PPO Prevention

Status
Not open for further replies.

Stram

Member
Joined
May 19, 2006
Messages
17
Location
leeds England
I copied this question from a UK Forum. It was posted by a 'Paul Robinson'.


Has anyone thought of connecting a rev-limiter to a G-meter to reduce engine power if in negative G conditions to prevent 'power push over 'developing.



It seems like a good idea to me, what do you think?

Kind Regards 'Stram'
 

DennisFetters

Gold Supporter
Joined
Jul 18, 2005
Messages
3,182
Location
Changsha, China
Aircraft
582 Commander Elite
Total Flight Time
Stopped counting years ago after 5,000
Better, safer,much more reliable and less to go wrong by just teaching the pilot not to push over.

In other words, there is no substitute for proper training, which includes the prevention of PPO, and how not to PIO.
 

iconnary

Senior Member
Joined
Aug 9, 2004
Messages
403
Location
Atlanta, GA
Aircraft
Monarch
Total Flight Time
80 - FW, 100 - Gyro
Better, safer,much more reliable and less to go wrong by just teaching the pilot not to push over.
Isn't the best, safest, and most reliable means of preventing PPO to simply not have a thrustline offset?
 

gyromike

Administrator
Staff member
Joined
Oct 29, 2003
Messages
3,739
Location
Abbeville, Louisiana
Aircraft
Bensen B8MG
Or...

Better, safer,much more reliable and less to go wrong by just designing the instability out of the machine.

Minimize/eliminate the high thrustline, or damp it with a suitably designed horizontal stabilizer, and you don't have to train to avoid a PPO.
 

DennisFetters

Gold Supporter
Joined
Jul 18, 2005
Messages
3,182
Location
Changsha, China
Aircraft
582 Commander Elite
Total Flight Time
Stopped counting years ago after 5,000
Or...

Better, safer,much more reliable and less to go wrong by just designing the instability out of the machine.

Minimize/eliminate the high thrustline, or damp it with a suitably designed horizontal stabilizer, and you don't have to train to avoid a PPO.
.............................No
 

Chuck_Ellsworth

Platinum Member
Joined
Oct 31, 2003
Messages
1,695
Location
Vancouver Island
DennisFetters Quote:
Originally Posted by gyromike
Or...

Better, safer,much more reliable and less to go wrong by just designing the instability out of the machine.

Minimize/eliminate the high thrustline, or damp it with a suitably designed horizontal stabilizer, and you don't have to train to avoid a PPO.


.............................No


Dennis, I am in the training business working for the insurance underwriters, please explain your answer so I can pass it on to the underwriters.

If unstable gyros are safe with training it would stand to reason that the same would hold true for all other flying machines.
 

Douglas Riley

Senior Member
Joined
Mar 27, 2004
Messages
140
Dennis, why on earth would you NOT design out PPO?

PIO, or porpoising, is different from PPO.

Anyone can PIO any device, from the hot water faucet in the shower to a NASA spacecraft. However, it is not hard to design a device that is user-friendly in this regard -- one that won't PIO unless the operator severely abuses it. Again, why settle for anything less than a design that is highly PIO-resistant?

BTW, I have more hours in Air Commands -- mostly in my "classic" 1986 no-HS Commander -- than I have in any other aircraft. I had great fun, but I have come to recognize that CLT and adequate H-stabs are key to safe gyro design.
 

CLS447

Platinum Member
Joined
Oct 30, 2003
Messages
6,320
Location
Reading, PA
Aircraft
Air Command 503 & Air Command SxS /EJ2.5
Total Flight Time
Aprox 400 gyro
I just want to say to Dennis....I bought my 447 Commander from Bill Parsons back in 1986.

Still runs great, flies great & looks great ! BEST MONEY I EVER SPENT !


Thanks to you, I got into this fun hobby ! I'm still alive !
 

FlyFast

Newbie
Joined
Nov 11, 2006
Messages
42
Location
Palmer, Alaska
Aircraft
Cessna 170A, Ercoupe
Total Flight Time
~600
If someone is inclined to continue to fly a gyro with known pitch instability and PPO tendencies, then it might help. If the accelerometer is set correctly, and if the ignition interruption occurs soon enough (but not too soon), it might help.

Then again, the possibility of either component failing or being incorrectly adjusted could easily decrease available engine power, shut down the engine, or fail to activate when needed. Also, how would you test it to see if it is set correctly and working?!

I agree with the other comments. Fix the aircraft or fly something else. I doubt this idea is really a fix but I do like the creative thinking.

Keith
 

Steve McGowan

Gold Member
Joined
Jul 12, 2004
Messages
2,517
Location
Macon Ga.
Ppo Prevention

Ppo Prevention

Now I'm gonna get lotts of flack on this answer...

U CANNOTT design a machine that will not PPO....Helicopter pilots will kill Ya quick in a gyro.... so I ask many questions before we fly.

"ANY gyro" or helicopter will PPO... I have been told that the Parsons Trainer I use to instruct with is a death trapp because of the HTL it's built with..

The driver/pilot of the gyro can be taught NOT To PPO.. In ONE/1 hour of the proper instructions the gyro will NOT PPO...

it's NOT the machine that does it.. It's the pilot..I have learned from a lotta slammin into the ground and thats what I instruct students NOT to do.. The ones that PPO outta the air and kill themselves have NOT the proper training or time in the seat.. Money issues, being too cheap to pay for instructions and wanna do it themselves.. Bad move...


NOW,,, I didn't say a CLT doesn't help to avoid the problem,,

But it WILL NOT ASSURE you won't do it..

