A330 overweight landing procedure = optional?
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A330 overweight landing procedure = optional?
Hi all
Just come up for my first sim since Airbus released the new procedures for inflight landing distance calculation - the one where there is now a flat extra landing distance increment that must be applied, in case of "overweight landing distance procedure applied". This is in addition to the runway distance modifier for a landing weight +/- the reference weight of 190 ton.
Looking at the worked example for the new procedure, of how to calculate a landing distance procedure with failure (this is in FCTM - SI - 090 - Landing Performance), it clearly states that "In the case of an overweight landing both the WGT and the OVW should be applied".
However the example given is an aircraft landing at 190 ton, with an engine shut down. The various permutations of runway state, wind, pressure alt etc are all factored for but the OVW correction is not! Given that to the best of my knowledge all A330s have a MLW of 182 ton, I find this a bit odd.
Furthermore, unless I'm greatly mistaken, I'm trying to work through a landing distance required procedure based on what I suspect I'm going to get in my upcoming sim check, which is taking off at MTOW and having a dual hydraulic G+B failure. Allowing for standard ISA sea level conditions and slats at 0, the number I'm coming up with is well in excess of 4000 meters under the new rules? This is rather inconvenient considering it's a red LAND ASAP and I'm not aware of a single 4000+ meter runway anywhere near the departure airfield.
I'm certain when I did this sim profile last time we had no problem getting back onto a 3500 meter runway so I'm wondering am I doing something wrong? Is Airbus correct by giving an example of a landing at 190 ton and NOT applying the OVW correction? Is the OVW landing procedure not compulsory? Is there any other way I can get that required landing distance down for the G+B overweight scenario?
Just come up for my first sim since Airbus released the new procedures for inflight landing distance calculation - the one where there is now a flat extra landing distance increment that must be applied, in case of "overweight landing distance procedure applied". This is in addition to the runway distance modifier for a landing weight +/- the reference weight of 190 ton.
Looking at the worked example for the new procedure, of how to calculate a landing distance procedure with failure (this is in FCTM - SI - 090 - Landing Performance), it clearly states that "In the case of an overweight landing both the WGT and the OVW should be applied".
However the example given is an aircraft landing at 190 ton, with an engine shut down. The various permutations of runway state, wind, pressure alt etc are all factored for but the OVW correction is not! Given that to the best of my knowledge all A330s have a MLW of 182 ton, I find this a bit odd.
Furthermore, unless I'm greatly mistaken, I'm trying to work through a landing distance required procedure based on what I suspect I'm going to get in my upcoming sim check, which is taking off at MTOW and having a dual hydraulic G+B failure. Allowing for standard ISA sea level conditions and slats at 0, the number I'm coming up with is well in excess of 4000 meters under the new rules? This is rather inconvenient considering it's a red LAND ASAP and I'm not aware of a single 4000+ meter runway anywhere near the departure airfield.
I'm certain when I did this sim profile last time we had no problem getting back onto a 3500 meter runway so I'm wondering am I doing something wrong? Is Airbus correct by giving an example of a landing at 190 ton and NOT applying the OVW correction? Is the OVW landing procedure not compulsory? Is there any other way I can get that required landing distance down for the G+B overweight scenario?
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Make the corrections on your landing weight according to the reference weight of 190T, ie if your landing weight is 230T then add the figure that it mentions in your QRH per 10T above 190T, in my case it's +170 per 10T so it would be +680 (170 x 4). If your landing weight is below 190T, just do the opposite. Regarding the overweight increment that has to do with your landing technique to be within the 360ft/min max ROD, therefore shallow flare and increased landing distance. If your max landing weight is 182T, and you land with 183T, you would take the reference distance for 190T (unless you are really willing to to abstract math for 7T less and find out something like 23m of decreased landing distance) and add the figure for overweight ldg proc (+650m). To summarise, anytime you land overweight, add the overweight ldg proc distance, regardless if you are above or below 190T, that is a reference weight, but 183T for you is already overweight.
