Elevator use during landing approachs
 

I'm interested in people's comments on the use of elevator to slow the plane down on the landing approach. In full scale, elevtor trim gets a good work out, triming out the back pressure on the elevator. We don't have to deal with back pressure, nor do we use the trim on the elevator to increase up trim during the landing approach. So, I'd be interested to know if we all have similar methods of performing landing approaches? Describe your downwind, base and final aproach's use of the elevator. Thanks!!

RE: Elevator use during landing approachs
 

There's no way you trim for landing approach on a model like you do on a real plane

Trim your model for level flight cruise and leave it there

If you trim for approach and on a take off or go around you are going to have a surprise

RE: Elevator use during landing approachs
 

On a flat wing model you trim it for flat & level at about 3/4 throttle and then, on approach, you reduce height by reducing throttle. Very little elevator up or down on approach.

On a symmetrical wing you slow it down and fly it at the ground at a survivable angle and then flair in the last foot or so while cutting the throttle. In that case the flair takes up elevator, and I guess it serves as a means to slow the model, but more for spilling lift and prevernting a nose-over.

Using the elevator to slow a scale (aka: "low") powered biplane will turn it into a stalled biplane on it's side or back. You have to arrange for them to stall just as the wheels touch grass. And, in fact, one wing (upper usually) is stalled purposely at that point.

You use elevator to control pitch, but not as an airbrake or to bleed-off speed. I was taught to do flat rudder turns to bleed off height if you are too high and don't want to or can't fly another circuit of the field. Throttling down to lowest idle causes the prop to drag and helps slow a model.

RE: Elevator use during landing approachs
 

I use throttle for Altitude and elevator for airspeed
control. I also have a tendancy to rest my thumb on
a tad up elevator on final. I breath more on the downwind
leg. lol

Bob

RE: Elevator use during landing approachs
 

We have an airline pilot in the club i fly at. He is a real warbird guy, and builder. He trims for landings. Im scared to do that, that i might forget to neutralize trim when i gas up and fly again

RE: Elevator use during landing approachs
 

Speak for yourself. :)

I do precisely that on a regular basis, for PRECISELY the reason I do it in a "real" plane...to eliminate back pressure on the elevator.

We don't? The elevator stick moves all by itself then, with no force involved?

====================

You asked for us to "Describe your downwind, base and final aproach's use of the elevator." Fair enough:

I set up a downwind at an "appropriate" height for what might be called a "short field landing" in scale terms...that is to say, I fly the downwind higher than is necessary. Just personal preference...I happen to like to hang on to the altitude as long as possible *heh*. Granted, it makes for a steeper and faster final, which is more demanding than a slower descent, but again...just personal preference. A more subtle and smooth descent has advantages as well, to be sure. I just like the advantage of excess power provided by the steeper final.

I'll fly as flat a turn as reasonable to turn base, at that time throwing in a "couple" beeps of up elevator during the turn. I use "couple" loosely here, as it's obviously different for each airplane, field, approach altitude, etc. Usually, it's a beep or two, sometimes as many as 4-5. Just depends. I'll typically throw just a BIT more up trim in right before the turn to final.

I try to fly the approach so the moment I'm wings level on final, I can chop the throttle to idle. Obviously, practice, stick time, and just dumb blind luck all go into having judged that approach correctly to do that. By no means do I always achieve it, but that's my target.

IF I've nailed one, then I'll fly elevator trim and aileron all the way to the ground, never using the elevator stick. (I use the index finger and middle finger on the stick, thumb on the elevator trim) Again...doesn't always work out that way, but if I nail one, that's the end result I'm looking for. You'll never see a bigger smile on my face than when I land my 33% Pitts S2S and never touch the throttle after I cut to idle on the final. :)

Contrary to what Charlie P said above, I WILL use pitch as speed control, power as altitude control, in both full scale and rc situations...yes, even with bipes. Now, I'll admit, he said full scale bipes, and my total landings in one of those is precisely 1....but, interestingly, I was told by its owner to fly the final in precisely that fashion. *shrug*

================================================== =========

WHY do I do it all that way? I dunno...it makes sense to me. I use to argue whether newton or bernoulli caused airplanes to fly, and I used to argue whether pitch controlled airspeed or altitude. I decided to give all that up because...well...you know what they say about arguing on the internet.

