The Jesus bolt

How to keep the Cessna 170 flying and airworthy.

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ghostflyer
Posts: 1423
Joined: Mon Apr 21, 2008 3:06 am

The Jesus bolt

Post by ghostflyer »

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.
bagarre
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Joined: Thu Sep 30, 2010 11:35 pm

Re: The Jesus bolt

Post by bagarre »

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.
hilltop170
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Re: The Jesus bolt

Post by hilltop170 »

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.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
2023 Best Original 170A at Sault Ste. Marie
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
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bagarre
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Re: The Jesus bolt

Post by bagarre »

Thanks. Certainly no clunking sound, just a mild oscillation in bumpy air.
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GAHorn
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Re: The Jesus bolt

Post by GAHorn »

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.)
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
4-Shipp
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Joined: Mon Apr 22, 2002 11:31 pm

Re: The Jesus bolt

Post by 4-Shipp »

George, I believe the reference referes to whom you will meet next should the bolt fail, not comparing said pilot or bolt to Jesus... :D
Bruce Shipp
former owners of N49CP, '53 C170B
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Bruce Fenstermacher
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Re: The Jesus bolt

Post by Bruce Fenstermacher »

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... :D
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.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
T. C. Downey
Posts: 548
Joined: Sat Jan 26, 2013 5:58 am

Re: The Jesus bolt

Post by T. C. Downey »

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.
T. C. Downey
Posts: 548
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Re: The Jesus bolt

Post by T. C. Downey »

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?
ghostflyer
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Joined: Mon Apr 21, 2008 3:06 am

Re: The Jesus bolt

Post by ghostflyer »

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 .
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