Regarding the abnormals, for G+B the basic distance I get is 2430m for 190T. Now you need to add the difference for your weight which you stated to be almost the MTOW, so let's take 233T. The difference is 43T. That is +300m per 10T above 190T becomes 1250m. 2430+1250 = 3630m. It's a lot but you're landing 233T of airplane with 2 spoilers per wing and accumulator only...
ps in abnormal you don't have the overweight correction like in normal conditions. That is already taken care by the margins given in the abnormal computations.
Regarding the abnormals, for G+B the basic distance I get is 2430m for 190T. Now you need to add the difference for your weight which you stated to be almost the MTOW, so let's take 233T. The difference is 43T. That is +300m per 10T above 190T becomes 1250m. 2430+1250 = 3630m. It's a lot but you're landing 233T of airplane with 2 spoilers per wing and accumulator only...
ps in abnormal you don't have the overweight correction like in normal conditions. That is already taken care by the margins given in the abnormal computations.
Last edited by sonicbum; 22nd May 2014 at 08:46. Reason: ps
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I'm happy with all that, up to
Not true unfortunately, or at least not any more. The QRH clearly gives the OVW correction to be applied in all these failure cases, and it's also spelled out in the FCTM, you have to add both the WGT correction and THEN the OVW correction.
And therein lies the problem, this new OVW correction has added an extra several hundred meters that wasn't required before, to all these difficult ones like slats/flaps jammed and dual hydraulic failures, basically made it impossible for an immediate return at heavy weights. I don't know if we've been flying around unsafe in these things for the last 30 years or if they've suddenly decided to change things for the sake of change
ps in abnormal you don't have the overweight correction like in normal conditions. That is already taken care by the margins given in the abnormal computations.
And therein lies the problem, this new OVW correction has added an extra several hundred meters that wasn't required before, to all these difficult ones like slats/flaps jammed and dual hydraulic failures, basically made it impossible for an immediate return at heavy weights. I don't know if we've been flying around unsafe in these things for the last 30 years or if they've suddenly decided to change things for the sake of change
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Hi Luke,
the tables of my latest QRH still show no overweight landing distance procedure in abnormal conditions. I know for a fact that Airbus is planning to change that so you might have a more updated version than I do.
What is the issue date of your FCTM ? Thanks
the tables of my latest QRH still show no overweight landing distance procedure in abnormal conditions. I know for a fact that Airbus is planning to change that so you might have a more updated version than I do.
What is the issue date of your FCTM ? Thanks
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Luke...
Think you need to read that again... using the force!
In the FCTM Supplementary Info on calculating landing performance....
WITHOUT FAILURE there are "Additional Corrections" to be applied for Overweight and Autoland.
In the WITH FAILURE section there are no Additional Corrections to Landing Distance.
Think you need to read that again... using the force!
In the FCTM Supplementary Info on calculating landing performance....
WITHOUT FAILURE there are "Additional Corrections" to be applied for Overweight and Autoland.
In the WITH FAILURE section there are no Additional Corrections to Landing Distance.
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Nope. Never mind, we're obviously using different QRH's, because mine clearly states in both the QRH-IFP and the FCTM, that the OVW correction is to be applied both in failure and non failure cases. Mine is all dated 5 Mar 2014. Will try to upload a pic or something later.
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Nope. Never mind, we're obviously using different QRH's, because mine clearly states in both the QRH-IFP and the FCTM, that the OVW correction is to be applied both in failure and non failure cases. Mine is all dated 5 Mar 2014. Will try to upload a pic or something later.
Thanks
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Dual Hydraulic G+B Failure, the QRH reference is IFP-PER-29 page 1/6.
Our aircraft are pretty old, all the MSNs are in the 200s and 300s, engines are PW4168.
Dry runway, landing weight 225 tons, Slats <1, ISA, sea level, no thrust reverser allowance, Overweight landing procedure applied. Ignoring ALT, WIND, TEMP, SLOPE corrections for purpose of example.
