For airliners, what prevents wing strikes on landing in bad weather?
$begingroup$
For any low-wing aircraft, particularly the MD-80 or some of the private jets, CRJ's, the wings appear about 5ft or less above the ground. It seems that just few degrees of roll before touchdown would cause a wing strike on the runway and a disaster.
How do pilots and aircraft manufacturers avoid this ? It seems like with the thousands of daily flights - in all sorts of inclement weather conditions - this (fortunately) isn't a problem. (I'm not saying it's never happened, just that it seems exceptionally rare.)
So my question is, why isn't this a serious problem? I would expect turburlence and wind gusts to do all sorts of unpleasant things to aircraft, one of which might be disrupting the roll a couple degrees and planting the wingtip into the runway. What steps do pilots and aircraft designers take to mitigate this?
aircraft-design airliner pilot-technique
asked 10 hours ago
mikemike
321126
$endgroup$
add a comment |
$begingroup$
For any low-wing aircraft, particularly the MD-80 or some of the private jets, CRJ's, the wings appear about 5ft or less above the ground. It seems that just few degrees of roll before touchdown would cause a wing strike on the runway and a disaster.
How do pilots and aircraft manufacturers avoid this ? It seems like with the thousands of daily flights - in all sorts of inclement weather conditions - this (fortunately) isn't a problem. (I'm not saying it's never happened, just that it seems exceptionally rare.)
So my question is, why isn't this a serious problem? I would expect turburlence and wind gusts to do all sorts of unpleasant things to aircraft, one of which might be disrupting the roll a couple degrees and planting the wingtip into the runway. What steps do pilots and aircraft designers take to mitigate this?
aircraft-design airliner pilot-technique
asked 10 hours ago
mikemike
321126
$endgroup$
4
$begingroup$
Pilots? If the crosswind/gusts are too much to handle, you use another runway or go to another airport.
$endgroup$
– jamesqf
7 hours ago
$begingroup$
Remember that while for regulation the wings are bended "downwards", and the bending needs to be taken into account. However while it is landing the wings are bended "upwards" as lift is more than gravity of the wing itself, only after full touchdown with all wheels the lift becomes zero.
$endgroup$
– paul23
42 mins ago
add a comment |
$begingroup$
For any low-wing aircraft, particularly the MD-80 or some of the private jets, CRJ's, the wings appear about 5ft or less above the ground. It seems that just few degrees of roll before touchdown would cause a wing strike on the runway and a disaster.
How do pilots and aircraft manufacturers avoid this ? It seems like with the thousands of daily flights - in all sorts of inclement weather conditions - this (fortunately) isn't a problem. (I'm not saying it's never happened, just that it seems exceptionally rare.)
So my question is, why isn't this a serious problem? I would expect turburlence and wind gusts to do all sorts of unpleasant things to aircraft, one of which might be disrupting the roll a couple degrees and planting the wingtip into the runway. What steps do pilots and aircraft designers take to mitigate this?
aircraft-design airliner pilot-technique
asked 10 hours ago
mikemike
321126
$endgroup$
For any low-wing aircraft, particularly the MD-80 or some of the private jets, CRJ's, the wings appear about 5ft or less above the ground. It seems that just few degrees of roll before touchdown would cause a wing strike on the runway and a disaster.
How do pilots and aircraft manufacturers avoid this ? It seems like with the thousands of daily flights - in all sorts of inclement weather conditions - this (fortunately) isn't a problem. (I'm not saying it's never happened, just that it seems exceptionally rare.)
So my question is, why isn't this a serious problem? I would expect turburlence and wind gusts to do all sorts of unpleasant things to aircraft, one of which might be disrupting the roll a couple degrees and planting the wingtip into the runway. What steps do pilots and aircraft designers take to mitigate this?
aircraft-design airliner pilot-technique
aircraft-design airliner pilot-technique
asked 10 hours ago
mikemike
321126
asked 10 hours ago
mikemike
321126
asked 10 hours ago
mikemike
321126
asked 10 hours ago
mikemike
321126
asked 10 hours ago
mikemike
321126
321126
4
$begingroup$
Pilots? If the crosswind/gusts are too much to handle, you use another runway or go to another airport.
