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"We are the protagonists of our stories called life, and there is no limit to how high we can fly."


Type rated on A330, B747-400, B747, B757, B767, B737, B727. International Airline Pilot / Author / Speaker. Dedicated to giving the gift of wings to anyone following their dreams. Supporting Aviation Safety through training, writing, and inspiration.

Thursday, October 6, 2011

A330 The Law of Landing

Surprise Surprise... I'm still in New York on my extended layover due to work stoppage in Athens. Five days in New York... but somebody's got to do it. So the memory of Athens will have to hold over from the first time I visited on during my first trip on the A330.


Now as promised... more on landing the A330.

It's all about the Approach and touchdown.

Can the A330 Slip? Of Course. Why does Airbus recommend landing in a crab? My thought is that a "wings level" approach provides a better chance of not catching an engine upon landing.

For my earthbound friends...

Crab: The airplane's nose is pointed into the wind with wings level, while the aircraft tracks toward the runway.


Slip
: The airplane's nose is positioned in alignment with the runway with the rudder and the ailerons are used to prevent the plane from drifting with the wind.


Back to landing the Bus...

In addition--- since the A330 shifts modes during the landing, slipping the aircraft becomes a bit of a challenge, and could be the attributing factor to the A330 Crosswind Landing Statistics mentioned Tuesday.

The handling differences in a Fly-By-Wire aircraft are significantly different in some maneuvers--- especially Landing.


If a slip is to be flown just before landing, lateral stick input is used to establish the amount of bank and must be returned to a neutral position to hold the amount of bank requested, while opposite rudder is established. Not a big deal. Now we're flying neutral stick with a bank established and cross rudder, creating a slip.

But there is a little more to landing this plane due to the modes of operation in Normal Law.

Normal Law--- the flight control law used for normal operations when everything is working.

  • Flight Mode
  • Landing Mode
  • Ground Mode

Flight Mode becomes operational 5 seconds after takeoff. We climb, cruise, and approach with full Fly-By-Wire technology.

Landing Mode is when the logic begins to change. Airbus decided that when descending below 100 feet RA, they wanted to give us a "conventional feel" for the flare and touchdown.

This feel only effects the pitch handling characteristics. Then at 50 feet RA a slight pitch down elevator input is applied requiring the pilot to give a bit of aft stick movement to maintain the same pitch.

At 30 feet— flare. The pilot brings the nose up just enough to arrest the descent rate. Not the traditional flare that you'd expect in a Cessna or a B747. Then bring the power to idle when commanded. The aft main wheels touchdown first. Front main wheels land second. Then we fly the nose to the runway. Do not hold the nose off. If you hold it off too long, she'll run out of airspeed and drop hard.

During the flare, rudder should be applied to align the aircraft with the runway heading.

Ground Mode is where the fun begins in crosswind conditions. Sidestick control of elevators, ailerons, and spoilers, is now directly proportional to the deflection of the sidestick. Therefore, if we had a bank established, but our stick was neutral--- once on the ground we'd be required to input the same amount of bank as necessary to counteract the wind, and hold the stick in that direction.

If you had no bank established, once on the ground, you may need to add some, remembering the direct stick to controls logic--- just like Direct Law. The flying does not stop when this plane is on the ground. It may just begin.

~Enjoy the Journey!

XOX Karlene

22 comments:

  1. Karlene, all that mode-switching would drive me nuts! From my spam-can driver's perspective, I'd think it would be better to shift to a "conventional feel" somewhere around the FAF and leave it there! After all, you folks do know how to land an airplane in a crosswind.

    Thanks for the peek into your world,

    Frank (whose 182 has only one mode)

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  2. Frank, you... and probably every other Airbus Pilot... feel that way. I think if Airbus could change one thing on their design, and only one thing, I do believe your suggestion would be the change: Give us a conventional feel for landing.

    My first crosswind landing in the simulator I defaulted to my traditional feel. Don't do that. Then I was trained to slip it... which worked fine. However, when all pilots I was flying with on the line were crabbing, I decided to do a little more research to see what airbus wanted us to do.

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  3. Again, this seems counter intuitive, but certainly learnable. So... let me make sure I have this straight. You touch down in a crab, and then put the nose on the centerline with the rudder before you lower the nosewheel? But then you don't need to input aileron while doing so to keep the airplane tracking straight down the runway? What an interesting system! Can you make reasonably smooth landings in a crab?

