Max Landing Weight Dispatch and Actual
Thread Starter
Join Date: Mar 2010
Location: in a dirty cockpit
Posts: 431
Likes: 0
Received 0 Likes
on
0 Posts
Max Landing Weight Dispatch and Actual
Hi guys,
here a nice question for you all.
Let's assume your airplane (B737-400 i.e.) has a Max Structural Landing Weight of 56200 Kg.
You are going to fly to a short runway and/or high missed approach climb gradient (more than 2.5%), by your calculations through the Runway Tables, your Landing Weight is limited to 54000 Kg.
Your Regulated Max Landing Weight is of course the lowest one, so 54000 Kg thus your fuel calculations will be based on this and that day (obviously) you are going to leave expecting to be barely close to this maximum.
You are tasting an awful coffee so you decide it's better to focus on something that could take your attention off that s**t
You check your Actual Landing Weight (expected, but Actual meaning you are not dispatching) on landing, and you notice it will be 54500 Kg due to some shortcuts and a more economical cruise level obtained.
Checking the Actual Landing Distance tables (for Boeing those are "Advisory Landing Distance") and you notice that your LDA (available) is longer than your LDR (required by your aircraft).
Even your Actual Missed Approach Climb gradient 1EO (tables provided by the airline) satisfy the missed approach gradient required.
This is due to the fact that no factoring is applied to those distances.
Are you allowed to land claiming you are IN FLIGHT so dispatch calculation are no longer applicable?
Or you must comply with the weight limitation obtained (54000 Kg) thus holding before landing and/or increasing the fuel consumption?
Here some EU OPS hints (notice the bold sentence):
OPS 1.515
Landing — Dry runways
(a) An operator shall ensure that the landing mass of the aeroplane determined in accordance with OPS 1.475(a) for the
estimated time of landing at the destination aerodrome and at any alternate aerodrome allows a full stop landing from
50 ft above the threshold:
1. For turbo-jet powered aeroplanes, within 60 % of the landing distance available; or
2. For turbo-propeller powered aeroplanes, within 70 % of the landing distance available;
3. For steep approach procedures the Authority may approve the use of landing distance data factored in accordance
with subparagraphs (a)1 and (a)2 above as appropriate, based on a screen height of less than 50 ft, but not
less than 35 ft. (See Appendix 1 to OPS 1.515(a)3);
4. When showing compliance with subparagraphs (a)1 and (a)2 above, the Authority may exceptionally approve,
when satisfied that there is a need (see Appendix 1), the use of short landing operations in accordance with Appendices
1 and 2 together with any other supplementary conditions that the Authority considers necessary in order
to ensure an acceptable level of safety in the particular case.
(b) When showing compliance with subparagraph (a) above, an operator must take account of the following:
1. the altitude at the aerodrome;
2. not more than 50 % of the head-wind component or not less than 150 % of the tailwind component; and
3. the runway slope in the direction of landing if greater than +/-2 %.
(c) When showing compliance with subparagraph (a) above, it must be assumed that:
1. the aeroplane will land on the most favourable runway, in still air; and
2. the aeroplane will land on the runway most likely to be assigned considering the probable wind speed and direction
and the ground handling characteristics of the aeroplane, and considering other conditions such as landing
aids and terrain.
(d) If an operator is unable to comply with subparagraph (c)1 above for a destination aerodrome having a single runway
where a landing depends upon a specified wind component, an aeroplane may be despatched if 2 alternate aerodromes
are designated which permit full compliance with subparagraphs (a), (b) and (c). Before commencing an approach to
land at the destination aerodrome the commander must satisfy himself/herself that a landing can be made in full compliance
with OPS 1.510 and subparagraphs (a) and (b) above.
(e) If an operator is unable to comply with subparagraph (c)2 above for the destination aerodrome, the aeroplane may be
despatched if an alternate aerodrome is designated which permits full compliance with subparagraphs (a), (b) and (c).
Hereunder, referenced paragraphs (OPS 1.475):
OPS 1.475
General
(a) An operator shall ensure that the mass of the aeroplane:
1. at the start of the take-off; or, in the event of in-flight re-planning;
2. at the point from which the revised operational flight plan applies, is not greater than the mass at which the
requirements of the appropriate Subpart can be complied with for the flight to be undertaken, allowing for
expected reductions in mass as the flight proceeds, and for such fuel jettisoning as is provided for in the particular
requirement.
