Today's Amazing Airliner Tricks: Crosswinds, 'Cat IIIC' Landings
You might have seen these before. But just in case...
1) The "Crab Into Kick" Crosswind landing technique: A few weeks ago I posted a video of a dramatic landing by a Lufthansa plane, in Canada, as it coped with gale-force crosswinds. It was a useful demonstration of the classic "crab into kick" technique of landing in a crosswind. The airplane approaches the runway at a "crabbed" angle, to offset the wind -- then at practically the last instant before touchdown the pilot uses the rudder to "kick" the plane into alignment with the runway, so when the wheels make contact they are pointed straight ahead. That post also had a lot of links to how-to discussions of landing techniques.
Here is a fascinating demonstration of how various pilots apply the technique, during tough crosswinds last week in Dusseldorf, Germany. As you watch the sequence of planes coming in, you're looking to see how close each touchdown point is to the runway's center line, and whether the plane has been "kicked" so that it points straight ahead.
The landings shown here range from very precise, to "good enough." The results are a combination of the pilots' handling of the approach and the control characteristics of the various airplanes. Also, you get to see some crosswind takeoffs. At time 1:15 you'll note a plane "going around" -- breaking off an approach so it can circle around for another landing attempt -- because the pilot didn't like the way things were set up.
2) A 'Cat IIIC' automatic landing. Those crosswind landings require advanced "hand-flying" or "stick and rudder" skills. What autopilots can do is shown by this amazing cockpit video of a recent landing at, I believe, Schiphol airport in Amsterdam.
Background here: the whole point of "instrument approaches" is to get an airplane close enough to the ground, through clouds, that the pilot can eventually see the runway (or the "runway environment," including guidance lights etc) and can take over and complete the landing. Depending on the type of approach, the type of airplane, the surrounding terrain, and other circumstances, the approach can guide the pilot to within a few hundred feet of ground level (or in some cases only to within 1000 feet or more) -- before he has to "go missed" if he still cannot see the runway or lights at that point.
The "Cat IIIC" approach is unique in having no minimum "decision height" and no visibility requirement at all. The autopilot takes the plane all the way to the ground, even if the pilots cannot see anything outside their windows. That's what is happening in this video. This is where you really are putting your faith in technology -- and it's a sign of the robustness of the aviation safety system that such "auto-landings" routinely occur. (Not many airports, airplanes, and air crews are certified for fully blind "Cat IIIC" automatic landings, but slightly less demanding Cat IIIA and IIIB systems are more normal.)
And, as pilot discussion boards always point out, the real problems with a Cat IIIC landing begin after the plane has touched down and has to find its way to the gate without running into anything.