Five crosswind fixes: use these tips to help fix problems you might be having with crosswind takeoffi and landings.
These days and unless you only fly on calm days or from an aircraft carrier, it's not uncommon to have at least some crosswind with which to contend during your normal takeoffs and landings. Depending on the runway, the terrain and the local meteorology, a crosswind may be the norm where you fly, and you may have gotten pretty good at it. For the rest of us, handling crosswinds may fall into the category of a rarely used skill. If that's you, or if you're haying trouble mastering some aspects of crosswind landings and takeoffs, read on.
Anytime landings are the topic, airspeed control has to be near the top of anyone's list of possible problems. The same can be true for takeoffs in a crosswind, something we'll get to in a moment. In fact and in keeping with other landing problems, the most common error pilots can make when dealing with a crosswind is to start adding knots to their target speeds.
In reality, the only time we need to pad our target airspeeds on landing is when the wind is gusting. Even then, the maximum additional airspeed we should add is half the gust value. As an example, presume winds at 10 knots, gusting to 20. The normal approach speed is 65 KIAS. We'd fly the approach at no more than 70 KIAS. Why?
The gust value is 10 knots, not 20; half of 10 is five. Using our half-the-gust-value rule of thumb, add the five knots to the normal approach speed and you get 70 KIAS. That little extra speed helps two ways. First, it helps improve the airplane's control feel and response, especially the ailerons. More air moving over the control surfaces means crisper handling, something that's never a bad thing.
The five extra knots also adds a to the margin above the airplane's stall speed. The idea isn't that the gusts will be too strong but that they'll fall off at the wrong time, like when you're flaring. For example, if your 65-KIAS target speed reflects 1.3 Vso, the airplane you're flying stalls at about 50 knots. Presuming that same 10-knot gust value, what happens if, as you begin to flare, a strong gust dies off? Suddenly, your airspeed is "only" 55 KIAS. You'll get a sinking, sideways feeling right before the mains hit.
But isn't some additional speed appropriate when dealing with crosswinds, even if they're steady? Not really. The airplane and its wing are still moving through the air as they would be if the wind was directly down the runway, or even if there was no wind at all. Adding knots only imparts that much more energy to the airplane, lengthening the distances required.
That's for landing; on takeoff, a little extra speed likely won't hurt if there's enough runway. I'll usually accelerate slightly past normal liftoff speed when dealing with a crosswind. That extra bit of energy helps establish a climb more easily, and improves control responsiveness. How much more speed? Just a couple of knots, to make sure I have control authority sufficient to counter the crosswind.
TAKEOFF AND CLIMB
A big part of flying crosswinds is the takeoff and initial climb. And many emphasize preventing crosswind landing accidents, sometimes omitting crosswind takeoffs from the discussion. They can be problematic, also, especially when the airplane is, by definition, the heaviest it will be on this flight.
We always were trained to establish a wings-level attitude as soon as feasible after liftoff in a crosswind, and maintain it to our cruising altitude. The explanation involves lift's horizontal component when the wings are banked: To maximize lift when you need it most--right after liftoff--keep the wings as level as you can.
As referenced earlier, climbing at a slower, more-shallow rate allowing higher airspeed than in still air when it's gusty isn't a bad idea, and for the same reason airspeed control is important when landing: gusts. A Vx climb over obstacles isn't a good time for the bottom to fall out, and gusts can subside abruptly.
But again, we're concerned primarily with the gusty winds when suggesting higher-than-normal airspeeds on takeoff and climb. If the winds are steady but still a crosswind, we don't need as much extra speed.
If you haven't figured out that competency with the rudder is key to handling crosswinds, (or you're flying an Ercoupe) well, we're not sure what to suggest. But it's a fair bet that someone who has trouble with using the rudder also has trouble with crosswinds. Fixing one can fix the other.
Meanwhile, rudder use is critically important on the runway in a crosswind (unless you're flying a WWI airplane off a wide field). Depending on the airplane and the wind, you may have to come in with all available rudder early in the takeoff roll to maintain directional control. As speed increases, you may be able to relax rudder input, but that's about it. Again. depending, active rudder inputs may be needed to keep the nose pointed in the right direction throughout the takeoff roll.
