acdii

Iam having a slight problem with my 4*120. They planted corn again this year, and that junk is TALL! Its over 6', and now I am finding that getting the plane over the tops and not scraping bottom to be a challange. Ineed to get it from 6 feet down to 1 foot as quickly as possible so I dont float into the other side of the field and take out some corn( or more likely damage the plane). The 4* is a floater even with removing the outer bay on each wing. Igot the DLE 20 down as slow as it can go too. Since I have to bring it in steep so I dont loose it over the corn, it comes in fairly hot, so not sure what I can do at this point.

Ialready skimmed the corn with my LT40, thankfully it landed safe, but was rather close as it got the last 2 rows. The last time Iflew the 4* I basically slammed it in, which wasnt pretty, but got it down safe, amazing how much spring that landing gear has.

Oh for the want of a reverse pitched prop with the flip of a switch.

speedracerntrixie

My Feedback: (29)

Odds are you are nose heavy. Moving the CG back to a more nuetral position will make landing speeds lower. Making your base to final slower will also help. If you can go up in dia and lower in pitch will help slow the airplane too but getting the CG back to 30% to 33% will help the most.

JohnBuckner

My Feedback: (1)

Reflex both ailerons up slightly from the in trail position when in neutral. Usually done with just equal amounts of clevis turn for both. This is not flap and in effect is the opposite.

John

acdii

CG on this one is actually slightly tail heavy according to the manual. I could play with props, but my main reason for this post is how can I tell I cleared the corn?   This plane is rather large and I usually fly it late evening of course when the sun is at the same angle.  Any visual cues I could look for?  I could bring it in low and slow and put it down on the numbers if there wasn't these huge stalks of corn in the way, but the problem is, I don't want to dump it in the corn. 

a70eliminator

I crashed my bipe in for a landing didn't quite make the field, my depth perception was off and didn't quite make the field. I've been concentrating on comming in low and slow just above stall speed then making my final turn and landing all sorta at the same time, that way I can see better and judge disrance.

Hossfly

If you work at it you may well learn to "SLIP" it in as you pass the corn-line. Standard procedure for short field operations in many instances with 1:1 scale.

Best done with a little bit of extra airspeed. Aileron into the wind, with a 10-30* bank, and OPPOSITE Rudder. In the situation you present you need to be quick like QUICK!
At the corn-line roll into the bank, apply opposite rudder and descend, then as the model drops, go back to level and you will have dropped several feet.
One item that will assist control of that 4* is to cut the aileron tips at about 3-4" from the end and attach the end back solid with 4-8 degrees UP. This really helps that kind of wing. I have 4-star, 4-star 60 and a 120. Any straight wing model with full length ailerons will make landing control much nicer if the tips of the aileron do NOT extend to the end of the wing.
As far as CG is concerned, any CG behind 28% MAC will only hinder your positive control of the machine during such a maneuver. Your choices! [:-]

jester_s1

Past about 40 yards depth perception becomes pretty inaccurate. About all you can do is get a precise landing routine going where you know the timing. On the landing hot issue, have you learned how to crab your plane? That's where you roll it one way and rudder it the other, making it fly straight with the wings tilted a bit. It kills some lift without increasing airspeed which will let you have a steeper approach than normal.

Here are a couple of videos of it. The first is a model where the crab (or sideslip as some call it) is pretty extreme, the other is a full scale plane where it's much more subtle. In both though, the approach is done without the wings level and the rudder is being used to make the plane come in straight.

http://www.youtube.com/watch?v=wW8GRJI6Kz4

http://www.youtube.com/watch?v=9fTS-fKX13U

Villa

acdii and a70eliminator
It may be a shock to learn that depth perception is only about 17 feet. Look it up! I have hit the tall grass before the runway many times. "We simply do not know where the runway starts". Go to about three mistakes high and practice flying as slow as possible, but still maintaining control. Most planes can fly very slow. Here is how I land now:
. Every now and then I hear someone at the field mention that they crashed during a landing because “THE WIND GOT THEM�. This looks like a strong downdraft pushed the plane into the ground. That ever happen to you? Since I always insist on determining the cause of every one of my crashes, I kept questioning that “THE WIND GOT ME� reason, since I used it also. Then I realized that these types of crashes always happened when the plane was very far away, or when I was landing at a much different angle to me than usual.

