The International Cessna^® 170 Association

My A&P is nearly finished with repairing the outer two ribs on the wings of my 170b. All new parts were used such as ribs and skins. The stringers had to be cut and repaired according to the Cessna 100 series service manual. After reading the CFR's I am reasonably sure that the service manual is approved data. All was done under the eyes of an IA. From my further reading of the CFRs this is a major repair and requires an inspection by the IA before sign-off. Am I correct in my appraisal of the CFR's?

Ron Fenili wrote:My A&P is nearly finished with repairing the outer two ribs on the wings of my 170b. All new parts were used such as ribs and skins. The stringers had to be cut and repaired according to the Cessna 100 series service manual. After reading the CFR's I am reasonably sure that the service manual is approved data. All was done under the eyes of an IA. From my further reading of the CFRs this is a major repair and requires an inspection by the IA before sign-off. Am I correct in my appraisal of the CFR's?

The 100 service manual is not approved data for major repairs, a 337 with the repair described in block 8 and a FAA approval stamp in block 4 would be required.

From FAR 43-A
(b) Major repairs—(1) Airframe major repairs. Repairs to the following parts of an airframe and repairs of the following types, involving the strengthening, reinforcing, splicing, and manufacturing of primary structural members or their replacement, when replacement is by fabrication such as riveting or welding, are airframe major repairs.

(i) Box beams.

(ii) Monocoque or semimonocoque wings or control surfaces.

(iii) Wing stringers or chord members.

Thank you for the help. Are there any examples of 337's that we can use for guidance?

Ron Fenili wrote:Thank you for the help. Are there any examples of 337's that we can use for guidance?

There are two sources of acceptable data for a repair like this.

they are the 43,13-1b chapter 4 -58 and the Cessna structural repair manual for the later models of the 172. Simply have your A&P make the entry in block 8 as to how they did the repair.and use either of these for supporting data.

when the 337 comes back from FSDO it will be approved data for the repair, then your A&P that did the work can sign block 6 and your (-IA) can return the aircraft to service on that 337 by signing block 7.

And remember it requires 3 copies of the 337 to complete every ones records, 1 for the FAA, 1 for the owners maintenance records, and 1 for the -IAs activity sheets for their renewal. (but that is the -IAs responsibility)

Tom, what is the difference between the Cessna Structural Repair manual and the structural repair sections of the 100 series 62 and prior Service Manual.

Is it that Cessna had one approved and the other not?

And why would a repair manual approved for a 172 be approved for a 170?

Bruce Fenstermacher wrote:Tom, what is the difference between the Cessna Structural Repair manual and the structural repair sections of the 100 series 62 and prior Service Manual.

Not much

Is it that Cessna had one approved and the other not?

I wouldn't expect one to be approved and the other not

And why would a repair manual approved for a 172 be approved for a 170?

In the cover letter to the ASI at FSDO would be asking why the data from Cessna can't be used as approved data for the repair. and it would be a rare occasion that it would not be. it is the same structure, repaired in the same way.

Going strictly from memory ( ) and without service manual and/or structural repair manual part numbers, but I did not recall any service manuals for 170/172 (well, all of single engine piston Cessnas) being "approved." I know they are the "manufacturer's recommendation" but do not carry the magical FAA stamp of "approval." I could be wrong on the SRM...again, I don't have a copy of it in front of me to reference.

Either way, what Tom describes would be an avenue to follow as the field approval process only approves the data that is to be used for the repair or alteration.

I really appreciate the input on this. The question arose because around our little airport there was disagreement over whether the manual was approved data or not. That included other IA's. So I think the safest route would be to send the 337's to the FSDO and get data approval. It has only been 10 months since the project started, what a few more months.

Ron Fenili wrote: whats a few more months.

It should not take months, follow the guidance given in AC-43-210-? and the ASI should have it back to you in a couple days.

Ron,

The first page of AC42.13-1B has a letter from the acting Deputy Director, Flight Standards service that states the data may be used as approved data.

There are a few conditions, but they are listed in that first page.

Tim

tps500 wrote:Ron,

The first page of AC42.13-1B has a letter from the acting Deputy Director, Flight Standards service that states the data may be used as approved data.

There are a few conditions, but they are listed in that first page.

Tim

Only when the aircraft have no other supporting publications.

The service manual, written by the manufacturer for a specific model airplane, is not approved data? What about all the other information in the manual, is it all just advisory? Lubrication locations and types, hydraulic fluid types and pressures, and electrical loads? How about the parts manual?

DaveF wrote:The service manual, written by the manufacturer for a specific model airplane, is not approved data? What about all the other information in the manual, is it all just advisory? Lubrication locations and types, hydraulic fluid types and pressures, and electrical loads? How about the parts manual?

Manuals, SB, and any other material that is written by the manufacturer are ACCEPTABLE data for the FAA to approve for the repair or alteration of the aircraft. they are not APPROVED data by them selves.

I was expecting someone to post that the latest revisions of the 100 series Service Manual, 1962 and Prior is now "Approved Data".

This has come up from time to time, that although the earlier Service Manual was not "approved",... that subsequently Cessna has obtained approval on the document. While true, that statement needs explanation.

To clarify the point, let it be known that the latest revision (2003) is indeed "Approved"... but only for 150, 172, 180, 182, and 185 aircraft. That manual states that "Although not specifically written for earlier models which have been discontinued, much of the information can be used as a guide for maintenance of the Model 120, 140 and 170. ..." etc.

Hope that helps anyone avoid the wrong impression.

Just because the manual is " Approved " by the FAA Does not make it "APPROVED DATA " to make major repairs or alterations, it simply means the instructions given with in the manual has been approved for the intended purpose of the manual. servicing, disassembly procedures, etc. These manuals do not give a specific repair, they only give typical procedures

IF I were to use the chapter for structural repairs of the service manual as acceptable data to design a repair, I would still be required to fill out a 337 (IAW AC43.210) and send it to FSDO for approval to complete the repair.