After liftoff and throughout initial climb, rudder use should revert back to normal: whatever is necessary to control yaw and coordinate turns. Since we like to keep the wings level when climbing, you shouldn't need any more rudder than normal. Until landing, that is.
Rudder use during a crosswind landing isn't a mirror image to takeoff, but it's close. You need rudder to establish the correct wings-level-or nearly-so crab into the wind, you'll need it to keep the nose straight when lowering the upwind wing, and you'll definitely need it if you .* prefer some combination.
Another word about airspeed: To establish and remain aligned with the runway, you may need full rudder deflection at times. If that's not enough rudder authority for the conditions, you have two choices: go somewhere else or (slightly!) increase your target approach speed. The former is self-explanatory: the latter will flow more air past the vertical, increasing its authority.
One of the crosswind problems I've seen is reluctance to use ailerons. They should be fully deflected into the wind at the start of the takeoff roll and relaxed as speed increases. I t's unusual to not need at least some aileron input all the way through the takeoff roll.
On landing, you'll need aileron to place the wings where von want them before touchdown, and afterward you'll still need them--sometimes all the way to the ramp. Too many pilots think of ailerons as something to be ignored on the ground. Especially in crosswinds, and especially with high-wing configurations, the airplane needs to be "flown" all the way to its parking spot, and that usually means smart and timely aileron use.
One problem might be simple confusion on which way to deflect the ailerons and when. Obviously, when airborne, the ailerons control he airplane's roll about its longitudinal axis, and work in the conventional fashion. On the ground, at taxi speeds, the ailerons should be deflected so as to minimize the wind's ability to lift a wing, perhaps beyond the vertical.
Of course, as we taxi and turn on the ground, what was a crosswind from the left can change to the right, or even be nose- or tail-on. When the wind is from directly in front or directly behind, neutral ize the ailerons. If its a quartering tailwind, lower the aileron on that side. Otherwise, we'll generally want to prevent lift on that wing, so we'll deflect the upwind aileron up, into the wind, hoping to spoil lift.
If one or the other approach methods (see the sidebar on the opposite page) isn't working for you, perhaps some combination of the two might? The silly little secret of the debate about whether to sideslip or crab clown final in a crosswind is we all usually end up doing a I il tle bit of both (but don't tell anyone.)
The punchline is don't be afraid to use both: Doing so isn't immoral, illegal or fattening. That said., there are times when one method might be preferred--for instance, when living a low-wing airplane with pod-mounted engines under its wings, you'll probably want to use the crab method. Perhaps the poster-child airplane for using the crab method is the B-52, which was designed with crosswind landing gear that could be aligned with the runway while the airframe pointed into the wind.
Other airplanes have been equipped with crosswind gear from time to time. but most designs fell out of favor when it was determined good crosswind skills don't require the extra expense.
Crosswinds aren't risky: they're a fact of flying, and it can be a lot of fun to handle them well. As with so many things, learning how to do that requires a full understanding of the tools available, and their complications. A little practice never hurt anything, either.
RELATED ARTICLE: HOW MUCH CROSS IS TOO MUCH CROSS?
Any cursory look at an airplane's specifications will come across something called its "maximum demonstrated crosswind component." The term exactly describes this number, usually expressed in knots: It's the maximum crosswind the manufacturer has demonstrated the airplane can handle. It is not, however, the maximum crosswind the airplane can handle.
According to the FAA's Airplane Flying Handbook, FAA-H-8083-3A, "Before an airplane is type certificated by the FAA, it must be flight tested to meet certain requirements. Among these is the demonstration of being satisfactorily controllable with no exceptional degree of skill or alertness on the part of the pilot in 90-degree crosswinds up to a velocity equal to 0.2 [V.sub.so] This means a windspeed of two-tenths of the airplane's stalling speed with power off and landing gear/flaps down." The demonstrated crosswind velocity is supposed to be on a placard in airplanes certificated after May 3, 1962.
That doesn't mean the airplane can't handle crosswinds of greater velocity, especially with an extra knot or two, or when using an extra-wide runway (land on the downwind side).
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|Title Annotation:||STICK AND RUDDER|
|Author:||Burnside, Joseph E.|
|Date:||Jul 1, 2014|
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