Runway Loss of Controll

[Ed Cesnalis]

We talk about landings a lot and guess what? It turns out its a very good idea because 65% of LSA crashes or due to R-LOC.

 

http://flightdesign.com/files/Media/The%20Aviation%20Consumer%20-%20LSA%20Accidents.pdf

 

"If you fly an LSA the best way to avoid your own NTSB entry is to keep your landing skills razor sharp and leave it in the hangar when the wind is gusting above 20kts."

 

[coppercity]

Good transition training and the right attitude towards this training are key to reducing these rates for LSA. As the article suggests, these airplanes are not like your 182.

[FastEddieB]

Thanks so much for that link. I just read the article and I'm trying to absorb its message.

 

The wind here today is about 12g18. I would probably not choose to fly today for fun, but I think I could handle it if I had to.

 

FWIW, it was quite gusty Thursday when I landed at Peru. I was prepared to go to Grissom or Kokomo instead if need be.

 

I angled my approach to land at about a 30° angle to the runway to reduce the left crosswind component. As I got into ground effect, the crosswind subsided, and the correction was not necessary. BTW, this WAS one of the very rare occasions I chose 10° flaps with the intent to "fly it onto the runway" - as it was I just landed a hair faster than normal but was glad to get down.

 

I do see the problem with pilots used to heavier and faster planes not adequately allowing for gusty conditions - I have to constantly remind myself to take gusts more seriously in my Sky Arrow than I would have in my Cirrus.

 

Oh, and I did get a bit of time in Prof. Shuch's Evektor. I saw nothing unusual about its handling qualities, and it landed just like a normal plane. He did warn me strongly and repeatedly about foot position on the rudder pedals, and I did see how easy it would be to hit the passenger's left rudder pedal when you meant to be on the pilot's right pedal. For safety, I really think the plate they mention in the article should be a requirement, not an option.

[Ed Cesnalis]

I just read the article and I'm trying to absorb its message...

 

Same here,

 

I wonder how relevant these small number statistics are once you have the light aircraft mindset. My first aircraft weighed 355lbs and I learned to fly it out of Mammoth Lakes so I have always had the very light aircraft mindset and transitioning for me was a non-event.

 

None the less the fact that R-LOC is statistically highly likely I am all the more persuaded that minimizing energy before contact in order to minimize damage is more important in light sport. I strive to demonstrate to myself a high level of control in gusty conditions without minimizing flaps or relying on power.

 

In 2006 I didn't work on my landings at all now I work on them a lot. I'm preparing myself for a wind shear related event on the runway like I have not yet experienced. My CTSW is quite capable but it doesn't react on its own, I have to manipulate the controls correctly.

[Ed Cesnalis]

Roger,

 

Bouncing and ballooning result from high airspeed and poorly done control inputs or lack of them. If you slow to a speed that puts you behind the power curve you can't balloon, if you slow to stall speed you won't bounce. Bouncing or ballooning due to excess energy leads to PIO, nose wheel first contacts and gear damaging contacts resulting from a failure to achieve and maintain a landing attitude, maintain alignment and failure to control vertical speed.

 

Excess energy leads to a failure to deal with that excess energy and results in the damage that you describe.

 

A transitioning pilot could attempt to stall while thinking he is close to the ground but this is a short lived period that goes away when he learns where the ground is. To think CTs are mostly damaged this way is hard for me to accept. 1 out of 10 CTs are in an accident, most of them R-LOC. There is no handy video record to look at but landing incident videos in general are plentiful and the scenarios generally involve nose wheel first contacts, bounces, balloons or un-aligned contacts to get things started.

 

I would be interested to know how many are related to poor landing skills and how many are related to wind shear overcoming a light weight aircraft.

 

Not sure why you are arguing about rolling too fast, its true I don't like rolling too fast in case something goes wrong like a flat or a gust.

[Ed Cesnalis]

High sink rates can contribute to a bounce, sink rates have to be controlled.

 

The type of bounce that I see both at the airport as well as in landing videos has to do with excess energy. The proof lies in the planes willingness to continue flying, if it was held off as long as possible before contact even if there was a bounce you wouldn't be off and flying again.

