Flying an IFR final approach in a crosswind
Are you working on an instrument rating, or thinking about adding one when you've finished your primary training? Winds affect flights under instrument flight rules (IFR) in the same way they affect visual flight rules (VFR) flying. Correcting for a direct crosswind on an instrument final approach is a piece of cake, if you'll figure out the drift correction required ahead of time and fly a disciplined approach. No more snaking down final.
Here's how: First of all, figure out what your crosswind component is. It probably won't change much between the final approach fix and the missed approach point. If your final approach airspeed is 120 kt, the drift correction required to counter the crosswind will be equal in degrees to one-half the speed of the crosswind component affecting you. For example, if the wind is a direct crosswind blowing at 18 kt, use about 9 degrees of drift correction into the wind. If your final approach airspeed is 90 kt, use two-thirds: crab 12 degrees. If your airspeed is 60 kt, you'll need to use the full velocity of the wind, taking care to carefully transition from 18 degrees of crab on final to a wing-down sideslip in sufficient time to accommodate stable tracking of the runway centerline before touchdown.
Try it. Your IFR final approaches will magically smooth out. |
Looking back over 50 long years of flying, four memorable episodes associated with the wind vividly stick in my mind.
The first lesson occurred nearly 50 years ago at the height of the Cold War. I was a copilot on a shiny new six-engine jet bomber at a Strategic Air Command base in Savannah, Georgia. Late one night, we were called out to evacuate the entire fleet--70 sleek, silver, swept-wing B-47 bombers--in harm's way because of a fast-approaching hurricane.
The wind was screaming. Awaiting takeoff clearance on the taxiway, we sat 90 degrees to that wind, and I could clearly feel swirling and buffeting throughout the airframe. We were lucky that the B-47 was equipped with "outrigger" landing gear on the outboard portion of the wings. Boeing had a good design there.
As we lifted off, I got a firsthand look at a 200,000-pound homesick angel, climbing what seemed to me like straight up--in a 75-knot headwind. It was the ultimate VX. In my mind, it still is.
My second significant wind experience happened during single-engine airline transport pilot training in the 1970s. I owned a Piper Arrow at the time. The episode sticks out in my recollection because the wind in San Antonio, Texas, that day was strong, too--a fresh 50 kt or so, again right down the runway.
I flew some tolerable approaches that day, but it really took a lot of headwork and perspiration just to keep up. That day I learned that you can fly a pretty good instrument landing system (ILS) final approach at a groundspeed of 40 kt--especially when it's into a 50-kt headwind. But who really needs that kind of training? A much wiser choice would have been to stay on the ground. I just didn't know any better at that time. Evidently, neither did my CFI!
In retrospect, it was so turbulent that day that I'm lucky to still have a tooth left in my head. That was when we didn't know as much about low-level wind shear as we do now. But it was a significant lesson in my wind memory: Flyable doesn't necessarily mean you should fly.
The third wind lesson came at the end of my first-ever flight in a high-wing airplane. I started flying in low-wing airplanes and at that point had flown for many years and done many, many spins. But it was not until just before my CFI checkride that I flew a high-wing Cessna for the first time. The big event was the required spin demonstration with my instructor. Upon completion, the instructor endorses your logbook, making it unnecessary for the examiner to actually see you spin an aircraft during your CFI practical test.
The air work went well, as did the landing, which happened to be in a rather stiff crosswind. But after we were on the ground, I relaxed just a little--and you know what happened. The upwind wing started to move up from the ground. My instructor's response was instinctive and decisive. He snatched the airplane from me with a cool "I got it" and recovered. It had never occurred to me that such a thing might happen.
Admonishment from my instructor was professional, but swift and direct. "Wally, don't ever relax or turn loose of a high-wing airplane in a crosswind! Fly it until you have it chained down in the chocks," he said. Several thousand hours later, that seems painfully obvious, but it wasn't at the time.
My fourth wind lesson occurred just a few months ago, and I guess it proves that even we old CFIs can still learn something. After all these thousands of hours of flying time, it was just one more reminder of something I already knew, but didn't take into account.
I was flying with another instructor to regain landing currency in a model of aircraft I hadn't flown in about a year. Our flying club requires its members to fly every model of every airplane at least once every six months, or you lose currency in that make and model. It's a good policy, especially since I instruct in several different airplanes.
This was a night flight, so I was maintaining my night landing currency as well as becoming current again in that particular make and model. I had the chance for some good crosswind practice, too, and wasn't about to pass it up.
I was landing with full flaps in a wind right at the demonstrated crosswind component for that airplane, just for the practice. The usual manufacturer recommendation is to land with partial or no flaps in that situation. I encourage students flying with CFIs to practice landing with full flaps in maximum crosswinds when conditions permit--mindful of the challenges that can occur after touchdown.
I just couldn't pass up the opportunity to do that myself with another CFI. And I found--as I had expected--that 18 kt of direct crosswind required more than a little concentration to maintain alignment with the runway on the ground after landing--to the extent that I ended my roll after straying at least 50 feet upwind of the centerline before I stopped. Bad news if you do that on a narrow runway! I'd forgotten how much the crosswind affected that particular airplane's after-landing roll, even with a strong awareness ahead of time of what would happen. But that's why we practice in actual conditions, isn't it?
Real versus simulated conditions
These might not sound like such meaningful experiences to some readers, but all of them left indelible impressions on me. The lesson they all taught me is that you can see things and practice things and learn lessons under actual conditions that are difficult to understand in a simulated environment. So don't be afraid of flying in the wind, and don't avoid winds--as long as they are within your limits and those of the airplane you fly.
