Cessna C337 SID

[WebMaster]

Originally Posted by Roger

Have there been any Service Difficult reports or have any A&P's reported real life issues with the area in question, or is this entirely a Nerd generated computer simulation?

It's worse, Roger. There are no Service Difficulty reports, and there is no computer simulation. It's an engineer saying, "we ought to do this".

Think about it, and we have, all 0-2's were based on 337's, and in all the time in SE Asia, and other activities, the only time a wing failed at the fuselage attach point was when it was hit with a large caliber shell, or a missile.

Cal Fire used them a lot, and there was never a failure at the fuselage attach point, or the wing strut attach point.

[hharney]

Cessna did not use any computer based analogy to provide any rational to the proposed SIDs. Cessna says that all proposed documents are based on SDR information. There are NO SDR's that relate to the wing/strut attach points. This is the main issue with these specific proposed inspections. Cessna's opinion is that because the aircraft are over 20 years old, they need a routine checkup in these areas to determine if there is a potential problem. The red herring is that the process they require will necessitate removal of the tail, then the booms and finally the wings to perform an eddy current inspection on the attach points. Unless someone comes up with some kind of device that can safely allow the bolts to be removed without removal of the tail and booms, the cost of this inspection is huge. Then you have to take into account the damage that will be subdued to aircraft when non-qualified shops try to perform this inspection. There may be no damage to any Skymasters out there right now but there will be once shops start to perform this inspection.

Don Nieser has even gone as far to search all the military SDR's for the aircraft and I understand that there is nothing in that data base also that would point to a problem. The aircraft is just overbuilt in that area and there are other related components that would fail first before these attach points would be a problem. We addressed this with Cessna but the engineers just think that it's a good idea to inspect these locations. No basis, just a good idea.

I suggested several times at the meeting in Wichita that Cessna should soften these inspections to some type of visual without removal of the bolts. All reports of these inspections could be sent in as information to determine if there is a problem. I don't know if that was the best alternative or not for us because there is still no rational for the inspection.

[rschimizze]

I have a 6mm diameter articulating borescope, 3 meters in length that I use for failure analysis work. I am sure it could be wriggled to the area in question and get a very good look (photos and all) at the fittings. If those joints appear pristine then I would be very surprised to find anything more seriously wrong, given the lack of documented historical problems. This seems to me to be a more practical method for performing field examinations of otherwise good aircraft, but as others have stated Cessna has no motivation to be practical to the benefit of the Skymaster community.

[skymstr02]

With some minor disassembly of the wing fairings, the attach points are visually accessable, so the borescope is not necessary.

What you won't see are potential cracks emenating from the bolt holes, or corrosion that may be hiding in the bolt holes, or the laminated layers where the outer wing spar mates with the center section carry thru.

[Skymaster337B]

I have a good idea too -- since Cessna can just come up with good ideas. It seems to me that Cessna is admitting to gross negligence in the way they designed and built the Skymaster. I know that aircraft manufactures are protected from suits on airplanes older than 20 years old, in the U.S. But I don't think they are protected in a case of knowingly producing a faulty product at the time and only now admit it today. Perhaps a motion for discovery is in order to determine what they knew and when they knew it...i.e., engineering data. I'm sure Cessna wouldn't like that one bit.

[tropical]

Perhaps Cessna should consider a program to buy back the 337's and destroy them.

[John Hoffman]

Originally Posted by skymstr02

With some minor disassembly of the wing fairings, the attach points are visually accessable, so the borescope is not necessary.

What you won't see are potential cracks emenating from the bolt holes, or corrosion that may be hiding in the bolt holes, or the laminated layers where the outer wing spar mates with the center section carry thru.

Way back in the dark ages when I worked as a quality assurance engineer the team was constantly coming up with ways to perform NDE on new assemblies that were being designed as the plant was being built. It seems that 30 years latter there can be a creative examination designed for this application if it comes to that.

[John Hoffman]

Originally Posted by Skymaster337B

I have a good idea too -- since Cessna can just come up with good ideas. It seems to me that Cessna is admitting to gross negligence in the way they designed and built the Skymaster. I know that aircraft manufactures are protected from suits on airplanes older than 20 years old, in the U.S. But I don't think they are protected in a case of knowingly producing a faulty product at the time and only now admit it today. Perhaps a motion for discovery is in order to determine what they knew and when they knew it...i.e., engineering data. I'm sure Cessna wouldn't like that one bit.

This is exactly where I am on this Cessna proposal - if they want to hide behind the protection they got for legacy planes then they are asking for a reopener on the whole thing if they want to impose new inspections on those planes. That is - if the tests and exams are performed then Cessna steps in and assumes responsibility for those planes.

[Skymaster337B]

It sounds like Cessna is assuming liability for these planes...or are they covering something up, such as a way to make $14 million on new parts? Either way, it is my understanding that under the old way of aircraft certification (CARs) the only thing mandatory are AD's. And that the maintenance manual published at the time the aircraft was built is the only other authority for required maintenance (other than the 100hr/annual)...periodic updates to the maintenance manual is informational only, if you chose to ignore them.