I am now convinced that these types of crashes are due to the wing stalling. Yes, stalling. The plane falls straight down because the wing lost lift. And the reason is that the plane is so far away and almost coming toward you, that you have lost your ability to estimate the air speed. So it stalls and crashes. My answer is to land the plane directly in front of you as much as possible, going right to left, or left to right, only. In that location you will be better able to judge the air speed of the plane, and how far off the ground it is. Use the throttle and the elevator during the full length of the landing approach to position the plane to touch down near to “in front of you�. Throttle extends the landing point, while elevator shortens the landing point. I usually hold a little throttle during the landing and only go to idle in the last foot or two of elevation. Please give this idea some thought. I would appreciate hearing any input on this.

daveopam

My Feedback: (9)

We have power wires and a pole at the North end of our runway. There is no easy way to tell which side of the lines you are on. We have learned to watch for the shadow of the plane on the ground below the power lines. After 10 years of flying at this site it is second nature to us, but visitors do get spooked at times.


David

Top_Gunn

My Feedback: (6)

Flying the whole landing pattern very slow is an invitation to a crash We have no way of knowing our airspeed, and if your airspeed gets low on the downwind leg you may not realize it, especially if there's substantial wind, and then when you turn to base, or from base to final, you stall. As Villa says, the usual name for this is "The wind got me," although some pilots call it "radio failure." The best pattern is one in which you make 90 degree turns and your final approach is straight down the centerline of the runway (crabbed if necessary because of a crosswind). If you practice this pattern until it's close to automatic you can concentrate on other things, like whether you're high enough to clear the corn, when landing. Many pilots fly a "final approach" that comes in at an angle to the end of the runway; sometimes as much as 45 degrees. Then they have to turn at the last minute. Unless you have to do this to clear a tree. it makes things harder. Fling a half-circle from downwind to final can work, but it's tricky because your angle on the plane is constantly changing and that makes it hard to judge speed and height.

bogbeagle

Sideslip. Perfectly do-able, but will take some practise before you can do it accurately right down to the round-out.

Fit a large, fine-pitch prop to increase drag at tick-over. Quick and easy.

Find a better flying site. Best solution.

Get a more appropriate model... something with powerful flaps and a light loading.

BobFE

I agree with slipping. I had a guy at my last club that harped on using the rudder for landing. He was one of those old crotchety guys that always had some comment, usually negative, about everyone's flying but I listened to him because he had been flying for years. I started using the rudder to control my plane while on approach and only used the ailerons to keep the wings level. Because the roll rate was much slower with the rudder I had more control of the plane on final, and this allowed me to have more control on short final. Most of the time I now grease my landings, nice and smooth. If you think about this it creates a natural slip. If you are adjusting for a crosswind, then you will have to hold in a rudder input to keep the plane on centerline, and by correcting the roll with the ailerons, you are now in a slip. All you have to do is increase or decrease the amount of rudder and aileron you use pending on wind.

Another good practice, like was said before, is to fly a rectangular box pattern for landing. Again, this will allow you to adjust how far out you start your approach by extending or decreasing your downwind leg. A good rule of thumb is if you do not have a good approach, you will not have a good landing. Work on the good approaches and you will find your landings will get much better.

Acdii, something you might also want to think about, the field might be too small for your 4Star120. Hard to say without seeing it.

flycatch

My Feedback: (26)

Small tight fields are a problem but are not an issue if you visualize a funnel with you being on the bottom of the spout. Instead of using the normal rectangular pattern to land use a spiral approach instead. I learned this long ago when I belonged to the "league of Silent Flight" flying gliders. You start from above flying a large descending circle decreasing in diameter on your way down. The last circle should place you about twenty feet above ground level and in a direction with the runway.

acdii

Thanks guys, yes I do side slip a lot, but never tried it on approach, That may work for this.  The runway is long enough for the 4* if I can set it down in the right spot, but with the corn being damned near 7 feet this year, I have to come in much higher than I usually did, and thats where I have been having issues, but crabbing it may be just the ticket for this. Oh and standing on a platform so I can see over the corn may help a lot too! 

acdii

LOL That is kind of the way I have flown the last two times out. With the Corn being so tall I have to fly it in closer to me as I get lower to the ground or I will lose it over the corn. I circle it in and make smaller circles the lower I get until I bled off enough speed to bring it down.