$endgroup$
– jamesqf
7 hours ago
$begingroup$
Remember that while for regulation the wings are bended "downwards", and the bending needs to be taken into account. However while it is landing the wings are bended "upwards" as lift is more than gravity of the wing itself, only after full touchdown with all wheels the lift becomes zero.
$endgroup$
– paul23
42 mins ago
add a comment |
4
$begingroup$
Pilots? If the crosswind/gusts are too much to handle, you use another runway or go to another airport.
$endgroup$
– jamesqf
7 hours ago
$begingroup$
Remember that while for regulation the wings are bended "downwards", and the bending needs to be taken into account. However while it is landing the wings are bended "upwards" as lift is more than gravity of the wing itself, only after full touchdown with all wheels the lift becomes zero.
$endgroup$
– paul23
42 mins ago
4
4
$begingroup$
Pilots? If the crosswind/gusts are too much to handle, you use another runway or go to another airport.
$endgroup$
– jamesqf
7 hours ago
$begingroup$
Pilots? If the crosswind/gusts are too much to handle, you use another runway or go to another airport.
$endgroup$
– jamesqf
7 hours ago
$begingroup$
Remember that while for regulation the wings are bended "downwards", and the bending needs to be taken into account. However while it is landing the wings are bended "upwards" as lift is more than gravity of the wing itself, only after full touchdown with all wheels the lift becomes zero.
$endgroup$
– paul23
42 mins ago
$begingroup$
Remember that while for regulation the wings are bended "downwards", and the bending needs to be taken into account. However while it is landing the wings are bended "upwards" as lift is more than gravity of the wing itself, only after full touchdown with all wheels the lift becomes zero.
$endgroup$
– paul23
42 mins ago
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
It's not how high the wing is off the ground, but the angle between the main landing gear when compressed and the tip of the wing (which with the wing dihedral makes it even higher off the ground – on the MD-80 that's 2.8 m / 9'1"). This will be the roll angle limit.
It's for that reason, unlike smaller high-wing general aviation planes, big jet-liners don't decrab as much in a crosswind landing, whereas decrabbing (going one-wing-low) would be a problem. From an MD-80 flight manual:
Crosswind Landing
On final approach, establish a crab angle into the wind to hold the aircraft on the extended centerline of the runway. Maintain the crab angle until just before touchdown, then use the rudder to align the aircraft with the runway. The touchdown is made with cross-controls as necessary to track straight down the runway. Keep wings as level as possible as the wingtip will touch at an 8° bank angle. Do not hold off downwind wheels; prompt and firm runway contact will greatly assist in rollout stabilization.
So the prevention is respecting the limits, good training, and knowing when the weather is too gusty to just abort the landing.
It does remain a concern though. Wikipedia has an article on it, and the issue would also affect the engine when wing mounted, but with the engine typically forward of the wing, it's given better clearance when the nose is still higher for flaring. The A320 accident mentioned on Wikipedia seems to have been the result of both pilots controlling the plane during landing.
In 1997 a 747 hit the runway with the outer engine when landing in Kai Tak:
(flickr.com)
A more recent one is a Bombardier Global 6000 in 2014.
answered 9 hours ago
ymb1ymb1
68.3k7216363
$endgroup$
1
$begingroup$
Thank you for the data. I attempted to look up the MD-80 "wing height" from google before posting and I couldn't find it, so I guessed. Also thank you for mentioning decrabbing. I knew of the concept and mentioning it in my question would have made my intent clearer. Because if a pilot were to decrab, that further lowers the error margin on that side's wing.Is the situation any worse for private jets such as a Citation? I would expect them to get blown around much more due to having less mass.
$endgroup$
– mike
9 hours ago
2
$begingroup$
@mike The effect of crosswind also varies with fuselage side area, which is generally going to be lower if the mass is lower. If you decrab late enough, inertia will keep you on the centerline just long enough to touch down before the crosswind accelerates you sideways. The stronger the crosswind, the later you have to decrab and thus the more skill required. If you decrab too early, you have to sideslip, which risks an expensive wing tip or engine strike.
$endgroup$
– StephenS
8 hours ago
$begingroup$
Kai Tak was a graveyard for engine and wing strikes... even on a good day it was a nightmare. When a suitably performant aircraft might legitimately consider a split-s as a reasonable approach pattern, you know there's going to be some excitement.
$endgroup$
– J...
