Hi,

I could use some advice on landings. I am flying a trainer, a Tiger with a 69" wingspan. I have a 0.52 4 Stroke on it and have been doing reasonably well with takeoffs and and in flight maneuvers, but I am having issues with landings.

I am flying off of tarmac and always seem to be coming too fast. I am landing OK but with a couple of bounces that are not great for the lansing gear.

Any help would be appreciated.

jon

It is normal that you have issues with landing, since it is the hardest part of any flight (at least for me).

Get familiar with the stall speed of your model, by flying high and as slow as possible, many times.

The landing speed should be a little above that, but not too much.
In theory, it should be 1.2 the stall speed, or 20% above it.

It just takes practice and practice,........and more practice.
Try to master properly aligned approaches, since they are the base of good landings.
Keep the wings level, and control the descend angle with the throttle until just before final flare.

Have you checked your CG lately? A nose heavy condition can cause higher speeds when landing. Of course you should notice it on takeoff as well. Inewqban's advice on taking it up high and getting intimately familiar with its stall characteristics is excellent. That's one of the first things on my checklist whenI do the maiden flight on a plane. You gotta know how slow you can go and - on the other side of that coin - you gotta know how slow you should NOT go

It also depends on what prop you have and how low your idle is set. If you can drop a click or two of trim on your throttle it will really help (obviously don't if you are afraid the engine will quit).

Thanks for all the replies !!!

I have actually been dead sticking in from about 5 or 10 feet off the ground because in trying to lower my engine speed Iend up killing it. I come in nice and level, but Ijust seem to be moving too fast. Take offs havent been an issue and I did check the CG and it is right where the kist said it should be. I am spinning an 11X8 prop, Could that be the issue, should I go to something that will fly a little slower ?

jon

Use a 12x5 or a 12x6 prop and it will make a world of difference. Larger diameter (i.e. heavier) will let the engine idle at a slower speed, and the lower pitch will fly the plane slower.

These prop suggestions came from Tower's site for a Magnum .52 four stroke.

I have used a 5 or 6 pitch prop on all of my trainer and sport planes. I use 8 or 10 pitch for my competition planes.

This explination I give to students that have soloed and are now ready to learn to fly


landing is a product of power managment vs speed.

Speed is a product of power vs drag.

you have two forms of drag. aerodynamic drag, the shape and frontal area of the wing and fuse. this you have no control over other than which model ya buy

the other is induced drag. this is the drag in simplest terms produced by a high angle of attack buy the wing.


what this means to you is to control speed by increasing and decreasing the angle of attack of the wing.
you do that with the elevator.

Next time your at the feild get the model up 3-4 mistakes high and practice flying slow, really slow. once you do that fly even slower. you may even want to get back with your instructor on the cord to do it the first couple times

reduce the power to 1/3 and start to pull up slighly until you maintain level flight, you should be able to maintain level flight but now flying slower. the controls will be very mushy and slugish

to fly even slower reduce the throttle to idle. and pull up gentrly to maintain level flight just before it stalls add some power and maintain level flight, if done right you should be flying just under stall speed with 1/3 power. this is called being behind the power curve, it basic manuvers for 3-d flight but basic trainning in real planes

your learn two thing that are very useful here. one maintaining control in slow flight. two you will land better once you understand how to control decent with power and speed with your elevator.


a good landing start from downwind. reduce power and add some up elevator, even some up trim if ya just can't cowardinate it. reduce more power until it starts to decend holding some up elevator. turn base and final holding almost half up elevator and control the decent rate with power. by touchdown you should have full up elevator. by doing this you should be coming in allot slower. again you should concider doing this back on a buddy box if your not good at judging corrections.

The weight of your aircraft will affect landing speed as well.  I'm currently flying a School Girl bipe that ended up on the porky side and it comes in HOT.  Nothing much to be done about it but control the rate of descent.  At least it doesn't balloon when I flare for the landing   Ya gotta know your plane; what the stall speed is, how it behaves when it stalls, how fast it loses altitude when the power is cut (both at idle and dead stick).  The best landings are flying in formation with the ground until suddenly it's gone from flying to rolling.  This takes practice.