When you can take along a good flight instructor who wants to help you get the experience or practice that only the right conditions can provide, it's smart money.
The practical significance of wind to a pilot, however, relates directly to what kind of flying you do. To professional pilots who fly often, wind correction is second nature. But for the majority of pilots, facing the demonstrated crosswind component in the aircraft handbook--or even a lesser crosswind--is a big deal and handling it takes a lot of planning, thinking, and practice. Not everybody flies several times a week, and crosswinds are challenging to many pilots. To some of us they are sources of major anxiety and stress. But you can do something about these uneasy feelings.
Learning to fly in the wind
There are two remedies for the undue stress caused by winds: forethought and practice. They are separate but equally important ingredients for success when flying in windy conditions.
Forethought speaks for itself. Thinking prepares us to perform. Generalized forethought can prepare us for actual practice "in the winds," and it is an essential precursor to it, if actual practice is to be productive.
There are two kinds of practice, too, only one of which actually needs to take place in the airplane itself. Those two kinds of practice are headwork and handwork. Both sharpen you for the contest when the winds blow across your runway on a specific day. The unfortunate sidebar to this story is that too many pilots bypass the opportunity for either kind of practice before facing the elements. Fewer still take advantage of in-plane practice when the winds blow. If the wind is blowing, they just avoid it. If that happens, real training and improvement opportunities are lost.
A healthy 10- or 15-kt crosswind near your airport--if used to advantage with a good CFI at your side--can yield great dividends.
Buried somewhere in your aircraft's documentation is the demonstrated crosswind component (DCC). The mere label scares some pilots, but it shouldn't. This is not a limitation unless your flight school, flying club, or other local authority places such a limit on its pilots or airplanes. There are no legal "limits" to the wind in which you can operate, except the limits of good sense and practicality.
So what is the demonstrated crosswind component? It specifies the crosswind in which the airplane was tested by a factory test pilot and found to be routinely manageable, in the opinion of the manufacturer.
You should not read that to mean DCC is a safe limit for a pilot who only flies a couple of times a month--especially if he or she avoids the airport when any crosswinds exist.
On the assumption that the folks who wrote the book know more than I do, I'd recommend that you avoid exceeding that demonstrated crosswind component. Discuss the topic further with your own instructor. Pilots who are unprepared for winds can have trouble even in lighter winds.
The role of headwork
Wind headwork is an important part of safety. Headwork involves thinking about the wind ahead of time and internalizing the approaches that you think might work best for you in certain circumstances.
My approach to a 30-kt crosswind--when I can't avoid it by landing on another runway, for instance--is simple. I just don't fly. I'll wait for a better forecast, or I'll go somewhere else where I don't have to face a crosswind that exceeds my capability. I look at the terminal aerodrome forecast (TAF) and see what it tells me.
In my personal experience, anything up to the demonstrated crosswind component, however, is fair game--because I practice and have been flying conscientiously for 50 years.
A plan for wind proficiency
If you are uncomfortable flying in windy conditions, or have concerns about your capability in unexpected circumstances "on the road," vow to do something about it. Even if you just want a crosswind refresher, here's a plan to consider. You can take charge and come up with your own plan to improve your skills--and your comfort level.
First of all, find a CFI you trust and let him or her know that you want to make sure you're competent in crosswinds up to the demonstrated crosswind component of your airplane If above that, don't fly! Determine what limits you're comfortable with and fly in winds exceeding your personal limit only with an instructor.
Now comes the most important part of your program. In consultation with your CFI, don't pass up an opportunity to practice in winds up to the maximum demonstrated crosswind component of the airplane. Purposely look for opportunities that present challenging situations and call your CFI to fly in them. You'll be amazed at how quickly your overall capability will improve. Also schedule regular flights with your CFI and specifically look for crosswinds; if necessary, go to airports and runways that provide them.
Use the Internet and follow weather trends to sharpen your ability to read reports and forecasts. Pay close attention to winds. Then follow up to see if predicted winds actually developed along the timelines forecast at airports to which you typically fly.
Establish objectives for yourself, ratcheting up the performance you're shooting for to ensure improvement. If you're uneasy in some situations, dispel your discomfort by forcing yourself to operate within performance parameters that steadily improve.
I'm not just talking about final approach here, either. Don't forget the traffic pattern. Analyze the winds that you expect to affect you before you even enter the pattern. Use the correct drift correction for each leg. Make sure that downwind, base, and final follow a solid ground track that results in the right geometry to permit a stable final approach and a good landing.
Once on final approach, correcting for crosswind can be done with either the wing-low method between the base-to-final turn and touchdown or by using the crab-and-slip method--"crabbing" into the wind along final to correct drift, then transitioning to wing-low just before or during the landing flare.
Following the weather trends, looking for good crosswind training opportunities, taking advantage of them with a competent CFI, and good planning should result in improvement of your crosswind performance.
The next time you look outside and see the leaves blowing or the water rippling with waves, tell yourself, "Hey, bring it on! I think I'll go flying." Then, phone your favorite CFI and have at it. You might just have some fun on your way to becoming more confident and proficient in the wind.
Wally Miller is president of an aviation training, consulting, and marketing firm in Monument, Colorado. He is a Gold Seal CFI who has been instructing for more than 30 years and flying for more than 40.
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