2 hours ago
add a comment |
$begingroup$
On heavies, as ymb1's answer shows, the wings level crab and kick method (basically air-skidding into the touchdown) is used because the mass of the airplane means you don't have the roll rate necessary to screw around safely with the wing tips close to the surface. On the other hand, the mass gives a good delay between initiating the skid into the crosswind and the airplane starting to drift laterally (because you are in effect in a skidding turn and eventually you will start turning, which is perceived as a downwind drift) so it favours this technique.
On lighter jets like Regionals and corporate, you use light aircraft side slip technique, wing down with rudder to align with the runway. On the CRJ IIRC, you have about 8-10 degrees of roll available before wingtip contact, which is actually quite a bit. Side slipping to correct for a crosswind when you are at 125-135 kt rarely requires more than, say, 5 degrees of bank.
If a crosswind is strong enough to require more than 5 degrees, you usually end up touching down with a bit of crab in, or you may use an extra shot of rudder to kick it straight without lowering the wing any more, and lower the nose more aggressively to plant the plane right away before it starts to drift because you have more rudder than necessary for the bank (and live with a firm touchdown).
That being said, on the CRJ fleet there are usually several wing tip strikes a year during crosswind landings in gusty conditions, where a gust dropped the wing more than expected. The result is usually just a bit of wing tip road rash. Winglet repair schemes are a recurring event at the OEM's support organization.
answered 7 hours ago
John KJohn K
23k13267
$endgroup$
$begingroup$
"wing tip road rash". Holy moly, that's terrifying but reassuring at the same time, knowing the aircraft can take that kind of abuse if absolutely necessary.
$endgroup$
– mike
5 hours ago
1
$begingroup$
By the time the tip touches the pilot flying already has counteracting aileron applied, just not enough soon enough, and airplanes like the RJ have really powerful roll control, so the tip is off the ground again right away.
$endgroup$
– John K
5 hours ago
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "528"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e) {
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom)) {
StackExchange.using('gps', function() { StackExchange.gps.track('embedded_signup_form.view', { location: 'question_page' }); });
$window.unbind('scroll', onScroll);
}
};
$window.on('scroll', onScroll);
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2faviation.stackexchange.com%2fquestions%2f61610%2ffor-airliners-what-prevents-wing-strikes-on-landing-in-bad-weather%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
It's not how high the wing is off the ground, but the angle between the main landing gear when compressed and the tip of the wing (which with the wing dihedral makes it even higher off the ground – on the MD-80 that's 2.8 m / 9'1"). This will be the roll angle limit.
It's for that reason, unlike smaller high-wing general aviation planes, big jet-liners don't decrab as much in a crosswind landing, whereas decrabbing (going one-wing-low) would be a problem. From an MD-80 flight manual:
Crosswind Landing
On final approach, establish a crab angle into the wind to hold the aircraft on the extended centerline of the runway. Maintain the crab angle until just before touchdown, then use the rudder to align the aircraft with the runway. The touchdown is made with cross-controls as necessary to track straight down the runway. Keep wings as level as possible as the wingtip will touch at an 8° bank angle. Do not hold off downwind wheels; prompt and firm runway contact will greatly assist in rollout stabilization.
So the prevention is respecting the limits, good training, and knowing when the weather is too gusty to just abort the landing.
It does remain a concern though. Wikipedia has an article on it, and the issue would also affect the engine when wing mounted, but with the engine typically forward of the wing, it's given better clearance when the nose is still higher for flaring. The A320 accident mentioned on Wikipedia seems to have been the result of both pilots controlling the plane during landing.
In 1997 a 747 hit the runway with the outer engine when landing in Kai Tak:
(flickr.com)
A more recent one is a Bombardier Global 6000 in 2014.
answered 9 hours ago
ymb1ymb1
68.3k7216363
$endgroup$
1
$begingroup$
Thank you for the data. I attempted to look up the MD-80 "wing height" from google before posting and I couldn't find it, so I guessed. Also thank you for mentioning decrabbing. I knew of the concept and mentioning it in my question would have made my intent clearer. Because if a pilot were to decrab, that further lowers the error margin on that side's wing.Is the situation any worse for private jets such as a Citation? I would expect them to get blown around much more due to having less mass.
