Opinions on this Crosswind Take-off from heavy metal flyers please
 

Video of crosswind take-off of a JAL 738 doing the rounds.

https://www.facebook.com/TheAcquaPla...1095577182053/

Some are saying "just a normal crosswind takeoff" - others are saying "Waaaay over the limit". It's looking pretty dicey to me - just wondering what you chaps who fly these think of this in terms of aircraft and airline operational limits?

Typical of Facebook commenters, most of them thought the tires were smoking as well.

It's hard to make a call from one video, and telephoto lenses such as that used here can make things look worse than they do out the front windows.

Our takeoff crosswind limit on the 738 is 33 knots including gusts. This takeoff could certainly have been hovering around that number, so while looking a bit dicey, was within the requirements.

Thanks BleedingAir - is that limit only for a dry runway (this one was obviously a bit on the damp side)?

Looked fine to me, quite well controlled down the centreline. Maybe a little more Aileron into wind perhaps at around 100 kts where you can see the into wind wing ( left ) rising up a little. That's not a big deal and they did a good job.

Thanks.

I was somewhat concerned about the side-loading / slipping put on the tires (admittedly a little less in this situation with the damp runway).

Actually ACMS I thought there was too much left aileron because you can see the spoilers deploying on the left wing. The increased drag then requires more right rudder to keep straight.
Overall I think they did a good job, must have been on the limit.

A good training video reference aileron use in crosswind. Certainly one of the better ones I have seen.

Following on from Ancient's comment - from the 737-800 FCTM

"Large control wheel inputs can have an adverse effect on directional control near V1(MCG) due to the additional drag of the extended spoilers."

Yes the limit is lower on a wet runway, but moisture on the runway doesn't automatically qualify it as "wet". It may have been justified to use dry limitations on this occasion. And different operators specify different limitations.

As for side loads on the tires, the gear is designed to handle that.

Looked OK to me. Didn’t let the into-wind wing pick up, tracked the centreline more-or-less, didn’t try and snatch it off the ground, reacted well to gusts.

It doesn’t look like full control deflection was used at any point, so they had more authority if they needed it. I’d say that was a well-flown crosswind takeoff in the prevailing conditions.

Facebook drama queens.

Kept the wings level during rotation which is desired.

Thanks everyone.

So just to clarify, a degree of visible tyre side-slip is OK?

I kinda liken it to applying a bit of opposite steering when power-sliding a car around a corner; on one hand the vehicle is still under control, but on the other, the very fact that tyres are slipping does indicate that it's reached a "new level" when compared to normal cornering.

Just wanting opinions on whether that is considered "OK" from a heavy metal point of view? (in an industry that's generally considered to be very conservative).

Opinions given above...

Don't the later 737's have main wheels that castor slightly? They seemed to maintain the centre line reasonably despite the way the aircraft was pointed!

I see ab-so-lu-te-ly nothing wrong with that video.*
There is no tire slip.
And I'm almost sure that it wasn't even near the limits.
As a passenger you would have felt some rocking and rolling along the runway, not much else. Certainly no scratching and scrapping tires.

If this benign takeoff video gives rise to concern, then better don't watch the landing videos!
As someone posted before, the telelens distorts what is really happening. The plane is hurtling at more than 200 kilometers per hour down the runway but all you see is a plane 'sliding' left and right from behind.


(*other than maybe a tad too much into wind aileron+spoilers, but that's a different story)

Spot on PENKO.

A long lens down the runway gives a highly exaggerated perspective. Just look at all the crosswind landing videos posted on youtube to see how 'exciting' routine landings can look.

None event, but for competeness, I'd love to hear what the wind was doing at that time.

Not sure about the later ones, but the classics (100-500 series) had a shimmy damper between the torque link knuckles that allowed a certain amount of castoring. I don't think it was designed for easier crabbing but I could be wrong.

The take off looks fine! Well done! :ok:

p.s. Don't listen to Fb 'experts'! As a matter of fact, just cancel your account, it's pure KGB/NSA/Stasi! ;)

The 800 series do too.

Judging by the (little) work this guy was doing to track the centreline and the apparent ease had keeping wings level on rotation I'd say 25 knots cross, no more. But that's just a guess, every crosswind is different. Max is what, 38?