Crosswind Landings in FS

[walterleo]

Some years ago in the Project Tupolev Forum we had a discussion about crosswind landings. Denokan a real Tu-154 and B 737 pilot explained it here:

www.protu-154.org/forum/viewtopic.php?t=2193&highlight=crosswind

The most important thing is, to land ON THE DOWNWIND SIDE OF THE RUNWAY IN FS, as the "weather-vane effect" turning the aircraft INTO the wind is very strong in FS, so steering to the downwind side after touchdown may not be sufficient to keep the bird on the concrete.

Here the CV990 landing in a 25 kts crosswind from the left.

THIS PROCEDURE IS NOT FOR LANDING A REAL AIRPLANE!

[aerofoto - HJG Admin]

If I remenmber correctly ....

Part of the cross wind procedure for landing aircraft like the B707/720, CV880/CV990, and DC-8 was to also drop the wing/turn the wing "slightly" (into the wind) on the aircrafts windward side/axis.

I'd say 25 KTS of crosswind is probbably getting very close to the limits for these aircraft though .... BUT .... I gues there's nothing like "a bit of fun"

FS .... in a lot of cases .... doesn't reaslly handle crosswind component particularly well .... and is, sometimes,inclined to allow excessive drift .... even for very little crosswind influence .... or so we've fiound through our own past experimentation.

Mark C
AKL/NZ

[Mike Monce - HJG]

Also, if the MOI for yaw is wrong that will affect cross wind characteristics. All of HJG's are correct! The other factor, is: TURN OFF THE YAW DAMPENER! For any approach I always switch the YD off below 200kts. That give me the rudder authority needed to handle small changes on approach, and also makes those xwind landings much more manageable. Having rudder pedals is also helpful

Mike

[Herman]

Just happen to be flying when I read the crosswind landing posts so I thought I would set up some crosswind conditions at my destination airport which was Punta Raise LICJ Palermo, Italy.

The landing runway was RW 25 which has a magnetic heading of 245*. I set the wind direction of 300* at 16knts. I don't exactly know what the calculated Crosswind component is for those conditions, and it is certainly not a 90* direct crosswind.

I disconnected the Auto pilot about 500ft AGL and flew the remainder of the approach manually. Because I was flying an Airbus A320 I knew that I was very limited as far as dipping a wing because of the low engine to ground clearance.

I flew the approach as prescribed, that is....maintain the runway center line by crabbing into the wind using right rudder to negate drift, and maintain wings level. Just a few feet above runway and in a nose high attitude, apply left rudder to bring the nose back to line up with the runway center line before the nose gear touches down.

Well...that last part did not work perfectly for me as can be seen by my screen shots....so I need a bit more practice in doing that.











Basically, what I was trying to demonstrate, is, that it is possible to land FS airplanes using the prescribed procedures as used in real world airliners, in crosswind conditions.

After a few more practice runs I will try some approaches using higher crosswind conditions.

Herman

[walterleo]

Hi Hermann:

Using a quick formula for crosswind component: 0-30 deg nil, 30-45 deg half, 45 or more full you had a crosswind component of 16 kts.
In my cited thread of Denokan there are a lot of references to real world procedures, the most imported difference is to land at the downwind half of the runway.
The other difference is dictated by the high wingseep of most of the old Russian jetliners forbidding the wing down method and as Denokan says at the end: The B 737 is much easier to fly.
Many other good advice of real flying such as higer approach speed, planting the nose wheel immediatly after touchdown and braking hard is valid also in FS.

Kind regards

Walter

[walterleo]

Hi:

Notoriously difficult in crosswind landings are the tip-tank Learjets and many lucky ones rubbed off the painting of a tip tank and many unlucky ones cartwheeled down the runway. This happened even on checkflights with a FAA check-captain in the right seat.
Although the Tu-134 was admired by INTERFLUG pilots they hated her behaviour in crosswind landings.

Kind regards

Walter

[Mike Monce - HJG]

Herman, that looks like the project airbus A320 that I also use; correct? I've done some mods on the FDE for that if you're interested.

For the general topic of xwind landings, one test of the FS FDE (from the old guru Ron Freimuth) is that with YD off, and in level cruise, input full rudder and in FS you should see a net yaw of about 15 degrees. If not, adjust the rudder effectiveness in the flight tuning section of the cfg accordingly. Getting that parameter set right, will make xwind landings much better using the crab technique.

BTW, way back in my real world days, I learned that technique to perfection when I face a 90 degree xwind at about 20 kts during a solo xcountry for the PPL. The airport was my scheduled refueling stop, and the weather changed as I arrived. Though I had done some practice with the crab technique I had never really put it to use in the C172 like that before. Amazing how one's powers of concentration go up in more stressful situations like that... I greased the landing; and was better than most of my landings in calm conditions

Mike

[walterleo]

Hi Mike:

As in many FS airplanes there is no Yaw-Damper switch (like in the HJG CV 990A) I understand you mean to disable "autocoordination" in the FS "Reality settings" submenue. Works only satisfactory if you have rudder pedals installed. Besides most "Yaw Damper" switches in FS have no effect on the flight dynamics.
If unable to use the wing low method, which is basically a side slip, you have to use the crab turning the nose into the wind to counteract the drift. This brings you in FS to the situation that after touchdown you can run out of concrete, less you touch down at the downwind side of the runway and at touchdown start steering downwind.
In a real light airplane the wing low method is a much easier procedure, espacially if you are sitting in a high wing aircraft.
Of my real light airplane flying I remember only one really satisfactory application of the crab method and it was in a Piper Archer a low winger.

Kind regards

Walter

[Mike Monce - HJG]

Walter,

Actually, no. I don't mean disable autocoordination; I always have that off. The YD switch does have an effect in FS if properly setup in both the cfg and air files. It does actually work. On a plane with a YD, try the rudder test I mentioned; you should see anotcieable difference in yaw with and without the YD. The HJG MadDogs YD works quite well.

Mike

[Herman]

Mike....yes, I do use a few of the POSKY A 320's and also ifdg models. Please do send the cfg mods that you have.I will PM you with my e-mail address.

Walter....thank you also for your input regarding crosswind landings.

During my flying days with my Piper Cherokee, I always used the wing low (cross control) method for crosswind landings as opposed with the crabbing into wind and then slamming the rudder to re-align with the runway. Somehow I felt more comfortable with that method and I didn't want to bend\break the landing gear.

With the crabbing method, timing is of the utmost importance so as to touchdown without any drift.

Herman

[walterleo]

Hi Friends:

Although a lot of time went by for that thread, took some pictures with the Tu-154 B2 with 18 kts of crosswind (full cross wind component):

Looks not so bad on final, on the HSI the Tu-154 has a drift marker (yellow diamond atop) driven by its doppler-radar navigation system.



Touching down at the downwind side:



Gear on the ground, the crosswind immediately pushes the nose violently into the wind, if we would have landed at the centreline like in a real airplane we would end up in the grass as directional control in FS seems lower than in a real airplane.



Kind regards

Walter