Amberair732 From , joined Dec 1969, posts, RR: Posted (9 years 11 months 2 weeks 6 days 22 hours ago) and read 3520 times:
Hello everyone. This may have been discussed before, but I can't find it so please point me in the right direction if it has. Here goes.
Having spent a lot of time at BLK recently - it's opposite my house - I have noticed that the FR 738's which land here appear to have a slower approach speed if they have winglets.
Could any of our experts out there tell me if the extra lift provided by winglets on a 738 ( or any other aircraft ) would be sufficient to produce a noticeably slower approach speed or for that matter take off speed, or have I been sat in the sun for too long.
777WT From United States of America, joined Jan 2005, 881 posts, RR: 1
Reply 2, posted (9 years 11 months 2 weeks 6 days 20 hours ago) and read 3482 times:
It's only a few knots slower the most.
CO had a problem with CAT III autoland with their 752 after addition of APB blended winglets and during flight testing. It was 'floating' a bit longer during flare, an solution has been used to fix the float. I do not know what the solution is.
EssentialPowr From United States of America, joined Sep 2000, 1820 posts, RR: 1
Reply 4, posted (9 years 11 months 2 weeks 6 days 15 hours ago) and read 3424 times:
Quoting CptSpeaking (Reply 3): I was under the impression that US part 121 carriers were prohibited from CAT III approaches...is it the specific airlines that restrict them, the FAA, or what? That or am I way off on this one?
Waaaaaaayyyy off. A 777 for any US airline is capable of a SINGLE ENGINE Cat 111.
The winglet versions of the 737 are easier to land, ie they will float a bit at idle, Vref +5 from 20 feet Agl or so...
I realize they are capable, as well as almost any other model (737, 767, A320, yada yada yada...), but are they allowed? If so, why do so may flights get diverted for low level fog or other limiting weather?
I saw a video on flightlevel350.com of a Swiss A340 on a CAT III autoland that was pretty sweet...you see the spoilers deploy and then see the runway edge lights barely appear.
IAHFLYR From United States of America, joined Jun 2005, 4790 posts, RR: 21
Reply 7, posted (9 years 11 months 2 weeks 6 days 7 hours ago) and read 3380 times:
Quoting CptSpeaking (Reply 5): I realize they are capable, as well as almost any other model (737, 767, A320, yada yada yada...), but are they allowed? If so, why do so may flights get diverted for low level fog or other limiting weather?
I can't think of an airline with aircraft that are certified for CATIII ops that don't use them. There is an issue of crew training and currency for sure so that could acocunt for some diverts but for the most part not to big an issue.
Most diverts at IAH due to low vsby is due to the crew not being qualified fot CATIIIB and the RVR being less than 600'....but that just doesn't happen more than a few months out of the year.....some of it could be they get all balled up in a holding pattern with aircraft that are not CATIII able and the center for whatever reason can't get them out of it before they have no more gas to hang around.
There are other reasons for diverts such as flow rates at the airport going to hell if the fog wasn't forecast and a much lower arrival rate has to be put in place. Or, the airport has departure runways that are dependent on arrivals not missing an approach or you'll might have 2 airplanes in the same place, one departure and the other a missed approach. IAH is a good example of an airport that can take about 130 arrivals an hour but can't get departures out in low weather conditions due to having to protect for the missed on 27 crossing the 15 complex.
But back to the original post.....: winglets on the 800's I hear do make them easier to land but don't change the ref speed from around 155 kts on the 800's with flaps 30.....but folks sure don't like following them on final too close.
[Edited 2006-06-15 15:00:20]
Any views shared are strictly my own and do not a represent those of any former employer.
Quoting IAHFLYR (Reply 7): I can't think of an airline with aircraft that are certified for CATIII ops that don't use them. There is an issue of crew training and currency for sure so that could acocunt for some diverts but for the most part not to big an issue.