I know what makes sense to me, what has allowed me to land RC and scale airplanes successfully. The principles are precisely the same for one very good reason...they're both airplanes. As such, they do the things that airplanes do, for the reasons that airplanes do them.

I'm not ABOUT to suggest that it's the "right" or "only" or "best" way to land an RC airplane. Heck, I figure the same standard that applies to full scale applies here...if you can fly the airplane again, then you did the landing the right way :D

But an RC airplane quite definitely CAN be landed the same way full scale ones are. My RC instructor taught it to me that way, he does it that way. My CFI taught me scale landings that way, and I taught him RC landings that way. *shrug* Whatever works, right?

RE: Elevator use during landing approachs
 

I use the throttle to control the decent. I use a small amount of elevator back-pressure
during the base and final turns to help regulate the decent. Once I have made the final
turn I stay off the elevator, letting the plane decend until I'm ready to begin the flair.
It's simple technique, but it works for me. I make adjustments for different models and
wind conditions. [sm=shades_smile.gif]

RE: Elevator use during landing approachs
 

On the other hand, my Contender has a flap mix to feed in down elevator when the apron flap is deployed for landing. Guess that counts as trimming the elevator for landing.

RE: Elevator use during landing approachs
 

I was taught to land using throttle, elevator and rudder, I was told to keep my hands off the ailerons except to level the plane. To bleed off speed i will often flare my planes to slow them down, sometimes several times depending on the plane. My old TX had a landing feature set to a switch you could use to add trim for landings and take offs. I did have it set up on one plane I was having a problem with, a small 40 size Fokker D-VII, it worked quite well. I know several people that have a switch set up to add some up trim for landings but I no longer have any planes that I need to do it with, if I was having a problem I would add a trim mix. I have no qualms about making my life easier.;)

RE: Elevator use during landing approachs
 

With my ol trainer, I just traded altitude for airspeed since it would glide all day and give up elevator to flair and hold it on the back wheels till the nose comes down. I practically land it like a fullsize jetliner the way I hold the nose up for so long after touching down. The decathlon lands using throttle control, it has so much elevator that I rarely use it on take offs and landings. My extra is a different puppy, she changes with the wind conditions. I have her tail heavy for aerobatics so I have to use the elevator to get her to come down and basically do a 3 point landing.

RE: Elevator use during landing approachs
 

I basically fly the base at a normal comfortable height. However much throttle is needed to fly the plane hands off, no trim or mix.
On the final turn the throttle is decreased greatly and I let the plane start to decend. Whatevers comfortable for the plane Im flying. Then on final I keep the plane flat and level. I use throttle to control the decent and elevator to maintain near zero pitch. Then when the plane crosses the threshhold I can start my flair or wait until the planes in ground effect until I flair. Again depends on the airplane and wind conditions.

Fun to read the different approaches.

Cheers.

RE: Elevator use during landing approachs
 

A new guy came to the flying field. He had been flying full size planes since back in the 60's. So being new to R/C he built a Flying King and put a Saito 91 on it. Some of the guys buddy boxed him and eventually got him going. After he soloed it wasn't long before he crashed the plane on approach trying to reset the trim for the approach glide. All the old timers around the field talked about that for some time and kidded each other for all of them keep their trim set for cruise.

