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	<title>Comments for tapman.net</title>
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	<link>http://tapman.net</link>
	<description>"Two things are infinite: the universe and human stupidity; and I'm not sure about the universe." A. Einstein</description>
	<pubDate>Wed, 09 Jul 2008 11:28:34 +0000</pubDate>
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		<title>Comment on The Wall Street Journal Does Things Differently by Wall-Street &#187; photoman</title>
		<link>http://tapman.net/archives/92#comment-37</link>
		<dc:creator>Wall-Street &#187; photoman</dc:creator>
		<pubDate>Tue, 17 Jun 2008 01:21:42 +0000</pubDate>
		<guid isPermaLink="false">http://tapman.net/?p=92#comment-37</guid>
		<description>[...] The Wall Street Journal Does Things DifferentlyIn a recent post, The Atlantic Mimics The WSJ In An Article On The WSJ, I talked about the Wall Street Journal’s recent changes under the control of Rupert Murdoch. An article on the US Open on June 14th epitomizes the different &#8230; [...]</description>
		<content:encoded><![CDATA[<p>[...] The Wall Street Journal Does Things DifferentlyIn a recent post, The Atlantic Mimics The WSJ In An Article On The WSJ, I talked about the Wall Street Journal’s recent changes under the control of Rupert Murdoch. An article on the US Open on June 14th epitomizes the different &#8230; [...]</p>
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		<title>Comment on Your 33 Black Angels by Curt's Little Brother</title>
		<link>http://tapman.net/archives/58#comment-23</link>
		<dc:creator>Curt's Little Brother</dc:creator>
		<pubDate>Fri, 04 Apr 2008 14:32:43 +0000</pubDate>
		<guid isPermaLink="false">http://tapman.net/archives/58#comment-23</guid>
		<description>Hey Micah. If you go to www.myspace.com/your33blackangels and scroll down to below the album cover on the right hand side of the screen, you will see two 'buy now' buttons that are accompanied by text that tells you whether the button is for the CD ($10) or Vinyl ($11). I have to fix the order form, though, since after you click the buttons it does not tell you what is in your shopping cart, unless you take special note of the price of the item in your cart. Thanks for checking it out! Maybe we'll see you in D.C. this spring/summer!</description>
		<content:encoded><![CDATA[<p>Hey Micah. If you go to <a href="http://www.myspace.com/your33blackangels" rel="nofollow">http://www.myspace.com/your33blackangels</a> and scroll down to below the album cover on the right hand side of the screen, you will see two &#8216;buy now&#8217; buttons that are accompanied by text that tells you whether the button is for the CD ($10) or Vinyl ($11). I have to fix the order form, though, since after you click the buttons it does not tell you what is in your shopping cart, unless you take special note of the price of the item in your cart. Thanks for checking it out! Maybe we&#8217;ll see you in D.C. this spring/summer!</p>
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		<title>Comment on Lufthansa landing video by Ken</title>
		<link>http://tapman.net/archives/45#comment-6</link>
		<dc:creator>Ken</dc:creator>
		<pubDate>Thu, 06 Mar 2008 15:32:57 +0000</pubDate>
		<guid isPermaLink="false">http://tapman.net/archives/45#comment-6</guid>
		<description>A little more Monday morning quarterbacking here...  I've been flying for almost 30 years, the last 20 in scheduled airlines.  I've been flying large jets since 1995 and I currently fly the Boeing 757 and 767 for a major US airline.  Having said that, let's remember that the only accurate analysis can come from the two pilots that were in the airplane--and I'm sure they've done a LOT of analysis over the past few days.  I'm not going to pass judgment on their decision to land because "there but for the grace of God go I..."

First, I'll respond to a couple of the comments:

Yamatuti said:  "Spectacular pilots check the weather forecast before leaving, check it en route, and check it before landing. Spectacular pilots will plan their flight so that the aircraft is not put into a position where it is beyond its limitations."

and

Manuel Carcamo Says: "Tipical human error from the pilot, secondly from flight control in Hamburg and Lufthansa Operations Management. All of them should be fired."

