The International Cessna^® 170 Association

If you are concerned about safety of your undercarriage inspect it more often and change the main bolt that holds the spring (leg) onto the airframe . If memory serves me correctly cessna requires it changed every 500hrs however it should be changed if landing in rough conditions or a series incident that has occurred. The bolt doesn't cost that much and changing it isn't that hard. I had done some rough landing s (surface has many wash always in it ) and some thing made me want to change the main bolts on the spring legs . Due some of the landings I knew some thing had to give. They had been in (the bolts)around 270hrs so out they came and found one with the top of the bolt had cracked . So now they get a good inspection and and replaced due to landing environments or situations.

Along these lines (landing gear worries)...
Is it possible to observe the landing gear (later model lady legs) leg move slightly while in light turbulence?
There is no clunking sound (in flight or upon landing) and the movement is slight. It catches my eye but I have to brace my head against the side window to really observe it.

I'd like to think its just the sprung leg moving from the inertia of the wheel but, it's disconcerting.

180 gear in a 170 will oscillate in cruise, 185 gear will do it, they all do, some worse than others. It is caused by wind-induced oscillation but also by turbulence. As long as no clunking sounds are associated with the oscillation, no problem. If clunking is heard, the gear wedges are probably loose.

Thanks. Certainly no clunking sound, just a mild oscillation in bumpy air.

Annual inspections should include looking at that bolt (which for Bruce and myself would be much more frequently than every 500 hours) and the airplane suspended from wing-jacks or fuselage-support-frames, and the landing gear legs forcibly shaken to determine security of the wedges and mounting.

(Jesus was reportedly sacrificed for the salvation of others, so I don't think it a valid comparison.... and I doubt if anyone other than Barabbas was greatly relieved.)

George, I believe the reference referes to whom you will meet next should the bolt fail, not comparing said pilot or bolt to Jesus...

4-Shipp wrote:George, I believe the reference referes to whom you will meet next should the bolt fail, not comparing said pilot or bolt to Jesus...

Bruce Shipp is right. In the helicopter world this is the one BIG nut that was commonly found holding the entire rotor system on the main shaft of 60s vintage rotor systems.

The only statement I'd disagree with is the bolts is cheap.

$47.50 plus shipping is what I just paid for one NAS147-34.

gahorn wrote:Annual inspections should include looking at that bolt (which for Bruce and myself would be much more frequently than every 500 hours) and the airplane suspended from wing-jacks or fuselage-support-frames, and the landing gear legs forcibly shaken to determine security of the wedges and mounting.

If you do the PeePonk mod can you delete this inspection?

If the bolt breaks on landing it could be the word one utters as things become bad. One would have to admit $50 each bolt is cheap insurance . I would be still doing a 500hrly inspection especially having a p ponk mod done. Corrosion is still a item regardless of mods fitted. Plus there is other structures that's now being put under stress and that has to be inspected .