RE: Elevator use during landing approachs
 

i always fly the downwind at reduced throttle (if i cruise at 3/4 then i will use 1/2) and on base i will progressively reduce throttle and on final depending on alt, will cut throttleto high idle. If the plane is too fast or too high, the best way to slow down or bleed off alt/speed is to enter a forward slip (ailerons in opposite direction of rudder) If the plane stalls easily, keep a bit of power on and pitch the nose down to maintain speed. hold the slip till u are about ready to flair, then as you flair, slowly stop the slip. If you release controll inputs too fast or too high, the plane will pickup speed and lift, and baloon. it takes alot of practise to get it down pat, but after a couple flights of touch and go's you will start to get a good feel for it.
Just remember, like everyone else has been saying: dont play with trim (it will get you in trouble) throttle controlls alt pitch contolls speed. Like i was told when i got my PPL: its all 3d thinking. Picture what will happen with every controll input and be ready to react.

RE: Elevator use during landing approachs
 

My approach, and the way I teach my students, is very simple. Whether I do a full downwind, base, and final, or whether I just do a short circle approach.

Its this:
Get the plane into a level or slightly nose up attitude with the plane sinking.

If you're sinking too fast, bump the throttle and bring it back down. If you're coming in too fast, gently pull pack a little more on the elevator. If you're to high, pulling back a little more will slow it down, causing it to descend faster. Just fly the plane. when you get to the runway, if you're wings level, nose up, and sinking, you'll grease the landing everytime.

I guess this means I use some gentle back pressure on the elevator to keep the plane level or nose up. The key is to fly the plane, not the transmitter. I don't teach them about "flare" on approach, as its already built in to the method.

Brad

RE: Elevator use during landing approachs
 

Per W8ye: "There's no way you trim for landing approach on a model like you do on a real plane". If this is a general statemnet to the readers, fine, however my original post on the tiopic was: "nor do we use the trim on the elevator to increase up trim".

Within the first few posts, it can be seen that the above statement isn't necessarily true, as obviously some R/Cers actually do use trim during landing approaches.

Per my original post: "We don't have to deal with back pressure". Then per gboulton: We don't? The elevator stick moves all by itself then, with no force involved? The back pressure felt in R/C is caused by a spring on the elevator stick, not by air pressure as in a full scale airplane and I'm only talking about airplanes without mechanical/electronical assists. If you use up elevator to control airspeed, you are applying back pressure (or up elevator) to the stick, the back pressure isn't being telegraphed by pressure felt from aerodynamic pressures

Some of you seem to allude to using flat turns during the approach. I'm unsure what you really mean here; but, would say, uncoordinated turns are bringing you closer to the stall then nice coordinated turns using aileron, elevator and rudder.

It's interesting how some of you come to this discussion on approaches so declaratively, like your way, is the only way! If your consistantly getting the plane back on the ground without splattering it, your doing this the right way, for yourself!

I thought this discussion here, in the beginners forum, would be interesting, as I knew there are many different "Approaches" to approaches. I also thought it would be good for the beginners to see decriptions of how it is done. It is also a demonstration that there should only be one instructor teaching a student, as more than this will only increases confusion!

RE: Elevator use during landing approachs
 

There is no way I can describe for you how I use elevator on every landing every time, as all landings are different..altitude you enter the descent..wind speed and direction..traffic..etc....What I don't do is trim for landings.....
like everyone else throttle is altitude and elevator is speed.....
Good landings come from good approaches..very little correction left and right..with the airplane heading so that the touchdown point is on the runway...which is several feet in front of where you are standing....

RE: Elevator use during landing approachs
 

Well guys, I guess my “approach” to landing is a bit different from those described above.

Because we have some trees off each end of the 600’ grass runway I prefer to make a carrier approach with the touch down about 100’ from the turn on final. Because of the side viewing angle of the model I can better judge the speed and decent rate. I don’t like long straight in approaches because of the trees for one and because the down the throat viewing angle makes it difficult to judge the speed on final. Plus when the sun is at the right angle and you are looking right down the throat, the model may not appear to move at all. Add that to the trees in the background adding to the clutter and sometimes the model just about disappears.

