Zero G Piper Cherokee Archer

FlyingMonkey

FlyingMonkey

Pre-takeoff checklist
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FlyingMonkey
Curious about doing a zero G maneuver in a Piper Cherokee 180..just a simple parabola to achieve zero G for a second or two. The POH for an Archer describes load limits as negative load factor: No inverted maneuvers approved.

Thoughts?
 
You can do it, both legally and safely. You will, however, want to preflight the cabin very carefully, making sure there is nothing loose which can float up and get in the way. Same for anything in your shirt pocket (there's a reason we had those flaps over the pencil pocket on our USAF flight suits and all the rest had zippers). You will also want to vacuum the carpets, as the grit and dust which floats up can get in your eyes. For execution, you'll want to dive or otherwise accelerate to maneuvering speed, go full throttle and pull to about 15 nose-up, then push forward and float the plane through the arc, reducing power as needed. Begin the recovery pull at or before 15 nose-down.
 
Ron Levy said:
....For execution, you'll want to dive or otherwise accelerate to maneuvering speed, go full throttle and pull to about 15 nose-up, then push forward and float the plane through the arc, reducing power as needed. Begin the recovery pull at or before 15 nose-down.
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....and don't forget to have an unsecured dog in the plane, as some have done, caught on video, and posted to youtube :yikes:
 
I don't think the PA28-xxx is approved for any kind of negative G load factors in normal or utility is it?
 
Ron Levy said:
You can do it, both legally and safely. You will, however, want to preflight the cabin very carefully, making sure there is nothing loose which can float up and get in the way. Same for anything in your shirt pocket (there's a reason we had those flaps over the pencil pocket on our USAF flight suits and all the rest had zippers). You will also want to vacuum the carpets, as the grit and dust which floats up can get in your eyes. For execution, you'll want to dive or otherwise accelerate to maneuvering speed, go full throttle and pull to about 15 nose-up, then push forward and float the plane through the arc, reducing power as needed. Begin the recovery pull at or before 15 nose-down.
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Thanks Ron. I appreciate the info. So I guess "inverted maneuvers" are different than negative G's? I'm trying to understand the limitations of the plane as best as possible. Sounds like this maneuver is routinely done safely in the PA28-180 though.
 
The direction of the load factor has to do with the direction you pull/push on the yoke or stick, not whether or not you're inverted.
 
fiveoboy01 said:
The direction of the load factor has to do with the direction you pull/push on the yoke or stick, not whether or not you're inverted.
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Understood. The Only information that the POH gives for negative load factors is that inverted maneuvers are not approved. It does indicate a numbered limit for positive G's on the other hand.
 
A floatie would be no issue then, just secure the loose things, as Ron stated. They're kind of fun to do, me and CFI back in the summer of 2013:

FLOATY-L.jpg
 
Inverted maneuvers are negative G maneuvers. That's why you're hanging in your seat and everything thing goes to the ceiling. Zero G isn't an inverted maneuver. Just pitch up to 30 degrees and push forward on the yoke. You're floating in your seat but not against the ceiling.

As Ron said be careful with unsecured items. Years ago a UH-60 was doing a zero G and the chocks floated up from the rear and got lodged in the collective resulting in a fatal crash. Now, you don't need to worry about something getting lodged in a collective but you don't need crap floating around either.

Oh yeah, I've flown some aircraft that aren't real receptive to zero G and the engine would sputter at the apex. Just be careful.
 
fiveoboy01 said:
A floatie would be no issue then, just secure the loose things, as Ron stated. They're kind of fun to do, me and CFI back in the summer of 2013:



FLOATY-L.jpg
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Did any one else think that Vince Vaughn and Jason Biggs making the pencil float?
 
fiveoboy01 said:
I don't hang in the seat through a loop, nor a barrel roll....
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Nether do I when I do rolls and loops in my Glasair. My interpretation of the OP's question on inverted maneuvers is rolling the aircraft inverted and keeping it there.

I would think the 180 would specify in limitations sections of either 30 degrees pitch and 60 degrees roll. If it doesn't, I know it'll list approved acro maneuvers. Loops and rolls being unapproved.
 
I don't know how you got "sustained inverted flight in an Archer" out of the OP's post, without some creative interpretation:)
 
fiveoboy01 said:
I don't know how you got "sustained inverted flight in an Archer" out of the OP's post, without some creative interpretation:)
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It seemed like the OP was confused with the difference between zero G and negative G. I actually hear it a bunch and pilots will refer to a push over as a negative G maneuver when it is actually a zero G...unless you push to the point of being negative G. I used the "inverted maneuver" as being negative G to distinguish between the two. Guess I should have put "sustained" with that so everyone would understand.

Doesn't matter anyway because I'm sure in the POH there is more listed than just inverted maneuvers not approved. My AA-5 said 30 / 60. That would pretty much nullify inverted maneuvers.
 
IIRC the PA-28 POH simply says "acrobatic maneuvers prohibited" or something along those lines. My Mooney says the same, as well as "inverted maneuvers not approved" No specifics on what "acrobatic" means.
 
I know for fact a Warrior/ Cherokee will quit running in about 3 seconds if it a carbed motor.......

If you do keep it running, the oil pressure will drop and the pump quits picking up oil...:redface::redface::redface:
 
N801BH said:
I know for fact a Warrior/ Cherokee will quit running in about 3 seconds if it a carbed motor.......

If you do keep it running, the oil pressure will drop and the pump quits picking up oil...:redface::redface::redface:
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Is that bad for the engine? Does it recover in a few seconds?
 
