RANS s7-ls training

[Barneyfife]

new private pilot (probably write up a post on that later on), fbo has a rans s7ls to rent, ive talked to instructor about it a little, says 5-10 hr for training but need 10 hr before i can rent it. so figure 10 hrs.
question is, any tips for the transition to tailwheel? ive read many of things for the transition and know i figure it out just going and doing it, just wanted to ask the question about the tailwheel endorsement as well as the rans itself.

 

[PilotRPI]

I enjoyed the Tailwheel 101 DVD. Got my instruction from the guy that did the DVD, and he is probably one of the best tailwheel guys around. Certainly one of the top instructors I've ever had. Other than that just getting time in the plane is what really does it, and I had an absolute blast.

 

[steingar]

Since when can an experimental aircraft be rented?

 

[Clark1961]

Since when can an experimental aircraft be rented?

Factory LSA

 

[steingar]

Factory LSA

Silly me. Didn't know.

 

[zaitcev]

question is, any tips for the transition to tailwheel?

The biggest realization for me was just how close to the ground the wheels must be for a safe landing.

This is a topic not terribly well covered in textbooks and or explained by instructors. In a tricycle gear airplane, as long as the pilot lands on the mains, the nose rotates down upon the contact. This reduces the angle of attack, thus kills the lift, so even if you bounce, you will not porpoise. In a tailwheel airplane, letting the wheels hit the pavement increases the AoA (or keeps it the same in case of a perfect 3-pointer), so a bounce is liable to produce a dangerous porpoising.

Ideally you should get those wheels within 6 inches off the ground while flaring, in any wind.

Everything else was trivial by comparison for me: wing down to cut the drift, align the direction of motion with the direction of the fuselage, be aggressive but measured on the rudder. All these things that fill up taildragger tactics books were easy to gauge by horizontal alignment of the runway, but finding where the wheel meets the ground needed a serious ability to glance aside at a critical moment!

S-7 makes it easier by having a tail so long, that you can hook tailwheel first. It's going to be ugly and uncomfortable, but a safe landing. In any case you'll have to land the way the checkout CFI prefers you do it, else they will not let you rent.

 

[Greg Bockelman]

The biggest realization for me was just how close to the ground the wheels must be for a safe landing.

I am confused. Don’t the wheels have to be ON the ground for a safe landing?

In a tailwheel airplane, letting the wheels hit the pavement increases the AoA (or keeps it the same in case of a perfect 3-pointer), so a bounce is liable to produce a dangerous porpoising.

Actually, it is the pilot’s reaction to the bounce that causes the porpoising. If it is a slight bounce, I advocate just holding the yoke steady and maybe adding a shot of power. A bigger bounce is reason to go around and try it again.

Ideally you should get those wheels within 6 inches off the ground while flaring, in any wind.

Wouldn’t that apply no matter what you were flying?

S-7 makes it easier by having a tail so long, that you can hook tailwheel first.

You can pretty much do that in any taildragger.

It's going to be ugly and uncomfortable.

Doesn’t have to be. If it is done right, you would hardly notice it.

 

[zaitcev]

Actually, it is the pilot’s reaction to the bounce that causes the porpoising.

Here's what FAA-H-8083-3A has to say about the matter:

"When the airplane contacts the ground with a sharp impact as the result of an improper attitude or an excessive rate of sink, it tends to bounce back into the air. Though the airplane tires and shock struts provide some springing action, the airplane does not bounce like a rubber ball. Instead, it rebounds into the air because the wing's angle of attack was abruptly increased, producing a sudden addition of lift."
"The abrupt change in angle of attack is the result of inertia instantly forcing the airplane's tail downward when the main wheels contact the ground sharply. The severity of the bounce depends on the airspeed at the moment of contact and the degree to which the angle of attack or pitch attitude was increased."

So, pilot's reaction has no input into it, only the pre-contact attitude does. However, here's where the handbook acknowledges the pilot's reaction:

"Since a bounce occurs when the airplane makes contact with the ground before the proper touchdown attitude is attained, it is almost invariably accompanied by the application of excessive back-elevator pressure. This is usually the result of the the pilot realizing too late that the airplane is not in the proper attitude and attempting to establish it just as the second touchdown occurs."

Still,

"In a bounced landing that is improperly recovered, the airplane comes in nose first setting off a series of motions that imitate the jumps and dives of a porpoise -- hence the name. The problem is improper airplane attitude at touchdown, sometimes caused by inattention, not knowing where the ground is, mistrimming or forcing the airplane onto the runway."

The whole issue is also restated w.r.t. tailwheel airplanes specifically thus:

"If the touchdown is made at too high a rate of descent as the main wheels strike the landing surface, the tail is forced down by its own weight. In turn, when the tail is forced down, the wing's angle of attack increases resulting in sudden increase in lift and the airplane may become airborne again. Then as the airplane's speed continues to decrease, the tail may again lower onto the runway. If the tail is allowed to settle too quickly, the airplane may again become airborne. This process, often called `porpoising,' usually intensifies even though the pilot tries to stop it."

Certainly, the "improper attitude" may be caused by a reaction to something. It really is a scholastic argument, not helping the OP to transition to a tailwheel airplane. His job is to level out in an attitude where the tailwheel does not descend any further, thus increasing the AoA, abruptly increasing lift, and so forth, as spelled out in the quote above.

 

[Greg Bockelman]

"When the airplane contacts the ground with a sharp impact as the result of an improper attitude or an excessive rate of sink, it tends to bounce back into the air. Though the airplane tires and shock struts provide some springing action, the airplane does not bounce like a rubber ball. Instead, it rebounds into the air because the wing's angle of attack was abruptly increased, producing a sudden addition of lift.

"The abrupt change in angle of attack is the result of inertia instantly forcing the airplane's tail downward when the main wheels contact the ground sharply. The severity of the bounce depends on the airspeed at the moment of contact and the degree to which the angle of attack or pitch attitude was increased."[/qoute]

Well, yeah. That is the CAUSE of the bounce in the first place.

So, pilot's reaction has no input into it, only the pre-contact attitude does.

Well, yeah again. By definition reaction happens AFTER the fact. So no reaction before the bounce.

"Since a bounce occurs when the airplane makes contact with the ground before the proper touchdown attitude is attained, it is almost invariably accompanied by the application of excessive back-elevator pressure. This is usually the result of the the pilot realizing too late that the airplane is not in the proper attitude and attempting to establish it just as the second touchdown occurs."[/qoute]

Not sure I agree with this as written. If the author would have added “by pushing forward on the yoke” in that last sentence it would have been more accurate in my opinion.

I am not going to quote most of the rest of this. All of what you have quoted seems to assume that the pilot remains static. IOW, does nothing, or freezes the controls. That is pretty much the opposite of what happens in my experience. What the pilot tends to do is push after the bounce, increasing rate of descent, which sets up the next bounce. The airplane, left to its own devices may very well behave as you described in what I cut, but I can tell you it is made much worse by the pilot’s improper reaction to the bounce

Certainly, the "improper attitude" may be caused by a reaction to something. It really is a scholastic argument, not helping the OP to transition to a tailwheel airplane. His job is to level out in an attitude where the tailwheel does not descend any further, thus increasing the AoA, abruptly increasing lift, and so forth, as spelled out in the quote above.

I might add that if the pilot can set up his attitude to where the tail wheel touches just prior to the mains, causing a slight decrease in angle of attack, thus reducing lift, that would tend to decrease if not eliminate the chances of a porpoise developing.