# What the heck happened to see-saw this KLM 777? **URL:** \ **Category:** Factual Questions\ **Created:** [August 1, 2015, 8:29pm UTC](https://boards.straightdope.com/t/what-the-heck-happened-to-see-saw-this-klm-777/726751 "2015-08-01T20:29:36Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [August 2, 2015, 3:15pm UTC](https://boards.straightdope.com/t/what-the-heck-happened-to-see-saw-this-klm-777/726751/21 "2015-08-02T15:15:08Z")
My scariest crosswind landing tale was when the pilot said he wasn’t sure if he could … it was a little Cessna 172. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [August 2, 2015, 4:00pm UTC](https://boards.straightdope.com/t/what-the-heck-happened-to-see-saw-this-klm-777/726751/22 "2015-08-02T16:00:09Z")
Overall the OP’s video looks like a gusty day at work. Out of the ordinary, but hardly a crisis or a miracle. A good argument can be made that the abrupt right wing drop close to the ground at 25 seconds should have triggered a go-around, but the recovery was handled very well. And a go-around solves the immediate problem but does mean you get to try the whole thing again, perhaps with even worse results. As to gear alignment: During the approach you correct for crosswind by crabbing: pointing the aircraft into the wind with wings level & rudder coordinated so the net motion through the air in an upwind direction is exactly offset by the air’s motion over the ground in a downwind direction. Ideally the result is the aircraft exactly tracks the extended centerline of the runway all the way to the threshold, while being continuously pointed off to one side or the other. Between gusts and the fact the wind is continuously changing both speed and direction at each location and each altitude as you descend, the result is you’re continually chasing that ideal path. Other than just a couple exceptional aircraft, you can’t land in a crab; that breaks landing gear. So in the last couple hundred feet you change to a “slip”. That is, bank into the wind and use opposite rudder to align the fuselage (and gear) with the flight path & the runway. At this point you’re flying straight over the ground, but sideways through the air. And it feels sideways to the occupants. In that situation the touchdown properly happens on the upwind gear leg first, followed by settling onto the other leg & carefully managing getting the nose down promptly to ensure positive directional control as you start slowing. Given long wings and underslung engines, there’s as upper limit to how much bank you can use before something other than landing gear drags the ground. This is normally what drives the maximum comfortable crosswind. Above that point you aim towards the upwind side of the runway, and relax out enough of the slip at the last moment to avoid dragging something, short-change the flare, and accept the fact you’ll instantly start drifting sideways & will hit a bit hard with some sideways slide. As long as you’re well aligned and don’t overdo it, nothing will break. The maximum practical crosswind occurs when you can’t do the above maneuver without needing excess good luck and Yeagerosity to make it work out without too much sideways drift. As to closing airports: It amazes me how many people think some government agency is in charge of everything. The decision to (try to) land or not rests with each individual aircraft. ---
**Author:** ![Donnerwetter](https://avatars.discourse-cdn.com/v4/letter/d/b2d939/32.png) [@Donnerwetter](https://boards.straightdope.com/u/Donnerwetter)\ **Post date:** [August 2, 2015, 4:14pm UTC](https://boards.straightdope.com/t/what-the-heck-happened-to-see-saw-this-klm-777/726751/23 "2015-08-02T16:14:57Z")
[Lufthansa Airbus wingstrike at Hamburg](https://www.youtube.com/watch?v=z42fchrzhHY) ---
**Author:** ![Morgenstern](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@Morgenstern](https://boards.straightdope.com/u/Morgenstern)\ **Post date:** [August 2, 2015, 5:24pm UTC](https://boards.straightdope.com/t/what-the-heck-happened-to-see-saw-this-klm-777/726751/24 "2015-08-02T17:24:05Z")
> [@LSLGuy](#): > > … > It amazes me how many people think some government agency is in charge of everything. The decision to (try to) land or not rests with each individual aircraft. And this explains why nothing will ever replace an experienced pilot at the controls. The day they start letting a computer fly an airliner is the day I start taking a train. ---
**Author:** ![Donnerwetter](https://avatars.discourse-cdn.com/v4/letter/d/b2d939/32.png) [@Donnerwetter](https://boards.straightdope.com/u/Donnerwetter)\ **Post date:** [August 2, 2015, 5:47pm UTC](https://boards.straightdope.com/t/what-the-heck-happened-to-see-saw-this-klm-777/726751/25 "2015-08-02T17:47:43Z")
Every discussion about computers autonomously flying airplanes in the next 100 years or so can be stopped cold by uttering these words: _Chesley Sullenberger_, _US Airways Flight 1549_ ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [August 2, 2015, 5:48pm UTC](https://boards.straightdope.com/t/what-the-heck-happened-to-see-saw-this-klm-777/726751/26 "2015-08-02T17:48:41Z")
> [@Donnerwetter](#): > > [Lufthansa Airbus wingstrike at Hamburg](https://www.youtube.com/watch?v=z42fchrzhHY) That very neatly demonstrates correct crabbing. The camera is on the runway centerline & we see the aircraft both coming and going with nice smooth flight path alignment with the centerline, yet heading well off to one side. Clearly the winds were strong, but fairly steady. The transition to the slip and the touchdown attempt was another matter. ---
**Author:** ![Novelty\_Bobble](https://avatars.discourse-cdn.com/v4/letter/n/a3d4f5/32.png) [@Novelty\_Bobble](https://boards.straightdope.com/u/Novelty_Bobble)\ **Post date:** [August 2, 2015, 5:50pm UTC](https://boards.straightdope.com/t/what-the-heck-happened-to-see-saw-this-klm-777/726751/27 "2015-08-02T17:50:12Z")
Thanks for the in-depth explanation **LSLGuy** , really interesting. I do love the fact that on this board you are only ever a post away from a clear explanation on pretty much any subject. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [August 2, 2015, 5:57pm UTC](https://boards.straightdope.com/t/what-the-heck-happened-to-see-saw-this-klm-777/726751/28 "2015-08-02T17:57:13Z")
> [@LSLGuy](#): > > … > A good argument can be made that the abrupt right wing drop close to the ground at 25 seconds should have triggered a go-around, but the recovery was handled very well. And a go-around solves the immediate problem but does mean you get to try the whole thing again, perhaps with even worse results… I think I saw this was the second approach after a go around, FWIW. > [@Novelty\_Bobble](#): > > Thanks for the in-depth explanation **LSLGuy** , really interesting. I do love the fact that on this board you are only ever a post away from a clear explanation on pretty much any subject. Yeah, “the any subject” part is true, but I like knowing that when the topic is remotely related to heavy metal in flight **Pearse** and **LSL** are in the vicinity. I haven’t kept track of the small-plain flyer regulars around here, but there’s a good number. And then, of course, is the rest of us, the TM. ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [August 3, 2015, 1:25pm UTC](https://boards.straightdope.com/t/what-the-heck-happened-to-see-saw-this-klm-777/726751/29 "2015-08-03T13:25:17Z")
> [@Novelty\_Bobble](#): > > Thanks for the in-depth explanation **LSLGuy** , really interesting. I do love the fact that on this board you are only ever a post away from a clear explanation on pretty much any subject. Also never more than a couple of posts away from crazy insane impossible answers. [Previous page](https://boards.straightdope.com/t/what-the-heck-happened-to-see-saw-this-klm-777/726751.md?page=1)