StinkBug said:
IIRC the PA-28 POH simply says "acrobatic maneuvers prohibited" or something along those lines. My Mooney says the same, as well as "inverted maneuvers not approved" No specifics on what "acrobatic" means.
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Hmmm, I better check my Cherokee's POH. I haven't specifically looked for any acrobatic comments. Though frankly, I doubt you'd find me doing any ribbon or jumping exercises in the Cherokee, it is pretty cramped in there. :goofy: Acrobatics vs Aerobatics

Now aerobatics, OTOH, that'd be fun. But I will have to check the POH for the exact wording. You put a bug in my head. Great going. Thanks a lot!! :(
:lol:
 
N801BH said:
I know for fact a Warrior/ Cherokee will quit running in about 3 seconds if it a carbed motor.......

If you do keep it running, the oil pressure will drop and the pump quits picking up oil...:redface::redface::redface:
Click to expand...

In 0G or negative G or inverted?

When I owned my Cherokee, I went 0 and slightly negative G and the engine never quit. Inverted, no.
 
eman1200 said:
....and don't forget to have an unsecured dog in the plane, as some have done, caught on video, and posted to youtube :yikes:
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Please -- don't do that to the dog, both to avoid being unkind to the dog and to avoid having the dog get really scared (which can become your problem as well as the dog's). We were cruising along in IMC over BDR with our Chocolate Lab Chewbacca. He was curled up in the back, sound asleep (as he normally did in cruise flight). We hit a downdraft and dropped about 50 feet. I looked back as we dropped, and saw a) daylight between the dog and the floor, b) two big yellow eyes the size of dinner plates, and c) four legs splayed out trying to find something on which to hold. Shortly after the airplane stopped descending, the dog caught up with a thump. And then he gassed us. Fortunately, the sliding canopy of a Grumman allows rapid and thorough cockpit ventilation. And it could have been a lot worse if he had passed more than just gas.
 
It's not so much the 0g part but the pull out at the end that can be problematic. We hadn't realized the tow bar was unsecured in the back until it came crashing down when we started pulling positive g's.
 
Thanks for the replies. Funny story about your dog and great name for a dog too.

As far as the legalities, I was looking over the FARs and the limitations on aerobatic flight. Is this maneuver not categorized as aerobatic flight?

The only stipulation I would be concerned about violating in my area would be the 4nm from a federal airway one. It's pretty hard to find any airspace in the LA basic that is clear of an airway like this.
 
FlyingMonkey said:
Thanks for the replies. Funny story about your dog and great name for a dog too.
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You should have seen the couch cushions which earned him that name.

As far as the legalities, I was looking over the FARs and the limitations on aerobatic flight. Is this maneuver not categorized as aerobatic flight?
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It's hard to say. Here's the rule (14 CFR 91.303):
[A]erobatic flight means an intentional maneuver involving an abrupt change in an aircraft's attitude, an abnormal attitude, or abnormal acceleration, not necessary for normal flight.
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What do you think?
But either way, this won't hurt an Archer, which by 14 CFR 23.337 must be able to handle negative g-load of at least -1.52 g's.
 
It seems like it might be considered aerobatic by the definition. However, so might practicing stalls. I don't want to get in trouble.... But I also want to have some fun while being safe. :)
 
Ron Levy said:
It will take rather more than 10 seconds of zero-g flight to cause the engine of an Archer to be starved of either fuel or oil.
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I was past 0 G... Probably -1/2..... Just enough to get the head set wires to float up a bit....

The gas in the float bowl of the carb rises and aux booster in the venturi starves for fuel...

I did this several times and the motor stumbled EVERY time....

The one time I did see the oil pressure drop I was right at 0 G an the motor still ran... Kinda...:redface::redface::redface:...

It did take 10 seconds or so for the oil pump pick up screen to suck air....
 
N801BH said:
I was past 0 G... Probably -1/2..... Just enough to get the head set wires to float up a bit....

The gas in the float bowl of the carb rises and aux booster in the venturi starves for fuel...

I did this several times and the motor stumbled EVERY time....

The one time I did see the oil pressure drop I was right at 0 G an the motor still ran... Kinda...:redface::redface::redface:...

It did take 10 seconds or so for the oil pump pick up screen to suck air....
Click to expand...

I've had that happen as well with 180 / Archer types. Engine always ran smooth once I got positive G back on it.
 
FlyingMonkey said:
It seems like it might be considered aerobatic by the definition. However, so might practicing stalls.
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However, if you look at the limitations placard in your Archer, you will see that stalls (except, I believe, whipstalls) are explicitly approved maneuvers.

I don't want to get in trouble....
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I don't think you have to worry about getting into trouble doing this maneuver.

But I also want to have some fun while being safe. :)
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I think you have all the information you need to do that.
 
BigBadLou said:
Hmmm, I better check my Cherokee's POH. I haven't specifically looked for any acrobatic comments. Though frankly, I doubt you'd find me doing any ribbon or jumping exercises in the Cherokee, it is pretty cramped in there. :goofy: Acrobatics vs Aerobatics

Now aerobatics, OTOH, that'd be fun. But I will have to check the POH for the exact wording. You put a bug in my head. Great going. Thanks a lot!! :(
:lol:
Click to expand...

My AA-5 POH uses the term "acrobatics." Although I usually use aerobatics, acrobatics is still a popular term in aviation.
 
Years ago, shortly after they invented electricity my brother and I were up in my Luscombe and having a great time floating my pocket watch off the dash. Unfortunately I had forgotten the box of screws behind the seat, it took over an hour to recover them from inside the rear fuselage. :-(


Jerry
 
Thanks for all the replies. This has been very helpful.


Sent from my iPad using Tapatalk
 
A lot of rentals I've seen have loose carpet on the floor, under the flight controls. Happens with so many people sliding in and out all the time and things down there get dislodged. Something else to consider.

I like to run a seatbelt through my flightbag handle when I'm solo so it won't fall off the pax seat onto the floor.
 
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