The International Cessna^® 170 Association

Now that hings are officially "together" again, I wanted to relay the story of how I think the gear-box reinforcement kit made by P Ponk seems to have saved me ANOTHER gear box rebuild.

A couple of years ago I tore-up my gear box and ended up on my nose with a major year-long rebuild of my 1952 170B. Because I felt part of the reason the whole event occured was due to the spongy stock gear legs, I decided to install 180 gear and the beef-up blocks made by P Ponk. On my 2nd flight after finishing the project, my instructor was demonstrating the "proper" wheels-landing technique and swerved right at high speed putting us into a broadside skid eventually slamming the left wing and horizontal stab. into the dirt. The force of the sideload was enough to bend the left gear leg (180) but a complete inspection of the gear box structure revealed it un damaged. I was amazed that it worked so well. I know there is a big mechanics' debate over if the P Ponk kit installation is wise or not because the stress transfer can bend everything up through the door posts when you might have gotten away with some gear box damage if the leg attach bolt were allowed to shear instead. I am of the opinion that any gear box damage is expensive to repair and why not go-for-broke and hope you end up as lucky as I did. My second "EVENT" seemed to have put about as much sideload on my gear box as is humanly possible and I am sure it takes quite a bit to bend a 180 leg on a plane as light as a 170.

ps:
P Ponk did not pay me for this endorsement. (although I will take money from anyone)

I had a pretty bad landing once that swerved me hard to the right then my over-correcting swerved me hard to the left. The tires sure made a lot of noise during that landing but no damage. I'm sure glad I had the P-ponk upgrade.

But just curious, who's footin' the bill for your latest repairs?

On my 2nd flight after finishing the project, my instructor was demonstrating the "proper" wheels-landing technique and swerved right at high speed putting us into a broadside skid eventually slamming the left wing and horizontal stab.

I think that I would get a new instructor.

Yes, I think a new CFI is in order. It's pretty big of you to report on the quality of the Ponk kit when your airplane is bent yet again on just the second flight after a year long rebuild...........

I think I would take the CFI who was responsible for this latest damage by showing you his "proper" technique of wheel landings out behind the barn for a demonstration of your "proper" technique of a good old ass kicking.

I believe one of our members has a reasonably priced set of "cross wind gear" for sale in the Trade Mart....... Might cut down on the repair expenses in the future.......

Haydon wrote:I believe one of our members has a reasonably priced set of "cross wind gear" for sale in the Trade Mart....... Might cut down on the repair expenses in the future.......

The best way to cut down on repair is to get a better instructor.

It isn't politically correct to kick ass any more. You have to see if you can have a social worker send him to a self-help reprogramming session.

While p ponk appears to do a good job ,the forces must be transmitted else where and some thing in the airframe must be doing a job it wasn't designed for .We must have a safety fuse some where . Electrical circuits have them ,even 747 ,s have them built into the airframe and all of there systems. Cessna is the same ,the cabin is hopefully the last piece to start tearing apart in a serious incident. So beefing up a joint (attach point ) in the airframe will transmit forces else where. If every thing is so rigid the forces are then transferred to the human body which is a lump of water contained in a organic mesh which tears very easy. Just look how cars are designed these days.
Hope the instructor paid for his mistake and I mean in dollar terms . That's not training that's stupidity.

Has anyone ever seen a PPonk'd gear leg get torn out? I'd be interested to know how much of the gear box went with it and if anything was pushed into the cabin area.

I saw the aftermath of a C-185 on wheel-skis in Nome, AK that was hand-propped without being tied down and it started with no one in the plane. Witnesses said it was about 4 feet in the air when it hit a 20 foot tall snow berm. The left ski and gear remained together but was ripped out of the plane. If you hold your arms out in front of your body and make a circle touching finger tips, that is about how big the chunk of fuselage was that got ripped out. It would have made no difference whether it had the P-Ponk kit or not, the plane was still gone.

My opinion is the P-Ponk kit will save the plane where otherwise it would be heavily damaged or destroyed without it. If there is enough energy being absorbed by the plane to rip a chunk out of the side with the gear attached, the plane is toast anyway. I have personally seen several planes with the kit that were repaired with minimum damage following hard wheel strikes that would have completely knocked out the gear otherwise and wrecked the plane. When a hard strike happens, thorough inspection and repair of all surrounding structure is warranted whether a P-Ponk kit is installed or not.

When Omac Aircraft Salvage was still in business they had 5 170 fuselages setting in a row, all had the PeePonk Gear mod and the gear ripped out. They all looked about the same with the flap handle virtually pulled out thru the bottom of the aircraft.

I don't know the circumstances of any of the accidents, I simply saw them setting in the junk yard.

In a crash landing, I'm not terribly concerned about the level of damage to the aircraft.
If the gear leg fails then the aircraft will take much more damage in the majority of accidents. But is the PPonk kit saving the aircraft at loads higher than a stock gear can withstand only to risk the passengers at even higher loads where the gear box finally fails?

If the accident has so much energy to rip the PPonk kit out of the plane, does that expose the passengers to more risk because the cabin area is compromised?

Either way, the aircraft belongs to the insurance company. I just don't wan to lose a leg in the process.

If I'm in a crash, I want the airplane to absorb as much energy as possible which hopefully will slow the deceleration. Every unit of energy the plane absorbs reduces the final amount of energy left to the occupants. So without the kit, the gear rips out and absorbs very little of the total energy of the plane. With the kit, much more energy is required to rip out the gear which slows the final deceleration leaving less energy the occupants absorb with their bodies. Whether or not the deformation in the passenger compartment is a higher risk to passengers with the kit has never been quantified as far as I know. The kit is always a positive thing in my mind and from everyone I know who has had an accident with one installed.

Since when did Cessna make any claims about crashworthiness of their weak gear attach?

Pponk only claims to prevent collapse of the gear due to common sideloads imposed by lousy pilots and instructors.....a lot more commen event, in my belief.

I'm with Richard and Steve (Knopp) on this. If you can say how hard and fast you're gonna side-load the gear...then you can predict how much damage is gonna be prevented by the beef-up kit...and whether or not you'll likely be recognizable after the event.

By the time the pax's are injured in an airplane improved by a Pponk kit...I doubt the absence of the kit would have helped them at all.

I wouldn't do anything to injure that instructor at all because he needs to be able to work to pay for that damage and my replacement airplane until mine's ready again.