210 Wing Spar AD

Mark talks about the Cessna 210 wing spar AD (AD 2020-03-16).

Here is a link to the AD in the Federal Register:

[jackmcdaniel]

"Not as depressed as the owner." I bet that's true!!!!

[patjparks]

As part of its backgrounding process, the FAA received reports of “widespread and severe corrosion of the carry-thru spar” on Cessna 210G through 210M models, including the T210 variants. “Further investigation identified that these early model airplanes were manufactured without corrosion protection or primer, increasing their susceptibility to corrosion. Additionally, the design of these early model airplanes, where the upper surface of the spar is exposed to the environment, allows a pathway for moisture intrusion. Model 210-series airplanes were also delivered with foam installed along the carry-thru spar lower cap. The foam traps moisture against the lower surface of the carry-thru spar cap, which can increase the development of corrosion, ” according to the AD.

[glenwoodriverresidentsgrou]

Retired aircraft structural engineer here. If this is just a web problem and the upper and lower flanges have not lost significant material and are not pitted, it seems like this could be repaired. In I-beams the upper and lower flanges take most of the bending loads and the web takes nearly all of the shear loads. For positive loads, the top flange is in compression and the lower flange is in tension. Shear loads from the outboard wing are reacted into the side structure before they reach the center of the cabin, so the I-beam in this area sees virtually no shear load and is in pure bending. In pure bending, the web material has nothing to do other than to locate and stiffen the upper and lower flanges. If this were a manufacturing defect at the military AC factory I used to work at we would have smoothed the damaged web material and reinforced it with two donut shaped doubler plates or patches, one on each side of the web.

If you look at a Cherokee wing spar it is completely built up of layers of plates, angels, and T sections all riveted together. This Cessna carry through could likely be reinforced in this fashion rather than replaced. Of course, you would have to get a field STC for the repair, but for $60, 000, that might be possible.

[azspotfree]

For an extra 100 dollars from the factory and an additional 20 pounds of aluminum, that spar could have been made 3 times stronger and never failed under any conditions. Cessna probably saved 50 dollars or so though during production, I guess they never dreamed those planes would fly 5 decades or more. And if they gave so little thought to the carry through spar, what's going to start snapping off next? Manufacturers should calculate how strong the wing spar needs to be, then double it for production like they did with the DC3. Nothing more unsettling than flying around in an old plane and hoping you don't hit turbulence because maybe the wing will snap off.

[buckerjungmann]

After we got a 210 spar inspected, the shop wanted to know if we wanted to glue the interior back on the refinished surface… uh, no. Very nice video.

[davidcampbell]

Shocker! Great video, as usual. Thanks!

[JohnDoe-weyk]

Mark you are an amazing teacher, i subscribed just after watching 2 of your videos. 👍

[rino]

Thanks for this video! I've flown on Cardinals and planning on flying a 210 and always wondered about thst carry-through spar. Good to know!

[Mrsournotes]

Someone once told me the cheapest part of aircraft ownership was the day it was purchased. I remember the day our A & P said we needed a new carburetor for our C-150. $750 for a used carb. And that almost brought tears. But this…ouch!

[donbenner]

Thanks, Mark! I really appreciate your informative videos on the AD requirements for 210 & 177 wing spar inspections… and the AD requirements for 172 & 182 wing strut inspections! Both can be very expensive repairs… and should be considered before buying these aircraft! Fortunately, 177 aircraft flown in TYPICAL usage do not need the AD inspection until 15, 000 flight hours if wing STC modifications have NOT been made…

[KTWardlaw]

Once again Mark, very informative 😎👍🏼Thx!

[shakey]

“Sleight depression, not nearly as much as the owner who found it though.”
Subtle British humor.

[DavidGallichan]

Hi Mark thanks again Pre buy inspections a must

[airfiero]

Thank God my 210s spar passed inspection

[ForgottenReels]

These are very good videos - Thank You

[peteranninos]

Well, its 3 years on and at least for Cardinals, the whole thing, parts and labor is in the $30K range. Hardly chump change but at least worth repairing (mine passed with no problems) I don’t know about the 210's but I do know that Cessna is now making replacement spars for the Centurion. The vast Majority of Cardinals are fortunately having no issues.

[robinj.]

Got it!
Buy the older model with the strut braced wing! 😉

[John-ncbl]

Mark, those depressions are called blend-outs of corrosion that you pointed out on the condemned one close to the lightening hole.
So someone has blended the corrosion out and the depth of the blend-out is beyone the manufacturers limits.

Is the material of the replacement one the same material as the condemned one-?
If it is so, then the only difference is the primer coat protecting the replacement one.

For that ridiculous price I would want that forging to be made from titanium material.

[danielconte]

Great video professor !! Always teaching ! 👍

[WillOstrick]

Boys, your sound is now perfect 👍 also keep up the great work