You forgot one more type: parasitic drag- really that just means is any foreignobject on the wing, bugs,tape, a little goblin on the wing, etc. Ilike that explinationonlanding, I'll have to remember that one

Have you ever flown your aircraft to a stall? You need to.....pull power off keep nose level and see how and at what speed it stalls...with altitude of course....one of the reasons for excessive speed on approach is fear of stalling.....another reason for too much speed is too much altitude on base leg and final....trade off for too much altitude is speed.......prop too small (not enough drag)......</p>

also throttle does not control your speed...altitude control is your throttle....speed is controlled by the elevator...try to descend at a nose level altitude......if the sink rate gets to be too much use your throttle to slow it down by adding a click or 2 of power and taking it off again......as you cross the threshold of the runway power all the way off if it wasn't already ....at a few inches slowly add elevator bring the nose up and slowing the airplane down until it settles onto the runway...</p>

Good flyin</p>

If you're cutting the throttle and it's still too fast, you are more than likely nose heavy</p>

Good advice on throttle and props so far. If you can't kill the idle thrust, then it will be a problem on approach. One way to tell is: will the plane sit still at idle on pavement or does it start rolling as soon as you let it go? If you can't cut it back to a sitting idle, it's too much.

If the motor won't idle down without dying, the idle mixture needs to be adjusted. It's probably too rich. See if it speeds up when you pinch the fuel line at idle throttle. If it speeds up and stays running for a few seconds after pinching the fuel line shut, you could lean out the idle mixture. That will allow you to slow the idle another click or two.

Also, when the plane is on approach, are you aiming for the end of the runway, or right in front of yourself. You need to have the plane on a glideslope towards the end of the runway. If you are aiming for the spot in front of you, half the runway is gone before you even had a chance. Then when you flare out the plane carries even farther, pretty soon you are out of runway. I know this is a problem I had many years ago. Adjust your pattern down the runway.

You could also just need a little more up trim. There's no guarantee the landing trim will be the same as flying trim. You could retrim manually. Or you could put a slight adjustment mixed on a switch.

I think a lot of people are missing one very important point - he said that he has even KILLED the engine and it is STILL too fast.</p>

The prop or idle would have nothing to do with the excessive speed if the engine is not running.</p>

This sounds like a classic example of a plane that is nose heavy</p>

I've found my planes fly better when I set the Center of Gravity as per the manufacturers specifications. So much that I rarely have to alter it again. But that's just me. My second trainer when I had the CG a little forward, takeoffs were hard (had to get a lot of speed up) and landings were fast. But what do I know.

Agreed, but one thing that none of us can tell without watching is the angle of approach to the field.. is the OPcoming in too steep?not waiting for the plane to bleed off speed in the ground effect zone? not flaring?

lots of variables

Everyone here has hit the nail on the head, in one way or another. But, with the info given, and not witnessing the anomoly personally, with your plane, the "nose heavy" diagnosis must be correct. A nose heavy plane will often over-flare. Since you have stated the "dead-stick" scenario as inaffective, there leaves no other remedy than to lighten the nose. You say a trainer is giving you this problem? Down-size the engine. (.40) Have you considered flaperons?

The suggestions that the plane is nose heavy and that a lower pitch/higher diameterprop are good ones but exeters comments on the variables is also valid. He could be just starting his final approach too high. I'm just a little curious about flying a 70" Tiger on a .52 4 stroke. I realize he's at sea level but that engine size choice is a just little odd for that plane

I'd bet this is the likely culprit of jonriley's issue and probably why he feels the need to cut the engine at 5' - 10'. Jonriley, do you have a lot of time on the RealFlight sim? That sim allows you to turn on final way too high, in real life the airplane would sail right past trying to get it down.

The guys posting to this thread probably assume he's flying with other guys, who would always say, "You're too high." Maybe no one is telling him this. Jonriley, where is your instructor in all this?

How much altitude do you have when turning on final?