(b) An operator shall ensure that the approved performance Data contained in the Aeroplane Flight Manual is used to determine
compliance with the requirements of the appropriate Subpart, supplemented as necessary with other data acceptable
to the Authority as prescribed in the relevant Subpart. When applying the factors prescribed in the appropriate
Subpart, account may be taken of any operational factors already incorporated in the Aeroplane Flight Manual performance
data to avoid double application of factors.
(c) When showing compliance with the requirements of the appropriate Subpart, due account shall be taken of aeroplane
configuration, environmental conditions and the operation of systems which have an adverse effect on performance.
(d) For performance purposes, a damp runway, other than a grass runway, may be considered to be dry.
(e) An operator shall take account of charting accuracy when assessing compliance with the take-off requirements of the
applicable subpart.
AND
OPS 1.510
Landing — Destination and alternate aerodromes
(a) An operator shall ensure that the landing mass of the aeroplane determined in accordance with OPS 1.475(a) does not
exceed the maximum landing mass specified for the altitude and the ambient temperature expected for the estimated
time of landing at the destination and alternate aerodrome.
(b) For instrument approaches with a missed approach gradient greater than 2,5 % an operator shall verify that the
expected landing mass of the aeroplane allows a missed approach with a climb gradient equal to or greater than the
applicable missed approach gradient in the one-engine inoperative missed approach configuration and speed (see applicable
requirements on certification of large aeroplanes). The use of an alternative method must be approved by the
Authority.
(c) For instrument approaches with decision heights below 200 ft, an operator must verify that the expected landing mass
of the aeroplane allows a missed approach gradient of climb, with the critical engine failed and with the speed and configuration
used for go-around of at least 2,5 %, or the published gradient, whichever is the greater (see CS AWO 243).
The use of an alternative method must be approved by the Authority.
here a nice question for you all.
Let's assume your airplane (B737-400 i.e.) has a Max Structural Landing Weight of 56200 Kg.
You are going to fly to a short runway and/or high missed approach climb gradient (more than 2.5%), by your calculations through the Runway Tables, your Landing Weight is limited to 54000 Kg.
Your Regulated Max Landing Weight is of course the lowest one, so 54000 Kg thus your fuel calculations will be based on this and that day (obviously) you are going to leave expecting to be barely close to this maximum.
You are tasting an awful coffee so you decide it's better to focus on something that could take your attention off that s**t
You check your Actual Landing Weight (expected, but Actual meaning you are not dispatching) on landing, and you notice it will be 54500 Kg due to some shortcuts and a more economical cruise level obtained.Checking the Actual Landing Distance tables (for Boeing those are "Advisory Landing Distance") and you notice that your LDA (available) is longer than your LDR (required by your aircraft).
Even your Actual Missed Approach Climb gradient 1EO (tables provided by the airline) satisfy the missed approach gradient required.
This is due to the fact that no factoring is applied to those distances.
Are you allowed to land claiming you are IN FLIGHT so dispatch calculation are no longer applicable?
Or you must comply with the weight limitation obtained (54000 Kg) thus holding before landing and/or increasing the fuel consumption?
Here some EU OPS hints (notice the bold sentence):
OPS 1.515
Landing — Dry runways
(a) An operator shall ensure that the landing mass of the aeroplane determined in accordance with OPS 1.475(a) for the
estimated time of landing at the destination aerodrome and at any alternate aerodrome allows a full stop landing from
50 ft above the threshold:
1. For turbo-jet powered aeroplanes, within 60 % of the landing distance available; or
2. For turbo-propeller powered aeroplanes, within 70 % of the landing distance available;
3. For steep approach procedures the Authority may approve the use of landing distance data factored in accordance
with subparagraphs (a)1 and (a)2 above as appropriate, based on a screen height of less than 50 ft, but not
less than 35 ft. (See Appendix 1 to OPS 1.515(a)3);
4. When showing compliance with subparagraphs (a)1 and (a)2 above, the Authority may exceptionally approve,
when satisfied that there is a need (see Appendix 1), the use of short landing operations in accordance with Appendices
1 and 2 together with any other supplementary conditions that the Authority considers necessary in order
to ensure an acceptable level of safety in the particular case.
