end.
As I think safetypee spoke of in their previous thread (which was very informative - in case my previous post didn't seem to appreciate your input SP), we're judged over the course of months on a decision made in a dynamic situation.
Thanks to all who've contributed and helped clarify this for me. Without wanting to sound too sentimental: Merry Christmas!
J M, 
A word of caution for all, beware of assuming that ‘close to the expected weight or landing conditions’ will be OK. There are some circumstances where the dispatch margins are very small, even though the planning data appear to provide large safety factors; this is particularly so for wet runways - how wet is wet, how close to a contaminated situation, what is the condition of the tyres, type of runway surface material (beware concrete), grooves or not, brake selection, …
The wet planning data (AFM) is only a factor applied to the dry figures; there were no wet flight tests to obtain the performance and only a conservative (mid-point) assumption is used. With increasingly wet conditions, the risks in operation increase rapidly, and with a combination of effects there may be no margin at all; factored data = ALD, and thus operations require all of the flight accuracies implied in the base data.
There have been many accidents where crews assumed that the conditions were ‘close enough’, having no idea of what the actual margins were. Regulations require a pre-landing check of landing performance for all approaches; this should help crew appreciate what margins there are. A given margin should be evaluated against flight variability to guard against unforeseen flight conditions (AC 91-79 / quick rules of thumb); 5 kts fast and an extended flare can easily eat up 1500ft (airspeed deviation or change in wind). Similarly to guard against inaccuracies in the reporting of runway condition or wind, check the next worst condition, and for system failures ‘what if’, particularly lift dump, autobrake, and reverse if relied on.
And from the TALPA work, do not rely on PIREPS; these are purely subjective, depending on aircraft type and operation, and subject to error in action and reporting.
This sounds like a lot of work, but it’s what we are paid for, to be safe; and you can tell the judge after the event. A full evaluation for every landing should help build knowledge of actual landing performance for the conditions, particularly for the more junior pilots. In every debriefing ask – ‘where would we have stopped, what was the achieved landing distance’?
Merry Christmas, and I hope that Santa will not miscalculate landing distance.
Managing the Threats ...”
A word of caution for all, beware of assuming that ‘close to the expected weight or landing conditions’ will be OK. There are some circumstances where the dispatch margins are very small, even though the planning data appear to provide large safety factors; this is particularly so for wet runways - how wet is wet, how close to a contaminated situation, what is the condition of the tyres, type of runway surface material (beware concrete), grooves or not, brake selection, …
The wet planning data (AFM) is only a factor applied to the dry figures; there were no wet flight tests to obtain the performance and only a conservative (mid-point) assumption is used. With increasingly wet conditions, the risks in operation increase rapidly, and with a combination of effects there may be no margin at all; factored data = ALD, and thus operations require all of the flight accuracies implied in the base data.
There have been many accidents where crews assumed that the conditions were ‘close enough’, having no idea of what the actual margins were. Regulations require a pre-landing check of landing performance for all approaches; this should help crew appreciate what margins there are. A given margin should be evaluated against flight variability to guard against unforeseen flight conditions (AC 91-79 / quick rules of thumb); 5 kts fast and an extended flare can easily eat up 1500ft (airspeed deviation or change in wind). Similarly to guard against inaccuracies in the reporting of runway condition or wind, check the next worst condition, and for system failures ‘what if’, particularly lift dump, autobrake, and reverse if relied on.
And from the TALPA work, do not rely on PIREPS; these are purely subjective, depending on aircraft type and operation, and subject to error in action and reporting.
This sounds like a lot of work, but it’s what we are paid for, to be safe; and you can tell the judge after the event. A full evaluation for every landing should help build knowledge of actual landing performance for the conditions, particularly for the more junior pilots. In every debriefing ask – ‘where would we have stopped, what was the achieved landing distance’?
Merry Christmas, and I hope that Santa will not miscalculate landing distance.
Managing the Threats ...”
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Dirk,
Yes it does, but only for dry and marginal conditions when alternates are available within the limits. When dispatch calculations for the destination are able to perform for the most favourable runway in still air, there is no requirement to apply the 60% in flight.
In wet conditions, neither dispatch nor en-route calculations mandate the within 60% of LDA requirement.
That paragraph that I quoted you clearly talks about factorization, making reference to full compliance with CAT.POL.A.230 from point (a) to (d), which includes the 60% factor, and before commencing the approach, which indicates without a doubt an in-flight situation.
In wet conditions, neither dispatch nor en-route calculations mandate the within 60% of LDA requirement.
Thread Starter
Kefuddle - the regulation, CAT.POL.230 (f), relates to one specific situation whereby your LDR is longer than the most favourable runway in still winds. Why does this preclude a wet runway? It could be a runway that becomes limiting when wet, and the only way LDR could be met is with a favourable wind condition, calculated using all the restrictions laid out in (a) - (d). In this extraordinary situation, you require a second alternate.
