Mild Aerobatics

"Jay Honeck" wrote in message
news_JKe.239722$x96.59507@attbi_s72...
During primary training, many moons ago, I was growing frustrated with the
sedate nature of our flying, so I asked my flight instructor (Bob -- a guy
with 20K hours in every known flying machine) when we were going to get to
the "fun stuff"? He didn't know what I was talking about, so I told him I
wanted to see what these things could actually *do*...

At which point he smiled that crooked smile of his, and proceeded to do a
wing-over with a recovery out the bottom, going the opposite direction!
I was whooping and hollering for more, but he just went back to our lesson
for the day....

Jay, I'm surprised at you. This sounds almost like, "Hey, watch this!"
Weren't you not long ago pondering your son's flying with his pals, someday?

Considering both factors, it's simply smart flying to keep the
"excursions" from normal flight to an absolute minimum. This is not to say
that the airplane will fall apart on you if you do a little "not straight
and level" flying with it, but it does say that doing this in aging
airplanes can increase that aging process somewhat.

Good point. This is something that concerns me, and I suspect I'm not
alone. Here's one recent experience that made me wonder about our aging
airframe.

While departing Iowa City last month, another pilot reported his position as
being 3 miles Southeast of the field, maneuvering. Since we were departing
to the Northeast, we determined that he would not be a factor.

Not! As we were climbing out, our direction-challenged fellow pilot became
visible in the haze, and I saw that he was on an intercept course -- with us
as the target.

For the first time in our flying lives (10 years, 1500+ hours), Mary and I
experienced an in-flight disagreement over what to do. She, in the left
seat, saw no reason for evasive maneuvers, determining that the plane would
pass over us with room to spare. I, in the right seat, saw the plane
growing larger in my starboard-side window by the second.

After a few more seconds of debate, I ended the discussion by pushing my
yoke firmly forward, inducing negative G and allowing us to pass harmlessly
beneath the traffic. We cleared the plane with room to spare.

Would we have hit him without my action? Probably not. Nevertheless, we
decided (after much debate) that I had acted correctly, given the
circumstances, since it fit into our pre-arranged agreement that the right
seater doesn't ever touch the controls unless they feel that their inaction
would put the plane at risk.

However, I did (and still) wonder about putting that much negative-G on our
34 year old airframe. Without a G meter it's impossible to know how much G
was induced, but I'd say it was 50% more than I've ever done before. (The
only negative G maneuver I ever do is the push-over at the top of a steep
pull-up, known by my kids as an "Up-Down".) Was 50% more too much?

We were climbing out, so our airspeed was relatively low -- probably around
80 knots. The entire maneuver lasted less than 5 seconds, and nothing
floated in the cockpit -- but in an old airplane, how much is too much?

As another reference point (and a crude way of measuring the negative Gs), I
routinely read about guys doing the "up-down" maneuver to the point where
their engine sputters due to fuel starvation. I've *never* done the
maneuver to that degree, even in this situation (although that may be due to
the short duration of the maneuver) -- so I'm assuming that I didn't push
the airframe beyond structural limits. Since that flight I've carefully
inspected the empennage, and there is obviously no visible stress or strain,
or I wouldn't be flying it -- but how can you really know without extensive
metallurgic testing?

If you've ever looked at the stabilator attachment on a Cherokee you will
marvel at the simplicity and apparent fragility of the design, so inducing
excessive negative-G is something we never, ever do. However, even though
there is (to my knowledge) no record of a stabilator departing the airframe
of a Cherokee, you've got to wonder how many days (weeks? months?) a sudden
push-over takes off the life of an airframe?

Thanks for the post, Dudley. As always, you have introduced a
thought-provoking angle to the discussion.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Honeck wrote:

Just curious -- what do you guys do with your spam cans? I've seen video
from inside a Cessna that shows a guy doing some pretty radical maneuvers,
but in real life what's the most you push your aircraft?

I've owned a Cessna 150 and a Maule MX-7. Neither were certified for aerobatic
maneuvers, and the Maule was placarded against spins and other aerobatics.
Closest I intentionally came to radical maneuvers in either was ~50 degree
turns. One of my instructors was going to show me chandelles in the 150 (it was
certified for those), but we never got around to it.