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  4. Daniel, the plane actually can touch down in a slight crab. But... we normally take it out before we touchdown. Yes... by stepping on the rudder to straighten it out. If you need a little aileron, just a touch, then back to neutral.

    Yes, you can make a smooth landing after flying the approach in a crab.... if you remember to flare. Wait.. we don't flare, we just stop the accent rate.

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  5. Wonderful.... now, how about trying a bush landing in that beast... I appreciate that this is your job, but I will hold on to my 'stick and rudder' and holding that nose off, using the wings as brakes to land in under 100' whenever possible!!!

    Great stuff, keep it rolling... how about comparing your Cessna to the ol' Airbus, speeds, handling and reaction times?

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  6. So if you remove the crab in a strong crosswind, just before touchdown, you only need a touch of aileron and then return to neutral? I want to try a simulator landing (or maybe a real one someday), this is way too interesting!

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  7. Well, you need as much as you need. But generally you just a touch should do it. The problem is if you give it more than a touch, then you get too much because it's not a direct feel until you touch down. You just don't know, and no feel. So... the best is, dip if you need it, and then go neutral. The point is, this happens close to the ground and quickly. Remembering... you might need to add aileron on the ground, as you would a traditional plane, if the wind is strong.

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  8. Love those diagrams of crab and slip landings. Good, descriptive words to show the approach, too. Have fun in NYC!

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  9. Maybe too much of a "touch"?

    http://www.airliners.net/photo/Delta-Air-Lines/Airbus-A330-323X/1987464/L/&sid=4a75b5c89fa5a8344246ff25a3326781

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  10. My very first flight instructor taught me both slip and crab but preferred me to crab. Every CFI after that wanted me to slip until I got to the A320! Yours is a great explanation, Karlene (better than Airbus's)! Took me lots of practice to get used to the transition, but you do get used to it. I still am incapable of bringing the aircraft to taxi speed in a strong crosswind without making the aft flight attendants ill!

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  11. Thanks Linda, Fun in NY is working. And I love it... because I have alone time, a king size bed, a bath tub, a good gym, and nice Captain to dine with every night. Life is good. Tomorrow, I'll practice my crosswind landings.

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  12. Daniel, yes... a little bit too much of a touch. Or too much wind and not enough. Hmmm. We'll never know.

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  13. Thank you so much for your comment Mikel. I hope that I'll get comfortable with this. Flying the Boeing I realized you did it, kind of like riding a bike. Not a lot of thought on how to, it was natural. This plane I feel like your brain needs lots of engagement. Sometimes it's hard to do at the end of a long flight over the ocean. I hope that one day, like you, I'll get use to the transition. And I'm always striving to not make the flight attendants ill.
    Thanks so much for your comment!

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  14. Worst landing I have encountered recently, was with an Airbus 319 pilot. A good friend of mine that I went flying with in the 172. Worst. Landing. Ever.
    I think he forgot that we only had one mode in the 172. It took me a while to regain my composure I as laughing so hard! :-)

    Thanks for sharing the flight info of your "Princess" fun to read!

    Tom - One mode CFI!

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  15. Tom, this is so true. He probably forgot. But more than likely, the really hard thing after flying the big planes is finding the runway. It's so hard!

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  16. Great information Karlene, lots of differences between the buses and the Boeings huh? If you do everything right on landing, maybe you'll get this:
    http://youtu.be/lowrM-780tg?hd=1

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  17. Steve, that was a beautiful landing! I'm going to strive for all mine to be that perfect. But... where was the wind? :) Thank you for sharing that video. I like it.

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  18. Oh my gosh, the things you get to see and do! I'm absolutely GREEN with envy.

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  19. Yes, I am very fortunate. It's been a good week and tomorrow I get to go to Barcelona. Life is good.

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  20. Capt. Yaw, your comment was hiding in spam. Maybe it was hiding in the bush. Yes, as soon as I get back into my Cessna, I will write more comparisons.
    You seriously have the best flying around!

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  21. Once you receive the fuel slip, do you send an acars report to the company telling them how much fuel was loaded, what type,etc.?

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  22. Jet airliners...no. Company tells them how much to put on.

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