I'll keep my emotional response to these posts in check here and just say that, had they been passengers on the airplane and the decision had been made to divert instead of attempting a landing at Hamburg, these two would probably be the first (and loudest) to complain because they ended up at their alternate instead of Hamburg...  They would be wondering why other planes were getting into Hamburg, but their particular crew couldn't.

Having said that, I will admit that pilots are very task oriented and have a "get the job done" mindset sometimes.  That, along with the fact that "everyone else is getting in" has sometimes gotten us in trouble... I am NOT saying that is what happened in this case, nor am I passing judgment on the decisions made by the crew involved.

Now that I have that off my chest, let's begin with the analysis...

When I first heard the reports of this, I seriously doubted that the winds were 155 mph.  If the wind was that strong straight down the runway, the airplane would have a ground spead of 10-20 knots, if that.  If it was a crosswind that strong, the airplane would be flying almost perpendicular to the runway to maintain a track down the centerline.  My guess is that the approach speed was 155 mph (about 131 knots).  Winds in the 35-45 knot range would be more realistic.  While that sounds like a lot, it's the angle to the runway that's important.  If the wind is 30 degrees from centerline, the crosswind component is about half of the wind speed, and 45 degrees is about 2/3--both well within the demonstrated limitations of the airplane. Close to the ground that wind is flowing over objects which induce turbulence (like rocks in a river).  Wind gusts also make life more complicated.

Technique:  Hiatt's "cross-control" technique is correct.  In a light airplane you can set that up quite a ways out on final.  In a jet with passengers, flying in a prolonged slip is pretty uncomfortable, so my technique is to crab (fly wings level with the nose slightly into the wind, as in the video) all the way to the flare (about 10-20 feet above the ground where you start bringing the nose up for landing).  When I begin bringing the nose up, I simultaneously add rudder to align the nose with the centerline and lower the wing on the upwind side to prevent the airplane from drifting sideways.  If I'm off the centerline, I can (usually) vary the bank angle enough to drift back to the centerline.  In the 757 and 767 (especially the 767-400), if you touch down with any sideways movement at all it sounds like you're about the rip the landing gear off the darn airplane (and yes--I've landed with a little drift a few times :-)   )

Aircraft Systems:
Being a Boeing guy, I can only speak with limited authority on the Airbus, especially the "Fly-By-Wire" system.  Having said that, I'm not so sure that some of the limitations built into the Airbus didn't play a role in this.

The Boeing philosophy for FBW is to let the pilot put the airplane where he/she needs to.  It will warn you if you're about to do something that is "out of the envelope", but it will let you do it if you need to.

The Airbus philosophy is different--it has limits built into the software that will not allow the pilot to put the airplane in a situation the computer does not think is safe.  That MAY have played a role in this situation.  