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I don't know. The only way I can rationalise those regs is that dry runways are by far the most common condition encountered by crews and so are treated in a more conservative fashion.
If the 60% of LDA requirement was mandated for contaminated runways, I'm guessing that it would be extremely limiting and would pretty much result in considerable disruption for operators servicing a large number of fields during the winter.
If the 60% of LDA requirement was mandated for contaminated runways, I'm guessing that it would be extremely limiting and would pretty much result in considerable disruption for operators servicing a large number of fields during the winter.
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Hello again everyone,
I read your posts carefully, yet still I see no trouble, please help me understand where the percieved dilemma comes from.
Typically (think of alternate aerodrome planning minima..), there are dispatch conditions, which are more restrictive than what is in fact operationally required to land. Then:
You can land safely if ALD (actual landing distance) is less than LDA - in flight calculation requirement. To put some margin in, the regulations require us to use ALD*1,6 coefficient in the dispatch phase. Thus: a) on purpose we dramatically reduce the statistical probability of really needing to land at ALD=LDA; b) if WX/MX/ conditions change unpredictably whilst airborne, the pilots are still allowed to use the full certified capabilities of the A/C without the 1,6 margin restraining them.
The NORMAL situation
1) big margins needs to be applied to dispatch
2) once in flight, as long as ALD < LDA, you may land "WHATEVER".
(statistical approach to hazards and risks)
I understand (f1) correctly, it provides - for a specific set of conditions - a waiver to the principle above:
So the ALTERNATIVE situation
1) the big margins normally in force (dispatch requirements) can be circumnavigated
(2 alternates et al.)
2) but only if you promise to adhere to them before starting the approach. Which is not normally the case required.
To summarize:
A) The regulators ask us to use a hazard filter (ALD*1,6 at dispatch), and then allow us to operate all the way to the limits (in-flight: ALD <= LDA) if the situation requires so.
B) The regulators via (f1) allow us to depart with special provisions (two alternates) without the 1,6 "hazard filter" applied yet, but we still need to show compliance before commecing to land.
I read your posts carefully, yet still I see no trouble, please help me understand where the percieved dilemma comes from.
Typically (think of alternate aerodrome planning minima..), there are dispatch conditions, which are more restrictive than what is in fact operationally required to land. Then:
You can land safely if ALD (actual landing distance) is less than LDA - in flight calculation requirement. To put some margin in, the regulations require us to use ALD*1,6 coefficient in the dispatch phase. Thus: a) on purpose we dramatically reduce the statistical probability of really needing to land at ALD=LDA; b) if WX/MX/ conditions change unpredictably whilst airborne, the pilots are still allowed to use the full certified capabilities of the A/C without the 1,6 margin restraining them.
The NORMAL situation
1) big margins needs to be applied to dispatch
2) once in flight, as long as ALD < LDA, you may land "WHATEVER".
(statistical approach to hazards and risks)
I understand (f1) correctly, it provides - for a specific set of conditions - a waiver to the principle above:
So the ALTERNATIVE situation
1) the big margins normally in force (dispatch requirements) can be circumnavigated
(2 alternates et al.)2) but only if you promise to adhere to them before starting the approach. Which is not normally the case required.
To summarize:
A) The regulators ask us to use a hazard filter (ALD*1,6 at dispatch), and then allow us to operate all the way to the limits (in-flight: ALD <= LDA) if the situation requires so.
B) The regulators via (f1) allow us to depart with special provisions (two alternates) without the 1,6 "hazard filter" applied yet, but we still need to show compliance before commecing to land.
Completely agree. This is the best explanation I’ve heard so far!!.
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This is an old but interesting thread and still it isn't clear to me. My company manual doesn't even refer to this specific situation, probably because we don't operate into any field length weight limited runway. I would like to know if my interpretation of these regulations is correct.
If dispatch calculations don't allow to land within 60% of the LDA in still air conditions, we can still dispatch with an estimated landing weight greater than the landing field weight limit for still wind provided that:
a) with actual wind conditions (50% headwind and 150% tailwind), dispatch calculation permit landing within 60%;
b) 2 alternates meet the dispatch requirement in still air;
c) a pre-landing assessment to ensure compliance with point a is required only up to takeoff or in case of inflight replanning.
I'm really unsure about point C, but so far my interpretation is that after takeoff we can dispense with the 60% of LDA requirement and just work by the Inflight/Enroute performance data. That is, if we get a shortcut, save fuel and current gross weight doesn't meet the 60% dispatch requirement with actual wind, we can land as long as the required landing distance does not exceed the LDA.
And our inflight performance data incorporates a 15% margin for normal configurations.
I might have missed something in the thread and admittedly English isn't my first language. Any inputs?
If dispatch calculations don't allow to land within 60% of the LDA in still air conditions, we can still dispatch with an estimated landing weight greater than the landing field weight limit for still wind provided that:
a) with actual wind conditions (50% headwind and 150% tailwind), dispatch calculation permit landing within 60%;
b) 2 alternates meet the dispatch requirement in still air;
c) a pre-landing assessment to ensure compliance with point a is required only up to takeoff or in case of inflight replanning.
