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HamiltonAir Member
Joined: 25 Dec 2006 Posts: 937 Location: Bangalore
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Posted: Tue Mar 20, 2007 5:52 pm Post subject: Crosswind landing |
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Hi guyz, sorry if this topic has been discussed before, but, how does a crosswind landing work?
Regards, _________________ HamiltonAir |
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HAWK21M Member
Joined: 19 Dec 2006 Posts: 8132 Location: Mumbai, INDIA
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the_380 Member
Joined: 19 Dec 2006 Posts: 2329 Location: Mumbai, India
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Posted: Tue Mar 20, 2007 9:10 pm Post subject: |
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I have experienced a heavy crosswind landing once at BBI...we had to abort landing in the first attempt then we decided to divert to Raipur but then hopefully the pilot decided to make another attempt and we landed succesfully.
The best would have been viewing all this from the cockpit!!! _________________ http://www.myspace.com/avsatsworld
A Walt Disney and 20th Century Fox Audio Producer!!!
Last edited by the_380 on Wed Mar 21, 2007 11:55 am; edited 1 time in total |
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the_380 Member
Joined: 19 Dec 2006 Posts: 2329 Location: Mumbai, India
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Birendra Member
Joined: 15 Feb 2007 Posts: 1411
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Posted: Wed Mar 21, 2007 8:18 am Post subject: |
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the_380 wrote: | I have experienced a heavy crosswind landing once at BBI...we had to abort landing in the first attempt then we decided to divert to Raipur but then hopefully the pilot decided to make another attempt and we landed succesfully.
The best was viewing all this from the cockpit!!! |
u were in the cockpit during time of landing? |
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stealthpilot Member
Joined: 19 Dec 2006 Posts: 2325 Location: BLR, DXB
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Posted: Wed Mar 21, 2007 9:58 am Post subject: |
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HamiltonAir, I can't talk about the big jets, but for smaller aircrafts the basic idea is ailerons into the wind and opposite rudder.
For example, landing in a northerly direction (runway 36) with winds coming out of the west you would bank left and apply right rudder. How much? Well depends on the cross wind component. You usually calculate and are worried about the direct cross wind component, because the other component should be a headwind.
On the PA44 the max cross wind component is 17 knots or so, it’s probably twice that for a big commercial aircraft.
The aircraft can land on one wheel- with one wing high/low. In a stiff crosswind that’s what you want to do, you bank (left) and right rudder which keeps you descending left wing low, but your nose will point in the direction of the runway (try and visualise it)
If you didn’t apply cross wind correction, you would crab. That is, fly straight and level but your nose would be 10 degrees off the runway heading. (Landing on runway 36 with winds from 280, your nose would point 340 but your ground track would be 360)
That is bad for the landing gear; ideally you want to land pointing 360. _________________ eP007 |
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the_380 Member
Joined: 19 Dec 2006 Posts: 2329 Location: Mumbai, India
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Posted: Wed Mar 21, 2007 11:53 am Post subject: |
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Birendra wrote: |
u were in the cockpit during time of landing? |
Sorry meant to say the best thing would have been viewing all this from the cockpit. I wasn't in the cockpit _________________ http://www.myspace.com/avsatsworld
A Walt Disney and 20th Century Fox Audio Producer!!! |
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stealthpilot Member
Joined: 19 Dec 2006 Posts: 2325 Location: BLR, DXB
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Posted: Thu Mar 22, 2007 8:26 am Post subject: |
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the_380 wrote: | then we decided to divert to Raipur but then hopefully the pilot decided to make another attempt and we landed succesfully. |
How do you know the pilot decided to divert because of a crosswind?
... and I think you meant thankfully, not hopefully _________________ eP007 |
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HAWK21M Member
Joined: 19 Dec 2006 Posts: 8132 Location: Mumbai, INDIA
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Posted: Thu Mar 22, 2007 8:41 am Post subject: |
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Remember the East West B732 that attempted to land in Bad weather at COK.Wing tip struck the Runway while attempting to land & the Aircraft diverted to CJB.
Amazing Skill & Luck
The Pilot is now Flying for 9W.
regds
MEL _________________ Think of the Brighter side !!! |
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the_380 Member
Joined: 19 Dec 2006 Posts: 2329 Location: Mumbai, India
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Posted: Thu Mar 22, 2007 1:23 pm Post subject: |
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stealthpilot wrote: |
How do you know the pilot decided to divert because of a crosswind?
