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Old 30th Aug 2007, 02:11
  #21 (permalink)  
AirRabbit
 
Join Date: Apr 2005
Location: Southeast USA
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Thanks for the response, Ashling.

I appreciate the fact that you fly your airplane the way you choose to fly it, and I have no intent to even try to convince you to do otherwise. However, I would respectfully suggest that you re-read what I posted. I did not say that you were to maintain “level flight,” nor did I say that you should “continue raising your attitude as the speed decreases” as you suggest I said. I specifically said that you maintain level flight attitude.

I also said that while you were obtaining that attitude, and after you achieved it, you would still be descending. While this would be true even if you did not reduce power (although you would land an unacceptable distance down the runway), if you were to flare to the level flight attitude either while reducing power, or reduce power reasonably quickly after reaching that attitude, the airplane will continue to descend. The only thing I said that you would have to “increase” at this time would be “back stick” pressure, and perhaps a bit of back stick movement. But that would be to MAINTAIN the attitude, not increase it.

Next, you seem to be correcting me in that somehow you presume that what I am advocating will result in “too gentle a touchdown.” Please note, that is not what I said either. I said what I am advocating should provide touchdown at a comfortable rate - not a "greased" landing, but very acceptable. Usually, a descent rate at touchdown of something less than 25 fpm will get you the accolades of a “greased” landing – depending on your particular definition of “grease.” An acceptable, comfortable rate of descent at touchdown will be “firm;” and a firm touchdown is all you need to “break through the surface layer” and give you a better chance to avoid hydroplaning if the runway is wet. By way of comparison let me point out that if the flare height you reach is between 5 and 15 feet above the runway, if you take between 1.5 and 3.0 seconds to get to the runway, you will arrive at the runway at a rate of descent between 100 and 600 feet per minute. The 100 fpm rate would be taking the full 3.0 seconds to descend 5 feet. The 600 fpm rate would be taking the 1.5 seconds to descend 15 feet. The preferred situation is to take the (plus or minus) 1.5 seconds to descend the (plus or minus) 5-foot distance – giving you a (plus or minus) 200 fpm rate of descent at touchdown; as I said, “firm but acceptable.”

Next, if you flare to achieve a level flight attitude, I would argue that you are not, as you suggest, “in tail strike territory.” I think you’ll find that you get into that territory when you get to 10 degrees of pitch. You can correct me if I’m mistaken, but I was under the impression that the B737-800 tail strike attitude is about 11 degrees with the gear struts fully extended. Level flight attitude with landing flaps, and a speed between 1.1 and 1.2 of stall speed should be in the neighborhood of 3 - 6 degrees of pitch; a considerable angular distance below that “tail strike territory.”

Obviously, I have no way of knowing your experience level; nor you mine. A part of that experience includes reading, understanding, working in compliance with, and collaborating (with pilot groups, regulatory authorities, airplane manufacturers, and others) regarding suggestions for changes to Flight Crew Training Manuals. That being a fact, statements like…
Boeings Flight Crew Training Manual for the type gives you a perfectly good repeatable technique for landing the aircraft. Its written down for a purpose I suggest you read it.
…I believe come off carrying just a bit too much of an arrogantly condescending tone – at least for my taste.
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