These airplanes record and transmit vast amounts of data.  I'm sure Lufthansa and the German equivalent of the FAA or NTSB is going through that data as we speak.  I'd be very interested to find out what they learn.</description>
		<content:encoded><![CDATA[<p>A little more Monday morning quarterbacking here&#8230;  I&#8217;ve been flying for almost 30 years, the last 20 in scheduled airlines.  I&#8217;ve been flying large jets since 1995 and I currently fly the Boeing 757 and 767 for a major US airline.  Having said that, let&#8217;s remember that the only accurate analysis can come from the two pilots that were in the airplane&#8211;and I&#8217;m sure they&#8217;ve done a LOT of analysis over the past few days.  I&#8217;m not going to pass judgment on their decision to land because &#8220;there but for the grace of God go I&#8230;&#8221;</p>
<p>First, I&#8217;ll respond to a couple of the comments:</p>
<p>Yamatuti said:  &#8220;Spectacular pilots check the weather forecast before leaving, check it en route, and check it before landing. Spectacular pilots will plan their flight so that the aircraft is not put into a position where it is beyond its limitations.&#8221;</p>
<p>and</p>
<p>Manuel Carcamo Says: &#8220;Tipical human error from the pilot, secondly from flight control in Hamburg and Lufthansa Operations Management. All of them should be fired.&#8221;</p>
<p>I&#8217;ll keep my emotional response to these posts in check here and just say that, had they been passengers on the airplane and the decision had been made to divert instead of attempting a landing at Hamburg, these two would probably be the first (and loudest) to complain because they ended up at their alternate instead of Hamburg&#8230;  They would be wondering why other planes were getting into Hamburg, but their particular crew couldn&#8217;t.</p>
<p>Having said that, I will admit that pilots are very task oriented and have a &#8220;get the job done&#8221; mindset sometimes.  That, along with the fact that &#8220;everyone else is getting in&#8221; has sometimes gotten us in trouble&#8230; I am NOT saying that is what happened in this case, nor am I passing judgment on the decisions made by the crew involved.</p>
<p>Now that I have that off my chest, let&#8217;s begin with the analysis&#8230;</p>
<p>When I first heard the reports of this, I seriously doubted that the winds were 155 mph.  If the wind was that strong straight down the runway, the airplane would have a ground spead of 10-20 knots, if that.  If it was a crosswind that strong, the airplane would be flying almost perpendicular to the runway to maintain a track down the centerline.  My guess is that the approach speed was 155 mph (about 131 knots).  Winds in the 35-45 knot range would be more realistic.  While that sounds like a lot, it&#8217;s the angle to the runway that&#8217;s important.  If the wind is 30 degrees from centerline, the crosswind component is about half of the wind speed, and 45 degrees is about 2/3&#8211;both well within the demonstrated limitations of the airplane. Close to the ground that wind is flowing over objects which induce turbulence (like rocks in a river).  Wind gusts also make life more complicated.</p>
<p>Technique:  Hiatt&#8217;s &#8220;cross-control&#8221; technique is correct.  In a light airplane you can set that up quite a ways out on final.  In a jet with passengers, flying in a prolonged slip is pretty uncomfortable, so my technique is to crab (fly wings level with the nose slightly into the wind, as in the video) all the way to the flare (about 10-20 feet above the ground where you start bringing the nose up for landing).  When I begin bringing the nose up, I simultaneously add rudder to align the nose with the centerline and lower the wing on the upwind side to prevent the airplane from drifting sideways.  If I&#8217;m off the centerline, I can (usually) vary the bank angle enough to drift back to the centerline.  In the 757 and 767 (especially the 767-400), if you touch down with any sideways movement at all it sounds like you&#8217;re about the rip the landing gear off the darn airplane (and yes&#8211;I&#8217;ve landed with a little drift a few times <img src='http://tapman.net/wp/wp-includes/images/smilies/icon_smile.gif' alt=':-)' class='wp-smiley' />   )</p>
<p>Aircraft Systems:<br />
Being a Boeing guy, I can only speak with limited authority on the Airbus, especially the &#8220;Fly-By-Wire&#8221; system.  Having said that, I&#8217;m not so sure that some of the limitations built into the Airbus didn&#8217;t play a role in this.</p>
<p>The Boeing philosophy for FBW is to let the pilot put the airplane where he/she needs to.  It will warn you if you&#8217;re about to do something that is &#8220;out of the envelope&#8221;, but it will let you do it if you need to.</p>
<p>The Airbus philosophy is different&#8211;it has limits built into the software that will not allow the pilot to put the airplane in a situation the computer does not think is safe.  That MAY have played a role in this situation.  </p>
<p>These airplanes record and transmit vast amounts of data.  I&#8217;m sure Lufthansa and the German equivalent of the FAA or NTSB is going through that data as we speak.  I&#8217;d be very interested to find out what they learn.</p>
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		<title>Comment on Lufthansa landing video by mjs</title>
		<link>http://tapman.net/archives/45#comment-5</link>
		<dc:creator>mjs</dc:creator>
		<pubDate>Wed, 05 Mar 2008 16:57:24 +0000</pubDate>
		<guid isPermaLink="false">http://tapman.net/archives/45#comment-5</guid>
		<description>You are not a pilot so why are you making speculations which contain innacurate information about this event? 
Any pilot who thinks it necessary to attempt a landing like this in 155mph winds had better have some very sound reasoning for doing so.  It's just not necessary unless you are in a min. fuel or other emergent situation. So again- I'm gald they are safe, but if there wasn't an emergency- the crew will certainly have some 'splaning to do and the pax are owed an explanation as to why this was necessary.  The pilot was attempting to land the plane in excess of the max. demonstrated xwind component which, isn't necessarily a bad thing, but 155mph winds is excessive. I can tell by watching the video- based on how much crab angle they had in and how much the wind was affecting the airplane's track down the rwy centerline- that those winds were in significant excess of 40 knots.  With an aircraft of that size, it would be hard to see a x-wind landing in 40 knots of wind.</description>
		<content:encoded><![CDATA[<p>You are not a pilot so why are you making speculations which contain innacurate information about this event?<br />
Any pilot who thinks it necessary to attempt a landing like this in 155mph winds had better have some very sound reasoning for doing so.  It&#8217;s just not necessary unless you are in a min. fuel or other emergent situation. So again- I&#8217;m gald they are safe, but if there wasn&#8217;t an emergency- the crew will certainly have some &#8217;splaning to do and the pax are owed an explanation as to why this was necessary.  The pilot was attempting to land the plane in excess of the max. demonstrated xwind component which, isn&#8217;t necessarily a bad thing, but 155mph winds is excessive. I can tell by watching the video- based on how much crab angle they had in and how much the wind was affecting the airplane&#8217;s track down the rwy centerline- that those winds were in significant excess of 40 knots.  With an aircraft of that size, it would be hard to see a x-wind landing in 40 knots of wind.</p>
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		<title>Comment on Lufthansa landing video by Hiatt</title>
		<link>http://tapman.net/archives/45#comment-4</link>
		<dc:creator>Hiatt</dc:creator>
		<pubDate>Tue, 04 Mar 2008 18:44:23 +0000</pubDate>
		<guid isPermaLink="false">http://tapman.net/archives/45#comment-4</guid>
		<description>While the wind conditions were bad and this is not an easy maneuver,  it appears to me that good crosswind landing techniques were not used in this situation.  A much safer landing was possible with these winds.

