From a teaching point of view, I hate big engines and pretty airplanes. It is hard to get the owner of a show airplane to rapidly transition from using tail wheel steering to rudder steering on takeoff. This is necessary to level for acceleration. If he has a big engine he doesn't need to until heavily loaded, or at a high density altitude airfield, or something happens. On landing we need to slow down (tail low) before we get there. When we mush down, or touch down a little fast, we need to level for visibility and good rudder control.

But wait! There are ways to cheat. One is to mount a wooden prop. The other is to use dynamic proactive fore/aft stick movement (not pressure.) When ground speed, relative wind, and buoyancy pick up, push the stick too far forward/pull back/forward/back, etc. to find a level airplane you're happy with. This rapid transition increases precession. If we are dynamically and proactively walking the rudders, we will control precession. This dynamic proactive porpoise is not a problem. Static reactive porpoise is a problem. As we control the longitudinal axis (yaw) with dynamic proactive rudder, we control the lateral axis (pitch) with dynamic proactive fore/aft stick.

The same for/aft stick movement is necessary when landing. As we settle on, or just before with some airplanes, we need to push the stick too far forward, pull back, etc. dynamically until we find a level airplane we are happy with. Waiting and reacting does not help. No wind or light headwind and we are already level touching down, we are way too fast. In strong headwinds or strong crosswinds, we will already be level. We should already be slow. When properly slow (ground speed) in a fairly strong downwind, the tail will likely touch down first. It takes quite a bit of power to fly slow enough (behind the power curve) thus the nose will be high.

Just curious what the motivation behind these daily theoretical postings is? Not trying to be rude or mean or anything like that, just curious. I have a hard time understanding some of them. Are you writing an instruction book or just tossing out helpful hints? Thanks

Have already written the book. Retired, bored. Just throwing out hints. Wife will retire from 36 years teaching in two weeks. You won't be bothered with me as much then.

My wife has been a teacher 37 years. Retires in 5 weeks. Help! Any advice?
My Landings are ok. On the other hand she can wear out a left main in 90 hours.
Read your book already

contactflying wrote:Have already written the book. Retired, bored. Just throwing out hints. Wife will retire from 36 years teaching in two weeks. You won't be bothered with me as much then.

Not bothered at all just curious! Keep up the good work!

contactflying wrote:Have already written the book. Retired, bored. Just throwing out hints. Wife will retire from 36 years teaching in two weeks. You won't be bothered with me as much then.

Tell her she has to keep teaching. I'm loving your posts.

Jeredp wrote:Just curious what the motivation behind these daily theoretical postings is? Not trying to be rude or mean or anything like that, just curious. I have a hard time understanding some of them. Are you writing an instruction book or just tossing out helpful hints? Thanks

Here's his book: http://www.amazon.com/Contact-Flying-Jim-Dulin/dp/0615209831

Wish it were available on kindle.

Gracias.

contactflying wrote: No wind or light headwind and we are already level touching down, we are way too fast. In strong headwinds or strong crosswinds, we will already be level. We should already be slow. When properly slow (ground speed) in a fairly strong downwind, the tail will likely touch down first. It takes quite a bit of power to fly slow enough (behind the power curve) thus the nose will be high.

My feeble brain is a bit confused by this. Are you saying that you land with a higher angle of attack in a tailwind vs a headwind? Wouldn't they be roughly the same, just different ground speeds?

Kindle +1

Its always amazing what one can find on the internet.

Nice work Jim and keep your posts coming. They are refreshing!

http://www.iaftp.org/members-only/training-practice-promotion-winners/

AKT

I too have been enjoying your posts tremendously. Don't let you wife being around stop you, keep them coming.

I still need to get your book, sounds like a good read.

Marty

I read it, learned a lot, gave it to other pilots and bought another to read again. Your posts are good short reviews, thanks.
Mike

I was/am enjoying the posts. Very informative. Please keep it up. Thanks!

contactflying wrote:From a teaching point of view, I hate big engines and pretty airplanes. It is hard to get the owner of a show airplane to rapidly transition from using tail wheel steering to rudder steering on takeoff. This is necessary to level for acceleration. If he has a big engine he doesn't need to until heavily loaded, or at a high density altitude airfield, or something happens. On landing we need to slow down (tail low) before we get there. When we mush down, or touch down a little fast, we need to level for visibility and good rudder control.