So my approach will be to throttle back to idle on downwind and play the throttle to maintain my altitude and decent rate on base and final. I have my models balanced to be a bit tail heavy so that as I slow down the nose comes up naturally. I make my turns with a good bit of rudder and try to keep the wings fairly level in order to give better pitch control. When I am on final, I am already over the runway and 1/3 of the way down from the threshold. Depending on the wind and how far away I am from my intended touchdown point I will keep a bit of throttle on until the model is right in front of me then ease the throttle back for the landing on the mains. I may use a bit of elevator for a full stall landing or keep the throttle on for a wheel landing.

The short field approach works well for me if there is a cross wind because the model will not be subject to the wind as long as it would be on a long straight in approach. Plus, using the rudder on final will help set up the crab angle on final. With a cross wind, I will try to hold a little more speed on final.

RE: Elevator use during landing approachs
 

I just close my eyes and pray

RE: Elevator use during landing approachs
 

Wow Mike, you fly the same way you drive!!!!! ;) :D:D:D:D

Ken

RE: Elevator use during landing approachs
 

No, I only do that when my WIFE is driving! [X(]

RE: Elevator use during landing approachs
 

Mode one,

I had more than One Instructor, I had 4 if
my memory is correct. I soled on my 5th
or 6th flight though.
Having full scale experience really helps.

Bob

RE: Elevator use during landing approachs
 

The LHS must love you. :D

Re landings tho, I'm still figuring the things out really... I was taught to idle the throttle as I turn onto final and use the elevator to bleed off speed which seemed to work fine on trainers but was less successful on sports planes. I read up a lot on landings and put in a bunch of simulator time teaching myself to use elevator to control attitude and throttle for descent rate which seems to work a lot better on my Super Skybolt and Dual Ace. Ailerons are only to keep the plane level and rudder's for heading.

I recently dug my old Harmon Rocket 3 out of retirement, repaired the muffler and got it airborne again which upset my nice tidy landings as the thing just doesn't want to slow down but floats 3' in the air most of the way down the runway before burying itself in the longer grass as the end of the runway (thankfully it's soft grass :D). Slowing down earlier to get the approach speed lower isn't really an option as the short stubby wings give it a fairly high stall speed, and using the elevator to bleed off speed when it's being "floaty" will make it balloon and stall. After looking at the similarly sized Great Planes RV4 kit (from which the real Rocket 3 derives) I finished kit-bashing some flaps into it yesterday to help slow it down, and am just waiting for the rain to clear so I can test fly it - hopefully tomorrow. I'd tried flaperons and all they did was make it floatier and reduce the aileron efficiency due to the shallow flap angles I had to program in to keep some aileron control. Hopefully flaps at 15 degrees will lower my stall speed, and at 40 degrees will drag the plane to a stand still so I can get it on the ground. Either that or I'll plow it into the threshold nose first and that'll resolve my problem permanently.

RE: Elevator use during landing approachs
 

You'll notice I'm not offering up much information on how I do it either! Being a Mode One guy I feel this stuff is trade secrets and there needs to be some money in my hands, before I talk.

RE: Elevator use during landing approachs
 

There was a 60 size fullwing cub at the field one day that deadsticked from way out. He was coming upwind, and the wind was maybe 10 mph. It almost didn't want to land, it practically hovered out there. He had to point the nose down to get some groundspeed. When he got it over the runway, it was almost like landing a heli.:D Gave us all a laugh. She practically defied gravity.

RE: Elevator use during landing approachs
 

I was out this morning for the first time in quite a while-so I took my trainer. Forgot how it likes to float. I had about a 8mph 1/4 cross wind and when it finally touched down I was full up and low idlealmost made a decision to go around as I was running out of good smooth ground. When it did touch down it didn't roll 2 feet.
I still get that pucker factor every now and then