RobertL18C wrote:
Interesting it doesn’t affect the other cantilever wing Cessnas eg 177/190/195.A C180 was lost in mountain wave conditions, but the strut wing Cessnas have been quite immune to in flight structural failure.
The 177’s are affected by the service letter, but not the AD. They have a much longer life than 210’s
The 190/195 has a very different spar carry through structure, so not the same vulnerability.
Right now, the 120/140/150/152/170/180/185 are the only common strut braced Cessna singles not affected by wing strut concerns. The 172/182/205/206/207 and early 210’s are all subject to wing strut attachment concerns. One of my projects is to develop a repair kit for the 182 (then 172, then 206 after). The random 182 airframe I borrowed, with 3300 hours total time had structural cracks in the spar attachment – the Cessna service letter for that is a real thing too. However, the structure affected has more than one load path, so crack development is a little less critical (and much more easily inspected). I saw a 172 last week, which was having a Cessna kit installed to correct that defect.
The difference with the 210 is that the defect is not easily detected in inspection, and totally critical. Coupled with suspiciously scarce replacement parts. When I inquired, I was told that the replacement part from Cessna would be US$86,000, then add the cost of installation. I’ll have a better idea of that cost when we finish the 210 we’re doing now.
That’s an amazing post, Pilot_DAR, especially in light of how many people moved their Cessnas from e.g. D-reg to G-reg purely to escape these inspections.
@Pilot_DAR great post. Interesting the tailwheel types are not encountering this SB/strut attachment concerns. Might this be because the main gear is further back, and the wing struts on the nose gear type are suffering more compression on landings? The wing struts should behave the same airborne, arguably the workhorse Skywagons getting more wear and tear due to higher MAUW.
I’m going to buy the removed C 210 spar, and when it is mine, I’ll do some defect analysis, and post some pictures. I’ve had a god look, and have photos now, but it’s not quite my story to publish just yet. We’re discussing making the spars new as STC’d replacement parts, ’cause the 210 fleet of the world is probably going to need them!
In the mean time, yes, 170/180/185 have a different landing gear box and wing strut arrangement, and thus don’t seem to suffer that same strains. And, many 170/180/185’s are operated seasonally on floats, which means they are equipped with a “V” brace in the windshield. The V brace greatly stiffens the fuselage as a parallelogram, and reduces the strain on the underfloor bulkhead in which the cracks are being found.
If you’ve even noticed while taxiing a 172/182 on uneven grass surfaces, the windshield will move a little left and right relative to the glare shield, well, it’s supposed to (it’s deliberately not bolted in), but that motion tells you that the front fuselage is moving a little as a parallelogram, and that is straining the underfloor bulkheads. The taildraggers seem to carry these loads better. It’s worth noting that the very earliest (narrow body) 182’s (which are my favourite Cessnas) are actually simply a C 180 with a nosewheel fitted to the firewall. Those models are not affected by this defect, as their underfloor structure is different. Indeed, they are fairly easy to convert back to being taildraggers. It’s worth noting that Cessna figured this out a while back, and the newer 172’s and 182’s come reinforced from the factory.
There’s more work to be done on this, and I’m working with a group of specialists on several of these types to optimize fixes, which we will STC. In the mean time, all of these planes are long past their intended lives, yet they keep going, so it’s fair that maintenance is required – this is just big maintenance!
I just got the estimate for Eddy Current inspection which includes 2 hrs travel each way cost estimate 1500 Euros. From Munich to a Bavarian area airport anyone have any cost estimates or has anyone doe the inspection?
We had the inspection and the mandated corrosion inhibitor application done last year and as per our shop are in compliance with the AD. IIRC the cost for the eddy-current inspection was around $ 500. That’s in SoCal.
With us being a 210 operator we are indeed impacted by the issue.
It’s been said before: with access being so difficult, the area sometimes gets neglected until damage goes beyond recovery. No maintenance technician in his right mind would sign off an annual on a corroded spar he has inspected, a different matter is if he has not seen it…
210’s were designed at a time when labour was relatively cheap, so difficult access was not an issue and maintenance technicians were more manually skilled than today’s average, for most of whom the main goal is leaving GA and running towards airlines. Furthermore, we are operating 40-60YO machines which, if well looked after, will continue to provide good service with Cessna’s excellent continued factory support, but it comes at a price. They are as capable and versatile as SEP’s go, but there is a price (even beyond $) to pay in maintenance. Some owners have not been savvy enough, able or willing to ensure good maintenance and the result is this.
Yes we are operating machines valued $100k-$250k in today’s market, but they are effectively $1M-$2M aircraft (if sold new today) and maintenance is in line.
The issue with the headliner is that it is a large single piece of cloth or vinyl front to back (210’s have long cabins) held at the edges by glue and some aluminum teeth and in the middle by some span-wise piano wires. It thus invariably gets damaged (more or less depending on the subject’s ability and care) at every removal, so if you remove it every annual you will need to replace it after three-five years at a high cost. Ours has four access zippers that, especially with the help of a borescope, are enough for inspection, but if you need to do any wiring work or parts removal in the area (typically O2 bottles or generators, pitot/static lines, stall and gear warning unit, air conditioning, vent ducts and fan….) then at least a partial removal is unavoidable.
Our aircraft is not subject to the AD . It has no corrosion since it has a fully chromated spar, lived in dry-country US for the past 40 years, we keep it CIC’d and have permanent moisture removal inside our cabin, but we nonetheless inspected it and found no cracks or corrosion, as expected. There have been very few reports of cracks, but as hinted by @PilotDAR almost half of the reported inspections showed some corrosion, and a few spars have required replacements due to corrosion beyond repair.
A couple of friends asked me what to do (well before the AD came out) and for the same reasons indicated by @PilotDAR, I advised them to bite the bullet and get it inspected. Neither of them had any findings.
The inspection should be 300-500EUR max (plus expenses), but you have to plan at least 1000eur for removal and reinstallation of the headliner, assuming it can be reused. @C210flyer I assume your quote includes the headliner R/I?
Below a couple of pictures of a T210 with headliner partially removed (it can be seen at the bottom) looking up at the ceiling, before and after the inspection and reprotection of the spar.
While spar replacement is costly, it is nonetheless amazing that, 40 years after production ceased, Cessna has designed a new machined spar (the original one was a forged unit) and will be offering it in support of those 210’s needing it. I don’t know the price, but it is surely a five-digit figure, which brings a market for good-willing people like @PilotDAR to assist owners out of this issue. A few years back, when there was a concern about spar cap cracks after improper maintenance (also the subject of an AD in the inboard wing outside the cabin area) Cessna went so far as to buy a used wing and do load testing of the spar showing that even if the concerned spar member was cracked all the way through, the spar was nonetheless able to carry design load factors. Again, surprising that an OEM is willing to spend that kind of money on an aircraft decades out of production…I guess there must be a reason why spare parts are so costly, but at least they are available!
Picture of recent 210 spar load testing:
In summary: an important aging issue not to be overlooked, but not to worry about if your aircraft has been well looked after, and even if not, there will be a way forwards with the support of Cessna and other vendors.
Antonio wrote:
have permanent moisture removal inside our cabin
Slight thread drift, but how do you implement “permanent moisture removal”?
Moisture removal in the cabin:
https://www.amazon.es/gp/product/B07LC5BK98/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
On the engine:
https://www.aircraftspruce.com/catalog/eppages/engsaver.php
And on all the structure, some kind of CIC (LPS3 or ACF-50 depending on areas)
Thoughts on DV9 in lieu of ACF-50?
