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> On Tue, 15 Jul 2008 13:06:54 -0700 (PDT), VectorVictor wrote:
>
> Cool.
> Here's the AOPA training article on the subject. I post the full article
> because I don't know if you can get in their site without a membership.
>
> Crosswind tutorialhttp://flighttraining.aopa.org/ft_magazine/fullstory.cfm?id=5596&issu...
>
> Crab it or slip it, but don't avoid it! Four steps to better crosswind
> landings
>
> "I don't want to fly with that guy anymore. He almost ran me off the
> runway," confided my good friend Dennis, a highly experienced business-jet
> pilot. "Did he land long? I asked, knowing full well that the Challenger
> can float halfway down the runway if you carry too much speed on final.
>
> "No, no, no," he said, "he almost ran me off the side of the runway on
> account of the crosswind!"
>
> Holy smokes! I thought. Here's a situation where a highly trained, very
> experienced jet pilot couldn't muster the basic stick-and-rudder skills to
> keep his jet from drifting perilously close the edge of the runway. That's
> bad. In fact, that's really bad. If the wheel of a 32,000-pound jet goes
> off into the mud at 120 knots, that's a roller coaster ride you may not
> walk away from.
>
> The truth is, it really doesn't matter what size airplane you're flying,
> crosswind technique is crosswind technique. Pilots who don't learn how to
> cope with crosswinds early on never seem to learn to cope with them--that's
> why it's so important to learn now. So, with the sincere hope that you
> never go off into the mud, here are four steps to help make your crosswind
> landings easier and safer.
>
> 1. Get linedupearly
> You may have heard the old aviation adage "A great landing starts 10 miles
> out." What that really means is that a great landing usually follows a
> great approach. While a Chuck Yeager might produce a great landing from an
> unstable, rickety approach, the rest of us use the stabilized approach
> concept to give us a fighting chance.
>
> A stabilized approach is nothing new; airline and business aviation pilots
> have been using it for years. It's so important they've incorporated it
> into their training programs and standard operating procedures. Basically,
> a stabilized approach is an approach where the airplane is linedupfor the
> runway, on target airspeed, on glide path (electronic or visual), and fully
> configured for landing (flaps and gear down, propeller at high rpm). The
> airplane should be stabilized at an altitude no less than 500 feet above
> airport elevation.
>
> It's best tolineupearly on the extended runway centerline. Here, the
> difference between heading and track becomes crucial. Heading, of course,
> it the actual heading of the airplane, or simply where the nose is pointed.
> Track, on the other hand, is the course it follows over the ground--the
> actual flight path referenced to the surface. In a no-wind condition,
> heading and track are the same. But throw a little crosswind into the mix,
> and you can see that the airplane will drift downwind as it flies.
>
> To compensate for this drift, you're going to have to point the nose of the
> airplane into the wind slightly to setupa crab angle or wind correction
> angle to maintain a straight track. The amount of crab angle depends on the
> strength of the wind. And don't make the rookie mistake of trying tolineupby putting the runway directly out in front of the windshield. If
> there's a good crosswind, and you're holding a crab, the runway may not be
> in front at all; it could easily be at your 11 or 1 o'clock position. The
> nice thing about flying with a wings-level crab angle (as opposed to a side
> slip with opposite rudder) is that it's much more comfortable for your
> passengers.
>
> How do you know if you're on the extended runway centerline? That's another
> troublesome issue for students. One easy way to tell is to compare the far
> end of the runway to the near end. If the ends are positioned vertically,
> with the far end centered above the near end, then the airplane is on the
> extended centerline. However, if the far end is to the right of the near
> end, the airplane's to the right of the centerline. Conversely, if the far
> end is to the left, the airplane's to the left.
>
> Another thing to keep in mind is that usually, you'll need less crab as you
> descend toward the runway, because the wind speed is being reduced by
> surface friction. However, if you're flying over a flat surface, like
> desert or water, the wind speed may not decrease as you descend. In that
> case, you may have to land with the full force of the crosswind at the
> surface. Moreover, surface inversions can cause a noticeable change in wind
> speed and direction during approach.
>
> 2. Use partial flaps
> This is one of the best-kept secrets of crosswind landings, and
> surprisingly, many pilots don't even consider it! Since most general
> aviation airplanes have landing distances of fewer than 2,000 feet, runway
> length is rarely a factor even with partial-flap landings. For example, the
> pilot's operating handbook (POH) for the Cessna 172P states that for a
> flapsuplanding you should allow for a 35-percent increase in landing
> distance. That's insignificant if you're landing on a 5,000-foot-long
> runway.
