Cessna 210 177 Wing Spar Bulletin - InTheHangar Ep 47 

So sorry for your loss. And thank you for the information.

@@TakingOff I own a 1972 210L. I complied with the service letter with in a week of issuance. My TT airframe is a little over 6200 hours, and is flown weekly. The airplane has lived in N. California in a hangar for decades, and has impeccable maintenance. Visual inspection, my Thru-Spar looked like factory new! BUT further inspection with the "eddy current", showed something MUCH different. By the time we were done with the inspection, my thru-spar looked like a Dalmatian after blending out. There were many non-visible pin size corrosion spots found on my spar. From my experience in complying with this service letter, a visual inspection is a waste of time. Eddy current is a MUST! I'm a professional pilot, and one of those guys that feels that you should always go above and beyond on your maintenance. I just want everyone safe flying all of these affected planes.

Interesting. So Im guessing you already replaced the spar?

@@TakingOff No, I didn't replace the spar, just blended out the tiny corrosion pits that the eddy current picked up, and treated per the service letter. Sent info and pictures to Textron. I just feel that pilot/owners should be aware that "I believe" a visual inspection is NOT enough. And I realize to comply with the service letter you have to do an eddy current. Again, looking at my spar, it looked as good as new, but it wasn't. And thank you for your post, it is excellent information that needs to be out there.

so sad .. I remember the old wood Wing blank has and Muniz and the problem was invisible wood rot. I've got a friend in the US with a 210 and I'm going to send him this video.

That would be very rare... only a couple were ever done (that really needed it.) The corrosion around the shoulder harnesses is also a different situation... one which also impacts the 210. That issue does not lead to the specific type of failure discussed here.

If I still had my T210 I would certainly be inspecting. I was always concerned with that part during annuals and my mechanic assured that was Very important inspection point. It's time to be very serious about this. These birds are all old enough, and lots of enjoyable hours, so far.

@Hard Facts It will if you try to load it like a 210 and fly it out of a high DA airport. :-P

Get a Cessna 206 or an older strutted 210. Best of both worlds. If you can get the doors closed she’ll fly... and those big struts are piece of mind.

Literally.

I THINK ID COP A BOO AT THAT ONE

If the assessment of the accident described here is correct, the spar pulling away from the roof *in* the cockpit, a Cyrus-type CAPS unit would have been of no help. The system has saved comparatively few lives, but again, probably wouldn’t have helped in this instance.

AND....they were at low level, so no time to deploy.

Are you from South Africa?

Yup. May of 2018 as I recall, at Embry-Riddle Aeronautical University in Florida. Commercial student taking his checkride, just did a touch & go and the left wing (as I recall) came off on climb out. Both the student and a 25000+ hour examiner died. There's a video here on RU-vid discussing that very accident (ATC audio, but no video footage of the actual accident as it happened), and I found it a month or so ago when I was researching various aircraft to acquire for the purpose of offering instrument training in a technologically-advanced aircraft. Ironically I was looking at a somewhat high-time Arrow, like 6300TT, in Texas at the time: New paint, nice interior, G500 Garmin, GTN 650...all for $105K. Yeah, too good to be true. Once I saw the video on the ERAU Arrow fatal accident, I pretty much turned away from flight school aircraft--which is where the Arrow I was looking at came from. Interestingly, another aircraft I was considering was the 177 and/or the 177RG. But I'll wager that it's only a matter of time before the Textron SL makes its way out as an AD. So then you've just bought yourself a problem for years to come--because just because a one-time eddy current inspection is negative for a stress riser or even an early crack defect, what happens the hour after that? Seems to me that you're almost going to be obligated to do the eddy current inspection again every couple of years, just for the piece of mind that the wing isn't going to come apart. Looks like a decent way to go might be a C-182, although they aren't terribly fast--but that's not necessarily a bad thing for an instrument student. A 182RG would be nice, but instrument training would add a lot of cycles to that retract system, which could get pricey. I'm an A&P too by the way, and sometimes too much knowledge can be a hindrance. Of course being the mayor of fat-dumb-and-happy-ville isn't the answer either...something the ERAU student and his examiner sadly discovered the hard way. RIP.

April 4 2018 I was working for piper during this time and flight training in a piper arrow for CSEL. All piper arrows were shutdown and a lot of them sold off from the schools for Cessnas go figure.

@@gerryortiz7276 Yeah, the ERAU accident was in April...not May like I mentioned in my first post. And I see now that the Commercial student's father is suing Piper. Very understandable about how the flight schools are dumping these older Arrows into the market. I was told "They no longer need the aircraft, as the FAA dropped the requirement(s) for a complex aircraft for a Commercial Pilot rating." I suppose that's a good cover story, but I suspect it has just as much to do with dumping the expense and the potential liability...because it's only a matter of time until the AD is in place and last I heard a spar replacement (should there be a crack) costs north of $8K per side. And that's the good news. The bad news is that there's no crack on the day of the inspection, but then one develops the day after that. I think if I was serious about looking at such an aircraft, an Arrow from a flight school, I would be looking to negotiate two new spars into the sale price. Otherwise that thing seems like a ticking time bomb--and the other PA-28 aircraft aren't much better, as I've heard. No wonder the price of used 172 and 182 aircraft is going up...