I don't know what the issue is witha 70" trainer on a 52 four stroke but I am in agreement with all the guy's who are saying his approach angle is too steep,he should look at full size aircraft they usually have an approach angle of 3 degree's. My house faces the approach to our local airport at six miles out the planes are flyingin just slightly nose down and about a 600 ft up, and they make it onto the runway at that angle.The biggest problem we have with learners and some guy's who don't realise it is that the stick on the left is more than an on off switch,it is about reducing power halfway down the down wind leg of their approach to a landing,not at the last turn onto the runway.
A slower aproach speed will develop into a better landing than trying to slow down and dump it on the runway because you are coming too hot.
Jim.
www.modelclub.org

Hi!
11x8 is no good for a .52 fourstroke in a high winged trainer if you fly at sea level! Use a 12x5 or 12x6 APC.
Second, you have to fly your airplane and test stall speed the first you do. That way you know at what speed your plane gives up flying. Thta's very important to know if you want to land smoothly.

hi   get the idle down as low as is possible but steady -before the flight  when turning on to  final be as low and as flat -as is possible -you should plan on  touching down right in front of you feet-  that gives you  your best look at the plane to touch the gear to the groundif you are still fast-   GO AROUND !!!!  and just cut your throttle sooner than you did before on your approach- i usually am 2-3 clicks above my idle speed  on my approach   -i find it best to bleed off all speed on final and have to come on the throttle a click or two-when and if you see the plane start to  flownder-as   it is about to stall (wings will start to flop around some )   do always GO AROUND_____ any time you are not exactlly happy with your planes landing conditionsdo not force a plane down if any landing condition is not on the money-   go around and get it feeling right    -nothing better than a good landing to make your day - hope this helps some-i run a 5-6 pitch on most of my 20 flying planes-makes for great verticals-and landing control

Hi Everyone,</p>

</p>

Thanks for all the additional feedback.  I am running the four stroke because I like it and it is significantly quieter than the 2 strokes I have. </p>

I  am flying in a very little used area of a closed navy base and have so far been flying by myself. (I always have at least one other guy with me for safety reasons, but no instructor).  I know that there is a strong prevailing school of thought that one should only fly as part of a club, but so far I have visited two in the area and no one even bothered to talk to me.  (Before anyone starts tossing stereotypes areound as to why I might not be approachable, I am in my mid 40s, driving a new jeep commander and typically am with one of my friends and one or two of our kids.) </p>

I have consigned two planes to the big hangar in the sky so far, a SPAD that I built ( Dumb Thumbs), and a Big Stick (flying a white plane on a foggy day is not wise......smile).  That is not counting a few small electrics along the way.  Luckily I enjoy repairing and building them about as much as flying them</p>

I will work on the throttle control settings so that I can idle down nicely and go to a 12X5 and see how things go. </p>

thanks again</p>

jon</p>

Planes fly slower when the engine is running .



Why ? You should control the speed of the airplane with the elevator. By increasing the angle of attack, you slow the plane down.And you also increase the lift the wing generates. More lift means more drag. More drag requires more thrust. So, to fly an approach slowly, you need the engine to be running.

PS. control speed with elevator

control sink with throttle

When I'm preparing for a landing (not counting in deadstick landings), I always do a full landing pattern - yes sometimes I guess it would be quicker just to cut a part out of the circle and come in for landing - but I don't. On final I almost always cut the throttle and bring up the elevator. This will bring the plane to descend and the speed to cut down. When I see the plane at the level/height I want it (at that time the speed is to slow for making the runway) I bring back the elevator a bit and up the throttle -bringing her in at a constant speed just above throttle with the nose pointingup a bit and then I bring her down for the landing. I have found by doing it this way around - basically bring the plane to landing speed even before reaching the runwaythen constantly controllingthat speed the rest of the way down makes for an more "on-the-spot" landing.</p>

When I started flying I tried to drop speed as close to the runway as possible and always came intoo fast. Then I started to get my speed just above stall as I level the plane after the last turn into final. Yes you then have to work extra hard with your rudder to get the plane in the middle of the runway, since elevator can have a nasty effect if you overcompensate at that altitude and speed - but what works for me doesn't always work for others. But it's just what I do.</p>