I allowed one of my "Young Eagles" to do some of what you call "Ups & Downs"
once. Her two friends in the back seat became pretty queasy in short order and
were not pleased with her. That sort of thing got removed from the menu for my
flights.

George Patterson
Give a person a fish and you feed him for a day; teach a person to
use the Internet and he won't bother you for weeks.

I allowed one of my "Young Eagles" to do some of what you call "Ups &
Downs" once. Her two friends in the back seat became pretty queasy in
short order and were not pleased with her. That sort of thing got removed
from the menu for my flights.

Yeah, up/downs can get pretty ugly, if done too often.

My kids usually beg for one, ask for one more, and then are happy not to do
a third, especially when it's hot.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

At which point he smiled that crooked smile of his, and proceeded to do a
wing-over with a recovery out the bottom, going the opposite direction! I
was whooping and hollering for more, but he just went back to our lesson
for the day....

Jay, I'm surprised at you. This sounds almost like, "Hey, watch this!"
Weren't you not long ago pondering your son's flying with his pals,
someday?

Ah, yes -- but I was young and foolish back then!

Which, of course, is precisely why I'm going to be worried when my kid(s)
gets his/her ticket...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

And, as a wise old pilot once observed, the flight envelope is altitude
going up and airspeed going right. We mostly push the upper right corner of
the envelope. And that is also where the stamp gets cancelled.

Jim



". You have
a POH that offers you figures to follow that define your flight envelope,
then you have the reality involved with an aging airplane.

Jay Honeck wrote:
Ah, yes -- but I was young and foolish back then!
Which, of course, is precisely why I'm going to be worried when my kid(s)
gets his/her ticket...

The year is now 2007, the sticker next to the door on Atlas read:
"My other airplane is a Pitts!"

As opposed to the one that is there now on this low-wing troglodyte that
says: "This girly-girl low winger is the Pits."

{;-)

Jim


The year is now 2007, the sticker next to the door on Atlas read:
"My other airplane is a Pitts!"

Try this in anticipation of a future conflict. Unless it is a direct
head on conflict, i.e. directly in front and not moving on the
windscreen, try turning into it.

This is much harder to describe than to experience. And it's not
natural unless you practice a bit. But if an a/c is *converging* on you
and you can put your nose on it before the anticipated collision, you'll
miss it, almost no matter what the other a/c does.

If you try to turn away from a converging a/c the opposite occurs - a
collision becomes more likely.

Try it with some hand held models. Try it with some real traffic at a
good distance. You'll get the idea.

Then when that a/c appears out of no where, you will tend to do a
positive G turn rather than a push over or pull up.

If it's converging, turn into it. If it's diverging - turn away. Keep
it positive.

comments?

Jay Honeck wrote:
... As we were climbing out, our direction-challenged fellow pilot became
visible in the haze, and I saw that he was on an intercept course -- with us
as the target.

After a few more seconds of debate, I ended the discussion by
pushing my
yoke firmly forward, inducing negative G and allowing us to pass harmlessly
beneath the traffic. We cleared the plane with room to spare.

However, I did (and still) wonder about putting that much negative-G on our
34 year old airframe. Without a G meter it's impossible to know how much G
was induced, but I'd say it was 50% more than I've ever done before. (The
only negative G maneuver I ever do is the push-over at the top of a steep
pull-up, known by my kids as an "Up-Down".) Was 50% more too much?

In article 7kLKe.239817$x96.9166@attbi_s72,
"Jay Honeck" wrote:

[snip]
However, I did (and still) wonder about putting that much negative-G on our
34 year old airframe. Without a G meter it's impossible to know how much G
was induced, but I'd say it was 50% more than I've ever done before.

I've been told that what people usually think of as negative Gs are actually
just a reduction in positive g loading. As you said, without the g meter,
you don't know. But if you weren't "hanging" from the seat belts, I would
think you didn't see negative g's at all, just something noticably less than
the usual 1.0 positive g.

Sounds like you have an excuse er reason to go and get some real aerobatic
training to see what -1 g really feels like. :-)

--
Bob Noel
no one likes an educated mule