Ref distance for 190 ton is 2460.
WGT correction is +310 for every 10 tons over 190.
OVW correction is +570.
Landing distance required therefore is 2460 + (3.5 x 310) + 570 = 4115.
In that table I'm referring to, the new factor for OVW landing is on the far right just next to REV. Do you not have it in yours?
And furthermore as a direct quote from the FCTM, section SI-090 page 16/28, "Inflight landing distance with failure"
Our aircraft are pretty old, all the MSNs are in the 200s and 300s, engines are PW4168.
Dry runway, landing weight 225 tons, Slats <1, ISA, sea level, no thrust reverser allowance, Overweight landing procedure applied. Ignoring ALT, WIND, TEMP, SLOPE corrections for purpose of example.
Ref distance for 190 ton is 2460.
WGT correction is +310 for every 10 tons over 190.
OVW correction is +570.
Landing distance required therefore is 2460 + (3.5 x 310) + 570 = 4115.
In that table I'm referring to, the new factor for OVW landing is on the far right just next to REV. Do you not have it in yours?
And furthermore as a direct quote from the FCTM, section SI-090 page 16/28, "Inflight landing distance with failure"
Note: In the case of an overweight landing both the WGT and OVW should be applied.
- WGT correction to reflect the actual aircraft landing weight
- OVW correction to reflect the use of the Overweight Landing Procedure
- WGT correction to reflect the actual aircraft landing weight
- OVW correction to reflect the use of the Overweight Landing Procedure
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Hi, you guys. If you will permit a mere lightweight A320 person to add to your very interesting discussion, I think it can be boiled down thus:
The OVW increment is due to the landing technique demanded by the OVW Landing QRH.
THE WT increment is due simply due to the aerodynamics of putting on weight.
Thus, both apply.
I've just had a trawl through my FCTM about the subject - and, jeez, my head hurts. As a matter of supreme indifference, I had a look at the example, guessed at circa 2000m and, guess what, they made it 1850m. I don't advocate taking that line for real, but they sure have made it time consuming!
Thanks for the discussion guys.
The OVW increment is due to the landing technique demanded by the OVW Landing QRH.
THE WT increment is due simply due to the aerodynamics of putting on weight.
Thus, both apply.
I've just had a trawl through my FCTM about the subject - and, jeez, my head hurts. As a matter of supreme indifference, I had a look at the example, guessed at circa 2000m and, guess what, they made it 1850m. I don't advocate taking that line for real, but they sure have made it time consuming!
Thanks for the discussion guys.
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Very interesting topic.
As far as I know, according Airbus policy, no overweight correction under non normal condition is required.
But if you have to divert because of a sudden decommpression or passenger illness these scenarios are not covered as non normal on QRH. So, just according to the papers the overweight landing correction should be applied.
BUT it is funny (against any airmanship) because if you have to divert to a short strip (i.e.ETOPS era), paperwise it might be better to denergize the yellow hyd system or even shutdown an engine (really radical) than correct the normal landing distance by the overweight factor. In the first case resulting landing distance (on paper) will be lower than the second.
As far as I know, according Airbus policy, no overweight correction under non normal condition is required.
But if you have to divert because of a sudden decommpression or passenger illness these scenarios are not covered as non normal on QRH. So, just according to the papers the overweight landing correction should be applied.
BUT it is funny (against any airmanship) because if you have to divert to a short strip (i.e.ETOPS era), paperwise it might be better to denergize the yellow hyd system or even shutdown an engine (really radical) than correct the normal landing distance by the overweight factor. In the first case resulting landing distance (on paper) will be lower than the second.
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If its any help, when this came to our 320 fleet it was explained by the fact that if you are in an abnormal condition then more emphasis is placed on landing and stopping your aircraft with the relevant failure than re-using it straight afterwards. Hence no extra distance required. If you are just putting it on the ground for a sick pax then please go softly and get airborne again asap...Extra landing distance therefore required.