$endgroup$
– mike
9 hours ago
2
$begingroup$
@mike The effect of crosswind also varies with fuselage side area, which is generally going to be lower if the mass is lower. If you decrab late enough, inertia will keep you on the centerline just long enough to touch down before the crosswind accelerates you sideways. The stronger the crosswind, the later you have to decrab and thus the more skill required. If you decrab too early, you have to sideslip, which risks an expensive wing tip or engine strike.
$endgroup$
– StephenS
8 hours ago
$begingroup$
Kai Tak was a graveyard for engine and wing strikes... even on a good day it was a nightmare. When a suitably performant aircraft might legitimately consider a split-s as a reasonable approach pattern, you know there's going to be some excitement.
$endgroup$
– J...
2 hours ago
add a comment |
$begingroup$
It's not how high the wing is off the ground, but the angle between the main landing gear when compressed and the tip of the wing (which with the wing dihedral makes it even higher off the ground – on the MD-80 that's 2.8 m / 9'1"). This will be the roll angle limit.
It's for that reason, unlike smaller high-wing general aviation planes, big jet-liners don't decrab as much in a crosswind landing, whereas decrabbing (going one-wing-low) would be a problem. From an MD-80 flight manual:
Crosswind Landing
On final approach, establish a crab angle into the wind to hold the aircraft on the extended centerline of the runway. Maintain the crab angle until just before touchdown, then use the rudder to align the aircraft with the runway. The touchdown is made with cross-controls as necessary to track straight down the runway. Keep wings as level as possible as the wingtip will touch at an 8° bank angle. Do not hold off downwind wheels; prompt and firm runway contact will greatly assist in rollout stabilization.
So the prevention is respecting the limits, good training, and knowing when the weather is too gusty to just abort the landing.
It does remain a concern though. Wikipedia has an article on it, and the issue would also affect the engine when wing mounted, but with the engine typically forward of the wing, it's given better clearance when the nose is still higher for flaring. The A320 accident mentioned on Wikipedia seems to have been the result of both pilots controlling the plane during landing.
In 1997 a 747 hit the runway with the outer engine when landing in Kai Tak:
(flickr.com)
A more recent one is a Bombardier Global 6000 in 2014.
answered 9 hours ago
ymb1ymb1
68.3k7216363
$endgroup$
1
$begingroup$
Thank you for the data. I attempted to look up the MD-80 "wing height" from google before posting and I couldn't find it, so I guessed. Also thank you for mentioning decrabbing. I knew of the concept and mentioning it in my question would have made my intent clearer. Because if a pilot were to decrab, that further lowers the error margin on that side's wing.Is the situation any worse for private jets such as a Citation? I would expect them to get blown around much more due to having less mass.
$endgroup$
– mike
9 hours ago
2
$begingroup$
@mike The effect of crosswind also varies with fuselage side area, which is generally going to be lower if the mass is lower. If you decrab late enough, inertia will keep you on the centerline just long enough to touch down before the crosswind accelerates you sideways. The stronger the crosswind, the later you have to decrab and thus the more skill required. If you decrab too early, you have to sideslip, which risks an expensive wing tip or engine strike.
$endgroup$
– StephenS
8 hours ago
$begingroup$
Kai Tak was a graveyard for engine and wing strikes... even on a good day it was a nightmare. When a suitably performant aircraft might legitimately consider a split-s as a reasonable approach pattern, you know there's going to be some excitement.
$endgroup$
– J...
2 hours ago
add a comment |
$begingroup$
It's not how high the wing is off the ground, but the angle between the main landing gear when compressed and the tip of the wing (which with the wing dihedral makes it even higher off the ground – on the MD-80 that's 2.8 m / 9'1"). This will be the roll angle limit.
It's for that reason, unlike smaller high-wing general aviation planes, big jet-liners don't decrab as much in a crosswind landing, whereas decrabbing (going one-wing-low) would be a problem. From an MD-80 flight manual:
Crosswind Landing
On final approach, establish a crab angle into the wind to hold the aircraft on the extended centerline of the runway. Maintain the crab angle until just before touchdown, then use the rudder to align the aircraft with the runway. The touchdown is made with cross-controls as necessary to track straight down the runway. Keep wings as level as possible as the wingtip will touch at an 8° bank angle. Do not hold off downwind wheels; prompt and firm runway contact will greatly assist in rollout stabilization.
