Improper Crosswind Correction Leads to Incident

I observed the approach of this aircraft, which resulted in a ground loop and some damage to the aircraft shown in the accompanying photo. In this particular instance, numerous aircraft were doing touch-and-go landings in the fun-fly circuit at Oshkosh, Wisconsin, landing toward the northwest with a light crosswind from the southwest. The base leg was essentially downwind with an estimated wind of 5 to 8 mph. With the downwind wing in the approximate position to offset the crosswind, this should have set up the aircraft ideally during the turn to final approach.

Now here is the clincher: apparently some ultralight pilots use what is called a forward slip to lose altitude. This appeared to be what a number of pilots were doing under these conditions; however, for undetermined reasons about one in four of the various ultralight pilots were conducting the slip manoeuvre with the downwind wing in the down position, thus slipping with the wind. In other words, the pilots would level off then place the wrong wing down in a forward slip that actually exacerbated the effect of the crosswind.

This unorthodox procedure caught one chap off guard and fowled up his landing when he was unable to hold the centreline and control the right drift with the right wing down. As the ultralight touched down hard on the right wheel it bounced, became uncontrollable and groundlooped. The excessive forces exerted on the right wheel caused by the improper correction for wind and the forward slip collapsed the wheel as the aircraft spun around. The pilot was unhurt but probably a little embarrassed by the outcome of his landing. The damage was light considering that it could have been much worse if a wing had dug in and flipped the aircraft, which is often the case under similar conditions.

I would like to point out that sometimes as a result of inexperience a pilot may not recognize the direction of the crosswind. If this is the case, more training is required until there is no doubt about how to determine the crosswind on landing. Many aircraft of all types are damaged each year because instructors have failed to get this point across to the student. As for the forward slipping manoeuvre, it will also work fine with the into-wind wing down. This facilitates having the correct (into wind) wing down during the final approach and will enhance the recovery for landing as the pilot should change the attitude of the aircraft on short final in preparation for landing. At this point the pilot can choose a crab, side-slip or combination thereof to align the longitudinal axis of the aircraft with the runway centreline. The following is a summary of information on slipping, which can be found on pages 86–87 of Transport Canada’s Flight Training Manual, Fourth Edition. The accompanying diagrams can also be found on the same pages of the Flight Training Manual.

Slipping is used for two purposes: to increase the rate of descent without increasing airspeed and to counteract the effect of "drift" when landing. The former is called a "forward slip". The forward slip is one that takes place with the longitudinal axis of the aircraft at an angle to the desired flight path. If there is any crosswind, the forward slip is more effective if it is made into wind as illustrated. The second type of slip is called a "sideslip" and is performed keeping the longitudinal axis of the aircraft parallel to the original flight path. Bank applied into the wind is balanced by opposite rudder application. Pilots should be able to recognize a properly performed slip by the aircraft attitudes and the feel of the flight controls.

Crosswind landing tip: If you feel you are having difficulty with this manoeuvre, sign up for some dual training tailored to improving this specific skill — it may save both your pride and aircraft from damage. — Ed.

Sideslip to counteract drift landing in a crosswind.	Forward slip to lose altitude without increasing airspeed.