Air Canada 'rough' landing

[RooFlyer]

Just an item of interest, sourced from OMaaT

 

[Quickstatus]

I note the windsock.

 

[RooFlyer]

I'm sure (hope ) 74Gear will review it soon.

 

[VeniVidiVici]

I note the windsock.

That's as cross as you'll get

 

[jb747]

That's as cross as you'll get

True, but that's not the cause per se. The approach is quite stable, crosswind not withstanding, and then there's the sudden right wing drop. So, my guess would be that the crossind has suddenly reduced. There's no control input that I can see to cause the drop, though there's very quickly some applied in an attempt to stop it...and that's a large part of the left wind drop that follows. If 74Gear does look at it, I expect he'll point out that it was lucky that it was a twin, as they have appreciably more leeway before things hit the ground.

 

[flyer89]

It’s reported that this was AC002 so that’s quite the wake up call after flying for 12 hours….

 

[Saab34]

True, but that's not the cause per se. The approach is quite stable, crosswind not withstanding, and then there's the sudden right wing drop. So, my guess would be that the crossind has suddenly reduced. There's no control input that I can see to cause the drop, though there's very quickly some applied in an attempt to stop it...and that's a large part of the left wind drop that follows. If 74Gear does look at it, I expect he'll point out that it was lucky that it was a twin, as they have appreciably more leeway before things hit the ground.

I was playing it in slow mode, and I can see the right wing drop slightly at 15 seconds, however it’s quite a correction soon after from the PIC which seems to get worse as they go back and forth. Note the rudder correction at 16 seconds.

Bit of overcorrection here?

 

[Quickstatus]

It's weird Thread starts talking about a sudden roll in a crosswind landing. And up pops Mentour's video about a sudden roll during a crosswind takeoff.

 

[jb747]

I was playing it in slow mode, and I can see the right wing drop slightly at 15 seconds, however it’s quite a correction soon after from the PIC which seems to get worse as they go back and forth. Note the rudder correction at 16 seconds.

Bit of overcorrection here?

Very possibly. The right gear actually hits the ground in that first roll, which of course stops it going any further. But the left wing is being pushed down now by the spoilers in their roll control mode, so we get a combination of that, and the mechanical roll induced by the impact. Rudder motion initially only seems to be the lower section of the rudder, which may be yaw damper/FBW input. Not a landing to be proud of.

 

[RooFlyer]

Kelsey at 74gear discusses the Air Canada landing, together with a more recent, American Airlines one, here: (tip - mute the sound when the American plane starts to wobble)

 

[jb747]

It's weird Thread starts talking about a sudden roll in a crosswind landing. And up pops Mentour's video about a sudden roll during a crosswind takeoff.

In a swept wing aircraft during the take off roll the effective sweep on the upwind wing is a lot less than on the other side. The upshot is there is quite a difference in the amount of lift being produced, so it's quite normal to have to apply a lot of aileron during the takeoff roll to keep things level. You'll try not to put so much in that you start getting spoiler rise, but if you need the control input, then you'll have to live with a bit of spoiler as well. As the aircraft lifts off, you can let it weathercock, so you don't need to do anything with the rudder, but you'll have to ensure you're actively controlling the bank angle. Basically that translates to easing off the rudder pressure (which will have been applied to keep it straight) and neutralising the roll input. Not rocket science.