Yay! Another post about commercial landings. This has been the main focus of my flight training the past few weeks. Last week I went into detail about some tricks that have helped me with my commercial landings. This week I am going to go further into detail about the effect wind has on power-off 180s.
For short field and soft field landings, I see a negligible effect of wind on those landings. I have the same procedure despite windspeed for short and soft field landings. This is not the case for power-off 180s. The wind plays a huge role in each power-off landing. As a pilot, you need to consider the winds and tailor each landing to the winds on a given day.
On days where there are light to no winds, you have to stay in the downwind leg longer. When there are calm winds, your groundspeed is much slower on downwind since there is not a tailwind making you fly across the ground faster. Yesterday the winds were calm and I had a groundspeed of about 90 mph on downwind in a Cessna 172. From trial and error I have figured out it works best for me to always turn base leg when I am at a 45 degree angle from my landing spot. It takes me much longer to reach my 45 degree angle when there are calm winds since I am moving over the ground at a slower speed.
Today I practiced more power-off landings with wind straight down the runway at 16 knots gusting 20. I had a groundspeed of 120 mph on downwind. I got to my 45 degree angle almost immediately after configuring the aircraft for landing. With calm winds, it can take about 10 seconds after configuring the aircraft before you reach your 45 degree angle from your landing spot since you're flying slower. You have to constantly look outside the aircraft to determine when you are approximately at a 45 degree angle. It takes practice to figure out that sight picture.
Once I turn base, I can tailor my landing to the wind. If I am low, I can keep my base turn going into final without leveling out on base. This also takes trial and error to judge if you're high or low on base. I like to glance over at my altimeter to check my altitude. If I am still 700 feet off the ground on base, I know I am high. If you're high, you can level out on base to lose more altitude before turning final. You can also add more flaps, which I would recommend. When adding flaps, you need to anticipate the ballooning of the nose (drop in indicated airspeed) and the steeper descent. It all comes down to knowing your aircraft and the way it glides as well as the different sight pictures.
You might have a handful of bad landings before you figure it out, and that is normal. When I first started practicing power-off 180s, I was always too high or too low. I had a lot of go arounds because I needed more practice to figure out the "sweet spot" for my plane. I also found that 65-70 mph on final worked great to keep floating to a minimum so that I can place the plane right down on my spot on the runway. Pitching for 65-70 mph can also help the aircraft descend due to the increase in induced drag associated with that pitch attitude.