So the prevention is respecting the limits, good training, and knowing when the weather is too gusty to just abort the landing.
It does remain a concern though. Wikipedia has an article on it, and the issue would also affect the engine when wing mounted, but with the engine typically forward of the wing, it's given better clearance when the nose is still higher for flaring. The A320 accident mentioned on Wikipedia seems to have been the result of both pilots controlling the plane during landing.
In 1997 a 747 hit the runway with the outer engine when landing in Kai Tak:
(flickr.com)
A more recent one is a Bombardier Global 6000 in 2014.
answered 9 hours ago
ymb1ymb1
68.3k7216363
$endgroup$
It's not how high the wing is off the ground, but the angle between the main landing gear when compressed and the tip of the wing (which with the wing dihedral makes it even higher off the ground – on the MD-80 that's 2.8 m / 9'1"). This will be the roll angle limit.
It's for that reason, unlike smaller high-wing general aviation planes, big jet-liners don't decrab as much in a crosswind landing, whereas decrabbing (going one-wing-low) would be a problem. From an MD-80 flight manual:
Crosswind Landing
On final approach, establish a crab angle into the wind to hold the aircraft on the extended centerline of the runway. Maintain the crab angle until just before touchdown, then use the rudder to align the aircraft with the runway. The touchdown is made with cross-controls as necessary to track straight down the runway. Keep wings as level as possible as the wingtip will touch at an 8° bank angle. Do not hold off downwind wheels; prompt and firm runway contact will greatly assist in rollout stabilization.
So the prevention is respecting the limits, good training, and knowing when the weather is too gusty to just abort the landing.
It does remain a concern though. Wikipedia has an article on it, and the issue would also affect the engine when wing mounted, but with the engine typically forward of the wing, it's given better clearance when the nose is still higher for flaring. The A320 accident mentioned on Wikipedia seems to have been the result of both pilots controlling the plane during landing.
In 1997 a 747 hit the runway with the outer engine when landing in Kai Tak:
(flickr.com)
A more recent one is a Bombardier Global 6000 in 2014.
answered 9 hours ago
ymb1ymb1
68.3k7216363
edited 8 hours ago
answered 9 hours ago
ymb1ymb1
68.3k7216363
answered 9 hours ago
ymb1ymb1
68.3k7216363
answered 9 hours ago
ymb1ymb1
68.3k7216363
68.3k7216363
1
$begingroup$
Thank you for the data. I attempted to look up the MD-80 "wing height" from google before posting and I couldn't find it, so I guessed. Also thank you for mentioning decrabbing. I knew of the concept and mentioning it in my question would have made my intent clearer. Because if a pilot were to decrab, that further lowers the error margin on that side's wing.Is the situation any worse for private jets such as a Citation? I would expect them to get blown around much more due to having less mass.
$endgroup$
– mike
9 hours ago
2
$begingroup$
@mike The effect of crosswind also varies with fuselage side area, which is generally going to be lower if the mass is lower. If you decrab late enough, inertia will keep you on the centerline just long enough to touch down before the crosswind accelerates you sideways. The stronger the crosswind, the later you have to decrab and thus the more skill required. If you decrab too early, you have to sideslip, which risks an expensive wing tip or engine strike.
$endgroup$
– StephenS
8 hours ago
$begingroup$
Kai Tak was a graveyard for engine and wing strikes... even on a good day it was a nightmare. When a suitably performant aircraft might legitimately consider a split-s as a reasonable approach pattern, you know there's going to be some excitement.
$endgroup$
– J...
2 hours ago
add a comment |
1
$begingroup$
Thank you for the data. I attempted to look up the MD-80 "wing height" from google before posting and I couldn't find it, so I guessed. Also thank you for mentioning decrabbing. I knew of the concept and mentioning it in my question would have made my intent clearer. Because if a pilot were to decrab, that further lowers the error margin on that side's wing.Is the situation any worse for private jets such as a Citation? I would expect them to get blown around much more due to having less mass.
$endgroup$
– mike
9 hours ago
2
$begingroup$
@mike The effect of crosswind also varies with fuselage side area, which is generally going to be lower if the mass is lower. If you decrab late enough, inertia will keep you on the centerline just long enough to touch down before the crosswind accelerates you sideways. The stronger the crosswind, the later you have to decrab and thus the more skill required. If you decrab too early, you have to sideslip, which risks an expensive wing tip or engine strike.
