Bolt Kit for a 170

How to keep the Cessna 170 flying and airworthy.

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cessnaford
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Bolt Kit for a 170

Post by cessnaford »

My mechanic said he bought a bolt kit for his old straight tail 182 when he went through it. I look in aircraft spruce but was unable to find one for the 170. Does anyone know if you can get one (I have a 1948) for a 170 or is there one for perhaps a 172 that would give you 95% of what you would need.
If so some hints would be appreciated.

thanks
bill w.
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GAHorn
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Re: Bolt Kit for a 170

Post by GAHorn »

Perhaps you are looking for a stainless steel "screw" kit? A 172 kit will be the closest thing to it.
'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. ;)
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wingnut
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Re: Bolt Kit for a 170

Post by wingnut »

Because of the recent influx of 170's through our hangar for various maintenance and repairs, I've definately noticed a need to replace 60 year old hardware. I'm not speaking of a "stainless screw kit" that only includes screws for panels typically removed during annual inspections.
If there were enough interest among the members, I would consider putting together kits to include the important stuff, the harware that holds the major components of these airframes together; wing and lift strut attach bolts, the bolts the retain the wing attach fittings in the spar carry-thru's, the internal wrenching bolts at the aft vertical spar attach, and etc. It would take take me more time to put one kit together than the hardware would cost, but with several interested parties I could do this. The kits would be extensive, including all major airframe assembly bolts, washers, nuts and would be bagged and labeled for location, with accompanying IPC copy with applicable hardware highlighted for easy identification, and torque specs.
Any interest, let me know and I'll get prices together.
Del Lehmann
Mena, Arkansas
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GAHorn
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Re: Bolt Kit for a 170

Post by GAHorn »

wingnut wrote:Because of the recent influx of 170's through our hangar for various maintenance and repairs, I've definately noticed a need to replace 60 year old hardware. I'm not speaking of a "stainless screw kit" that only includes screws for panels typically removed during annual inspections.
If there were enough interest among the members, I would consider putting together kits to include the important stuff, the harware that holds the major components of these airframes together; wing and lift strut attach bolts, the bolts the retain the wing attach fittings in the spar carry-thru's, the internal wrenching bolts at the aft vertical spar attach, and etc. It would take take me more time to put one kit together than the hardware would cost, but with several interested parties I could do this. The kits would be extensive, including all major airframe assembly bolts, washers, nuts and would be bagged and labeled for location, with accompanying IPC copy with applicable hardware highlighted for easy identification, and torque specs.
Any interest, let me know and I'll get prices together.
As a matter of interest, ... While my airplane was at Del's (aka "wingnut") for other maintenance, he noticed that the hardware attaching my wing's rear spar to their carry-throughs was incorrect (and incorrectly oriented) and therefore could not be properly torqued.
Now those of you who know my airplane are aware that it underwent a 16-year professional-restoration immediately prior to my purchase, and the attention to detail in that restoration was better than commonly found. Yet there it was... incorrect hardware used to attach the wing to the fuselage.... and it had been overlooked by at least seven different inspectors and two Cessna Service Centers during inspections over the last 12 years.

My point is twofold:
1- It's not unheard of for such mistakes to happen, even in meticulously-maintained airplanes.
2- Del Lehmann and his co-workers found and corrected what many, many "experts" and my airplane's owner had missed. :oops:

Del's offer is a conscientiously good one.
'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. ;)
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Brad Brady
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Re: Bolt Kit for a 170

Post by Brad Brady »

George,
Something else for people to think about.....when running a AD compliance check....A compliance check run 40 years ago....might not be serviceable today!!!! The owner of the AC and the Mechanic need to be on the same page..... there's so much that can be missed....Even by a very experienced mechanic!!! 8O ,,,,Brad
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GAHorn
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Re: Bolt Kit for a 170

Post by GAHorn »

Brad Brady wrote:George,
Something else for people to think about.....when running a AD compliance check....A compliance check run 40 years ago....might not be serviceable today!!!! The owner of the AC and the Mechanic need to be on the same page..... there's so much that can be missed....Even by a very experienced mechanic!!! 8O ,,,,Brad
Absolutely! (And that is another reason why AD's are revised, so as to provide impetus to reconsider their effectivity.)
'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. ;)
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KG
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Re: Bolt Kit for a 170

Post by KG »

gahorn wrote:
As a matter of interest, ... While my airplane was at Del's (aka "wingnut") for other maintenance, he noticed that the hardware attaching my wing's rear spar to their carry-throughs was incorrect (and incorrectly oriented)
As a follow up, while my airplane was at Del's he also found some incorrect hardware, the most serious of which were the bolts which fasten the vertical and horizontal stabilizers together. Mine had some hex-head, low strength bolts in lieu of the correct internal wrenching, high tensile strength bolts. I don't know how long it had been flying that way and suspect it had passed numerous inspections without anyone noticing. Kudos to Del for have such a sharp eye!

Here is a pic of the correct hardware after Del fixed the problem. This is at the base of the rudder where the vertical stabilizer meets the horizontal stabilizer.
P5090142.JPG
Del looked over my airplane and replaced a lot of old and incorrect hardware. Here is a pic of some of the junk he took off of the airplane. I think there are even a couple of drywall screws in that mess.
P5090138.JPG
I would have to agree that with the age of these airplanes it might be a good idea to go over them and replace the nearly 60 year old hardware. Most of it isn't very expensive and I sure feel better knowing my tail feathers aren't likely to fall off.

Keith
53 170B
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GAHorn
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Re: Bolt Kit for a 170

Post by GAHorn »

Del definitely has a sharp eye! One of the hazards of common AN bolts in that location (vert attach angles) is that the angles require internally-radiused bolt-heads of the internal-wrenching (NAS) bolts. The flat washer which accompanies the bolt must also be correctly radiused.

