Wing Spar AD
 

Can anyone clue me in on the mandatory wing spar AD at 5000 hrs? Cost? How labor intensive? If the spar fails the inspection what happens next?
Thanks in advance,

Dave

Two costs. One for IA doing prep and part of the inspection ( I think it's a dye penetrant inspection). Second costs for a service company to do the eddy current inspection. It is very labor intensive.

The IA part should be about a day. The service company, I think, is about $400.

If it fails, you simply get a new wing. There is no repair except for a new wing. You call Don Neiser, and tell him to ship you one.

wing spar AD
 

Got it. Once again, thanks for the speedy reply Larry.

Dave

I'm not sure a "new wing" is required. There are ways to repair the spare that are "acceptable" to the administrator. However, to my knowledge no one has done it yet...nor ever had to.

You could be correct. I am not certain of the exact remediation steps that would be required.

There are no published corrective actions that I'm aware of. However, it would be up to the IA and his interpetation of the all powerful "acceptable methods to the administrator." Which just might require a new wing...if there is such a thing as a new wing.

The spar inspection and repair procedure does not have to be performed by a mechanic holding an inspection authorization, as any appropriately certificated mechanic may perform this function.

Since the airworthiness directive doesn't call out a specific repair, the mechanic is forced to either:

1. Replace the wing with a servicable unit (likely)
2. Replace the wing with a new unit (unlikely)
3. Hire the services of a designated engineering representative to evaluate the inspection results and develop a repair procedure, this can be very expensive, and will most likely require the existing wing to be removed to enact the repairs anyway. The IA will have to approve these repairs as they will be classified as major repairs.

I guess this is related but... have there been any reports of inflight structural failures in a 337, not related to flying into a storm? I know these did some high stress manuevers in Vietnam and wondered if they had any reported failures? Has anyone used a 337 for airshow aerobatic performances (I don't want to, just curious as to the strength).
Dan

Steve Weaver used to fly a Skymaster called "Bodacious" on the airshow circuit. Smoke on the rear engine only.

The FAC 337's all have to have the spar inspection before being registered as normal category.

The military O-2's have the same requirements that the pure civil aircraft have, that is 3,000 hours for the initial inspections in table 1, note 1, of AD78-08-05. It is not a requirement for civil airworthiness until the times are accumulated.

In my case, my airplane had 2880 hours on it when I had it certified, and it was not due at that time. (Reference Cessna Drawing 10337-065)

Just to clarify, AD 78-08-05 is for DC-10's. The AD we're talking about is 78-09-05. The way I read the AD is the 3,000 hour inspection is not mandatory...but suggested. But I thought the O-2's required an STC to convert them to an N number. And that STC required the spare inspection every 500 hours regardless of how many hours are on the airframe. Do I understand this right?

Otherwise, a "normal" Skymaster requires the inspection starting at 5,000 hours. And Pressurized Skymasters start that inspection at 10,000 hours.

I transposed the D number wrong. There is no STC required to get a civil certification for an O-2. The type certificate data sheet spells out what is required. There are no additional requirements for the spar inspection than what is specified for any other 337 airplane. Please see the AD and Cessna Service Bulletin for details.

anyone aware of civilian skymasters failing the wing spar inspection? Im not aware of any.

I was reading the spar AD again. I noticed it references the Cessna Multi-Engine Service Letter ME78-2 for some details. Does anyone have a copy of this service letter that they could post?

I have a copy I will post as long as it's ok with the admin.