Where I work, we have new manuals coming out shortly which do have overweight landing corrections for failures and also handle multiple failures.
I always found it strange that for a non-normal you didn't have to do an overweight correction.
I ran a couple of scenarios and found with the new tables. For a normal(?) overweight landing you may actually need less distance if you use auto brake medium instead of max manual. This is because auto brake will not wait until the nose wheel is on the ground before it starts braking (according to a PowerPoint presentation which I assume is an Airbus presentation)
I only found the new manuals by digging around the company's website after reading this thread!
I always found it strange that for a non-normal you didn't have to do an overweight correction.
I ran a couple of scenarios and found with the new tables. For a normal(?) overweight landing you may actually need less distance if you use auto brake medium instead of max manual. This is because auto brake will not wait until the nose wheel is on the ground before it starts braking (according to a PowerPoint presentation which I assume is an Airbus presentation)
I only found the new manuals by digging around the company's website after reading this thread!
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alatriste or nitpicker it would be fantastic if you were able to point me toward any reference anywhere in airbus documentation, where it says that it is optional to apply the overweight landing procedure in non normals? Or is it just a company SOP?
In my case I was taking it straight from the FCOM PERF section and the QRH tables it tells you to use. It's not mentioned as optional anywhere, indeed overweight landing isn't mentioned in the FCOM PERF section at all for normal or failure.
The QRH tables for Conf Full and 3 Inflight Landing Dist with different braking actions have a overweight correction in addition to the weight adjustment +/- 190T. We are advised then to add 15% safety factor.
The QRH tables for inflight landing distance assessment with failure do not have the additional correction for overweight. We are advised to then add 15% safety factor but in an emergency the commander can ignore it if required.
These new graphs with all the different failures, braking actions and runway condition matrix all came out only around a year ago.
Multiple failures have been a particular pain in the rear and I believe Airbus is coming out with data for this and a methology soon? Particularly since QF 32 in SIN with all their multiple failures made it impossible for the crew to calculate!!
The QRH tables for Conf Full and 3 Inflight Landing Dist with different braking actions have a overweight correction in addition to the weight adjustment +/- 190T. We are advised then to add 15% safety factor.
The QRH tables for inflight landing distance assessment with failure do not have the additional correction for overweight. We are advised to then add 15% safety factor but in an emergency the commander can ignore it if required.
These new graphs with all the different failures, braking actions and runway condition matrix all came out only around a year ago.
Multiple failures have been a particular pain in the rear and I believe Airbus is coming out with data for this and a methology soon? Particularly since QF 32 in SIN with all their multiple failures made it impossible for the crew to calculate!!
Last edited by nitpicker330; 24th May 2014 at 01:37.
In 2014 in the world of the iPad surely Airbus could come out with a good App that calculated all the data for us?
Indeed every Performance related table or graph in the QRH should be available in an App that works out an accurate answer for us, surely this is possible?
Indeed every Performance related table or graph in the QRH should be available in an App that works out an accurate answer for us, surely this is possible?
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Nit, in AUS, or Europe...in general, how many iPad apps do you find? You cant even get the Metro schedule on an iPad.
The issue is that the apps must go thru regulatory approval process, and approved by aircraft type, etc.
After that, the app must be written into the individual airlines sop and training prior for approval to be used.
As noted by the recent FAA guidance, anything other than approved and trained apps are illegal for use on the flightdeck.
The issue is that the apps must go thru regulatory approval process, and approved by aircraft type, etc.
After that, the app must be written into the individual airlines sop and training prior for approval to be used.
As noted by the recent FAA guidance, anything other than approved and trained apps are illegal for use on the flightdeck.
Yes I realise there is a process to follow.......
Airbus could do it if they wanted to bother.......there already is an Airbus performance program for Laptops isn't there?
Unless of course even they are confused as to how to do it properly....
Airbus could do it if they wanted to bother.......there already is an Airbus performance program for Laptops isn't there?
Unless of course even they are confused as to how to do it properly....