If the INcorrect bolts/washers are used, the attach-angle can be CRACKED...and that could ruin your day. Even if your day isn't ruined, your pocketbook will suffer when you try to find and pay for those angle replacements.
'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. ;)
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Bill Hart
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Re: Bolt Kit for a 170

Post by Bill Hart »

I don't think anyone has said it yet but I would be interested in Del's bolt kit.
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Brad Brady
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Re: Bolt Kit for a 170

Post by Brad Brady »

Something I just thought about....and spent about an hour finding, is the pic that is with this post.....When I did a lot of painting I would show this block, that is the wing attach block in the hat chanel of the center section...Both front and rear...And tell people this is why I disamble the entire airframe to paint......It isn't just the hardware it's everything.....Brad
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wingnut
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Re: Bolt Kit for a 170

Post by wingnut »

Hi Brad,
Your right, there are a lot of other things in addition to hardware to look at closely on these old birds. I think if an owner, or mechanic, takes the time to replace all of the old structural hardware, the consequential result will be seeing/inspecting things closer than ever before.
The corrosion on that fitting in your picture is a very good reason to pull the wings, remove the fittings, inspect, swab out the carry-thru's, primer, re-install with new hardware. My opinion is to do this, and other structural inspections every 10-20 years depending on enviroment.
When I find these fittings corroded I don't necessarily get alarmed enough to take the entire aircraft apart unless further inspection warrants it. This is because 99% of the aluminum in these planes is 2024 roll formed clad, which is not nearly as susceptible to corrosion (especially innergranular) as the 7075 extruded spar cap angles and wing attach fittings which (1) do not have the protective clad (2) the extrusion manufacture process, in my opinion, wasn't then and still is not a perfected method and allows impurities and sometimes voids which can lead to problems.

UPDATE: I just noticed I had written "swap out the carry thru's". Should have been "swab".
Last edited by wingnut on Thu Jun 04, 2009 6:18 pm, edited 1 time in total.
Del Lehmann
Mena, Arkansas
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jlwild
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Re: Bolt Kit for a 170

Post by jlwild »

Brad,

Is the part in your picture called a "Block - Bearing" as illustrated in Figure 24-3, p/n 0512122? The parts catalog indicates there are 2 of them in the fuselage Bulkhead assembly at station 65.33. But, more importantly, can they be inspected without removing the wing? Just asking since our planes are getting long in the tooth :wink:

And, perhaps others can chime in if they have noted corrosion in these blocks. It would be great to get a feeling on how serious a problem this could be.

Also, are ther similiar "bearing blocks in the forward bulkhead assembly? It looks like there are in Fig 21, but they are not identified.
Jim Wildharber, Kennesaw, GA
Past President TIC170A (2010-12) and Georgia Area Representative
'55 170B, N3415D, SN:26958, O-300D; People's Choice '06 Kelowna, B.C., Best Modified '07 Galveston, TX, Best Modified '08 Branson, MO.
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c170b53
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Re: Bolt Kit for a 170

Post by c170b53 »

The blocks are the same front and back. Without one in my hand I'll guess they might have had an anodized finish to protect them but then again maybe that's just wishful thinking on my part. If not anodized then they must have a primer coating to provide basic protection. The most likely cause of corrosion in extrusions would be some form of mechanical damage to the surface of the piece that would allow the elements access to the alloy grain paths. Then its not a matter of whether it will corrode its just how fast. Its possible that during manufacturing that a contaminate in the alloy might be the initiation point but given the age of these blocks if that were the case they would be well on their way to becoming a pile of dust. Another possible reason for the corrosion here would be if someone installed the block retaining bolts dry. If the bolts had some of their cad plating missing then while being inserted the bolts lightly score the bolt holes bores in the block. In such a way your providing corrosion that has started on the bolt and introducing it to the alloy material in the block. In other words you're just speeding up the process.
The areas most likely to corrode on our planes will be horizontal surfaces that allow moisture to remain in contact with the structure. The areas that come to mind are; above and between the door posts, the carry through spars and the horizontal bulkheads in the tail. Anything that assists moisture in maintaining contact with structure like dirt is a bad thing. One such area is the fuselage to inbd end of the flap, fuselage fairing. Dirt gets back there and retains moisture in close contact to the skin. Not a big deal unless you havent cleaned that area out in the last thirty years. This is the same reason that the tail area horizontal bulkhead can be prone to corrode. The tail in close proximity to the ground receives dust and dirt kicked up from the mains, which finds a home on these inside surfaces. When it rains water runs down the fuselage trickles underneath the horizontal stab combines with the dust and stays for awhile. There are many variables as in how and where the plane is operated that will determine whether corrosion is a concern thus corrosion will vary between examples.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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GAHorn
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Re: Bolt Kit for a 170

Post by GAHorn »

The "blocks" are indeed a problem area that needs occasional inspection. The wing must be supported and the attach bolts completely removed to gain access to them. Yes, if you truly want them inspected the wing must come off. Yes, this is a commonly-found corrosion problem in the aircraft series. Yes, mine were corroded and replaced when the aircraft was rebuilt. I have some nasty pics but they are not in digital format so I don't have easy access or I'd post them.

Anyone attending the Galveston convention seminar will have seen the pair which Tom Hall found. I still have them for teaching purposes and will make pics and post them.

Jim's comments are good ones. (And he should know, as he's a corrosion-specialist for a major airline.) If I ever remove my bolts/blocks again, I plan to use some of BeechCraft's super-duper wing-bolt grease on them during reassembly.
'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. ;)
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Brad Brady
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Re: Bolt Kit for a 170

Post by Brad Brady »

Jim,
Sorry to be so late to get back.....Looks like c17053 and George should have answered all your questions....Brad
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