A Different Angle

By Robert N. Rossier, EAA 472091

This piece originally ran in Robert’s Stick and Rudder column in the May 2022 issue of EAA Sport Aviation magazine.

The winds on Block Island (KBID) were pretty well howling. The automated surface observing system was calling it 320 at 18, gusting to 27. For an aircraft landing on Runway 28, the crosswind component would be in the range of 9 gusting to 14 knots — nearing the demonstrated crosswind capability of most light aircraft. Having just landed myself, I knew the approach was a serious workout that started well before entering the pattern and continued through touchdown and rollout. I chatted with the airport manager, who lamented about the windy conditions and how arriving pilots were fairing. The last airplane, a Cirrus, made a long, flat approach and was tossed about wildly. It finally had to go around. The crosswind landing itself was a factor, but for many pilots attempting to land on Block that day, it was only one part of the challenge. In fact, there’s a lot we should consider before embarking on a flight when conditions are less than smooth.

Passenger Briefing

Any time we’re taking passengers up in turbulent conditions, it pays to let them know what to expect. It’s a balancing act between providing a warning and instilling confidence. We want them to know that it will be bumpy. It’s not a fun surprise for those expecting a smooth ride. But we also want to let them know that the airplane is worthy of the shaking it will endure. No, the wings will not fall off. We should also warn them about how a crosswind landing works, and that throughout the approach, the nose of the airplane might not be pointing down the runway. For some passengers, having the nose pointed to one side or the other could be interpreted as a sure sign of an imminent crash.

Maneuvering Speed

One factor we might want to consider more closely for a flight in turbulent conditions is maneuvering speed. We should recall that the published maneuvering speed (VA) for our airplane is for max gross weight. If we are operating at a weight below max gross, our actual maneuvering speed will be lower than the published speed. We can determine the actual VA as a percentage change. The percent change in speed is approximately half the percent change in weight. If our weight is 10 percent below gross weight, our VA will be about 5 percent lower than at max gross weight. This can come into play when we’re approaching the pattern where turbulence might be more of a concern. When operating in turbulent conditions where we might also need to make abrupt maneuvers, we should first slow down to the actual maneuvering speed corresponding to our operating weight.

Pattern Adjustments

Flying the traffic pattern in windy conditions is an exercise in ground reference maneuvers. In order to maintain some semblance of a normal pattern, we need to apply some wind correction in our pattern. This requires us to pay attention to our track over the ground and make the needed corrections. Failure to do so can put us in a less desirable (and less safe) position, perhaps requiring steep turns to get us back on our final approach path.

Approach Speed

We should also recall the general rule of thumb that suggests adding half the gust factor to our approach speed. This provides an additional buffer against a sudden gust-induced stall. On this day, with winds 18 gusting 27, half the gust (27-18 = 9) is 4.5 knots. We should round up to 5 knots, and add that to our normal approach speed.

Crosswind Correction

If we wanted to, we could fly a slip into the wind all the way down our final approach path and on into touchdown. But the uncoordinated ride can be uncomfortable, especially for our passengers. The better tactic is to crab into the wind until we’re relatively close to the ground, and then lower the upwind wing and apply opposite rudder to track the centerline during the touchdown. The crab angle we use may need continual adjustment as we descend on final due to the wind gradient with altitude. Gusty conditions also require constant, rapid adjustments to stay on our final approach course. Combined with pitch and power adjustments to maintain our target approach speed, glide path, and then position over the runway, it might feel like we’re in a kickboxing tournament for the entire descent and landing.

Visualizing Turbulence

One way we can better prepare ourselves for an approach and landing in windy conditions is to learn to visualize how terrain and obstacles can affect the flow of wind. The effect is much the same as water flowing over a rocky stream bed. The wind will accelerate as it passes between obstacles, will flow up and over obstacles, and may tumble like a breaking wave as it drops over rapidly falling terrain. If we can visualize how water might flow over the terrain, we get a pretty good idea of what the wind might be doing, and how it might affect our approach. We can then use that knowledge to adjust our flight path and speed.

A Different Angle

The approach to Runway 28 on Block Island with a strong northwesterly wind is one in which the visualization of turbulence is helpful. Since the terrain drops off sharply on the east end of the runway, we can expect a significant downdraft — and some troubling turbulence — on short final. That may have been part of the problem experienced by the Cirrus pilot on this particular day.

The objective on final approach is to fly a stabilized approach. This means we have the aircraft properly configured for landing, and we fly a constant glide path with steady airspeed. Generally speaking, we like to see a 3-degree glide path to the touchdown zone, and that is typically what an instrument landing system glide slope, visual approach slope indicators (VASI), and precision approach path indicators (PAPI) provide. But when dealing with some environments and conditions, we might do better with some minor adjustments.

To compensate for the anticipated effects on the approach to 28 on Block Island on this day, we might choose to fly a steeper approach to the runway, thus avoiding some of the turbulence and downdrafts. Considering we’ll be touching down with a good headwind, we know that the extra airspeed to manage the gusts will be compensated for by our lower groundspeed, thus shortening our rollout. We also know that besides avoiding the turbulence, a steeper approach angle might keep us in a better position in the event of an unexpected loss of power or a sudden downdraft.

Final Thoughts

A few additional tips can be helpful when making such an approach to landing. First, we should know where our target touchdown point is, and keep that in the same spot on our windscreen as we fly the approach. As we approach the touchdown, we shouldn’t be in a rush. We need to keep working the controls to compensate for gusts and turbulence until we can safely get the gear on the ground, or make a safe go-around. But we can’t relax even then. We need to keep working the controls until we’re safely shut down on the pavement.

Making an approach and landing in gusty, turbulent conditions can be a real workout, and a real challenge. If we apply the right knowledge, skills, and tactics, we’ll have a much better chance of making a safe and successful landing.

Robert N. Rossier, EAA 472091, has been flying for more than 40 years and has worked as a flight instructor, commercial pilot, chief pilot, and FAA flight check airman.

Post Comments