But wait! There are ways to cheat. One is to mount a wooden prop. The other is to use dynamic proactive fore/aft stick movement (not pressure.) When ground speed, relative wind, and buoyancy pick up, push the stick too far forward/pull back/forward/back, etc. to find a level airplane you're happy with. This rapid transition increases precession. If we are dynamically and proactively walking the rudders, we will control precession. This dynamic proactive porpoise is not a problem. Static reactive porpoise is a problem. As we control the longitudinal axis (yaw) with dynamic proactive rudder, we control the lateral axis (pitch) with dynamic proactive fore/aft stick.

The same for/aft stick movement is necessary when landing. As we settle on, or just before with some airplanes, we need to push the stick too far forward, pull back, etc. dynamically until we find a level airplane we are happy with. Waiting and reacting does not help. No wind or light headwind and we are already level touching down, we are way too fast. In strong headwinds or strong crosswinds, we will already be level. We should already be slow. When properly slow (ground speed) in a fairly strong downwind, the tail will likely touch down first. It takes quite a bit of power to fly slow enough (behind the power curve) thus the nose will be high.

I not poblem unstanding post,lean fli in Bangladesh like himm...vely good...vely good...

No sweat GI. You want, we got.

contactflying wrote:.......... use dynamic proactive fore/aft stick movement (not pressure.) When ground speed, relative wind, and buoyancy pick up, push the stick too far forward/pull back/forward/back, etc. to find a level airplane you're happy with. This rapid transition increases precession. If we are dynamically and proactively walking the rudders, we will control precession. This dynamic proactive porpoise is not a problem. Static reactive porpoise is a problem. As we control the longitudinal axis (yaw) with dynamic proactive rudder, we control the lateral axis (pitch) with dynamic proactive fore/aft stick. The same for/aft stick movement is necessary when landing. As we settle on, or just before with some airplanes, we need to push the stick too far forward, pull back, etc. dynamically until we find a level airplane we are happy with. ........

Too many words. "Doing some pilot shit" is what I call it.

Lo and behold, the lift coefficient is 0.52, exactly the value provided in the original data. This application of the lift equation may seem backwards, but engineers often use it during the preliminary design process of a new aircraft. A cruise speed as well as an approximate weight and size are typically specified when the design effort begins. These values can be used in the above equation to solve for the lift coefficient necessary to maintain cruise flight at those conditions. Once that coefficient in known, designers can determine what wing shape and airfoil section will best provide that lift coefficient while minimizing drag. Other factors obviously come into play since an aircraft does not spend its entire flight at steady and level conditions, but this technique is a common first step in the initial sizing and design of a new flying vehicle.

The NASA report described earlier also provides some additional data that we can use to further explore this subject. Recall a previous article that discussed a method of estimating the lift coefficient called Thin Airfoil Theory. This article introduced the following equation to approximate the behavior of the lift coefficient as a function of angle of attack in radians.


The variable CL0 represents the lift coefficient when angle of attack is zero while CLα is a stability derivative that defines the slope of the lift curve line. Values for both of these variables are provided in the above table. These parameters allow us to construct the linear portion of the 747 lift curve up to the angle of attack where wing stall would occur.

SORRY, wrong website...Just answering some of the Boeing design team's questions...Done brain surgery for today so just relaxing...

Keep posting.

I need to get another copy of your book. You sent me two last time, not sure why, I only ordered one, but I thank you for that.
Gave the extra one away to a young friend who was going off to start a career in rural Alaska. I figured he needed it.
I got half way through my copy, when I took a job in Naknek Alaska, fixing beavers. I ended up loaning it to my employer and not getting it back. By the way he fly's, he needed it more than I did at the time.
Next week I am starting to learn tailwheel in a Cub Crafters Sport Cub. I will order another copy as soon as I get my first paycheck from my new job, at Cub Crafters. Until then, I will enjoy reading your posts.

David