 

You and many of us can land at 70mph because we have a developed feel and can contact at near zero vertical speed and control after contact as well because at 70 your wings are developing enough lift to support your weight so your mains are in contact but only planted because of your control. Not only is your feel allowing you to put it on the runway at flying speed it is also preventing you from ballooning when you raise the nose to a landing attitude without getting behind the power curve. The difference is at 70 if you pulled the stick back, or even got gusted you could be flying where with my full stall landing my aft stick is just providing braking.

 

I can't remember saying speed causes the accident instead I keep saying I want minimum speed in order to minimize damage. I say things like energy increases with the square of the speed increase. More energy = more damage if an incident occurs, plus excess energy is a factor that leads to bouncing, ballooning, porpoising, ...etc, for students or pilots with weaker skills.

 

If a student was ballooning at round out I could tell him with confidence that if he subtracted enough speed from his approach speed prior to round out that the ballooning would cease to be a problem for him. You know how to use only enough aft stick to arrest your descent, you are now level but still a bit nose low because your feel knows that patience is required here but the student without your number of landings is going to balloon above a certain speed.

[Jim Meade]

Ah, nothing like a familiar, comfortable discussion of dogma. Popcorn, anyone?

[Ed Cesnalis]

...Being "on camera" can impel us to do things other than we normally do...

 

I agree with Jim so I won't ask. I have to note that the full stall guys are prone to demonstrate with video, the fly it on - fast is ok guys, not so much, but that's ok.

[sandpiper]

I am in the camp of getting slowed up on approach and touching down with aft stick and holding it off. If I had a stall horn it would be chirping. Conditions permitting of course.

 

But this is not a FULL stall landing. Close but not. I wonder how many do what I do vs. a full stall??

[Ed Cesnalis]

John, I think full stall landing is a phrase that means what you describe. You have to land in a normal landing attitude, one from which a CT will only mush.

 

You can't do more than a pronounced flare and full aft stick and because you do that close to the runway the stall can't develop, you instead contact after 2" of sink.

[Ed Cesnalis]

This is a wonderful example of ballooning and bouncing the pilot has no feel so he over-rotates at round out and balloons. He is able to bounce and fly and bounce and fly and bounce and fly a fourth time due to excess energy. Landing at minimum speed does not permit this result.

 

If his approach speed had been right the ballooning tendency would have been less or non-existent and the planes willingness to climb and fly after contact would have been less or non-existent as well.

 

You can't watch this and blame all gear damage on landing slow.

[FlyingMonkey]

I level out a couple of feet above the runway, wait a moment for the speed to bleed off and there is the barest hint of sink, then progressively add aft stick through the mains contacting, holding the nose wheel off as long as it will stay up. This is from a 55kt approach, about 50-52kt over the threshold. I'm not really looking, but I'm guessing I make contact with the mains at 42-45kt. This seems to work well for me at 15° or 30°. I am still perfecting these until going to 40°. I don't think it's quite a full stall landing, but it's close.

[Jim Meade]

When I think of a full stall landing I think of a tail wheel airplane which plants all three gear at the same time. Maybe a tricycle gear has the same attitude when it plants on the mains, but in all candor I suspect most of us don't have the nose as high with a CT. I think even when we land very slowly, we still tend to roll it on a little. If we were in a full stall landing, I'd think the nose wheel would not be able to be kept up with the elevator, but most of us do strive to hold the nose wheel off.

[Ed Cesnalis]

And how many of you are 100% right on with technique on 100% of your landings. If a single person raises their hand?

So any thing at an time could happen and it's your training that helps keep you out of trouble when trouble happens.

 

Perfect 100% of the time is another straw man. The fundamental is minimal energy vs not. CTLSi says minimal energy is near impossible and risky yet many of us have done mostly that our entire careers.

[sandpiper]

The funny thing is Tom Duncan delivered my plane and transitioned me. He taught power off abeam the numbers, flaps 30, 50K on final. In this configuration keeping your wing tips (CTSW) level with the horizon ensured proper air speed.