$endgroup$
– StephenS
8 hours ago
$begingroup$
Kai Tak was a graveyard for engine and wing strikes... even on a good day it was a nightmare. When a suitably performant aircraft might legitimately consider a split-s as a reasonable approach pattern, you know there's going to be some excitement.
$endgroup$
– J...
2 hours ago
1
1
$begingroup$
Thank you for the data. I attempted to look up the MD-80 "wing height" from google before posting and I couldn't find it, so I guessed. Also thank you for mentioning decrabbing. I knew of the concept and mentioning it in my question would have made my intent clearer. Because if a pilot were to decrab, that further lowers the error margin on that side's wing.Is the situation any worse for private jets such as a Citation? I would expect them to get blown around much more due to having less mass.
$endgroup$
– mike
9 hours ago
$begingroup$
Thank you for the data. I attempted to look up the MD-80 "wing height" from google before posting and I couldn't find it, so I guessed. Also thank you for mentioning decrabbing. I knew of the concept and mentioning it in my question would have made my intent clearer. Because if a pilot were to decrab, that further lowers the error margin on that side's wing.Is the situation any worse for private jets such as a Citation? I would expect them to get blown around much more due to having less mass.
$endgroup$
– mike
9 hours ago
2
2
$begingroup$
@mike The effect of crosswind also varies with fuselage side area, which is generally going to be lower if the mass is lower. If you decrab late enough, inertia will keep you on the centerline just long enough to touch down before the crosswind accelerates you sideways. The stronger the crosswind, the later you have to decrab and thus the more skill required. If you decrab too early, you have to sideslip, which risks an expensive wing tip or engine strike.
$endgroup$
– StephenS
8 hours ago
$begingroup$
@mike The effect of crosswind also varies with fuselage side area, which is generally going to be lower if the mass is lower. If you decrab late enough, inertia will keep you on the centerline just long enough to touch down before the crosswind accelerates you sideways. The stronger the crosswind, the later you have to decrab and thus the more skill required. If you decrab too early, you have to sideslip, which risks an expensive wing tip or engine strike.
$endgroup$
– StephenS
8 hours ago
$begingroup$
Kai Tak was a graveyard for engine and wing strikes... even on a good day it was a nightmare. When a suitably performant aircraft might legitimately consider a split-s as a reasonable approach pattern, you know there's going to be some excitement.
$endgroup$
– J...
2 hours ago
$begingroup$
Kai Tak was a graveyard for engine and wing strikes... even on a good day it was a nightmare. When a suitably performant aircraft might legitimately consider a split-s as a reasonable approach pattern, you know there's going to be some excitement.
$endgroup$
– J...
2 hours ago
add a comment |
$begingroup$
On heavies, as ymb1's answer shows, the wings level crab and kick method (basically air-skidding into the touchdown) is used because the mass of the airplane means you don't have the roll rate necessary to screw around safely with the wing tips close to the surface. On the other hand, the mass gives a good delay between initiating the skid into the crosswind and the airplane starting to drift laterally (because you are in effect in a skidding turn and eventually you will start turning, which is perceived as a downwind drift) so it favours this technique.
On lighter jets like Regionals and corporate, you use light aircraft side slip technique, wing down with rudder to align with the runway. On the CRJ IIRC, you have about 8-10 degrees of roll available before wingtip contact, which is actually quite a bit. Side slipping to correct for a crosswind when you are at 125-135 kt rarely requires more than, say, 5 degrees of bank.
If a crosswind is strong enough to require more than 5 degrees, you usually end up touching down with a bit of crab in, or you may use an extra shot of rudder to kick it straight without lowering the wing any more, and lower the nose more aggressively to plant the plane right away before it starts to drift because you have more rudder than necessary for the bank (and live with a firm touchdown).
That being said, on the CRJ fleet there are usually several wing tip strikes a year during crosswind landings in gusty conditions, where a gust dropped the wing more than expected. The result is usually just a bit of wing tip road rash. Winglet repair schemes are a recurring event at the OEM's support organization.
answered 7 hours ago
John KJohn K
23k13267
$endgroup$
$begingroup$
"wing tip road rash". Holy moly, that's terrifying but reassuring at the same time, knowing the aircraft can take that kind of abuse if absolutely necessary.