I'm really unsure about point C, but so far my interpretation is that after takeoff we can dispense with the 60% of LDA requirement and just work by the Inflight/Enroute performance data. That is, if we get a shortcut, save fuel and current gross weight doesn't meet the 60% dispatch requirement with actual wind, we can land as long as the required landing distance does not exceed the LDA.
And our inflight performance data incorporates a 15% margin for normal configurations.
I might have missed something in the thread and admittedly English isn't my first language. Any inputs?
Last edited by Banana Joe; 2nd Nov 2019 at 13:53.
Only half a speed-brake
Quick observation:
your a) is overly simplified, I read the requirement differently
c) -> something probably lost in the translation, it does not add up (not a native language speaker either)
Few loose ends that stand out reading the whole thing again, happy to be corrected (and some goalposts may have moved over the time)
- AFM data are realistically achievable with equal conditions. It's not flight test data, flight test +10% springs to mind. As well flight test data is not ace-pilot data.
- under normal ops AFM data are not allowed to be used, Factored (+15% is a requirement)
- wish I never said "safely" as in the "you can land safely if ALD<LDA". I true pro should know better than to use the S word anyway, it's too amoebic and some of its inherent meanings do oppose each other. This is a realm of experts in that particular field. Proper wording should have been: "you are authorised to attempt the landing if ALD<LDA" which implies that a high degree of certainty about successful outcome exists.
- in a similar fashion to the
Although not quoted in full with the original meaning of "Having satisfied the ALD x 1,67 test at dispatch point, once in flight ..." it still was a poor choice of wording from my side. Saying " Having satisfied the ALD x 1,67 test at dispatch point, once in flight the scope of these paragraphs places no further restrictions as long as ALD < LDA" sounds 4 years wiser. 
Banana Joe note that both e.1) and e.2) must be complied with and each of them have a different alternate means of compliance offered by f) and g) respectively. This suggests that e.2 may be more restrictive than e.1 under some circumstances.
your a) is overly simplified, I read the requirement differently
c) -> something probably lost in the translation, it does not add up (not a native language speaker either)
Few loose ends that stand out reading the whole thing again, happy to be corrected (and some goalposts may have moved over the time)
- AFM data are realistically achievable with equal conditions. It's not flight test data, flight test +10% springs to mind. As well flight test data is not ace-pilot data.
- under normal ops AFM data are not allowed to be used, Factored (+15% is a requirement)
- wish I never said "safely" as in the "you can land safely if ALD<LDA". I true pro should know better than to use the S word anyway, it's too amoebic and some of its inherent meanings do oppose each other. This is a realm of experts in that particular field. Proper wording should have been: "you are authorised to attempt the landing if ALD<LDA" which implies that a high degree of certainty about successful outcome exists.
- in a similar fashion to the
once in flight, as long as ALD < LDA, you may land "WHATEVER".
That's a very brave outlook on risk management.
That's a very brave outlook on risk management.
Banana Joe note that both e.1) and e.2) must be complied with and each of them have a different alternate means of compliance offered by f) and g) respectively. This suggests that e.2 may be more restrictive than e.1 under some circumstances.
After the TALPA review, FAA advisory, EASA mandated, the revised operational landing performance (opposed to ‘actual’ distance) is much closer to the factored performance required for dispatch.
Thus a pre landing assessment based on the most recent performance standard (OLD), plus 15% Minimum (FOLD), should minimise any difference between pre-deprture landing performance and that required by a inflight assessment.
What is the basis of your in flight data (all of Airbus is OLD / FOLD)
Thus a pre landing assessment based on the most recent performance standard (OLD), plus 15% Minimum (FOLD), should minimise any difference between pre-deprture landing performance and that required by a inflight assessment.
What is the basis of your in flight data (all of Airbus is OLD / FOLD)
Only half a speed-brake
I know, strong suspicion it already was when the original discussion took place.
It is important to understand what you say, however, this thread about the regulatory requirements might best be served using the terms utilized in them. From the viewpoint of procedural compliance on how should we handle the algorithm of POL.A.230, the numerical definitions of LDA / RLD / ALD are not part of the equation. As vitally important as they are.
Thinking of which, on a lighter note: ALD is historically mislabelled, isn't it? The Actual Landing Distance would be something the AAIB arrives to determine.
It is important to understand what you say, however, this thread about the regulatory requirements might best be served using the terms utilized in them. From the viewpoint of procedural compliance on how should we handle the algorithm of POL.A.230, the numerical definitions of LDA / RLD / ALD are not part of the equation. As vitally important as they are.
Thinking of which, on a lighter note: ALD is historically mislabelled, isn't it? The Actual Landing Distance would be something the AAIB arrives to determine.
Last edited by FlightDetent; 2nd Nov 2019 at 19:28.