Oooh I just thought of something. A laser fan at the end of the runway with one of those beepers they use in laser tag. That would tell me when I am past the corn. FAA may frown upon that though.

Instructor

My Feedback: (16)

Hi Acdii,

This might sound a litt stupid, but this is what we do when we go to a new field we haven't flown off before. Take your airplane to the end of the runway, next to the corn. Walk back to your flight station. Notice the size of your plane at this distance. Get use to seeing your plane at this distance and you will have a better chance of getting it right over the corn every time. Like someone has already said, look for the shadow as the plane clears the corn, cut your power and land.

Since you have a extra set of wings, add flaps to them and use the flaps to land. If you haven't tried flaps before, this is how I do it. Flaps are made to get in and out of short fields. When making your approch, lower the flaps all the way, pull your power all the way out to idle. Push the plane over to a 45º down angle. It won't pick up speed with the flaps lowered all the way. Flair like you alway do and then land. Just my 2 cents worth. Good luck.....

Larry

bogbeagle

acdii,



It's not a quirk.

It's normal for the nose to drop and the speed to increase when you initiate a side-slip. Thus, you need to control the speed using elevator.

So, you find yourself way out of balance AND holding a deal of elevator ... in other words, you have your controls nearly set for a spin. That is why the sideslip, near to the ground, can be dangerous for the unwary and inept.

sunfly3

My Feedback: (34)

Having been flying a 4*60 since the late 90's, I understand the problem, they are real floaters, particularly with a .90 four stroke with a 13x8 prop. Reflexing the ailerons up about 15 degrees will take out some of the lift on approach, and if you can do this using a landing mode that does it at 25% throttle and less, makes it a *****cat to land. They are great flying planes in all respects, but this will make it a one touch landing with no bounce if flaired correctly.

M3Baker

I do the same thing. Watch for the shadow to cross the tree line and then I'm good.

Airplanes400

My Feedback: (349)

Here is another approach ...

http://www.youtube.com/watch?v=7IRiR3cF-cM

OliverJacob

My Feedback: (12)

How about adding flaps? This is a nice big plane, I'd probably just do that.

Slipping works also, but it's a little more work.
You can judge the distance better if you standing away from the runway and see the plane rather from the side then head on. Side tracking is a little more difficult though.

rgburrill

I learned to fly in a very short field with tall grass/weeds on each end of the runway.  And to make it more difficult we had very tall trees close to the north end of the runway.  Very simply we positioned ourselves as close to the landing end of the runway as possible - that was usually the north end, but not always.

acdii

Well last night was not too bad to fly, but a light misting rain made it uncomfortable.  I found flying on an overcast evening to be disorienting, cant make out the checkerboard bottom to the solid blue top.  However I flew 3 different planes last night and the only one that had a not so good landing was the 4*, mainly due to engine tuning. As I came over the corn, which is at LEAST 7' tall now!,  the speed was good, and it was settling nicely, and I nosed down a hair, and at the same moment the engine idled up,  Man do things happen fast when that happens, I barely had time to flare it out, and made another hard landing, bounced up 2 feet and hit again, hard enough for the engine to divet the ground.  The landing gear on this one has a lot of spring to it.  I need to look into why the engine sped up when it nosed down a bit, thats not a good thing.  When coming in it had a nice slow idle, and just as I dropped the nose, it went up about 400 RPM.  Had it not done that, it would have made a nice soft landing.  Nothing got damaged though, so grateful for that. 

Top_Gunn

My Feedback: (6)

"Nosing down" on final approach increases your airspeed. Then, when you flare, the plane wants to climb because of the higher speed. If you use throttle for altitude control on final you should have better results.

acdii

I know, I had anticipated a slight increase in speed, but not with the engine revving up 400 or so RPM.   I was at about 9 feet and wanted to come down a few feet and then settle it in, but that few feet got eaten up quickly with the slight burst of throttle.   I think I will ask about the throttle burst over in the gas engine forum, it was pretty strange that it did that. It was idling so nice and low.