What is a ground loop?

I've read the term ground loop in a lot of articles and accident reports but
what exactly is a ground loop?

--Mike

"Mike" wrote in message
...
I've read the term ground loop in a lot of articles and accident reports
but
what exactly is a ground loop?

I'm sure somebody can provide a textbook definition, but my general
understanding is that it is an abrupt turn of an aircraft moving at a fairly
excessive rate of speed. I imagine something like this happening, for
instance, if one were landing in a Piper Warrior with a pretty full
deflection of the rudder and one didn't straighten it out before the
nosewheel touched the ground... the nosewheel moves as the rudder does,
unlike a C-172, which has a spring actuated bungee mechanism to turn the
nosewheel.

--
Guy Elden Jr.
PP-ASEL

I imagine something like this happening, for
instance, if one were landing in a Piper Warrior with a pretty full
deflection of the rudder and one didn't straighten it out before the
nosewheel touched the ground..

In a Piper Cub or another taildragger, the ground loop is most often
begun when sloppy rudder inputs, a gust of wind, or even P factor
causes the aircraft to veer. As with a VW Beetle with the engine in
the rear (or a Corvair, for that matter), once the vehicle begins to
swap ends, it happens very fast, and it's very difficult to recover
from.

It can happen on takeoff as well as on landing.

A ground loop is most dangerous in a low-wing aircraft, where
centrifugal force causes the outside wing to dip, possibly dragging on
the ground.


all the best -- Dan Ford
email: www.danford.net/letters.htm#9

see the Warbird's Forum at http://www.danford.net/index.htm
Vietnam | Flying Tigers | Pacific War | Brewster Buffalo | Piper Cub

"Cub Driver" wrote in message
...
In a Piper Cub or another taildragger, the ground loop is most often
begun when sloppy rudder inputs, a gust of wind, or even P factor
causes the aircraft to veer. As with a VW Beetle with the engine in
the rear (or a Corvair, for that matter), once the vehicle begins to
swap ends, it happens very fast, and it's very difficult to recover
from.

I like the rear engine analogy. Difference between the Beetle and the
Corvair seems to have been that the Beetle didn't suffer from 'ground
loops' very frequently. The Corvair was looking for them. My father owned
3 or 4 of them. In #3, we did the classic Corvair 'ground loop' plus some.
I'm not sure to this day how many times we went around but I do know we
ended up upside down on the convertible roof. Unsafe at any speed indeed!
The Vdub bus seems to be immune too. Drove 3 of them in western PA snows
and never had them try to swap ends. Passed a lot of stuck people too. But
of course, they were one of the most lethal vehicles on the road. They
weren't in a lot of accidents, but you stood a good chance of buying it if
when they were.

Maule Driver wrote:

They [VW vans] weren't in a lot of accidents, .....

That's only because there weren't very many cars on the road that you
could catch if you were driving one.

George Patterson
The optimist feels that we live in the best of all possible worlds. The
pessimist is afraid that he's correct.
James Branch Cavel

"G.R. Patterson III" wrote in message
...

They [VW vans] weren't in a lot of accidents, .....

That's only because there weren't very many cars on the road that you
could catch if you were driving one.

But you didn't need cruise control. Just floor it. Tailwinds help too.

I like the rear engine analogy. Difference between the Beetle and the
Corvair seems to have been that the Beetle didn't suffer from 'ground
loops' very frequently. The Corvair was looking for them. My father owned

I live in New Hampshire, where it not only snows, but often rains on
top of the snow. I followed two gal skiers in a VW one time on the
road down from the mountains, and they began to oscillate,
overcorrect, and finally end up in the snowbank on the wrong side of
the road. I dug them out with the shovel I always carried in the front
trunk of my VW. Then, going around an extended traffic circle in
Alton, I too went off the road that same night. A plow truck pulled me
out.

3 or 4 of them. In #3, we did the classic Corvair 'ground loop' plus some.
I'm not sure to this day how many times we went around but I do know we
ended up upside down on the convertible roof. Unsafe at any speed indeed!

Driving home from Vermont in a friend's Corvair, me driving, I could
feel the front end move out from under me about every five minutes. I
was passed three times, and in every case the car that passed me wound
up in an accident a few miles farther along. In that case the Corvair
got home and they didn't, because of that early-warning system of
"black ice" on the road.

The Vdub bus seems to be immune too. Drove 3 of them in western PA snows
and never had them try to swap ends. Passed a lot of stuck people too. But
of course, they were one of the most lethal vehicles on the road. They
weren't in a lot of accidents, but you stood a good chance of buying it if
when they were.

Gosh, I had one of those, too. You're right; it never seemed to suffer
from understeer, perhaps because the passenger and the driver were
sitting on top of the front axle! As I recall the shoulder belt didn't
have an inertia reel, and if it was secured you couldn't reach the
instrument panel. So I cut mine off.

My wife and I drove to California and back, sitting out there on the
front axle, with our daughter in a basket between the two seats.
Yikes.

all the best -- Dan Ford
email: www.danford.net/letters.htm#9

see the Warbird's Forum at http://www.danford.net/index.htm
Vietnam | Flying Tigers | Pacific War | Brewster Buffalo | Piper Cub

Is there a connection between VDubs, Cubs, and Maules?

"Cub Driver" wrote in message
...
snippety snip
Driving home from Vermont in a friend's Corvair, me driving, I could
feel the front end move out from under me about every five minutes. I
was passed three times, and in every case the car that passed me wound
up in an accident a few miles farther along. In that case the Corvair
got home and they didn't, because of that early-warning system of
"black ice" on the road.

ahhhh, that's what it was, an early warning system. A quick swat to back of
the head would have sufficed.

Gosh, I had one of those, too. You're right; it never seemed to suffer
from understeer, perhaps because the passenger and the driver were
sitting on top of the front axle! As I recall the shoulder belt didn't
have an inertia reel, and if it was secured you couldn't reach the
instrument panel. So I cut mine off.

I kind of figured it was non-inertial so that you would be held firmly in
place during a head-on coup de grace. Should have cut it off too.

What did you do for heat? Not much there when new. Less in a couple of
years of salt corrosion. Auxiliary gas heater was great if you added it.
Almost died in mine due to lack of heat but that's another long story.

My wife and I drove to California and back, sitting out there on the
front axle, with our daughter in a basket between the two seats.
Yikes.

I ripped the seats, installed speakers, curtains, and a big bean bag chair.
I otherwise take the 5th.

We were all young and foolish once.... but sure had fun!

"Mike" wrote in message
...
I've read the term ground loop in a lot of articles and accident reports
but
what exactly is a ground loop?

--Mike

Take a shopping cart. Push it backwards across a parking lot or down the
grocery store aisle and release it. At some point, it is likely to do a
rapid piroutte. If it was an airplane instead of a shopping cart, that
would have been a groundloop.

Groundloops can apply very high forces to landing gear, tearing up the gear
and/or overturning the aircraft. Generally, they happen in tailwheel
aircraft.

KB

Mike wrote:
I've read the term ground loop in a lot of articles and accident reports but
what exactly is a ground loop?

A ground loop is what happens when a taildragger pilot isn't fast enough
on the rudder pedals to keep the tail from passing him/her while going
down the runway.
Because the center of gravity is behind the main landing gear on a
taildragger, the tail of the airplane wants to swing around to the
front.
The center of gravity is forward of the main gear on a tricycle gear
airplane, so the nose wants to stay out in front.