... and I think you meant thankfully, not hopefully |
Well i guess thankfully would be better
And the P1 announced that they would make a final attempt and if that was unsuccessful then we would request for a diversion to either Raipur or CCU _________________ http://www.myspace.com/avsatsworld
A Walt Disney and 20th Century Fox Audio Producer!!! |
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HamiltonAir Member
Joined: 25 Dec 2006 Posts: 937 Location: Bangalore
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Posted: Fri Mar 23, 2007 3:26 pm Post subject: |
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stealthpilot wrote: | HamiltonAir, I can't talk about the big jets, but for smaller aircrafts the basic idea is ailerons into the wind and opposite rudder.
For example, landing in a northerly direction (runway 36) with winds coming out of the west you would bank left and apply right rudder. How much? Well depends on the cross wind component. You usually calculate and are worried about the direct cross wind component, because the other component should be a headwind.
On the PA44 the max cross wind component is 17 knots or so, it’s probably twice that for a big commercial aircraft.
The aircraft can land on one wheel- with one wing high/low. In a stiff crosswind that’s what you want to do, you bank (left) and right rudder which keeps you descending left wing low, but your nose will point in the direction of the runway (try and visualise it)
If you didn’t apply cross wind correction, you would crab. That is, fly straight and level but your nose would be 10 degrees off the runway heading. (Landing on runway 36 with winds from 280, your nose would point 340 but your ground track would be 360)
That is bad for the landing gear; ideally you want to land pointing 360. |
Thanks mate, that was quite some information. Another thing, how accurate is a crosswind landing with the help of Autopilot? or is an Autoland considered during such situations? _________________ HamiltonAir |
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stealthpilot Member
Joined: 19 Dec 2006 Posts: 2325 Location: BLR, DXB
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Posted: Sat Mar 24, 2007 9:22 am Post subject: |
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Just adding/revising what I said last time.....
From what I now understand- most airlines will maintain a crab all the way down to the flare and then kick in the rudder (as opposed to the wing low method during descent)
I'm not too sure about this next comment, maybe Mel or someone can help us out but I believe the crosswind limit is based on how much rudder is needed to keep the aircraft on course and land without hurting the landing gear. Technically, you could land an aircraft with its nose 30 degrees off the centerline, but that would overstress the gear.
HamiltonAir wrote: | Thanks mate, that was quite some information. Another thing, how accurate is a crosswind landing with the help of Autopilot? or is an Autoland considered during such situations? |
Can't really give you the best answer here, sorry. I'm not too sure about all this (I still fly props hehehehe)
Anyway let's see what I do know. On any CAT3C equipped aircraft it's obviously not a problem provided the winds are within a specified envelope. (Those limitations will be lower than normal during an autoland). For example, if the crosswind limit is 30 knots to hand fly it; it would be 20 knots for an autoland.
I believe on a CAT 3b 744 the autopilot does a self check at 1000(?) feet (checks the 3 autopilots) and if there is any fault detected it warns the pilots and the autoland feature disengages. If the AP self checks (called a confidence check) and detects a fault, it will either downgrade itself to a CAT2/1 or not permit an autopilot descent.
If it's a CAT 1 or 2, I believe it can land with one AP inoperative. During the confidence check if one AP is not working satisfactorily it just gets kicked offline and the remaining 2 take over.
In either case, as long as it’s not a CAT 3C the pilots take over at minimums and land the aircraft.
Now with that background knowledge, to answer your question
Since there are no CAT3C ops in India as far as I know, the autopilots will have control down to minimums before the pilots take over. They are pretty good at flying in a crosswind. The FMS gets a bunch of data from multiple systems and knows the wind speeds/directions/crosswind components. They use that data in conjunction with a whole lot of other stuff (radio altimeter etc) and have a pretty good idea of what’s going on .
As long as the winds are not really strong and within the manufactures limits of a crosswind landing, I see no reason for an autoland to be unsafe. _________________ eP007 |
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HamiltonAir Member
Joined: 25 Dec 2006 Posts: 937 Location: Bangalore
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Posted: Sat Mar 24, 2007 7:28 pm Post subject: |
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Thanx stealthpilot, that was some great information!
Regards, _________________ HamiltonAir |
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