 

Now for the funny part. I didn't know I was supposed to be having problems until I read some of the posts on this forum!!

[FredG]

Regarding errors in the numbers in the article - note the November 2012 publication date. I think the information was correct at that time.

[Jim Meade]

I'm a subscriber to Aviation Consumer and remember when I read it at the time that I thought it was not the most in-depth reporting that could have been done.

Comparing LSA which are often flown by owners to C152s which are often flown by students and CFIs is not exactly apples to apples, I think. Without a detailed review, we all know of a number of LSA accidents that involve new pilots and longer distances. That is also an unlikely scenario in a C152.

The Cub clones may be flown into shorter and rougher strips than the C152 or C182.

As far as the preponderance of R-LOC accidents, I remember when I read the article that my impression was that instructors were using a fly-it-on technique as a way to deal with the student challenge of dealing with light input forces and susceptibility to misjudging the flare.

When I bought my CTSW, I had been flying Citations, KingAirs, a Cessna T210, a Piper SuperCruiser PA12 tailwheel and a glider. Maybe the PA12 and glider familiarization came through, because while not all my landings were pretty, I didn't drop it on.

The old geezers who have R-LOC problems almost certainly learned on something with light wing loading and their learned response must be to slow the plane down. Apparently, some are slowing it down too high. It's the "too high" that is wrong, not the slowing down part.

I wonder what speed the LSA tailwheel pilots are being taught to fly on touchdown?

[FredG]

Note that the two figures attached to the original post depict proportions, not numbers. So, the fact that runway LOC incidents account for a larger proportion of all LSA incidents than they do for all 152 incidents, doe not, in itself, permit the inference that each landing in an LSA has greater risk of loss of control than each landing in a 152. Without information on the numbers of events in each category and the total number of events used to calculate the proportions, such inferences are insecure.

 

For starters, for each aircraft type, if the number of events in the other categories are low, then the proportion of the remaining events in the LOC category will be greater, even if the actual number of incidents (and the fraction of landings) that did result in Runway LOC was unchanged. In addition, if the rate of incidents is lower per flight hour or per landing for one type versus another, such differences (which allow for more secure inferences about risk) are not depicted in proportion data. Hence, inferences from figures of the type provided by AC must be interpreted with considerable caution.

 

None of this is meant to suggest that landing our planes is not demanding (or even more demanding than other planes) nor to suggest that pilots are not well-served by building and maintaining skills necessary to safely manage this phase of flight.

[Ed Cesnalis]

...Using high flap setting, low speed, and misjudged height from runway when leveling off and flaring are a near impossible combination that gives the highest risk of bouncing and possible ballooning

 

Slow means less lift. Ballooning is unwanted lift resulting in climb. You have it upside down.

[GlennM]

I am with sandpiper. The CT is very easy to land. I like to chop the power somewhere in the pattern and land. It does have a quirk of the flap and aileron mechanism limiting deflection at higher flap angles. I think that lack of roll authority contributed to a number of crashes early on. I remember one where the guy tried to go around just as the wing started dragging, which added some energy and put him off the runway a number of yards. He walked away though.

 

My transition training spent time on the differences in roll rates with different flap settings. Once that was demonstrated, the rest was much easier. My first landing of my transition flight (and the first one in six years) was in a 15 kt. crosswind. It was not very pretty, but the gear stayed on!

[sandpiper]

I am with sandpiper. The CT is very easy to land. I like to chop the power somewhere in the pattern and land. It does have a quirk of the flap and aileron mechanism limiting deflection at higher flap angles. I think that lack of roll authority contributed to a number of crashes early on. I remember one where the guy tried to go around just as the wing started dragging, which added some energy and put him off the runway a number of yards. He walked away though.

 

My transition training spent time on the differences in roll rates with different flap settings. Once that was demonstrated, the rest was much easier. My first landing of my transition flight (and the first one in six years) was in a 15 kt. crosswind. It was not very pretty, but the gear stayed on!

 

Some other planes with this flap/aileron set up such as the C-180/185 and C-206 also have the lack of roll authority you mention. It's not bad on the 206 but can ruin your day on the 180/185.