"Severe" is really a subjective term. Each aircraft was a maximum crosswind (usually lower in a high wing aircraft than with a low wing). But you also need to take into account gusts and sudden changes in direction. Depending on pilot skill and general conditions, (particularly turbulence) anything within 5-10 knots of maximum crosswind component is probably "severe." One of the most spectacular examples of flying skill I have ever seen was a Qantas L188 Electra landing at Wellington. The wind was up around 70-80 knots with a cross wind component of around 50 knots. Nobody else was flying, though the airport was not officially closed as each aircraft has its own limits. The guy landed with the wingtip toward the wind not far off the ground, kept it straight using a lot of power on the upwind side and full rudder and even used assymetric reverse thrust (or gound fine at least) after both main wheels were on the ground. It was bloody amazing to say the least! He must have had a really hot date in town that night and was determined not to divert!!! ^_^

 

Cross winds are not just a problem on landing BTW. Take off can be a problem and even taxiing. I was scheduled to fly out of KGEG a few years ago in a Dornier Jet. As it was taxiing in to the terminal, a gust lifted the main wheels on one side completely off the ground. There were a lot of very pale faces deplaning afterwards and our flight was cancelled until they could book us on another flight. (MD80) I can recall more than one occasion when an aircraft was able to land but not able to taxy until the wind had abated.

 

To practice, try setting the wind in the default weather on the nose. (Don't use an external weather program as it will vary direction and speed). Then for each flight, move it ten degrees off the nose each time keeping the speed the same and see how it works out. Depending on how severe it is, turbulence, possible wind sheer etc, add about 10-15 knots to VREF and try it with less than full flap. Have fun!

 

Cheers

Ian

Re: Lining up on center line approach visually

 

In the real world and in FS you adjust your side drift until the far runway end center is in line with the center of the touchdown zone. The center of the touchdown zone may not be in the center of your windscreen due to crabbing the aircraft into the crosswind component or just from sitting left or right of the aircraft center. Just keep the two centers of the runway area lined up with each other and concentrate on the distant end to zero your drift and stay lined up.

 

It is a good idea to sit on a runway for each aircraft model before take-off and see where the center line falls on your windscreen keeping in mind that visual reference. Since you are sitting in the left seat (or right seat) that center line will be offset to one side slightly even with your aircraft lined up straight ahead. That is often referred to as a "site picture" and includes a reference for the visual horizon line as well. This latter part can assist in the visual flare for touchdown.

There are several methods used in the real world and most have been mentioned already.

1. Sideslip or wing down method
   This method seems to have it's origins in the military but I am not sure why or how widespread it's use is. It involves keeping the aircraft aligned with the runway centre line using rudder and eliminating the ensuing downwind drift away from the center line, that would otherwise ensue, by using opposite aileron (into wind). This configuration would be flown from below 500 ft AGL. The problem with it is that the controls are crossed having to hold opposite rudder to aileron for a long period of time. Large amounts of aileron can lead to the flight spoiler panels raising which increases drag and also induces yaw into wind aggravating the situation further. Gusty conditions can make this method tricky as the constant adjustments required are not intuitive. Try rubbing your hand on your head in a clockwise direction and a hand on your stomach in an anticlockwise direction and then when you feel comfortable with it reverse the directions. I guess the idea behind it was that it provided time to align the aircraft and not have to kick straight during the flare with the associated yaw/roll coupling problems. The yaw/roll couple effect is greatest on high wing sweep aircraft so perhaps fighter aircraft employ this technique.
    
    
   
2. Decrab method
   As discussed in previous posts this technique involves using rudder to kick straight and aileron to offset the induced roll moment as well as provide a wing down attitude to counter the drift from the centre line. This method is fine for most crosswinds although for aircraft with low under slung engine pods care is needed to ensure against pod strikes. Also as soon as the upwind wheels touchdown the ground spoilers will activate which can cause the opposite wing gear to come down with a wallop and spoil your day.
    