$endgroup$
– mike
5 hours ago
1
$begingroup$
By the time the tip touches the pilot flying already has counteracting aileron applied, just not enough soon enough, and airplanes like the RJ have really powerful roll control, so the tip is off the ground again right away.
$endgroup$
– John K
5 hours ago
add a comment |
$begingroup$
On heavies, as ymb1's answer shows, the wings level crab and kick method (basically air-skidding into the touchdown) is used because the mass of the airplane means you don't have the roll rate necessary to screw around safely with the wing tips close to the surface. On the other hand, the mass gives a good delay between initiating the skid into the crosswind and the airplane starting to drift laterally (because you are in effect in a skidding turn and eventually you will start turning, which is perceived as a downwind drift) so it favours this technique.
On lighter jets like Regionals and corporate, you use light aircraft side slip technique, wing down with rudder to align with the runway. On the CRJ IIRC, you have about 8-10 degrees of roll available before wingtip contact, which is actually quite a bit. Side slipping to correct for a crosswind when you are at 125-135 kt rarely requires more than, say, 5 degrees of bank.
If a crosswind is strong enough to require more than 5 degrees, you usually end up touching down with a bit of crab in, or you may use an extra shot of rudder to kick it straight without lowering the wing any more, and lower the nose more aggressively to plant the plane right away before it starts to drift because you have more rudder than necessary for the bank (and live with a firm touchdown).
That being said, on the CRJ fleet there are usually several wing tip strikes a year during crosswind landings in gusty conditions, where a gust dropped the wing more than expected. The result is usually just a bit of wing tip road rash. Winglet repair schemes are a recurring event at the OEM's support organization.
answered 7 hours ago
John KJohn K
23k13267
$endgroup$
$begingroup$
"wing tip road rash". Holy moly, that's terrifying but reassuring at the same time, knowing the aircraft can take that kind of abuse if absolutely necessary.
$endgroup$
– mike
5 hours ago
1
$begingroup$
By the time the tip touches the pilot flying already has counteracting aileron applied, just not enough soon enough, and airplanes like the RJ have really powerful roll control, so the tip is off the ground again right away.
$endgroup$
– John K
5 hours ago
add a comment |
$begingroup$
On heavies, as ymb1's answer shows, the wings level crab and kick method (basically air-skidding into the touchdown) is used because the mass of the airplane means you don't have the roll rate necessary to screw around safely with the wing tips close to the surface. On the other hand, the mass gives a good delay between initiating the skid into the crosswind and the airplane starting to drift laterally (because you are in effect in a skidding turn and eventually you will start turning, which is perceived as a downwind drift) so it favours this technique.
On lighter jets like Regionals and corporate, you use light aircraft side slip technique, wing down with rudder to align with the runway. On the CRJ IIRC, you have about 8-10 degrees of roll available before wingtip contact, which is actually quite a bit. Side slipping to correct for a crosswind when you are at 125-135 kt rarely requires more than, say, 5 degrees of bank.
If a crosswind is strong enough to require more than 5 degrees, you usually end up touching down with a bit of crab in, or you may use an extra shot of rudder to kick it straight without lowering the wing any more, and lower the nose more aggressively to plant the plane right away before it starts to drift because you have more rudder than necessary for the bank (and live with a firm touchdown).
That being said, on the CRJ fleet there are usually several wing tip strikes a year during crosswind landings in gusty conditions, where a gust dropped the wing more than expected. The result is usually just a bit of wing tip road rash. Winglet repair schemes are a recurring event at the OEM's support organization.
answered 7 hours ago
John KJohn K
23k13267
$endgroup$
On heavies, as ymb1's answer shows, the wings level crab and kick method (basically air-skidding into the touchdown) is used because the mass of the airplane means you don't have the roll rate necessary to screw around safely with the wing tips close to the surface. On the other hand, the mass gives a good delay between initiating the skid into the crosswind and the airplane starting to drift laterally (because you are in effect in a skidding turn and eventually you will start turning, which is perceived as a downwind drift) so it favours this technique.
On lighter jets like Regionals and corporate, you use light aircraft side slip technique, wing down with rudder to align with the runway. On the CRJ IIRC, you have about 8-10 degrees of roll available before wingtip contact, which is actually quite a bit. Side slipping to correct for a crosswind when you are at 125-135 kt rarely requires more than, say, 5 degrees of bank.