>
> In a crosswind or gusty situation, however, full-flap landings can be more
> trouble than they're worth. This is because fully extended flaps present a
> larger surface area for that crosswind to affect, blowing you around. Flaps
> catch the wind just like a kite. Now while it's true that flaps lower your
> stall speed, allowing for a slower approach speed, you may not necessarily
> want that. Besides, that benefit usually comes at some intermediate flap
> setting before full extension; any further flap extension generally just
> adds drag. But don't just take my word for it, read what the manufacturer
> has to say in the POH. Here's an excerpt from the Normal Procedures section
> of a popular four-seat general aviation airplane: "Normal landing
> approaches can be made with power-on or power-off with any flap setting
> desired. Surface winds and air turbulence are usually the primary factors
> in determining the most comfortable approach speeds." (Italics added)
>
> Plus, with partial flaps, your approach speed will have to be little
> faster. In the example above, along with the 35-percent increase in landing
> distance, the POH also recommends adding 7 knots to the approach speed for
> a no-flaps landing. In fact, assuming runway length is not a factor, adding
> extra airspeed is not a bad idea for any landing with crosswinds or
> gusts--with or without flaps. That's because a faster approach speed means
> better airplane control, especially lateral (or roll) control. In other
> words, with more airspeed, your ailerons will be more responsive--exactly
> what you want if gusty crosswinds are blowing you around. Just don't get
> carried away; coming in 15 or 20 knots faster than the recommended approach
> speed can cause problems. You will eatupmore runway during the landing
> flare, and are subjected to crosswind effects for a longer period of time
> as you float--and float--down the runway.
>
> 3. Touch down on one wheel only
> This seems like a no-brainer, but surprisingly many pilots just can't drive
> themselves to do it. Landing on both main wheels is fine when the wind's
> straight down the runway, but it's not desirable or safe when there's a
> crosswind. That's because you'll be touching down while the airplane's
> moving sideways or drifting downwind. Touching down while in a drift can
> cause damaging side loads on the tires, wheels, and landing gear--not to
> mention you and the airplane, if it results in a loss of control.
>
> The only way to touch down without sideward drift is to land on the upwind
> wheel. The slight bank generates a slight horizontal component of lift,
> which cancels the crosswind component. Of course, the airplane seeks to
> turn when you bank it, so you'll have to hold some opposite rudder to keep
> the fuselage linedupwith the runway. In other words, control drift with
> ailerons, control heading with rudder.
>
> Thus, one of the marks of a great crosswind landing is a touchdown with
> little or no sideward drift. You're trying to touch down in a wing-low
> sideslip, on the upwind wheel, with zero drift, and with the longitudinal
> axis of the airplane (from the tip of the spinner to the tail) parallel to
> the runway. Accordingly, this crosswind landing technique is called the
> sideslip or wing-low method.
>
> Therefore, at some point before touchdown, you'll have to transition the
> airplane from a crab to a wing-low sideslip. Depending on conditions, you
> could choose to do this at about 500 feet above the runway, or you could
> delay the transition until the airplane is closer to ground. It's all a
> judgment call that depends on the conditions at hand, your skills, and your
> comfort level.
>
> When you do decide to transition, you'll do so by lowering the upwind wing
> slightly, while simultaneously adding opposite rudder pressure to keep the
> airplane's nose from turning. The resulting bank should be adjusted to keep
> the airplane from drifting, and the rudder pressure adjusted to keep the
> fuselage aligned with the runway. If the crosswind component lessens
> because of surface friction as you descend on your approach, you'll have to
> reduce the amount of bank and rudder pressure as required; flare and
> touchdown should be made while holding these corrections. Because the
> upwind wing is banked slightly, touchdown should occur on the upwind main
> first, followed by the downwind main, and finally the nosewheel.
>
> 4. Keep flying until you're stopped
> Vigilance is the key here. A large number of pilots quit flying the
> airplane once it touches down. But this is precisely when you should be on
> the alert! Pilots let down their guard, become distracted, and endup
> losing control of the airplane to a wind gust. Never stop flying the
> airplane until it is shut down and chocked.
>
> Consequently, you should hold those aileron and rudder crosswind
> corrections until the airplane has slowed to taxi ...
>
> read more »