    
   
3. Composite method
   When crosswinds are approaching the maximum limits the decrab method can become a little hairy. A 747 landing in a maximum crosswind will have the cockpit tracking over the grass to the upwind side of the runway. Trying to get the right amount of rudder and aileron application is somewhat tricky as you only get one shot. There is significant movement going on that can get quite exciting. The aircraft is certified to land with full crab on but it ain't pretty. In these conditions it is best to aim to only remove just over half the drift angle and then allow the aircraft to align itself on touchdown. I believe it to be the safest method.It allows for good runway placement and almost symmetrical main gear contact which allows for rapid spoiler application and braking action.
   The other way is to partially use the sideslip method. Don't remove all of the drift angle .......just some of it. For a strong crosswind I start to apply a bit of rudder at around 200 ft AGL and hold it. In to wind aileron is used to arrest the resultant downwind drift but it is only a small amount and doesn't activate the inflight spoilers. Then during the flare I apply more rudder and more aileron as in the kick it straight method. I will leave some drift on in a very strong crosswind. This assists the aircraft to track the runway centre line after touchdown, especially if the runway is wet or otherwise contaminated. It also helps to reduce the downwind drift if the flare is misjudged and commenced a little too early. This results in a delayed touchdown with the aircraft being subjected to drift for longer. If you observe the 747 autolanding in a cross wind you will see that it reduces some of the drift angle at quite a high altitude and maintains this sideslip until the flare.
   

Which ever method you choose to use ensure that you fly the aircraft onto the runway and don't stop flying it until you reach taxi speed. Keep the aileron held into wind and apply some forward pressure on the control column to maintain nose wheel adhesion. For flight sim work make sure that you have auto rudder disabled and for some add ons you may need to turn the yaw damper OFF to get a descent rudder throw.

loads of exceptional and professional tips here.

 

however, it seems that crosswind landing is slightly more challenging with MD82 Maddog than other addons I have, like Airsimmer Airbus and PMDG 737. I know rudder isnt meant to direct the aircraft as I should use the aileron instead but I kicked the rudder fully left just before touchdown (50 below) when wind came from the left and still I missed the centerline, in fact I landed on the grass no matter how hard I tried to align with the rwy, it never (very rarely happens) with 737NG, written off wilco airbus and Airsimmer. I also found a post regarding this on Flythemaddog.com forum.

 

After Rob suggested me not to use the rudder until around 50 feet, I finally did better last night yet still, it was tougher than other non maddog crosswind landings

Cheers

Did you have the yaw damper on or off?

Yaw Damper is always on, anti skid, yaw damper and blue Emergency Light Test indicator are among the first procedures in preflight based on the manual.

 

I do strongly believe this is due to my limited knowledge and skills in handling the aircraft in crosswind landing, the fact that it is tougher than other addons I own makes this great addon more fun to fly.

 

However what does Yaw Damper actually do especially in terms of crosswind landing?

Yaw damper on or off depends on the a/c and its manual. Many a/c require it to be on throughout the flight. As said crabbing requires you to point the nose in the direction of the crosswind enough to stay on the centreline. In the real world one also has to contend with gusts which can severely upset your approach if you are not on top of it. Use the rudder only at the last moment before touch down to "kick-off" the drift. At the same moment a degree of aileron into wind to hold the wing down. A little or a lot depending on the crosswind. Unfortunately in the sim you do not have the feel so it's impossible to judge by just how much. That's down to rw piloting skill.

 

In the real world a good a/c with which to practice crosswind landings is the Socata Rallye. It has a very unforgiving castoring nosewheel. If you screw up the landing you will end up facing the way you came!

To practice, try setting the wind in the default weather on the nose. (Don't use an external weather program as it will vary direction and speed). Then for each flight, move it ten degrees off the nose each time keeping the speed the same and see how it works out. Depending on how severe it is, turbulence, possible wind sheer etc, add about 10-15 knots to VREF and try it with less than full flap. Have fun!

 

Thank you, Ian, I practiced with a Cessna 172, first at 000/16, then 045/16 and then 090/16 (landing on a runway 36). Your last two words I quoted were true I had to reposition the tower to the runway centerline, so that I could have the same view you all can see in the videos.

 

If I understand correctly, the crab should be set with ailerons, and the rudder is only used for the "kick" at flare?

 

If I understand correctly, the crab should be set with ailerons, and the rudder is only used for the "kick" at flare?

 

Not quite! Don't flare and kick off the drift otherwise "you" will do the drifting!! Kick off the drift just as the wheels are about to touch or as they touch. It's an art and requires lots of practice. And frankly can't be done realistically in either fs9 or fsx.

Kick off the drift just as the wheels are about to touch or as they touch. It's an art and requires lots of practice.

I understand, the kick should be just before/at touchdown, not at flare. However, I still have the question: when crabbing during approach, the rudder should be used for the kick only?

Yes, as mentioned don't touch the rudder in approach. There is no need to touch the rudder, the wind is pushing against the vertical stab, into wind aileron balances it out and puts you into a crab.

 

If you take a look at most airlines SOP it is hammered into flight crew that the rudder pedals should be used as an expensive footrest. Unless in an engine out situation or decrabing, stay off them while in flight.