Now, Yall say I've stuck my foot in my mouth..... Ya think??

Get in the BLACK..... I'll prove it to Ya...

Thanks for the question,, but the REV, Limiter is the fool driving..


Thats my Story,,, I'm stickin to it
 

DennisFetters

Gold Supporter
Joined
Jul 18, 2005
Messages
3,182
Location
Changsha, China
Aircraft
582 Commander Elite
Total Flight Time
Stopped counting years ago after 5,000
Now I'm gonna get lotts of flack on this answer...

U CANNOTT design a machine that will not PPO....Helicopter pilots will kill Ya quick in a gyro.... so I ask many questions before we fly.

"ANY gyro" or helicopter will PPO... I have been told that the Parsons Trainer I use to instruct with is a death trapp because of the HTL it's built with..

The driver/pilot of the gyro can be taught NOT To PPO.. In ONE/1 hour of the proper instructions the gyro will NOT PPO...

it's NOT the machine that does it.. It's the pilot..I have learned from a lotta slammin into the ground and thats what I instruct students NOT to do.. The ones that PPO outta the air and kill themselves have NOT the proper training or time in the seat.. Money issues, being too cheap to pay for instructions and wanna do it themselves.. Bad move...


NOW,,, I didn't say a CLT doesn't help to avoid the problem,,

But it WILL NOT ASSURE you won't do it..

Now, Yall say I've stuck my foot in my mouth..... Ya think??

Get in the BLACK..... I'll prove it to Ya...

Thanks for the question,, but the REV, Limiter is the fool driving..


Thats my Story,,, I'm stickin to it


............. dido
 

Aussie_Paul

A reforming stirrer!!!!!
Joined
Oct 30, 2003
Messages
4,441
Location
Ballarat Australia
Aircraft
None at the moment.
Total Flight Time
Since 1982 Gyro 5000+ mostly instructing, and approx. 200 fixed wing in the late 1960s.
Now I'm gonna get lotts of flack on this answer...

Thats my Story,,, I'm stickin to it
Steve, you should have said, "Thats my story BUT I am open to being convinced otherwise."

The ability to be string minded, strong willed and be open to new and/or others ideas instead of being headstrong is the better way to go.

To the original question, a correctly set up gyro does not need training wheels.

Aussie Paul. :)
 

Steve McGowan

Gold Member
Joined
Jul 12, 2004
Messages
2,517
Location
Macon Ga.
I am

I am

alway's open to a better mouse trapp ,, ANYTHING that helps save lives I'm open to it.

Till then I'll have to do the old school thang.. if Ya can't be sure of what your doin,, stay on the ground.. I'll get over bein imbarrassed by the Wrong Wording,, However you know I mean well by what I'm saying,, (I hope So anyway)

It's just that simple....
 
Last edited:

GyroRon

Former Gyro know it all
Joined
Oct 29, 2003
Messages
16,519
Location
Fort Mill South Carolina
Aircraft
Waiex/3300 Jab, Phantom UL, Flightstar II UL
Total Flight Time
ALOT
Dennis or Steve, could either of you give a rational explaination on how a gyro such as the one in the picture below can PPO?

Keeping in mind a PPO is short for POWER.... PUSH..... OVER.....

and also keeping in mind the thrustline was several inches below the CG and would be pushing the nose up if the rotor was unloaded.

I am just curious as I have heard the same thing you guys just said by others such as Jim Logan and I never got a explaination to go with the statement that could make sence to me.
 

Attachments

DennisFetters

Gold Supporter
Joined
Jul 18, 2005
Messages
3,182
Location
Changsha, China
Aircraft
582 Commander Elite
Total Flight Time
Stopped counting years ago after 5,000
Dennis or Steve, could either of you give a rational explaination on how a gyro such as the one in the picture below can PPO?

Keeping in mind a PPO is short for POWER.... PUSH..... OVER.....

and also keeping in mind the thrustline was several inches below the CG and would be pushing the nose up if the rotor was unloaded.

I am just curious as I have heard the same thing you guys just said by others such as Jim Logan and I never got a explaination to go with the statement that could make sence to me.
I have already done that a few weeks ago in another thread. Anyone that wants to learn from it just needs to search on my postings and read all about it.

The fact is, anyone that tells you that you can't PIO or PPO even a CLT machine don't know what they are talking about or is lying to you.
 

DennisFetters

Gold Supporter
Joined
Jul 18, 2005
Messages
3,182
Location
Changsha, China
Aircraft
582 Commander Elite
Total Flight Time
Stopped counting years ago after 5,000
I just want to say to Dennis....I bought my 447 Commander from Bill Parsons back in 1986.

Still runs great, flies great & looks great ! BEST MONEY I EVER SPENT !


Thanks to you, I got into this fun hobby ! I'm still alive !
Hi Chris,
Glad you like it. I had thousands of hours in mine an loved every minute of it. The 582 is even better. I'll have my Rotax 618 finished in a month.

If you put the Elite Pod and Super Thruster kits on it will be more stable and faster, with better climb.
 

GyroRon

Former Gyro know it all
Joined
Oct 29, 2003
Messages
16,519
Location
Fort Mill South Carolina
Aircraft
Waiex/3300 Jab, Phantom UL, Flightstar II UL
Total Flight Time
ALOT
I have already done that a few weeks ago in another thread. Anyone that wants to learn from it just needs to search on my postings and read all about it.

The fact is, anyone that tells you that you can't PIO or PPO even a CLT machine don't know what they are talking about or is lying to you.
Can I ask then why there has never been any evidence of a CLT or LTL gyro ever crashing due to PPO?
 
Status
Not open for further replies.
Top