Yes gross negligence. Because they should have built and sold the airplane with a service life limit...as new airplanes are built and sold today. Sorry they couldn't envision the airplane flying for 50 years, but what did they reasonably expect?

Corrosion! They had the knowledge and technology to zinc chromate all internal surfaces...but out of gross negligence and profit motive the airframes insides are bare metal...a crime against aviation in my opinion.

So you knew of this "gross negligence" and you purchased, and flew the airplane anyway??

Who's negligent?

CYA - What are the authorities?
 

Have you ever noticed that on all of your ground-fault outlets it says to "test them every 30 days?"

Like much of what goes on in the USA these days, many of these measures become an exercise to prepare a defense "in case anything happens."

"What? Do you mean that when your husband flew into the mountain out of fuel, he had failed to remove the wings every six months to inspect for cobwebs?"

From friends in high places, the only rule that is enforceable is one that has gone through a rulemaking process, which engages oversight and accountability. At least in theory.

Bureaucrats and lawyers often forget these limits. When someone tries to 'enforce' beyond their statutory authorities, they are literally abusing power by trying to exercise authorities not given to them in the first place.

As owner of Potomac Airfield I have become, alas, somewhat expert in these matters.

Unless its an AD it is just good advice, and maybe a defense for Cessna, but that's all.
D

I didn't know of Cessna's negligence until many years, and lots of corrective maintenance, after purchase.

Sorry, not gonna buy that. So you are saying before purchasing the airplane you never, nor did your mechanic, open an inspection cover? You or your mechanic never removed a cowling?


You're grasping at straws.

You buy junk, you get to fly junk. Or fix it.

My point is that I just expected better.

SID's are published
 

Just received the Maintenance Manual revisions, Part #D2500-2TR9, which update the February 1973 current Maintenance Manual, Part #D2500-2-13.

This is the second revision to the current Maintenance Manual indicated above. The first revision is Part#D2500-2TR8 and deals with the Reel Type Seat Stops, Landing Light Switch and Corrosion Inspection of the Main Landing Gear. This new revision released last October are the Supplemental Inspection Documents (SID) and the Corrosion Prevention and Control Program (CPCP) that have been discussed on this message board for the last 2 1/2 years. See the threads below for more information about SID's:

http://www.337skymaster.com/messages...ead.php?t=2513

This revision, D2500-2TR9, contains 176 double sided pages. This revision covers 1965 -1973 337. The following are the revision numbers for the applicable models.

336 - D238-2TR6
1965-1973 337 D2500-2TR9
1974-1980 337/T337 D2506-8TR9
1973-1980 P337 D2516-9TR8

These revisions were all released 4th Qtr 2010. I ordered mine through Yingling http://www.cessnadirect.com and it was $8.11 online order. These are available in paper only, no electronic format unless you subscribe to a service.

I have not reviewed the document yet as it just arrived by courier. I will start to review today and update soon. If anyone has any questions you are welcome to post here or use private message feature.

It's not bare metal. Zinc chromate doesn't prevent corrosion; and in some cases, it makes inspection more difficult. Corrosion takes many forms. So does corrosion prevention. A manufacturer isn't negligent because the manufacturer doesn't spray chromate on surfaces.

What do you mean zinc chromate doesn't prevent corrosion? That's not what I was told in A&P school.

my 73p riems was full zinc coated from the factory. all the aircraft part were
made in cessna's factory and then shipped to france for assembly.
so if mine was coated in 73 why did they stop? were all p's coated or
just the one riems purchased as cessna went broke?

Not sure Rick but it could be protocol that Riems set up or the fact that parts were being shipped across the pond and there would not be a controlled environment before assembly.

Following the conversation - Interesting!

Just curious, if the revision is dated Oct 2010, why are we just talking about it now?

Was it just released by Cessna, or has it been out since October 2010?

Hank

I don't get that either. The revision was dated July, but the effective date was last October. I would never have even known about it until next June 15th which is when my annual is and that's when I check to make sure I have the latest revision. I am in Canada and have gotten conflicting information as to whether they are mandatory so I have asked Ottawa directly (Transport Canada Headquarters). A fellow pilot did ask earlier in the year and was told he did NOT have to do them so the answer should be the same. I hope ;)

Exactly what I said.

Chromate is a surface treatment which acts in two ways; it protects the surface to some degree, and in some applications can serve to aid in retaining anticorrosive agents. What you're likely used to seeing as zinc chromate is a surface paint, although some people mistakenly refer to it as a chromate conversion (something entirely different), which is another process that converts the metal surface through a process of chemical change and oxidation.

Chromate conversion is better known as alodine, which is a much better method of treating aluminum surfaces than simply painting with zinc chromate paint (often used as a primer).

If you've had much experience around older airplanes that had zinc chromate (the real stuff; not the green spray paint that's sold today as "zinc chromate), you'd have seen it peeling and ineffective. It's no longer a barrier, it's not providing surface conversion, and it doesn't account for numerous forms of corosion (including those that form under surface coatings, such as filiform corrosion).

Some aircraft that have used surface sealants and treatments experienced increased rates of corrosion . If you've ever worked on Sabreliners, for example, you'd know exactly what I mean. Further, chromates do nothing for electrolytic corrosion in many cases, especially between faying surfaces, in bolt and rivet holes, and between layers, lap joints, etc. Surface paints and chromates don't prevent intergranular corrosion, fretting corrosion and other associated metal weakening and loss; in fact, where mechanical corrosion occurs, it removes the chromate.

Most aluminum comes with a surface of pure aluminum, sometimes referred to as Alclad. The alclad oxidizes, and provides a corrosion barrier to the underlying material.

spraying down the inside parts of your airplane sounds good, but doesn't stop corrosion from happening.