How is the PA-28 any worse than the 172, 182, Mooney, Musketeer, or any other small airplane? They’re all similar designs built from similar materials. None of these airplanes were designed to do what flight schools use them for: Repeated and numerous take offs and landings every day for years on end, many of them done by less-than-gentle student pilots. It’s the worst case scenario for the structure. What happened to that Archer shouldn’t be too surprising. Maintenance exists so we can catch stuff like this before it becomes a disaster. The only viable real-world solution is to increase maintenance requirements for these aircraft, especially when operated by flight schools.

Paul Fully-cantilevered wing, one main spar with a built-in dihedral. Go find a video showing how the Piper spar is built and attached and then get back to me. You can definitely see how 10000+ landings can take their toll.

And when I was in the trucking industry, and even on my personal vehicles...ALL Have Steel Wheels...Not saying steel doesn't crack (it can), however, it usually takes several permanent bends to do so, AND it will Bleed Rust from said crack. You wouldn't believe how many aluminum wheels I have seen in pieces in the trucking industry.

I'm keeping my wood spars in my ancient airplane

Be aware that the SIDS program on Cessna aircraft has found problems with the strutted models that were not expected.

@@peterlovett5841 Good point. Thanks for that info. All aging planes should have thorough structural inspections, detailed visual and non-destructive testing using high-frequency eddy current, or ultrasonic (or good old dye penetrant).

Bureaucracy.

Changing the material of the spar would require the whole structure be retested and recertified. This really just comes down to maintenance.

I was thinking why not replace the entire wing?

With 3D scanning to make the molds that should be totally possible without much complexity, but idk this case and the same issue with the piper spars drive me away from 1960s-80s models with cantilever wings. Strut braced designs are inherently a lot stronger.

Why titanium? It's main benefit is that it works in high temperatures

No. But they are working on having new ones made.

Cessna built 9,240 C210s of which it would appear 3,165 are still registered in the USA and countless others around the world. Putting carry-thru spars back into production would be the sensible thing to do. They aren't cheap though. The last new price I believe was $27,485 back in 2017. Good used ones go for between $2,000 and $10,000. Add 120 man-hours to replace one.

@@27degrees $27,485?!! Are you serious? Why so expensive? It seems like a rather simple component. What am I missing?

@@mustangszz My guess is that it's about $1485 to have it CNC'd on a Haas mill, and $26000 to cover the liability.

Wasn't aware of an issue.

MANY ...nearly every popular USA light aircraft has potentially fatal crack points - strut Cessnas have multiple. Ditto PA28 series, Cessna 310 & 402.....the list grows each year. All have corrosion, particularly inter - metal contact points like attachment & webs

There is alot of information that was left out about how this airplane was flown which ultimately led to the failure of the carry through.

2020 hind sight is perfect.

The later model Cardinals *were* anodized during manufacturing, starting I think in 1977.

Keith Peterson the cardinal does have steel wire reinforced air tubes that pass though the spar and can induce bimetallic corrosion.

I am being told it isn't the foam so much as the glue. It is Hygroscopic (absorbs moisture from the air)

@@derekboxwell9312 Exactly correct! We see that same glue in some sound dampening panels which can corrode underneath, same concept.

@@cardinalflyer Yea. I removed my spar, my sound damping. Then I removed my spar because it was F'ed. Just finished putting the new spar in. Had a kid spend 100hrs stripping all the adhesive from the interior. About the epoxy paint the interior. Plane will see another 50 yeas of low corrosion service I hope.

Hey facts, i disagree, wing loading happens in both directions, granted the majority of the load is on the underside, Compression is still a force.

On the Cardinal the spar *is* the top surface of the wing, so you can inspect it with a ladder. It is also painted so very unlikely to have a problem unless you have something getting under the paint.

@Hard Facts it's still loading You don't know how many planes have negative . My point was to checkThe upper part of the spar as well.

Hard Facts You may be technically correct but your sanctimonious attitude dissuades any appeal to your opinion. But let me speak on your terms. Your opinion is complete horse manure. As a wing flexes inflight, compression loads increase and decrease just as often as tension loads. The same structure experiences the same load cycle throughout. A positive G load to 1.2 increases the tension and compression load. Rebounding to say 0.9 G reduces the load. The structure experiences a load cycle within Design loads. It does not experience Limit loads. However the corrosion pit cannot transfer the load, hence a stress point, compression or tension. If the compression structure is compromised, then the extra load is transferred to the tension members The accident aircraft was not known to be overstressed, only small cyclic loads. Also I have yet to see inspection criteria that states ‘it’s a compression load , no action needed’. Maybe there is something like that, I don’t know everything but you sound like you do. So please enlighten us ignorant folks. P.S. Your strut braced 172 wing is cantilever outboard of the strut attach point.

