R

robpar

Active Member
I have a big interest in space technology and astronomy and was recently watching astronaut training in NASA's "Vomit Comet" and wondered if such a maneuver is possible in small aircraft? Could a pilot of an RV fly the maneuver and get 3 or more seconds of zero gravity?

I have no idea what the risks are to either aircraft or pilot, so if this is an absurd question, do not try at home. Zero G gives the impression that the airframe would not be stressed but I do not know what is required to get into the correct trajectory.

Bob Parry
 
I used to do it all the time in my little Grumman Yankee years ago. My kids loved it.

"Do the roller coaster, Dad!" Fortunately, none ever barfed.

However, aside from negative-G considerations, be advised that if your plane isn't SPOTLESSLY clean inside, you WILL find whatever **** has been hiding in every nook and cranny of your cockpit! :D
 
robpar said:
..... and wondered if such a maneuver is possible in small aircraft? Could a pilot of an RV fly the maneuver and get 3 or more seconds of zero gravity?......
Click to expand...
Bob,

Yes, zero gravity can be simulated in light aircraft. In fact, anyone who owns an AOA Pro or Sport knows that a brief zero G maneuver must be achieved in order to properly calibrate the instrument. Another (not recommended) example of an extended zero G condition in a light plane can be observed in this video: http://www.youtube.com/watch?v=SN77b9DqEbc
 
N8RV said:
I used to do it all the time in my little Grumman Yankee years ago. My kids loved it.

"Do the roller coaster, Dad!" Fortunately, none ever barfed.

However, aside from negative-G considerations, be advised that if your plane isn't SPOTLESSLY clean inside, you WILL find whatever **** has been hiding in every nook and cranny of your cockpit! :D
Click to expand...

Boy is Don right! The first time I took the RV6 and flew it completely inverted it was like a rainstorm of metal chips, dirt, dust, and other junk flying up to the canopy. I thought my plane was pretty clean until I flew it negative!

Also, I've been hit in the back of the head or the face with wheel chocks, a quart of oil, bottles of soda/water, etc.. in severe turbulence, so watch that cargo!

In the end the gentle up/down wifferdills are quite easy and fun...just don't start going down from level flight or you'll be picking up speed pretty quick. A good split-s is always a fun way to loose altitude too!

Cheers,
Stein
 
From a vertical line you can get ~8seconds.
Kids love to play "float the pencil."
Harder in the tandem to get the pencil from from glare shield to rear seat smoothly, but it is doable.

SbS makes float the pencil easy.

Dont get your eye poked out:eek:

Best,
 
Yup, as others have mentioned, it is pretty easy to do for about 5-8 seconds (depends on entry speed. I used to do it in my old Yankee when it had it's original engine. BTW, if you do it right, getting to true parabolic flight, the carbe'd engine will quit, then restart on the down-line, Of course, the oil pressure drops off as well. Which is why, when I bought an expensive new engine, I quit doing them. (This limitation does not apply if you have inverted systems....)

Of course, I have also gotten the "opportunity" to fly in NASA's "Vomit Comet " on occasion, and get my fill after about ten parabolas - then it is time to throw up, which makes me feel better, and I can go another 20, then dump again, and make it through the flight. Something about being in aerobatic flight with someone else doing the flying doesn't agree with me.....

I don't do zero-G maneuvers in the -8 (at least not intentionally) because I end up with too much oil on the belly....but it is certainly not dangerous to the airframe!

Paul
 
We had a 172SP that did zero G a few times during a lesson. Later on the instructor / student found out the fire extinguisher was not strapped in properly and just about destroyed the rear window.

The Chief Flight Instructor was not pleased. :rolleyes:
 
'Used to love to tell my dad to let me float in the back of our -182. One time when I was pretty young I accomplished a full front flip 0 -g. Good times..
 
wile e. coyote

Skydiving, we had numerous PIT events (Pilot Induced Turbulence), usually at altitude in a C-182 or C-206. Annoy the pilot and find your face stuck to the overhead :)
------------------------

The most memorable was early on, licenced jumper, working on spotting.
Door open, my focus entirely outside.

Gave the cut/brake signal, looked back at the pilot and saw the outside of the airplane as he slid me out the door on his boot. He had floated me up off the floor slightly, and my pals just watched gleefully.

I had one of those "wile e. coyote" moments of realization before I began skydiving that day. It made my day.
 
Ironflight said:
SNIP

Which is why, when I bought an expensive new engine, I quit doing them. (This limitation does not apply if you have inverted systems....)

SNIP
Click to expand...

Paul, the inverted oil systems cannot handle exactly zero g's either - there needs to be slight positive or slight negative. I seem to recall some little external sump system that was more of an accumulator for those who want to float around. I can get 5 or 6 seconds of zero before I see the oil pressure drop, probably due to the oil that is in the suction lines on the inverted system.

Now, that being said, it really is cool to float stuff around. I've needed stuff that was on the floor of the baggage area, but couldn't reach. So, no problem, just a nice little push - there it is, grab it. Good stick discipline, takes a very gentle touch!
 
It is fun - but...

be careful on those first flights with new passengers. Don't try to impress with your rollercoaster ride. For someone new to little airplanes, zero or negative, or heavy positive G's will make them hate little airplanes for life.

Save it for you daredevil veterans - or for yourself.
 
Catching foreign object

This reminds me of long caps (8hrs) in the F-15 during Gulf War I. I would take a liter bottle of water to stay hydrated. I would also do zero G unloads to help the sore butt, the seats where never designed for this long a mission. Once the water bottle came loose from its storage spot and ended up back on the turtle deck. Hmmm how do I get the bottle back up front. Do another unload and simultaneously put out the speed break! I caught the bottle just as it flew by my shoulder, it could have done some serious damage to the HUD. In hindsight just going to idle would have been a better plan. Luckily it was not one of the 2 piddle packs I would fill up on one of these missions that flew around the cockpit.

Cheers
 
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