Yes, but depending on the strength of the crosswind and any gusts you will need also as you kick off the drift to apply a little or a lot of into wind aileron at the same time to stop that wing from rising. Otherwise the wind can flip you over.

If an aircraft is fitted with a yaw damper then unless the Flight manual says otherwise it should always be on (modern aircraft it is left selected on all the time but earlier types may require it to be selected on or off as part of pre or post flight procedures). The point I am making, with turning the yaw damper off during the latter stage of the flight, is that Flight Sim has limitations and depending on the way a model was designed the yaw damper can significantly limit rudder application which may be needed to to maintain directional control in a strong crosswind.

 

When learning to fly in a crosswind start with something simple like a basic Cessna 172.

 

Take off

Aileron into wind.

Forward press on the control column. Don't overdo it. Just enough to feel that there is some pressure on the nosewheel to assist with steering. You will probably need to reduce this pressure as the forward speed increases and the elevator becomes more effective. Use differential brake, if required, to maintain directional control until sufficient forward speed for effective rudder control.

Rotate a few knots above normal rotate speed. Make the rotation positive don't try for a slow smooth rotate.

 

Landing

As an exercise set up a crosswind of around 10 knots. When on finals set up your approach speed and allow the aircraft to crab along with the nose pointing toward the wind. At about 50 ft or so above the runway level out with the aim being to fly above and along the runway at the same speed and then go-around.

As you fly along the runway squeeze in a bit of rudder to align the fore/aft axis of the aircraft with the runway centerline. Hold the rudder in this position. Now use aileron to stop the aircraft drifting off to the side of the runway. You will be flying along in an unbalanced position known as a sideslip. Try this several times until you feel confident in maintaining directional control. Whilst maintaining this control setup (sideslip) reduce some power (to set up a gradual descent from 50 ft) and land. Just aim to fly the aircraft onto the runway with a more minimal flare than usual. The objective here is to become accustomed to flying with the aileron and rudder being held in opposite directions. After landing this way a couple of times try maintaining the crab angle down to just above the normal flare height. Squeeze in the amount of rudder that you have become accustomed to and apply the aileron into wind . Aim for a more positive touchdown than a usual into wind landing. After ltouchdown keep the aircraft tracking straight using rudder and differential brake (if you can) and keep holding aileron into wind increasing the aileron displacement as you slow down. This is the trickiest part in flight sim. Now try setting up 15 kts crosswind and go back to the beginning.

After practicing this a few times you will become accustomed to what amount of control deflection to use and it will become instinctive.

You can try the same methods with the Maddog MD82.

Then go and try it in a tail dragger.....don't stop flying those until you have completely stopped!

What a brilliant thread, and great input from you RW pilots!

 

I suppose the passengers are not going to know if this is a great pilot performing miracles in impossible conditions, or a hamhanded one messing up a relatively easy landing. (I recently experienced the "Windy Wellington landing" mentioned earlier, and passengers were screaming on the go-around!)

 

Hard to say looking at the clips above, if weather was consistent; but that 757 really seemed uncomfortable.

Which led me to wonder if a winglet retrofit is a liability in crosswind conditions?

You are certainly getting some vertical surface where none existed in the original design!.

Thank you, Ian, I practiced with a Cessna 172, first at 000/16, then 045/16 and then 090/16 (landing on a runway 36). Your last two words I quoted were true I had to reposition the tower to the runway centerline, so that I could have the same view you all can see in the videos.

 

If I understand correctly, the crab should be set with ailerons, and the rudder is only used for the "kick" at flare?

That's correct Luis - though "kicking the rudder" will induce roll so you will need to use some aileron to correct for that. It's pretty instinctive - you probably won't even notice you're doing it as all you are doing is keeping the wings level. The key is to get the wheels on the ground tracking along the centerline using rudder and wings level using aileron.

 

So to summarize - use aileron to adjust for drift while on approach so your approach stays on the center line. (Nose will be off center toward the cross wind)

 

Flare as usual and use rudder to yaw the nose so it's on the center line. Keep wings level. As the aircraft settles onto the runway, continue using rudder to maintain directional control on the center line and differential braking to assist.

 

As the airspeed drops off, the rudder will become less effective so you will use more and more rudder and differential braking until nose wheel steering becomes available. If you have multiple throttles, use assymetric thrust to help if necessary.

 

Some extra speed will give you better control and in real world, especially in high wing aircraft like the Cessna, you would use reduced flap....

 

Don't be hard on yourself if it's not perfect - I really do think it's harder in the sim than in real life. Remember - any landing you can walk away from is a good landing! LOL