Hard Facts I am aware the 210 wing failed in tension not related to any compression structure defect. My issue is with your claim that the spar experiences 1/100 compression load cycles compared to tension loads. In regards to your sanctimonious claim : they ALL..... The T-34 wing spar failures are addressed by a doubler to the shear web. Same with the old Convair airliner. The Saunders strap was deemed ineffective by the FAA. The early Bonanza wings ( failed by exceeding Vne)were reinforced by giving the spar a full length shear web. Perhaps you are talking about Limit loads which is not germane to the 210 incident and the ensuing discussion.

It was a commercially used 210 in Australia. It was used for low level survey and had a (approved) boom extending after from the tail section. So we do have a lot of info on the plane that failed.

@@TakingOff It was a 40+ year old plane that was only in Australia for a couple years. We know about the last couple years, but there are decades of use and 12,000 flight hours that we are not familiar with. It makes me think of the T-34's that had wing failures. They were mostly doing high G aerobatics for years and then failed. Maybe this plane wasn't being abused at any point in its long history, but the jury is still out on that one. It will be interesting to see how many additional problematic wing spars they find.

Yeah, I agree. With the wingspar exams, it's like the Corona Virus--- there's people that say it's a shame and others that say its a pandemic.

@@TakingOff The funny thing is I got away from the Cherokee line due to wing spar issues. I've been looking at the Cessna 177RG. I just want a plane with a good spar! I guess I should have kept my Cirrus. At least I had a parachute.

Well, my own 210 wingspar came through exam with flying colors. I love my 210, and have full confidence in the wing.

Don't ever step foot in an aircraft then. Any aircraft.

Titanium

I agree and want to make sure that people that might profit by an AD aren’t the ones determining if us owners need to do it, but that it’s a rational decision based on real evidence.

I’m all for reasonable and cautious... but there’s a point where you can spend thousands and thousands to repair something that might even be politically based (see ECI AD). So I’d rather the AD’s come carefully and responsibly.

Don't worry...once the eddy current inspection becomes a requirement, it's only a matter of time until a "follow-up" inspection is required. And the more eddy current inspections there are being done, the more defects they're going to find. The defect might well have been there 10 years mind you, but once it's found on an EC inspection, given the current concerns, the more likely it is that you'll be looking for a new spar carry-through. (Or a new aircraft.)

@@bluehornet6752 or every 2 to 3 yrs. It's a matter of safety, I think...

@@TakingOff How much does non destructive testing of a wing spar actually cost? I think its a worthy investment. We should also think about introducing TBO times for wing spars and other structural elements. So much time and money is spent for engine maintenance (compression testing, regular oil changes and overhauls etc.) and at the same time people are flying around with 40 year old wing spars that had to endure thousands of rough landings, turbulence, and whatever other abuse previous owners might have put them through. Regular non destructive testing for metal fatigue and corrosion really is the least we should do.

Most aluminum is protected against corrosion. Typically they are covered in alclad which is pure aluminum which forms a barrier of corrosion to protect the aluminum underneath... or treated with etch and alodine. This is enough protection for 99% of aircraft that aren’t in corrosive environments. I’ve pulled open 50 year old Cessnas and you can still see yourself in the reflection with just a few white spots of surface corrosion that wouldn’t go anywhere in a million years. For an airplane manufacturer who had no idea people would keep planes this long it seemed like a good idea. Zinc chromate paint was poisonous and other primers and coatings were expensive and heavy and labour intensive to add.

Most aluminum is protected against corrosion. Typically they are covered in alclad which is pure aluminum which forms a barrier of corrosion to protect the aluminum underneath... or treated with etch and alodine. This is enough protection for 99% of aircraft that aren’t in corrosive environments. I’ve pulled open 50 year old Cessnas and you can still see yourself in the reflection with just a few white spots of surface corrosion that wouldn’t go anywhere in a million years. For an airplane manufacturer who had no idea people would keep planes this long it seemed like a good idea. Zinc chromate paint was poisonous and other primers and coatings were expensive and heavy and labour intensive to add.

I work on commercial airliners, where every piece of aluminum alloy structure is alodined and primed, at a minimum. I agree that this should be considered best practice in general aviation as well, but I also realize that our general aviation fleet is old and was never designed or expected to be flying this long.

Cessna was notoriously negligent in this endeavor, IMHO. I've found some black tar-like crap painted on the inside of skins between ribs, but never have I seen the skins/ribs primed like on many of the Piper aircraft I've worked on over the years. And in a Cessna there always seems to be many many little foci of corrosion seen. I get it that these manufacturers never intended for their product(s) to be in service 40, 50 or 60 years later, but it just seems like common sense to prime the interior structure of an aircraft. The anti-corrosion properties notwithstanding, it's much easier to inspect interior structures when there aren't shiny aluminum surfaces reflecting light in 100+ directions. The glare is distracting to say the least.

They were not poorly designed but they weren't designed to be still flying 30 - 40 - 50 years later. Cessna at least had the integrity to look seriously at the issue and instituted the SIDS program. The wealth of information coming out of that is amazing. In Australia the program is mandatory for all Cessna models, I understand that in the US it is only advisory but I may be wrong on that.