Are the terms nose-over and ground loop synonymous? Or are they aerodynamically different beasts with different preventative measures? Is it simple a case that one talks about nose-overs on take-offs and ground-loops on landings? What are the counter-measure for each/both?

An interest in flying WWI a/c leads me naturally to these questions.

From "The American Heritage Dictionary of the English Language": Fourth Edition. 2000.

"ground loop NOUN: A sharp horizontal turn made by an aircraft on the ground when taxiing, landing, or taking off. "

i.e. a ground loop and a nose-over is not synonymous.

/Red B.

How to prevent? Depends on whether you are using a trike gear or tail dragger. On a tail dragger, the main gear must be slightly ahead of the CG (usually right under the leading edge of the wing will work) and; you should have some toe-in on the wheels. The closer the wheels are to being under the CG, the more prone to noseovers but; if you get the gear to far forward you will have a great difficulty in landing without excessive bouncing. A compromise is mandatory.
If you are using a trike gear, nose overs are usually caused by excessive movement of the nose gear or springy gear--you only want about 5 to 10 degrees at full deflection. Toein also helps prevent groundloops on a trike gear.

Nose over in a plane with a tail wheel can be caused by a couple of things, the most common is that the main gear is too close to the C.G. and with the application of power the plane rotates on the axles rather than move forward. To correct just move the gear forward. The next most common cause is not knowing to hold full up elevator when applying power, and holding it until enough speed has been attained in the roll for the stabilizer to become effective.
Ground loop is caused by a loss of directional control during take off or landing causing the plane to veer very hard, and usually end up dragging a wing tip as it tries to roll over. The possible causes of this are too numerous to list, but the most common is not knowing how to use your left thumb for anything other than throttle.

Nose over, gear to far back. Ground loops , gear to far forward.

As someone with an interest in flying SCALE WWI a/c altering the location of the gear is not an option -- I just need to learn how to fly the planes like the actual pilots did! (Although I'm not adverse to using some little tricks like 1-2 degrees of toe-in or making sure the motion of the wheels are linked via the axel.) At this point my experience is strictly on sims but there the most common problem is the plane flipping over (i.e. the tail coming up and over) on take offs and landings. I had been calling this a ground loop but maybe it's actually a nose-over. If nose-over and ground loop are different I guess I still don't understand what a ground loop is then.

At this point my experience is strictly on sims but there the most common problem is the plane flipping over (i.e. the tail coming up and over) on take offs and landings. I had been calling this a ground loop but maybe it's actually a nose-over. If nose-over and ground loop are different I guess I still don't understand what a ground loop is then.


Ahh! yes a nose over does look like a mini loop on the ground, but swapping noses for tails and wheels for wings in the vertical plane is a nose over.

Ground loop the plane spins around on a wheel or a wing tip usually ending up right but in the wrong direction.

Since you cant very you landing gear position try moving the CG BACK in VERY SMALL increments. And HOLD full up elevator after you've landed and anytime the airplane is still moving.

HTH
Tom

The nose over.. is exactly that. The plane tips forward. On many of the WWI models, those which represent the rotary engine planes, the landing is long, the cig. is high above the lever.. the axle. Inertia of the plane lets it rotate around the axle especially when landing.
My Dr-1 almost -always- ends up resting on the top wing.
Ground loop. The plane rotates around one wheel, dragging a wing tip. WWI again, the high ground angle and narrow spacing between the wheels contributes to this. Prevention consists in trying to fly, and learning when to apply corrective rudder, AND when to take out the corrective rudder. You can cheat by adding a tail wheel.... Booooooooo!!

Standing above a taildragger looking down, its CG is located behind the main gear. When landing, if the airplane begins to yaw, the drag of the wheels and the momentum of the CG cause it to yaw further - a classic ground loop.

On a tricycle gear airplane, the CG is located ahead of the mains, so if a yaw is induced, the drag of the wheels and the momentum of the CG tend to reduce the yaw and reduce the tendency to ground loop (although it is still possible to ground loop a trike, it takes much more skill )

On a taildragger, a nose over occurs when the CG is longidudinally too close to the mains, or vertically too far above the main axle, allowing relatively small forces to pitch it nose down around the axle of the main gear... Also is made worse by bouncing the landing (especially with a little nose down attitude), or with uneven landing surfaces (rocks, dirt clods, potholes, small farm animals or children )...

Toe in of the mains tends to make the airplane track straight, even if it's yawed a bit. Having the mains toed out would increase the tire drag, causing the airplane to diverge once the yaw began.

HTH

Jim

And if all that still does not make it clear then think of a ground loop as a tight FLAT turn where the model spins around like a figure skater.

Thanks guys, I think I finally get it. I'd been thinking of the "ground loops" as a "spin out" and the nose-over as a ground loop. Some of the WWI a/c like the AVRO 540 and Sopwith Pup employed a skid built into the undercarrage to deal with nose-overs. And others used various sorts of skids on the underside of the lower wing to avoid the wingtip touching the ground on landings as thus presumably ground loops. I've been thinking of installing similar sorts of removable "training wheels" on a Dr1 to tame it down a bit.

I always wondered why the figure skating maneuver is called an "axel"...

The terminology is confusing, 'cuz an airborne loop is vertical while a ground loop is horizontal... Ain't aviation fun??

Jimmbbo:
That's simple. The skating maneuver in question is named "axel" after a Norwegian skater, Axel Paulsen that was active in late 19-th century.
In a similar way the skating maneuver "salchow" is named after the Swedish skater Ulrich Salchow who was a 10-time (!) world champion in the beginning of the 20-th century. He also won a gold medal in the 1908 Olympics in London

/Red B.

I read in 'Flight Journal' magazine an article that featured the building and flying of a replica full-scale Fokker DVII by someone in the NY area. The pilot who test flew it noted that this particular aircraft had an incredible tendency to ground loop upon landing. Only by staying ahead of it with the rudder pedals prevented it from happening (actually, I think he did admit to doing one). Seeking advice on what to do to tame the beast, a pilot well-versed in WWI aircraft suggested he tighten the bungees on the landing gear. As a test to see if they're properly adjusted, by sitting on a wingtip, the tip should drop no more than 3". Before adjusting, the tip dropped something like 12". Afterwards, the tendency to ground loop was far less and became much more stable.

Ted