I see a lot of people fly and when they reach the top of their loop and are heading toward Terra Firma they cut their throttle.

Now, obviously this is to not cause any undue stress on the airframe but I rarely see people open up the throttle until the plane is levelling out. Now, I'm new (few months, self taught) and I like to gun it all the way over and all the way down and through the bottom leg of the loop.

I see this with warbirds and more stunt like planes.

Is it purely for airframe reasons people do this, I've never asked to be honest as it sounds like a stupid, obvious question but I'm asking now


Thanks guys.

Its easier to keep the loop symmetrical and balanced if you reduce power at the top. You can use power on and complete the second part but you are going to be completing it a lot quicker than the first half so it may look out of balance. They may by doing it for airframe reasons? Also in real aircraft in a full power dive you could overspeed your engine pushing it past redline.

Its done to keep the airspeed constant as is required in pattern comps. You do not need full throtal all the time to fly, you need a constant speed, not flat out.

Cheers

Like the Ghost says, in F3A precision aerobatics or "pattern" competition, the judges mark down your score if your speed is not constant during the manuver. Also if your loop is not perfectly round or if it exits at a different altitude than it starts at, or if it is not perfectly centered, or if your heading changes etc.

Also, while most trainers will stand the forces of constant full throttle, a lot of lightly built 3D planes will flutter if you use full power on a down line.

One of the things you missed out on by not flying with a good instructor is some lessons in power management.

You might find that a habit you want to break when you advance to different airplanes.

I don't "Loop[>:]". I go fast-turn left

Either a defective airplane or you need a reverse servo so it turns right too.....

Hogflyer

As you can probably tell from above, it really depends on the flying you're doing. there are 'reasons', even if one is practicing careful power management (and indeed, BECAUSE one is) to do it both ways.

Certainly, many types of precision aerobatics expect any maneuver to be not only symmetrical in shape, but in "time" or "speed" as well...that is, the 2nd half of a loop should be flown at the same airspeed, and thus require the same amount of time, as the first half.

Of course, there are "performances"...or choreographed sets of maneuvers...outside of FAI or IMAC...that may require exactly the opposite. As an example, an aggressive demonstration with a high-drag airframe (think Pitts or Ultimate, for example) performed at low altitude may find you maintaining high throttle on the way down, unwilling to give away the energy you've obtained at the top of the loop. Of course, in a situation like this, the focus is more on "pleasing a crowd" by packing in multiple dynamic maneuvers, and less on "pleasing a judge" by flying them precisely.

Then, of course, there's the majority of RC flight...just having a good time with a toy airplane on the weekends. In which case, if the airframe will handle it, do whatever you enjoy.

Must agree with BaracudaHockey, however...LEARNING good power management will certainly improve your flying...and you'll find certain aspects of it (slow flight, landing approaches, flying in windy conditions) to be more enjoyable AND safer for your airplane once you do.

You do what you gotta do, no instructor, no fly or fly without so I learn the hard way My club is so disorganised it's untrue, no instructors at all, we just turn up, pay our membership and insurance.

I just ask guys who are there who have been flying longer and hope for the best.

I'm doing OK though (I think) but it's been a hard road at times. I'm definitely looking for a new club btw.

Anyway, yea I understand power management, I really couldn't fly all day with full power with my 1.00 Saito, it would kill me on fuel prices alone

I just see peeps all the time cutting power at the top of the loop which in general (I mean just flying for fun) seemed a bit slow and I figured it was just for protecting the plane.

I cut the power on top of a loop with my GP Cub .20/OS .26 Surpass mostly because that allows me to hear the sound of the wing struts whistling in the wind as the plane picks up speed in the dive. Sort of a neat sound to my ears.

You will find it much easier to make your loops round by cutting power on the down side of a loop....a loop is round not oval or egg shapped....you want to exit a loop at the same altitude as you entered....so cutting power on the down side you don't have the engine trying to flatten out the back of the loop....also if you watch someones thumbs while they're doing a loop they don't just throw in elevator...but at the top of the loop may be giving down elevator

I do cut the throttle but I was taught to do that. They said my high wing trainer would 'fold the wings'.

