What with Hurricane Sandy, airports all over the northeastern US have shut down.
Commercial airliners seem built to be capable of landing (and presumably taking off) in severe crosswind conditions, as this test footage demonstrates (pardon the music).
So how hard does the wind have to be blowing? Presumably crosswinds are the problem (60-knot winds coming straight down the runway just means you take off and land at lower ground speeds), so I guess the real question is how strong does the cross-runway component of the wind have to be in order to ground flights?
I fly a little as a passenger (usually just under 100 flights/yr), mostly standard commercial airliners.
From a wind perspective, anything much over 30 mph seems to trigger quite a few more ATC delays on my flights. Runways that are not oriented to the prevailing wind don’t get used. Philly, in my experience, is notorious for crapping out because of the paucity of runways. Or the planes will get spaced out more. I’d be surprised if planes are cleared to land (with special exceptions) when the wind from any direction is much over 35 or 40 mph.
I think part of the problem is that wind changes direction and speed often, so it’s not as if you can make a hard and fast rule. Airports don’t really usually “shut down”; they just go on delay, which can be indefinite. I believe each carrier may have its own internal guidelines, and these may vary by plane type as well.
Finally, I believe it’s the case that a Captain pretty much has a final say, even if the plane is officially cleared by company policy or air traffic control. That is, a Captain can decide not to fly or land. I doubt this situation arises often, but ultimate control of the situation is in the Captain’s hands, I think.
“Light aircraft manufactured in the United States are designed to withstand, on landing, 90° crosswinds up to a velocity equal to 0.2 (20%) of their stalling speed.”
I watched a nearly empty 757-200 take off during Sandy yesterday afternoon. The tower reported the winds as 090 at 38, gusting 56. The runway heading is 048. Someone more familiar than I can do the calculations on the actual crosswind component.
The plane rotated at about the 2500’ mark, and was off the ground by 3000’. Once he rotated, the wings wobbled like I have never seen, and as soon as the rear wheels came off the ground the whole plane yawed, starting a leftward climbing turn that I thought was going to roll the plane over. Scary.
One of two departures yesterday after 9am. The other was a 737-400 around 10:30 or so, I didn’t see that one.
If I’ve done my math correctly, the crosswind component was 25 mph, 37 mph during gusts. (Assuming that the direction was constant during the gusts.)
ETA: Also, you might find this old post by Broomstick, concerning (among other things) cross-winds at O’Hare & Midway, interesting. Basically, O’Hare was recently redesigned in a way that increases its capacity most of the time, but makes it more prone to shutdowns if the winds are wrong. Midway, on the other hand, can usually keep one runway open.
The local news stations in South Florida sometimes interview management from our airports before tropical storms and hurricanes. If I recall correctly, the said the airports don’t close. The airlines chose to stop flying in and out of there.
The answer will presumably have much to do with the direction of the wind and the orientation of the runway(s). But there’s some amount of wind in which any sensible pilot won’t want to land even if it’s straight down the runway.
I have seen C- 150’s & Cubs land backward. Hovered my C - 180 more than once. With about 6 other guys, I jumped on a Bonanza that was at a hover. Airliners, not so much.
A DC-6 sat on the end of a runway during an tropical storm in the past, Guam IIRC, used up his fuel flying that thing on the ground as he made a full 360 swing over a period of many hours. Taxied back after it was over, refueled, then went & took off.
When you are finally out of fuel because of being sensible, then you hope you are better than you think you are.
