Originally Posted by EGBKFLYER
Westhawk - if you say that less flap = higher approach speed, surely that doesn't square with your argument that using less flap in gusty/ x-wind conditions helps with the difference between app speed and touchdown spd (i.e. reduces it, if I understand your post?)
My point about the advantage of using less flaps when landing most light aircraft in a crosswind was related to the pitch attitude that goes with each flap setting at approach and touchdown speeds. Generally, the less flaps used, the higher the pitch attitude will be at both approach and touchdown speeds. Less change in airspeed during the flare and less change in pitch attitude is required as a normal consequence. The nose was allready nearer the touchdown attitude before flaring. This also allows the touchdown to occur with the nosewheel further above the runway while still retaining a reasonable stall margin to account for gusts. Once the mains are rolling, lowering the nose reduces AOA and lift, allowing weight to be transferred from the wings to the wheels. The chance of lifting back off are now reduced and the tires can now assist in controlling drift.
With full flaps, you must either land flatter or slower, often both. A larger pitch change is usually required in order to achieve an acceptable landing attitude when using full flaps, especially if approach speed additives were applied. A larger change in airspeed during the flare is required. Once on the ground, weight on wheels will be less with full flaps once the nosewheel is in contact with the runway if the landing was flatter because the nose will be closer to the runway at touchdown and the AOA cannot be reduced as much before the nose tire makes contact and prevents the nose from being further lowered without taking weight away from the mains. The wings are still producing plenty of lift with the flaps down and the plane is light on thr wheels. The flaps could be raised, but this not generally perceived as a good habit in complex aircraft due to a history of people inadvertantly raising the gear instead of the flaps!We've all seen both the flat landings with porposing, and the very slow landings with the associated drift and directional control problems. Not to say that everyone will have these problems, just that it is rather common.
Common crosswind landing errors such as wheelbarrowing, heavy side loading or skidding and porposing are seen more commonly when full flaps are used than when reduced flaps are used. The most common error exhibited in crosswind landings is the use of excessive airspeed, no matter what flap setting is used! I simply say that in my personal experience, using an intermediate flap setting increases the margin for error somewhat, and generally better results are achieved by most pilots of light aircraft in my observation.
Also keep in mind that some aircraft AFMs do contain recommended crosswind landing techniques which include the suggested use of reduced flap settings. The reasons for this probably include what I've stated above, as well as control effectiveness considerations and perhaps some other factors I have omitted.
Let me reiterate that different aircraft, different situations and different pilots may justify or even demand differing techniques. However, in general, I find that reduced flap settings provide for more consistent results for most pilots under most circumstances when performing crosswind landings in most light GA/trainer airplanes. There are bound to be exceptions! I encourage practicing at all flap settings in all aircraft flown, as much as the situation allows.
I do hope this clears up any confusion my earlier post may have induced, even though I can see by reading it myself that this may not be the case. This is difficult stuff for me to convey on the internet! I'll keep working on that.
Best regards,
Westhawk