I play with the throttle alot durring flight.

it doesent really make much diferance i do it both ways and never had any problems. Depends on how you build your planes

It also helps to reduce the elevator input at the top of the loop to make the loop "rounder".

Bingo! It has much more to do with getting a pretty, symmetrical loop with a nice constant speed then it does reducing stress on the airframe. Most sport pilots do eggs, not true loops. Try getting a round loop with a nice constant speed. Then try to do three of them in a row superimposed on top of eachother. It's not as easy as it looks.

It's even tougher when flying full scale, I've done it. No external reference points plus there is the G-load to contend with. You also hang from the belts at the top of the loop.

I know. I fly full scale.

What aircraft did you fly while doing this?

Pitts S2A

My trainer bit the dust because I pulled out of a dive at full throttle.

It was a castorphe! Wings buckled and the plane hit the ground like a missle. Sounded like dynmite. The wings come fluttery down about 30 seconds later.

Ever since that day if the nose of my plane is pointed to the ground, my throttle is cut!

Live and learn I guess...

Not all trainers can handle that maneuver. Best not to push your luck IMO.

While I'm sorry to hear that his happened to your plane, I am thankful for your posting this; I never thought about my trainer not being able to handle such a maneuver.

I was looking into pattern flying, and the 'judges' look for a smooth loop, therefore requiring a decrease in throttle for the downward leg of the loop to keep even speed.

I also don't like to 'gun it' coming down the loop because I can hear the rpm's rev up - if I'm full throttle on the way up, and the speed of the engine is increasing even further on the downward leg, it is probably operating faster than I care for it to do so - in my own beginner opinion.

I think it's a good idea to reduce throttle for the sole purpose of practicing control of the plane. Anyone can 'nail it' and leave it there, but it takes a pilot to smoothly accelerate to full throttle for the upward leg of the loop, and to smoothly reduce the throttle, maintaining speed and a clean line. I prefer to be a pilot.

Very good question, But there is no real answer. Some pilots cut the throttle on the top of every loop, and soemlike to fly it full throttle.
there are some arguments that will support both. I don't like to see people do either. If you shut the engine down at the exact top of the loop more
than likely you will flattten the top of it. Depending on the wind conditions, speed of plane and size of loop you will adjust when and if you cut the
throttle at all. A good rule of thumb is in an inside loop carry power over the top to about 25 degrees and then gently throttle back. as the plane coasts
around bottom start to smoothly advance throttle back to full. as airspeed increases the plane s elevator will seem more sensitive and less will be
needed to keep the radius contant. I rarely drop the throttle to idle, I prefer to keep some power throughout the maneuver.

What he saidd in both cases. When I'm doing big, expansive loops I gradually cut throttle starting at about 10:00 and plick it up again at 5:00 or so to keep the speed constant. I'm "old school" enough to feed opposite rudder in a banking turn, too. ;-)

Two of my models would tear themselves apart in a powered dive and I fly them at half throttle for level flight, blip more for upward verticals and cut on the downbeats. A 43cc 27% Ultimate and a .46 Hot Sick. My Contender 60 (with an OS-70II) is a tank and it shrugs off a full-powered loop or anything else. Deep, narrow wing and two full-width one-piece spruce spars. But I still manage the throttle when in the "smooth" mood to keep the speed constant through the loop. Looks nice.

Just read about how to do a loop in a real plane and you'll find the answer to this question. A perfect loop results in the plane coming out of the loop at the same altitude that you went into the loop. If I am remembering corectly, real pilots in real planes don't totally kill the throttle... they lower it to about 1/3. They don't do this at the top of the loop, they do it as they begin to come down out of the loop, or at about 2 O'Clock if you imagine the loop-circle as a clock. You then go back to full throttle as you level out. If you do it exactly right you come out of the loop at almost exactly the same altitude that you entered it.

Of course, this is all from 15-year-old memory of playing computer flight sims, so I might be forgetting a step or two:-)

Another reason to reduce throttle in full scale is that the pilot doesn't want to pull 4 Gs coming out of a powered high speed dive. It it painful! He wants to maintain full throttle through the top of the loop to avoid stalling but then reduce power just past the top.

I had several hours of aerobatic instruction many years ago when I was preparing for a commercial license. Loops are great for gaining confidence in one's stall and spin recovery abilities.