(b) When showing compliance with subparagraph (a) above, an operator must take account of the following:
1. the altitude at the aerodrome;
2. not more than 50 % of the head-wind component or not less than 150 % of the tailwind component; and
3. the runway slope in the direction of landing if greater than +/-2 %.
(c) When showing compliance with subparagraph (a) above, it must be assumed that:
1. the aeroplane will land on the most favourable runway, in still air; and
2. the aeroplane will land on the runway most likely to be assigned considering the probable wind speed and direction
and the ground handling characteristics of the aeroplane, and considering other conditions such as landing
aids and terrain.
(d) If an operator is unable to comply with subparagraph (c)1 above for a destination aerodrome having a single runway
where a landing depends upon a specified wind component, an aeroplane may be despatched if 2 alternate aerodromes
are designated which permit full compliance with subparagraphs (a), (b) and (c). Before commencing an approach to
land at the destination aerodrome the commander must satisfy himself/herself that a landing can be made in full compliance
with OPS 1.510 and subparagraphs (a) and (b) above.
(e) If an operator is unable to comply with subparagraph (c)2 above for the destination aerodrome, the aeroplane may be
despatched if an alternate aerodrome is designated which permits full compliance with subparagraphs (a), (b) and (c).
Hereunder, referenced paragraphs (OPS 1.475):
OPS 1.475
General
(a) An operator shall ensure that the mass of the aeroplane:
1. at the start of the take-off; or, in the event of in-flight re-planning;
2. at the point from which the revised operational flight plan applies, is not greater than the mass at which the
requirements of the appropriate Subpart can be complied with for the flight to be undertaken, allowing for
expected reductions in mass as the flight proceeds, and for such fuel jettisoning as is provided for in the particular
requirement.
(b) An operator shall ensure that the approved performance Data contained in the Aeroplane Flight Manual is used to determine
compliance with the requirements of the appropriate Subpart, supplemented as necessary with other data acceptable
to the Authority as prescribed in the relevant Subpart. When applying the factors prescribed in the appropriate
Subpart, account may be taken of any operational factors already incorporated in the Aeroplane Flight Manual performance
data to avoid double application of factors.
(c) When showing compliance with the requirements of the appropriate Subpart, due account shall be taken of aeroplane
configuration, environmental conditions and the operation of systems which have an adverse effect on performance.
(d) For performance purposes, a damp runway, other than a grass runway, may be considered to be dry.
(e) An operator shall take account of charting accuracy when assessing compliance with the take-off requirements of the
applicable subpart.
AND
OPS 1.510
Landing — Destination and alternate aerodromes
(a) An operator shall ensure that the landing mass of the aeroplane determined in accordance with OPS 1.475(a) does not
exceed the maximum landing mass specified for the altitude and the ambient temperature expected for the estimated
time of landing at the destination and alternate aerodrome.
(b) For instrument approaches with a missed approach gradient greater than 2,5 % an operator shall verify that the
expected landing mass of the aeroplane allows a missed approach with a climb gradient equal to or greater than the
applicable missed approach gradient in the one-engine inoperative missed approach configuration and speed (see applicable
requirements on certification of large aeroplanes). The use of an alternative method must be approved by the
Authority.
(c) For instrument approaches with decision heights below 200 ft, an operator must verify that the expected landing mass
of the aeroplane allows a missed approach gradient of climb, with the critical engine failed and with the speed and configuration
used for go-around of at least 2,5 %, or the published gradient, whichever is the greater (see CS AWO 243).
The use of an alternative method must be approved by the Authority.
Last edited by Breakthesilence; 20th Jun 2013 at 20:08.
Join Date: Feb 2008
Location: -
Posts: 36
Likes: 0
Received 0 Likes
on
0 Posts
My two cents,
I think the number that counts is the one obtained when calculating the landing distance during flight, so the 54,5t is OK.
The same thing applies if you were to find less than optimum conditions at your destination, something like a wet runway with medium brake action and a 10kt tailwind then your MLW of 54t calculated at dispatch goes out the window.
I don't fly anywhere near the EU but at my workplace what matters is the number you come up with during flight with the current weather, runway conditions and actual landing weight.
Also dispatch at our airline does all calculations with a dry runway.
I think the number that counts is the one obtained when calculating the landing distance during flight, so the 54,5t is OK.