[tropical]

Originally Posted by Skymaster337B

Either way, it is my understanding that under the old way of aircraft certification (CARs) the only thing mandatory are AD's. And that the maintenance manual published at the time the aircraft was built is the only other authority for required maintenance (other than the 100hr/annual)...periodic updates to the maintenance manual is informational only, if you chose to ignore them.

Not really. It's up to the person that is signing the inspection to make the determination.

Put yourself in the mechanics position, you sign off an annual inspection and decide to ignore to MM and recommended inspections. The airplane is in an accident and the first thing the attorneys want are the log books. They now find the mechanic ignored "factory recommended" inspections. See where this is going?

I think a lot of shops will be reluctant to sign off these planes without complying with the inspections.

[WebMaster]

Originally Posted by tropical

Not really. It's up to the person that is signing the inspection to make the determination.

Put yourself in the mechanics position, you sign off an annual inspection and decide to ignore to MM and recommended inspections. The airplane is in an accident and the first thing the attorneys want are the log books. They now find the mechanic ignored "factory recommended" inspections. See where this is going?

I think a lot of shops will be reluctant to sign off these planes without complying with the inspections.

Exactly, and Cessna has said that they consider the inspections mandatory.

[Ernie Martin]

They also consider Service Bulletins and Emergency Service Bulletins mandatory, and IAs don't require them for Part 91 operators.

There may be confusion at the outset, and some IAs may require them, but the inspection requirements are determined by the FAA and here the issue is clear: Part 91 and even some Part 135 operations won't be subject to them. Nor will they automatically become ADs.

I covered this in a message on the AV Web SIDS Article 12-24-09 thread. For those of you who haven't read it, here is an excerpt with the requisite link to the FAA's Final Rule:

I have been reading various comments on this Board about the possibility of an IA requiring the SIDs, either out of an abundance of caution or if Cessna issues a revised Service Manual with SIDs. While I can’t rule out a poorly informed IA taken such a stance, I think the record is clear that Part 91 operators will not have to do the SIDs.

My basis is the FAA’s Final Rule and Notices (“FRN”) on the matter, which is essentially the mandate for the SIDs. Later I will provide you a link so you may peruse the document, but here’s a summary.

The genesys of SIDs was the 1988 in-flight failure of a high-time Aloha Airlines Boeing 737, where a section of the upper fuselage ripped away because of fatigue. Congress pushed the FAA into evaluating steps that should be taken to prevent such future failures in high-time (or “aging”) aircraft. Initially only transport aircraft were considered but that was later expanded to cover smaller aircraft.

Both the heading and the first paragraph of the FRN make it clear that only Part 121, Part 129 and Part 135 operations are covered. Moreover, on Page 5 (3rd full paragraph of the 3rd column) Part 135 cargo-only and on-demand operations are excluded.

Concerns that SIDs may become ADs also appear unfounded. On Page 2 (1st full paragraph of the 3rd column) the FAA explicitly states that ADs will be issued only to address “unsafe conditions that have already been identified.” And the Cessna 400-series SIDs supports this, because only one of the SIDs became an AD after cracks were found and a fatal in-flight failure occurred.

Given that SIDs were mandated by the FAA and the FRN’s clear intention to exclude Part 91 and some Part 135 operations, I do not believe Cessna can take actions that would essentially contravene the FAA.

All of this is small consolation to many non-commercial foreign operators who will be subject to the SIDs.

The FRN may be found at http://edocket.access.gpo.gov/2002/pdf/02-30111.pdf.

Ernie

[tropical]

Originally Posted by Ernie Martin

They also consider Service Bulletins and Emergency Service Bulletins mandatory, and IAs don't require them for Part 91 operators.

Ernie

But there is FAA guidance that specifically states SB's are not mandatory for Part 91 operators.

Use of the Approved Aircraft Maintenance Manual is recommended by the FAA. Cessna will incorporate these SB's into their Maintenance Manual. Now the person holding the Inspection Authorization has to make the determination of how far to stick his neck out.

[skymstr02]

This is the primary reg that all mechanics perform to:

§ 43.13 Performance rules (general).

(a) Each person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or appliance shall use the methods, techniques, and practices prescribed in the current manufacturer's maintenance manual or Instructions for Continued Airworthiness prepared by its manufacturer, or other methods, techniques, and practices acceptable to the Administrator, except as noted in §43.16. He shall use the tools, equipment, and test apparatus necessary to assure completion of the work in accordance with accepted industry practices. If special equipment or test apparatus is recommended by the manufacturer involved, he must use that equipment or apparatus or its equivalent acceptable to the Administrator.

It is up to the individual as to what or how that is accomplished. Keep in mind, that should anything go awry, he will be answering to the attornies and the local FAA airworthiness inspectors on his actions for that inspection.

Are inspections for continued airworthiness the same as SIDS? That will have to be determined by a judge eventually. Whether its a NTSB or civil court at law remains to be seen. This is a question that begs for resolution.

[Ernie Martin]

All good points, but take a look at the specific elements I cite from the FAA's Final Rule (page, column and paragraph is listed for each citation). It's hard to believe that SIDs will be required when the FAA explicitly states that they "will not apply to" certain operations, such as Part 135 cargo-only and on-demand.

Ernie Martin