Requesting CAT II approach in CAT I Wx
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Not sure what a practice autoland is. But, if we want our autoland to be available for use, it has to have been done on the aircraft within the last 30 days(it is logged). Therefore if it is approaching the end of this time period we will do one. What the weather is at the time is irrelevent. As long as the autoland limitations such as crosswinds are met. If it is 200 and a half mile vis, we'll do an autoland as long as we have the required visual references to continue with the approach upon reaching the DH.
Last edited by JammedStab; 12th Mar 2013 at 10:26.
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JS -be aware, as nitpicker330 says in post #11
I was once told in can take LGW at least 20 minutes to 'implement' LVP if a/c need to be moved from South Terminal for tail fin obstruction.
In parallel with another thread on this forum, the whole question of manual landing/autolanding in less than Cat I is a nightmare. Way back in the dark ages the CAA got their knickers in a twist about pilots attempting a man land on a Cat II and flying into poor vis at the flare, and insisted on autoland only in less than Cat I. My last airline, Astraeus, got all snarled up here and a lack of management 'timber vision' (wood for the trees) prevented my suggestion of allowing manlands in Cat II (at KEF) in vis above some minimum (I suggested 550m). This left us with typical KEF weather, cloudbase around 120-150', vis 5km, and wind well outside autoland limits on a 737, the choice of either 'disregarding' company procedures (less desirable) and disconnecting at visual OR diverting. I wonder what I did?
Incidentally, for those poor folk 'puzzled' by the term 'Practice Autoland', it was a common term in my time, meaning I don't HAVE to do it but need it for either the a/c or crew currency/training. Very similar to the words 'Practice Forced Landing'
1/ Some ATC may be a bit slow implementing LVP and you may need to give them a nudge.
In parallel with another thread on this forum, the whole question of manual landing/autolanding in less than Cat I is a nightmare. Way back in the dark ages the CAA got their knickers in a twist about pilots attempting a man land on a Cat II and flying into poor vis at the flare, and insisted on autoland only in less than Cat I. My last airline, Astraeus, got all snarled up here and a lack of management 'timber vision' (wood for the trees) prevented my suggestion of allowing manlands in Cat II (at KEF) in vis above some minimum (I suggested 550m). This left us with typical KEF weather, cloudbase around 120-150', vis 5km, and wind well outside autoland limits on a 737, the choice of either 'disregarding' company procedures (less desirable) and disconnecting at visual OR diverting. I wonder what I did?
Incidentally, for those poor folk 'puzzled' by the term 'Practice Autoland', it was a common term in my time, meaning I don't HAVE to do it but need it for either the a/c or crew currency/training. Very similar to the words 'Practice Forced Landing'
Last edited by BOAC; 12th Mar 2013 at 13:39.
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BOAC,
Cat 2 manual landings are fine for many aircraft with only one autopilot fitted and have/are approved in the UK as im sure you know however for aircraft such as Boeings with multiple autopilots the UK does seem to be reluctant. I have worked for two European airlines (Boeing) that approved Cat 2 manual landings as long as 350m RVR was acquired. It is still allowed for exceptional cases in my current airline.
Jammedstab,
From what you said, you're operator needs to instill a far more careful approach to doing an Autoland with no LVP. There is no guarantee that the autoland will be successful without it and you really dont want to be performing recovery actions close to or on the ground in 1/2sm vis ! The weather at the time is always very relevant. The more things on you're side the better in this business. There have been numerous damaged airframes doing autolands outside LVP's over the years. Just ask Singapore airlines and their off road 777 experience last year at Munich.
Cat 2 manual landings are fine for many aircraft with only one autopilot fitted and have/are approved in the UK as im sure you know however for aircraft such as Boeings with multiple autopilots the UK does seem to be reluctant. I have worked for two European airlines (Boeing) that approved Cat 2 manual landings as long as 350m RVR was acquired. It is still allowed for exceptional cases in my current airline.
Jammedstab,
From what you said, you're operator needs to instill a far more careful approach to doing an Autoland with no LVP. There is no guarantee that the autoland will be successful without it and you really dont want to be performing recovery actions close to or on the ground in 1/2sm vis ! The weather at the time is always very relevant. The more things on you're side the better in this business. There have been numerous damaged airframes doing autolands outside LVP's over the years. Just ask Singapore airlines and their off road 777 experience last year at Munich.
Last edited by 8che; 12th Mar 2013 at 16:44.
8che, the approval of Cat 2 manual landings (and auto approach) with only one autopilot depends on more than having the equipment installed. Like an autoland system it depends what is in ‘the box’; the overall system integrity, redundancy, alerting and warning, a single or dual channel computation, etc.
In particular the approach delivery accuracy and failure protection - required down to 80% of the decision height or the certificated minimum use height.
Cat 2 manual approaches (FD) require system certification independent of the auto-coupled certification; this is expensive and rarely undertaken with modern high-reliability auto pilot systems.
Manual landings in low visibility require a sufficiently acceptable visual scene which will vary with altitude. This depends on the flightdeck / glareshield geometry, fog structure, lighting pattern, etc; thus 350m at 160ft (200ft DH) would not be acceptable, whereas 350m at 80ft (100ft DH) could be. The visual scene may have to consider the need for lateral maneuvering depending on approach accuracy.
Another significant issue is the variability of low visibility. The range of RVRs for Cat 2 is typical of fog formation or dispersal, which result in rapidly changing conditions and fog density with altitude.
Cat 2 is an operation where a decision to land in limiting conditions could be overturned 30-40ft lower.
Cat 3 conditions are typical of more stable fog structures and less variability, also with a lower DH there is less time for change.
In particular the approach delivery accuracy and failure protection - required down to 80% of the decision height or the certificated minimum use height.
Cat 2 manual approaches (FD) require system certification independent of the auto-coupled certification; this is expensive and rarely undertaken with modern high-reliability auto pilot systems.
Manual landings in low visibility require a sufficiently acceptable visual scene which will vary with altitude. This depends on the flightdeck / glareshield geometry, fog structure, lighting pattern, etc; thus 350m at 160ft (200ft DH) would not be acceptable, whereas 350m at 80ft (100ft DH) could be. The visual scene may have to consider the need for lateral maneuvering depending on approach accuracy.
Another significant issue is the variability of low visibility. The range of RVRs for Cat 2 is typical of fog formation or dispersal, which result in rapidly changing conditions and fog density with altitude.
Cat 2 is an operation where a decision to land in limiting conditions could be overturned 30-40ft lower.
Cat 3 conditions are typical of more stable fog structures and less variability, also with a lower DH there is less time for change.
