Continuous Descent Approach
Is there something new in this CDA thingy then?
Circa 30 years ago it was a matter of professional pride to close the thrust levers at top of descent (F330 or more) and not be spooling up until 3 or 4 miles from touchdown - and, by the way, this was hand flown with distance to touchdown being mentally calculated using VOR/DME (barrel type) and/or ADF.
With all the gizmos available now people seem to make such a song and a dance about it - KISS!
Circa 30 years ago it was a matter of professional pride to close the thrust levers at top of descent (F330 or more) and not be spooling up until 3 or 4 miles from touchdown - and, by the way, this was hand flown with distance to touchdown being mentally calculated using VOR/DME (barrel type) and/or ADF.
With all the gizmos available now people seem to make such a song and a dance about it - KISS!
Join Date: Apr 2010
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Maybe 30 years there werent so many restrictions,less traffic...most airports where a continious idle descent is possible are those which airspace isnt overcrowded...
Handflown with idle thrust aint a real challenge,or was it 30 years ago?
Handflown with idle thrust aint a real challenge,or was it 30 years ago?
Maybe 30 years there werent so many restrictions,less traffic...most airports where a continious idle descent is possible are those which airspace isnt overcrowded...
Handflown with idle thrust aint a real challenge,or was it 30 years ago?
Join Date: Aug 2010
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Oh boy...
I am one of the computer gamers, but I will give you a perfect CDA anytime, provided I have any information about track miles. That has nothing to do with hand-flying or computers, but is simple math. Loose 3000' per 10 miles and calculate about 4-5 miles for a 50 knot speed reduction and you can't go wrong. Throw in some experience on your aircraft (sub-type, weight) and ATC to make it perfect. Add/subtract another few miles (FEW!) to your initial descent point for wind and you are in a perfect position for idle power till glide path intercept...
LHR is one of the airports where this works really well, although not on idle power... CDA required below 6000', however the minimum descent rate may be less than the UK norm of 500'/min. CDA is given, if a descent of 50' in 4 miles (might be 5 or 6 even) is done and that is not really hard to achieve... The technique used in the first post makes me wonder, why I plan for a CDA approach every single time...
One of my instructors once said that one should rather go for the challenge and if you are bit high, you can always use a speed brake...
PS: The Airbus calculates its decent in a very conservative way, so being up to 500'-1000' high on its calculated profile (PROGRESS page on MCDU) will most propably still give you a stable approach.
I am one of the computer gamers, but I will give you a perfect CDA anytime, provided I have any information about track miles. That has nothing to do with hand-flying or computers, but is simple math. Loose 3000' per 10 miles and calculate about 4-5 miles for a 50 knot speed reduction and you can't go wrong. Throw in some experience on your aircraft (sub-type, weight) and ATC to make it perfect. Add/subtract another few miles (FEW!) to your initial descent point for wind and you are in a perfect position for idle power till glide path intercept...
LHR is one of the airports where this works really well, although not on idle power... CDA required below 6000', however the minimum descent rate may be less than the UK norm of 500'/min. CDA is given, if a descent of 50' in 4 miles (might be 5 or 6 even) is done and that is not really hard to achieve... The technique used in the first post makes me wonder, why I plan for a CDA approach every single time...
One of my instructors once said that one should rather go for the challenge and if you are bit high, you can always use a speed brake...
PS: The Airbus calculates its decent in a very conservative way, so being up to 500'-1000' high on its calculated profile (PROGRESS page on MCDU) will most propably still give you a stable approach.