The same thing applies if you were to find less than optimum conditions at your destination, something like a wet runway with medium brake action and a 10kt tailwind then your MLW of 54t calculated at dispatch goes out the window.
I don't fly anywhere near the EU but at my workplace what matters is the number you come up with during flight with the current weather, runway conditions and actual landing weight.
Also dispatch at our airline does all calculations with a dry runway.
Last edited by AVApilot; 20th Jun 2013 at 22:42.
Hmmm. I would have said the same. Once inflight the dispatch requirements are out the window (unless the operator specifies differently).
However, this quote:
Before commencing an approach to
land at the destination aerodrome the commander must satisfy himself/herself that a landing can be made in full compliance
with OPS 1.510 and subparagraphs (a) and (b) above.
confused me. Is it only applicable if the conditions in 1.515 d) apply?
Is this a new addition? Don't remember anything like that in JAR Ops at the time.
However, this quote:
Before commencing an approach to
land at the destination aerodrome the commander must satisfy himself/herself that a landing can be made in full compliance
with OPS 1.510 and subparagraphs (a) and (b) above.
confused me. Is it only applicable if the conditions in 1.515 d) apply?
Is this a new addition? Don't remember anything like that in JAR Ops at the time.
Last edited by 733driver; 20th Jun 2013 at 23:11.
Thread Starter
Join Date: Mar 2010
Location: in a dirty cockpit
Posts: 431
Likes: 0
Received 0 Likes
on
0 Posts
Hmmm. I would have said the same. Once inflight the dispatch requirements are out the window (unless the operator specifies differently).
However, this quote:
Before commencing an approach to
land at the destination aerodrome the commander must satisfy himself/herself that a landing can be made in full compliance
with OPS 1.510 and subparagraphs (a) and (b) above.
confused me. Is it only applicable if the conditions in 1.515 d) apply?
Is this a new addition? Don't remember anything like that in JAR Ops at the time.
However, this quote:
Before commencing an approach to
land at the destination aerodrome the commander must satisfy himself/herself that a landing can be made in full compliance
with OPS 1.510 and subparagraphs (a) and (b) above.
confused me. Is it only applicable if the conditions in 1.515 d) apply?
Is this a new addition? Don't remember anything like that in JAR Ops at the time.
However, I found this statement on an IFALPA document (written with the assistance of Boeing Flight Operations Department) called "Certified versus Advisory landing data on Boeing aircraft":
"Advisory data is provided to meet operational needs on varying
runway conditions with the expectation that crews will assess landing performance based on actual weather and runway conditions
at the time of arrival as opposed to those prevailing at the time of dispatch, when Certified data is used."
Notwithstanding what I've written above, the Missed Approach Climb gradient 1EO must be satisfied, at least 2.5% (or higher if the destination/Alternate requires).
If you are not able to comply with it and no runway change is available, you have to either reduce your weight (to the one you selected in the dispatch phase) or ask for another procedure with a different Missed Approach not requiring the limiting gradient.
In simple terms:
RUNWAY DISPATCH numbers may be disregarded in actual conditions due to the fact that those are factored and actual conditions still permit a safe landing with an adeguate margin (even if less than the dispatch one) at higher weights.
GO AROUND DISPATCH numbers, as they are not factored, are the same as the actual ones (you can basically use the same table if your airline provides the informations based on Max Weight to satisfy the requirement).
So, if the Landing limitation was the Missed Approach, and conditions are almost like the dispatch ones, you won't be able to comply with it with the higher weight obtained by shortcuts or optimum flight levels...
Last edited by Breakthesilence; 21st Jun 2013 at 00:10.
(a) An operator shall ensure that the landing mass of the aeroplane determined in accordance with OPS 1.475(a) for the estimated time of landing at the destination aerodrome and at any alternate aerodrome allows a full stop landing from 50 ft above the threshold:
1. For turbo-jet powered aeroplanes, within 60 % of the landing distance available; or
1. For turbo-jet powered aeroplanes, within 60 % of the landing distance available; or
) but I would have thought this paragraph says it all, making no distinction between Dispatch or Inflight.Under our rules, landing at a greater weight by not considering factors (once airborne) is not on unless an emergency exists. The way I read the above rule (1.515 a1), it's the same; it requires full factors when you touch down.