If a crosswind is strong enough to require more than 5 degrees, you usually end up touching down with a bit of crab in, or you may use an extra shot of rudder to kick it straight without lowering the wing any more, and lower the nose more aggressively to plant the plane right away before it starts to drift because you have more rudder than necessary for the bank (and live with a firm touchdown).
That being said, on the CRJ fleet there are usually several wing tip strikes a year during crosswind landings in gusty conditions, where a gust dropped the wing more than expected. The result is usually just a bit of wing tip road rash. Winglet repair schemes are a recurring event at the OEM's support organization.
answered 7 hours ago
John KJohn K
23k13267
answered 7 hours ago
John KJohn K
23k13267
answered 7 hours ago
John KJohn K
23k13267
answered 7 hours ago
John KJohn K
23k13267
23k13267
$begingroup$
"wing tip road rash". Holy moly, that's terrifying but reassuring at the same time, knowing the aircraft can take that kind of abuse if absolutely necessary.
$endgroup$
– mike
5 hours ago
1
$begingroup$
By the time the tip touches the pilot flying already has counteracting aileron applied, just not enough soon enough, and airplanes like the RJ have really powerful roll control, so the tip is off the ground again right away.
$endgroup$
– John K
5 hours ago
add a comment |
$begingroup$
"wing tip road rash". Holy moly, that's terrifying but reassuring at the same time, knowing the aircraft can take that kind of abuse if absolutely necessary.
$endgroup$
– mike
5 hours ago
1
$begingroup$
By the time the tip touches the pilot flying already has counteracting aileron applied, just not enough soon enough, and airplanes like the RJ have really powerful roll control, so the tip is off the ground again right away.
$endgroup$
– John K
5 hours ago
$begingroup$
"wing tip road rash". Holy moly, that's terrifying but reassuring at the same time, knowing the aircraft can take that kind of abuse if absolutely necessary.
$endgroup$
– mike
5 hours ago
$begingroup$
"wing tip road rash". Holy moly, that's terrifying but reassuring at the same time, knowing the aircraft can take that kind of abuse if absolutely necessary.
$endgroup$
– mike
5 hours ago
1
1
$begingroup$
By the time the tip touches the pilot flying already has counteracting aileron applied, just not enough soon enough, and airplanes like the RJ have really powerful roll control, so the tip is off the ground again right away.
$endgroup$
– John K
5 hours ago
$begingroup$
By the time the tip touches the pilot flying already has counteracting aileron applied, just not enough soon enough, and airplanes like the RJ have really powerful roll control, so the tip is off the ground again right away.
$endgroup$
– John K
5 hours ago
add a comment |
Thanks for contributing an answer to Aviation Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e) {
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom)) {
StackExchange.using('gps', function() { StackExchange.gps.track('embedded_signup_form.view', { location: 'question_page' }); });
$window.unbind('scroll', onScroll);
}
};
$window.on('scroll', onScroll);
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2faviation.stackexchange.com%2fquestions%2f61610%2ffor-airliners-what-prevents-wing-strikes-on-landing-in-bad-weather%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e) {
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom)) {
StackExchange.using('gps', function() { StackExchange.gps.track('embedded_signup_form.view', { location: 'question_page' }); });
$window.unbind('scroll', onScroll);
}
};
$window.on('scroll', onScroll);
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e) {
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom)) {
StackExchange.using('gps', function() { StackExchange.gps.track('embedded_signup_form.view', { location: 'question_page' }); });
$window.unbind('scroll', onScroll);
}
};
$window.on('scroll', onScroll);
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e) {
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom)) {
StackExchange.using('gps', function() { StackExchange.gps.track('embedded_signup_form.view', { location: 'question_page' }); });
$window.unbind('scroll', onScroll);
}
};
$window.on('scroll', onScroll);
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
4
$begingroup$
Pilots? If the crosswind/gusts are too much to handle, you use another runway or go to another airport.
$endgroup$
– jamesqf
7 hours ago
$begingroup$
Remember that while for regulation the wings are bended "downwards", and the bending needs to be taken into account. However while it is landing the wings are bended "upwards" as lift is more than gravity of the wing itself, only after full touchdown with all wheels the lift becomes zero.
$endgroup$
– paul23
42 mins ago