From what I can see, the pilot did not set the airplane up for landing, and after landing, the pilot did not use the proper controls to keep the wings level and maneuver straight down the runway.

The crab technique used alone is not safe for landing, and it causes the pilot to forget how to cross control the airplane after landing to keep the wings level and  and track straight ahead.  In my experience, a cross control(wing low into the wind and opposite rudder) and a slight crab are necessary to land safely in high crosswinds.  With this technique, last minute corrections for wind speed changes(which appeared to happen in the video) are much easier and safer.

After landing, the cross control positions must be continued and exaggerated in order to keep the wings level and to track straight down the runway. Evidence that the pilot did not use this procedure was the right wing lifting radically on touchdown causing the left wing tip to contact the runway.  As the airplane slows down to approximately 60  knots, it may be necessary to even use the nose wheel steering and differential braking to maintain the straight track.

While this is Monday morning quarterbacking, I still think a safer landing was possible the first time using the proper technique for crosswind landings.</description>
		<content:encoded><![CDATA[<p>While the wind conditions were bad and this is not an easy maneuver,  it appears to me that good crosswind landing techniques were not used in this situation.  A much safer landing was possible with these winds.</p>
<p>From what I can see, the pilot did not set the airplane up for landing, and after landing, the pilot did not use the proper controls to keep the wings level and maneuver straight down the runway.</p>
<p>The crab technique used alone is not safe for landing, and it causes the pilot to forget how to cross control the airplane after landing to keep the wings level and  and track straight ahead.  In my experience, a cross control(wing low into the wind and opposite rudder) and a slight crab are necessary to land safely in high crosswinds.  With this technique, last minute corrections for wind speed changes(which appeared to happen in the video) are much easier and safer.</p>
<p>After landing, the cross control positions must be continued and exaggerated in order to keep the wings level and to track straight down the runway. Evidence that the pilot did not use this procedure was the right wing lifting radically on touchdown causing the left wing tip to contact the runway.  As the airplane slows down to approximately 60  knots, it may be necessary to even use the nose wheel steering and differential braking to maintain the straight track.</p>
<p>While this is Monday morning quarterbacking, I still think a safer landing was possible the first time using the proper technique for crosswind landings.</p>
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